ceramic ball mill types

ball mills

In all ore dressing and milling Operations, including flotation, cyanidation, gravity concentration, and amalgamation, the Working Principle is to crush and grind, often with rob mill & ball mills, the ore in order to liberate the minerals. In the chemical and process industries, grinding is an important step in preparing raw materials for subsequent treatment.In present day practice, ore is reduced to a size many times finer than can be obtained with crushers. Over a period of many years various fine grinding machines have been developed and used, but the ball mill has become standard due to its simplicity and low operating cost.

A ball millefficiently operated performs a wide variety of services. In small milling plants, where simplicity is most essential, it is not economical to use more than single stage crushing, because the Steel-Head Ball or Rod Mill will take up to 2 feed and grind it to the desired fineness. In larger plants where several stages of coarse and fine crushing are used, it is customary to crush from 1/2 to as fine as 8 mesh.

Many grinding circuits necessitate regrinding of concentrates or middling products to extremely fine sizes to liberate the closely associated minerals from each other. In these cases, the feed to the ball mill may be from 10 to 100 mesh or even finer.

Where the finished product does not have to be uniform, a ball mill may be operated in open circuit, but where the finished product must be uniform it is essential that the grinding mill be used in closed circuit with a screen, if a coarse product is desired, and with a classifier if a fine product is required. In most cases it is desirable to operate the grinding mill in closed circuit with a screen or classifier as higher efficiency and capacity are obtained. Often a mill using steel rods as the grinding medium is recommended, where the product must have the minimum amount of fines (rods give a more nearly uniform product).

Often a problem requires some study to determine the economic fineness to which a product can or should be ground. In this case the 911Equipment Company offers its complete testing service so that accurate grinding mill size may be determined.

Until recently many operators have believed that one particular type of grinding mill had greater efficiency and resulting capacity than some other type. However, it is now commonly agreed and accepted that the work done by any ballmill depends directly upon the power input; the maximum power input into any ball or rod mill depends upon weight of grinding charge, mill speed, and liner design.

The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5 x 5 Ball Mill has a working diameter of 5 inside the liners and has 20 per cent more capacity than all other ball mills designated as 5 x 5 where the shell is 5 inside diameter and the working diameter is only 48 with the liners in place.

Ball-Rod Mills, based on 4 liners and capacity varying as 2.6 power of mill diameter, on the 5 size give 20 per cent increased capacity; on the 4 size, 25 per cent; and on the 3 size, 28 per cent. This fact should be carefully kept in mind when determining the capacity of a Steel- Head Ball-Rod Mill, as this unit can carry a greater ball or rod charge and has potentially higher capacity in a given size when the full ball or rod charge is carried.

A mill shorter in length may be used if the grinding problem indicates a definite power input. This allows the alternative of greater capacity at a later date or a considerable saving in first cost with a shorter mill, if reserve capacity is not desired. The capacities of Ball-Rod Mills are considerably higher than many other types because the diameters are measured inside the liners.

The correct grinding mill depends so much upon the particular ore being treated and the product desired, that a mill must have maximum flexibility in length, type of grinding medium, type of discharge, and speed.With the Ball-Rod Mill it is possible to build this unit in exact accordance with your requirements, as illustrated.

To best serve your needs, the Trunnion can be furnished with small (standard), medium, or large diameter opening for each type of discharge. The sketch shows diagrammatic arrangements of the four different types of discharge for each size of trunnion opening, and peripheral discharge is described later.

Ball-Rod Mills of the grate discharge type are made by adding the improved type of grates to a standard Ball-Rod Mill. These grates are bolted to the discharge head in much the same manner as the standard headliners.

The grates are of alloy steel and are cast integral with the lifter bars which are essential to the efficient operation of this type of ball or rod mill. These lifter bars have a similar action to a pump:i. e., in lifting the product so as to discharge quickly through the mill trunnion.

These Discharge Grates also incorporate as an integral part, a liner between the lifters and steel head of the ball mill to prevent wear of the mill head. By combining these parts into a single casting, repairs and maintenance are greatly simplified. The center of the grate discharge end of this mill is open to permit adding of balls or for adding water to the mill through the discharge end.

Instead of being constructed of bars cast into a frame, Grates are cast entire and have cored holes which widen toward the outside of the mill similar to the taper in grizzly bars. The grate type discharge is illustrated.

The peripheral discharge type of Ball-Rod Mill is a modification of the grate type, and is recommended where a free gravity discharge is desired. It is particularly applicable when production of too many fine particles is detrimental and a quick pass through the mill is desired, and for dry grinding.

The drawings show the arrangement of the peripheral discharge. The discharge consists of openings in the shell into which bushings with holes of the desired size are inserted. On the outside of the mill, flanges are used to attach a stationary discharge hopper to prevent pulp splash or too much dust.

The mill may be operated either as a peripheral discharge or a combination or peripheral and trunnion discharge unit, depending on the desired operating conditions. If at any time the peripheral discharge is undesirable, plugs inserted into the bushings will convert the mill to a trunnion discharge type mill.

Unless otherwise specified, a hard iron liner is furnished. This liner is made of the best grade white iron and is most serviceable for the smaller size mills where large balls are not used. Hard iron liners have a much lower first cost.

Electric steel, although more expensive than hard iron, has advantage of minimum breakage and allows final wear to thinner section. Steel liners are recommended when the mills are for export or where the source of liner replacement is at a considerable distance.

Molychrome steel has longer wearing qualities and greater strength than hard iron. Breakage is not so apt to occur during shipment, and any size ball can be charged into a mill equipped with molychrome liners.

Manganese liners for Ball-Rod Mills are the world famous AMSCO Brand, and are the best obtainable. The first cost is the highest, but in most cases the cost per ton of ore ground is the lowest. These liners contain 12 to 14% manganese.

The feed and discharge trunnions are provided with cast iron or white iron throat liners. As these parts are not subjected to impact and must only withstand abrasion, alloys are not commonly used but can be supplied.

Gears for Ball-Rod Mills drives are furnished as standard on the discharge end of the mill where they are out of the way of the classifier return, scoop feeder, or original feed. Due to convertible type construction the mills can be furnished with gears on the feed end. Gear drives are available in two alternative combinations, which are:

All pinions are properly bored, key-seated, and pressed onto the steel countershaft, which is oversize and properly keyseated for the pinion and drive pulleys or sheaves. The countershaft operates on high grade, heavy duty, nickel babbitt bearings.

Any type of drive can be furnished for Ball-Rod Mills in accordance with your requirements. Belt drives are available with pulleys either plain or equipped with friction clutch. Various V- Rope combinations can also be supplied.

The most economical drive to use up to 50 H. P., is a high starting torque motor connected to the pinion shaft by means of a flat or V-Rope drive. For larger size motors the wound rotor (slip ring) is recommended due to its low current requirement in starting up the ball mill.

Should you be operating your own power plant or have D. C. current, please specify so that there will be no confusion as to motor characteristics. If switches are to be supplied, exact voltage to be used should be given.

Even though many ores require fine grinding for maximum recovery, most ores liberate a large percentage of the minerals during the first pass through the grinding unit. Thus, if the free minerals can be immediately removed from the ball mill classifier circuit, there is little chance for overgrinding.

This is actually what has happened wherever Mineral Jigs or Unit Flotation Cells have been installed in the ball mill classifier circuit. With the installation of one or both of these machines between the ball mill and classifier, as high as 70 per cent of the free gold and sulphide minerals can be immediately removed, thus reducing grinding costs and improving over-all recovery. The advantage of this method lies in the fact that heavy and usually valuable minerals, which otherwise would be ground finer because of their faster settling in the classifier and consequent return to the grinding mill, are removed from the circuit as soon as freed. This applies particularly to gold and lead ores.

Ball-Rod Mills have heavy rolled steel plate shells which are arc welded inside and outside to the steel heads or to rolled steel flanges, depending upon the type of mill. The double welding not only gives increased structural strength, but eliminates any possibility of leakage.

Where a single or double flanged shell is used, the faces are accurately machined and drilled to template to insure perfect fit and alignment with the holes in the head. These flanges are machined with male and female joints which take the shearing stresses off the bolts.

The Ball-Rod Mill Heads are oversize in section, heavily ribbed and are cast from electric furnace steel which has a strength of approximately four times that of cast iron. The head and trunnion bearings are designed to support a mill with length double its diameter. This extra strength, besides eliminating the possibility of head breakage or other structural failure (either while in transit or while in service), imparts to Ball-Rod Mills a flexibility heretofore lacking in grinding mills. Also, for instance, if you have a 5 x 5 mill, you can add another 5 shell length and thus get double the original capacity; or any length required up to a maximum of 12 total length.

On Type A mills the steel heads are double welded to the rolled steel shell. On type B and other flanged type mills the heads are machined with male and female joints to match the shell flanges, thus taking the shearing stresses from the heavy machine bolts which connect the shell flanges to the heads.

The manhole cover is protected from wear by heavy liners. An extended lip is provided for loosening the door with a crow-bar, and lifting handles are also provided. The manhole door is furnished with suitable gaskets to prevent leakage.

The mill trunnions are carried on heavy babbitt bearings which provide ample surface to insure low bearing pressure. If at any time the normal length is doubled to obtain increased capacity, these large trunnion bearings will easily support the additional load. Trunnion bearings are of the rigid type, as the perfect alignment of the trunnion surface on Ball-Rod Mills eliminates any need for the more expensive self-aligning type of bearing.

The cap on the upper half of the trunnion bearing is provided with a shroud which extends over the drip flange of the trunnion and effectively prevents the entrance of dirt or grit. The bearing has a large space for wool waste and lubricant and this is easily accessible through a large opening which is covered to prevent dirt from getting into the bearing.Ball and socket bearings can be furnished.

Scoop Feeders for Ball-Rod Mills are made in various radius sizes. Standard scoops are made of cast iron and for the 3 size a 13 or 19 feeder is supplied, for the 4 size a 30 or 36, for the 5 a 36 or 42, and for the 6 a 42 or 48 feeder. Welded steel scoop feeders can, however, be supplied in any radius.

The correct size of feeder depends upon the size of the classifier, and the smallest feeder should be used which will permit gravity flow for closed circuit grinding between classifier and the ball or rod mill. All feeders are built with a removable wearing lip which can be easily replaced and are designed to give minimum scoop wear.

A combination drum and scoop feeder can be supplied if necessary. This feeder is made of heavy steel plate and strongly welded. These drum-scoop feeders are available in the same sizes as the cast iron feeders but can be built in any radius. Scoop liners can be furnished.

The trunnions on Ball-Rod Mills are flanged and carefully machined so that scoops are held in place by large machine bolts and not cap screws or stud bolts. The feed trunnion flange is machined with a shoulder for insuring a proper fit for the feed scoop, and the weight of the scoop is carried on this shoulder so that all strain is removed from the bolts which hold the scoop.

High carbon steel rods are recommended, hot rolled, hot sawed or sheared, to a length of 2 less than actual length of mill taken inside the liners. The initial rod charge is generally a mixture ranging from 1.5 to 3 in diameter. During operation, rod make-up is generally the maximum size. The weights per lineal foot of rods of various diameters are approximately: 1.5 to 6 lbs.; 2-10.7 lbs.; 2.5-16.7 lbs.; and 3-24 lbs.

Forged from the best high carbon manganese steel, they are of the finest quality which can be produced and give long, satisfactory service. Data on ball charges for Ball-Rod Mills are listed in Table 5. Further information regarding grinding balls is included in Table 6.

Rod Mills has a very define and narrow discharge product size range. Feeding a Rod Mill finer rocks will greatly impact its tonnage while not significantly affect its discharge product sizes. The 3.5 diameter rod of a mill, can only grind so fine.

Crushers are well understood by most. Rod and Ball Mills not so much however as their size reduction actions are hidden in the tube (mill). As for Rod Mills, the image above best expresses what is going on inside. As rocks is feed into the mill, they are crushed (pinched) by the weight of its 3.5 x 16 rods at one end while the smaller particles migrate towards the discharge end and get slightly abraded (as in a Ball Mill) on the way there.

We haveSmall Ball Mills for sale coming in at very good prices. These ball mills are relatively small, bearing mounted on a steel frame. All ball mills are sold with motor, gears, steel liners and optional grinding media charge/load.

Ball Mills or Rod Mills in a complete range of sizes up to 10 diameter x20 long, offer features of operation and convertibility to meet your exactneeds. They may be used for pulverizing and either wet or dry grindingsystems. Mills are available in both light-duty and heavy-duty constructionto meet your specific requirements.

All Mills feature electric cast steel heads and heavy rolled steelplate shells. Self-aligning main trunnion bearings on large mills are sealedand internally flood-lubricated. Replaceable mill trunnions. Pinion shaftbearings are self-aligning, roller bearing type, enclosed in dust-tightcarrier. Adjustable, single-unit soleplate under trunnion and drive pinionsfor perfect, permanent gear alignment.

Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15 x 21 to 8 x 12. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume. Mills are shipped with liners installed.

Complete laboratory testing service, mill and air classifier engineering and proven equipment make possible a single source for your complete dry-grinding mill installation. Units available with air swept design and centrifugal classifiers or with elevators and mechanical type air classifiers. All sizes and capacities of units. Laboratory-size air classifier also available.

A special purpose batch mill designed especially for grinding and mixing involving acids and corrosive materials. No corners mean easy cleaning and choice of rubber or ceramic linings make it corrosion resistant. Shape of mill and ball segregation gives preferential grinding action for grinding and mixing of pigments and catalysts. Made in 2, 3 and 4 diameter grinding drums.

Nowadays grinding mills are almost extensively used for comminution of materials ranging from 5 mm to 40 mm (3/161 5/8) down to varying product sizes. They have vast applications within different branches of industry such as for example the ore dressing, cement, lime, porcelain and chemical industries and can be designed for continuous as well as batch grinding.

Ball mills can be used for coarse grinding as described for the rod mill. They will, however, in that application produce more fines and tramp oversize and will in any case necessitate installation of effective classification.If finer grinding is wanted two or three stage grinding is advisable as for instant primary rod mill with 75100 mm (34) rods, secondary ball mill with 2540 mm(11) balls and possibly tertiary ball mill with 20 mm () balls or cylpebs.To obtain a close size distribution in the fine range the specific surface of the grinding media should be as high as possible. Thus as small balls as possible should be used in each stage.

The principal field of rod mill usage is the preparation of products in the 5 mm0.4 mm (4 mesh to 35 mesh) range. It may sometimes be recommended also for finer grinding. Within these limits a rod mill is usually superior to and more efficient than a ball mill. The basic principle for rod grinding is reduction by line contact between rods extending the full length of the mill, resulting in selective grinding carried out on the largest particle sizes. This results in a minimum production of extreme fines or slimes and more effective grinding work as compared with a ball mill. One stage rod mill grinding is therefore suitable for preparation of feed to gravimetric ore dressing methods, certain flotation processes with slime problems and magnetic cobbing. Rod mills are frequently used as primary mills to produce suitable feed to the second grinding stage. Rod mills have usually a length/diameter ratio of at least 1.4.

Tube mills are in principle to be considered as ball mills, the basic difference being that the length/diameter ratio is greater (35). They are commonly used for surface cleaning or scrubbing action and fine grinding in open circuit.

In some cases it is suitable to use screened fractions of the material as grinding media. Such mills are usually called pebble mills, but the working principle is the same as for ball mills. As the power input is approximately directly proportional to the volume weight of the grinding media, the power input for pebble mills is correspondingly smaller than for a ball mill.

A dry process requires usually dry grinding. If the feed is wet and sticky, it is often necessary to lower the moisture content below 1 %. Grinding in front of wet processes can be done wet or dry. In dry grinding the energy consumption is higher, but the wear of linings and charge is less than for wet grinding, especially when treating highly abrasive and corrosive material. When comparing the economy of wet and dry grinding, the different costs for the entire process must be considered.

An increase in the mill speed will give a directly proportional increase in mill power but there seems to be a square proportional increase in the wear. Rod mills generally operate within the range of 6075 % of critical speed in order to avoid excessive wear and tangled rods. Ball and pebble mills are usually operated at 7085 % of critical speed. For dry grinding the speed is usually somewhat lower.

The mill lining can be made of rubber or different types of steel (manganese or Ni-hard) with liner types according to the customers requirements. For special applications we can also supply porcelain, basalt and other linings.

The mill power is approximately directly proportional to the charge volume within the normal range. When calculating a mill 40 % charge volume is generally used. In pebble and ball mills quite often charge volumes close to 50 % are used. In a pebble mill the pebble consumption ranges from 315 % and the charge has to be controlled automatically to maintain uniform power consumption.

In all cases the net energy consumption per ton (kWh/ton) must be known either from previous experience or laboratory tests before mill size can be determined. The required mill net power P kW ( = ton/hX kWh/ton) is obtained from

Trunnions of S.G. iron or steel castings with machined flange and bearing seat incl. device for dismantling the bearings. For smaller mills the heads and trunnions are sometimes made in grey cast iron.

The mills can be used either for dry or wet, rod or ball grinding. By using a separate attachment the discharge end can be changed so that the mills can be used for peripheral instead of overflow discharge.

ceramic ball mill for grinding materials - ftm machinery

What kind of materials that the ceramic ball mills can process are always the focus of the miners. Can they show the safety and high efficiency? Does it really meet the demands or special demands of customers?

The ceramic ball mill is a small ball mill mainly used for mixing and grinding material. In ball mill ceramic industry, it has two kinds of grinding ceramic ball mill, one is dry grinding ceramic ball mill, and another is wet grinding ceramic ball mill.

Ceramic ball mill is mainly used in material mixing, grinding. Henan Fote Heavy Machinery Co., Ltd has two kinds of grinding ceramic ball mill, one is dry grinding ceramic ball mill, and another is wet grinding ceramic ball mill. The machine can use different liner types according to different production needs. The fineness of the grinding is controlled by grinding time.

The ceramic ball mill machinery has the advantages of less investment, lower energy consumption, novel structure, easy operation, stable and reliable performance and so on, which is suitable for grinding common and special materials. Customers can choose suitable types of ceramic ball mill jars according to the specific gravity, hardness, and capacity of materials.

It also named the ceramics ball mill, is a small ball mill mainly used for material mixing and grinding considering its products having features of regular granularity and power saving. China Fotes ceramic ball mill can do both dry and wet grinding and can choose different lining boards to meet various demands according to different production requirements.

The grinding ceramic ball mill uses different ball mill ceramic liner types according to production needs to meet different needs. The finess of ceramic ball mills depend on the grinding time. The electro-hydraulic machine is auto-coupled and decompressed to reduce the starting current. Its structure is divided into integral and independent.

The grinding fineness depends on the milling time. The motor of the ceramic ball mill is started by the coupling reduce voltage which lowers the starting electricity and the ball mills structure is divided into integral type and freestanding type; advantages of the ceramic ball mill are lower investment, energy saving, structure novelty, simply operated, used safely, ability even, etc.The ceramic ball mill is suitable for mixing and milling of the general and special material. Users could choose the proper type and line, media material depending on material ratio, rigidity, and output size, etc.

Ceramic ball mill is the typical grinding equipment which us ball mill ceramics, greatly improves the grinding fineness. Compared with the traditional ball mill, such kind of ball mill has a great advantage in function, structure, and operation. This machine also has great capacity, high technology, and no noise, which plays an important role in the field of Metallurgy, building materials, chemicals, industry.

The small tonnage glaze ball mill is the main machine used to make glaze ceramic grinding balls by the industries of producing household porcelain, electrical porcelain and building porcelain. It is applied to grind different glaze materials with different colors and has features of good grinding quality, compact structure, little noise, and simple maintenance.

The ceramic ball mill is a wet type grinding machine for the ceramic materials which can realize high efficiency for fine grinding of the medium crushed materials. Then, how to ball mill ceramic powder? Once users add raw materials, water, and ceramic grinding media in a proper proportion into the cylinder of the ball mill, they will get the ideal product particles by adjusting the required grinding period.

The fine material slurry is especially suitable to be applied in the industries of large-sized household porcelain, electrical porcelain, building porcelain and chemical engineering. And thats the main reason why the producers love ceramic glaze ball mill so much.According to the different demands, the ceramic grinding ball millcan produce different range of the partical ship.

This is a 3-foot by 6-foot continuous ball mill, and this machine will process one ton an hour at 65 mesh. You can actually process finer than that, down to about 200 mesh, but the throughput goes down. To the feed side, you can put three quarter to one inch minus here. then, ore enters into the scoop of ball mill, with a two-ton charge of balls. The material works its way through the ball mill, which turns about 35 RPM, with the water addition. To the discharge, they will go on to the shaker tables for concentration.

Here are three different size balls we use. And you add equal amounts of each size ball when you charge the mill. And then as the balls wear, you keep putting in larger balls. Again, it is about a two ton charge of balls. The machine empty weighs about 8,500 pounds, with the charge of balls, it weights about 12,500 pounds.

lets look inside the ball mill now, you can see it has cast armor lining the inside of mill. This is the feed side, and across the mill, here is the discharge side, and it has a grate to keep the balls in. There is an augur in there that screws the material back in, so only the finest material can exit the mill.

The mill weighs a little more than 3 tons, and you can easily turn the mill with one hand. So, its a really smooth mill, not a lot of friction. It runs with a 25 horse, 3-phase motor. And here in a couple weeks, well be getting this mill up and running and put a lot of balls in and run some material.

First. Installing the main bearing. In order to avoid the aggravating the wear of shoulder and bearing lining of the hollow journal, the gap between the base plate of two main ceramic ball mill bearings is no more than 0.25mm.

Second. Install the barrel of ceramic ball mill. According to the specific conditions, the pre-assembled whole simplified parts can be directly installed or installed in several parts. Check and adjust the center line of the journal and ceramic ball mill.

Third. Install transmission parts such as pinion gears, couplings, reducers, motors, etc. In the process of installation, measurements and adjustments should be made according to product technical standards. Check the radial slip off the ring gear and the meshing performance of the pinion, concentricity of reducer and pinion, and the concentricity of motor and reducer. Until all installations are ready, the foundation bolts and the main bearing bottom plate can be watered.

ball milling

A method of grinding particles in ceramic powders and slurries. A porcelain vessel filled with porcelain pebbles tumbles and particles are ground between colliding pebbles. Details A device used to reduce the particle size of materials, bodies or glazes. A ball mill is simply a container that is filled with pebbles (either of porcelain or stones e.g. Flint) into which a charge (powder or slurry) is put and that is then mechanically rotated to cause the tumbling pebbles to crush particles that happen between them. Ball mills can be continuous or periodic, they can be small or gigantic, low speed or high speed, rotated or vibrated or both. For maximum efficiency a ball mill should be made of, or lined with, a porcelain or other very hard surface (so grinding also occurs between the wall and the balls), the balls should be of a range of sizes (to maximize points of contact), the mill should have the correct quantity of balls, the slurry should be the right viscosity and the charge should be an optimal amount (over charging reduces efficiency). Various compromises are often made (for example rubber lined mills to reduce wear and noise). Large manufacturers hire ball mix supervisors, operators and mechanics. Technicians occupy themselves with getting a consistent and predictable product (surface area and particle size distribution), they employ mathematical formulas to determine the amount of balls needed, distribution of ball sizes and other operating parameters like duration and speed. They are wary of grinding products as mixes, it is often better to mill hard and soft powders separately and combine them later. Engineers typically use surface area measurement instrumentation to evaluate mill efficiency. Ball mills can reduce particles to the nano sizes, the process is very important in creating powders used in hi-tech industries (e.g. alumina). Ball mills are slow compared to other methods of grinding, it could take hours, for example, to grind all the particles in a clay to minus 200 mesh. Industrial mills seeking nano-sizes might run 24 hours or more! Ball milling is normally done in consort with wet screening and/or roller-milling/air floating, for example, so that large particles have already been removed by the time the material reaches the ball mill. Air floating can also be done in consort with dust ball milling. The milling process can also reduce particle sizes by too much for an application, so a means of measuring the distribution of ultimate particles is important to be able to set the parameters for the process. A clay body that has been ball milled will be more plastic, potentially much more plastic. Ball milling of the body or selected body materials will reduce or eliminate many types of fired glaze imperfections (especially specking, blistering and pin-holing). That being said and as already noted, iron particulates are best removed before milling). Milling a glaze will produce a cleaner fired result with less imperfections. Materials deliver their chemistry to the glaze melt only if their particles dissolve in the melt. But some glaze materials are refractory and resistant to dissolving (e.g. silica, alumina). When silica does not completely dissolve in a transparent glaze it will fire cloudy and its actual thermal expansion will be higher than it would otherwise be. By ball milling silica to very small particle sizes all the particles dissolve, producing a much better fired product. Milling of slurries presents less technical challenges than dust milling. We have found that thicker creamy slurries mill better than watery ones. A simple ball mill can be constructed by almost anyone, but obtaining the hard pebbles with the correct range of sizes for inside the mill can be challenge (they are expensive). Related Information How long do you need to ball mill a glaze? You can measure to see. How? Wash a measured amount through a 200 mesh screen and note the amount of residue. These two show the oversize on a 200 mesh screen of 100 grams of glaze slurry. On the left: Unmilled. On the right: Milled 1 hour. Clearly it needs more than 1 hour in this mill. A factor here is the high percentage of silica in this recipe. And the fact that US Silica #95 rather than #45 was used. DIY wheel mount ball mill rack Courtesy of Lawrence Weathers Ball mill jar and rack made by @andygravesstructures Make your own ball mill rack - Front side Possible to grind your own ceramic grade rutile? Yes, the granular and powdered grades are the same material. But grinding it is very difficult. Commercial ceramic grade powder is minus 325 mesh, the companies doing this obviously have very good grinding equipment. They also have patience because even in this efficient porcelain ball mill, 90 minutes was only enough to get 50% to minus 325 mesh! The color of the powder is a good indication of its quality, the finer the grind the lighter will be the tan coloration. Particle size drastically affects drying performance These DFAC testers compare the drying performance of Plainsman A2 ball clay at 10 mesh (left) and ball milled (right). This test dries a flat disk that has the center section covered to delay its progress in comparison to the outer section (thus setting up stresses). Finer particle sizes greatly increase shrinkage and this increases the number of cracks and the cracking pattern of this specimen. Notice it has also increased the amount of soluble salts that have concentrated between the two zones, more is dissolving because of the increased particle surface area. Can we ball mill a clay and make it more colloidal? Yes. This 1000 ml 24 hour sedimentation test compares Plainsman A2 ball clay ground to 10 mesh (left) with that same material ball milled for an hour (right). The 10 mesh designation is a little misleading, those are agglomerates. When it is put into water many of those particles break down releasing the ultimates and it does suspend fairly well. But after 24 hours, not only has it settled completely from the upper section but there is a heavy sediment on the bottom. But with the milled material it has only settled slightly and there is no sediment on the bottom. Clearly, using an industrial attrition ball mill this material could be made completely colloidal. Links URLs http://www.thecementgrindingoffice.com/typesofballmills.html Types of Ball Mills Articles Make Your Own Ball Mill Stand Pictures of a ball mill rack that you can make yourself Articles Ball Milling Glazes, Bodies, Engobes Industries ball mill their glazes, engobes and even bodies as standard practice. Yet few potters even have a ball mill or know what one is. By Tony Hansen Tell Us How to Improve This Page Or ask a question and we will alter this page to better answer it. Email Address Name Subject Message Content of message Prove you are not a robot: Enter this text (CAPITAL letters only) or Refresh https://digitalfire.com, All Rights Reserved Privacy Policy

A device used to reduce the particle size of materials, bodies or glazes. A ball mill is simply a container that is filled with pebbles (either of porcelain or stones e.g. Flint) into which a charge (powder or slurry) is put and that is then mechanically rotated to cause the tumbling pebbles to crush particles that happen between them. Ball mills can be continuous or periodic, they can be small or gigantic, low speed or high speed, rotated or vibrated or both. For maximum efficiency a ball mill should be made of, or lined with, a porcelain or other very hard surface (so grinding also occurs between the wall and the balls), the balls should be of a range of sizes (to maximize points of contact), the mill should have the correct quantity of balls, the slurry should be the right viscosity and the charge should be an optimal amount (over charging reduces efficiency). Various compromises are often made (for example rubber lined mills to reduce wear and noise). Large manufacturers hire ball mix supervisors, operators and mechanics. Technicians occupy themselves with getting a consistent and predictable product (surface area and particle size distribution), they employ mathematical formulas to determine the amount of balls needed, distribution of ball sizes and other operating parameters like duration and speed. They are wary of grinding products as mixes, it is often better to mill hard and soft powders separately and combine them later. Engineers typically use surface area measurement instrumentation to evaluate mill efficiency. Ball mills can reduce particles to the nano sizes, the process is very important in creating powders used in hi-tech industries (e.g. alumina). Ball mills are slow compared to other methods of grinding, it could take hours, for example, to grind all the particles in a clay to minus 200 mesh. Industrial mills seeking nano-sizes might run 24 hours or more! Ball milling is normally done in consort with wet screening and/or roller-milling/air floating, for example, so that large particles have already been removed by the time the material reaches the ball mill. Air floating can also be done in consort with dust ball milling. The milling process can also reduce particle sizes by too much for an application, so a means of measuring the distribution of ultimate particles is important to be able to set the parameters for the process. A clay body that has been ball milled will be more plastic, potentially much more plastic. Ball milling of the body or selected body materials will reduce or eliminate many types of fired glaze imperfections (especially specking, blistering and pin-holing). That being said and as already noted, iron particulates are best removed before milling). Milling a glaze will produce a cleaner fired result with less imperfections. Materials deliver their chemistry to the glaze melt only if their particles dissolve in the melt. But some glaze materials are refractory and resistant to dissolving (e.g. silica, alumina). When silica does not completely dissolve in a transparent glaze it will fire cloudy and its actual thermal expansion will be higher than it would otherwise be. By ball milling silica to very small particle sizes all the particles dissolve, producing a much better fired product. Milling of slurries presents less technical challenges than dust milling. We have found that thicker creamy slurries mill better than watery ones. A simple ball mill can be constructed by almost anyone, but obtaining the hard pebbles with the correct range of sizes for inside the mill can be challenge (they are expensive).

You can measure to see. How? Wash a measured amount through a 200 mesh screen and note the amount of residue. These two show the oversize on a 200 mesh screen of 100 grams of glaze slurry. On the left: Unmilled. On the right: Milled 1 hour. Clearly it needs more than 1 hour in this mill. A factor here is the high percentage of silica in this recipe. And the fact that US Silica #95 rather than #45 was used.

Yes, the granular and powdered grades are the same material. But grinding it is very difficult. Commercial ceramic grade powder is minus 325 mesh, the companies doing this obviously have very good grinding equipment. They also have patience because even in this efficient porcelain ball mill, 90 minutes was only enough to get 50% to minus 325 mesh! The color of the powder is a good indication of its quality, the finer the grind the lighter will be the tan coloration.

These DFAC testers compare the drying performance of Plainsman A2 ball clay at 10 mesh (left) and ball milled (right). This test dries a flat disk that has the center section covered to delay its progress in comparison to the outer section (thus setting up stresses). Finer particle sizes greatly increase shrinkage and this increases the number of cracks and the cracking pattern of this specimen. Notice it has also increased the amount of soluble salts that have concentrated between the two zones, more is dissolving because of the increased particle surface area.

This 1000 ml 24 hour sedimentation test compares Plainsman A2 ball clay ground to 10 mesh (left) with that same material ball milled for an hour (right). The 10 mesh designation is a little misleading, those are agglomerates. When it is put into water many of those particles break down releasing the ultimates and it does suspend fairly well. But after 24 hours, not only has it settled completely from the upper section but there is a heavy sediment on the bottom. But with the milled material it has only settled slightly and there is no sediment on the bottom. Clearly, using an industrial attrition ball mill this material could be made completely colloidal.

choosing ball milling media for firework chemical milling skylighter, inc

In his book Ball Milling Theory and Practice for the Amateur Pyrotechnician, Lloyd includes a section on casting your own lead media. Some folks melt used lead automobile wheel weights or hardened linotype as the raw material for casting media. Lloyd does begin this chapter with the warning, though: "Casting metals is dangerous. If you don't have experience, make up the molds, then seek a plumber or firearms reloader for assistance." There are other types of media as well. Here's a shot of some stainless steel media and ceramic media. The stainless steel must be spark-resistant, non-magnetic steel in the 300-series. Alloys 304 and 316 are the most common stainless steels of this type. High-density alumina ceramic media is the type I've heard of most often being used in ball mills.

what particle size range does ball mill grinding produce?

Ball Mill The ball mill has been around for eons. There are many shapes and sizes and types. There is a single enclosed drum-type where material is placed in the drum along with a charge of grinding media. These can be in various shapes, and typically they are balls. There is a whole science in the size of the starting material versus the ball size, shape material of construction and charge percentage of grinding media. All of these variables affect particle size, shape, and grinding efficiency. This type of grinding is very good for abrasive materials to prevent contamination. The grinding media as well as the interior surfaces of the mill can be lined with abrasion resistant materials suited to the material being ground. In some cases, it can even be the material being ground. However, the batch type system is not a very efficient means of grinding. There is a variety of ball mill that is a continuous process versus a batch process. It has an external classifier which returns the oversized material to the ball mill for further milling. This system is much more efficient in the grinding ability, but it is much more difficult to line the entire system with wear parts to grind an abrasive material.

Ball mill grinding is one method of crushing ore to an appropriate size fraction.Specifically, ore is put into a large receptacle (a drum) and then it rotates slowly around.Inside the receptacle, there are balls, usually made of metal, that as the ore is rotated around the revolving drum the ore is crushed as the balls rise and fall.The drum has a slight tilt to it, from one end to the other so that the ore slowly works its way to discharging end.The trick or art to all of this is to rotate the drum at a distinct rpm and the balls are harder than the ore so as to efficiently crush the continuous stream of ore to the desired size at the discharge end.

The ball mill is a key piece of equipment for grinding crushed materials, and it is widely used in production lines for powders such as cement, silicates, refractory material, fertilizer, glass ceramics, etc. as well as for ore dressing of both ferrous and non-ferrous metals. The ball mill can grind various ores and other materials either wet or dry. There are two kinds of ball mill, grate type and overfall type due to different ways of discharging material. There are many types of grinding media suitable for use in a ball mill, each material having its own specific properties and advantages. Key properties of grinding media are size, density, hardness, and composition.

The grinding chamber can also be filled with an inertshield gasthat does not react with the material being ground, to prevent oxidation or explosive reactions that could occur with ambient air inside the mill.

ball milling glazes, bodies, engobes

A true ball mill is a porcelain jar partly filled with spherical or rounded cylindrical porcelain balls. Industrial versions are made of metal and have porcelain linings. Small scale operations most commonly employ ball mills for grinding glazes. The suspension is poured in, a lid secured, and it is rotated on a motorized rack, sometimes for many hours. The tumbling balls within grind particles smaller and smaller as they impact each other (and crush particles that happen to be at the points of contact). The creamier glaze that milling produces applies better, has more stable viscosity, fires more consistently and cleaner with less specks and imperfections (eg. pinholes and blisters), and melts better. Glazes can be overmilled, this can produce solubility, crawling, opacification and slurry issues (since certain materials in the glaze need to be kept above a certain particle size to behave correctly).

Potters and hobbyists are generally not aware of the importance of the ball mill to industrial ceramic ware production. For a small-scale stoneware operation it is possible to survive without one using a narrow range of glazes and techniques. But when production is ramped up consistency, reliability of the glaze appearance and defect free ware become paramount. Many materials in ceramics are simply not ground fine enough for glazes (they produce fired specks or defects related to expulsion of gases around larger particles); ball, native and slip clays are an example. In other materialsfine particles agglomerate into larger ones (e.g. barium carbonate, tin oxide, wollastonite). Others are supplied as a grain-type material rather than a powder and obviously have to be milled (eg. lithium carbonate, alumina hydrate). Engobes that must be sprayed, sink screened or even inkjet printed must be ball milled or nozzles will clog and screen will blind. Obviously, bottled engobes and glazes that potter's buy are ball milled when produced.

Amazingly, many industries routinely grind their body materials in ball mills (e.g. the insulator and even tile industries). One Kalemaden plant we visited in Canakkale, Turkey (one of the largest in the world) airfloats and mills local clays for all their products. They even collect their own flint rocks and break and mill them to round. Companies may be seeking residues of less than 0.1% on 325 mesh. Other benefits also ensue, including more plasticity, better fired maturity and strength. The benefits are not only very high quality and defect defect-free products, but better consistency. Typically a slurry of 65% clay and 35% water is made (only possible if deflocculated) and ball milled, then dewatered (using filter presses, spray driers, etc) to make powder or pellets. In addition, materials will melt or go into solution in the melting glaze significantly better or sooner if they are ground finer.

A small mill rack is $700-1300 US. However you can build your own (see the links here). href="https://www.digitalfire.com/gerstleyborate/ballmill/">https://www.digitalfire.com/gerstleyborate/ballmill/ Or you google the booklet "Thoroughly Modern Milling" by Steve Harrison (it is intended to assist the potter in building a ball mill with a roller mechanism to handle a jar in the 3 to 5 gallon range). The text describes how to assemble the parts illustrated in the detail drawings and briefly describes making your own jar and ball from porcelain clay body. A4 size, 6 pages of text and 6 x A3 pages of detail mechanical drawings. There is one color photograph.

If you are using a ball mill in your operation resist the temptation to think that using one is just a matter of throwing in some pebbles, pouring in the glaze, and turning it on for an hour or so.As a general rule you should mill for the same amount of time, fill the jar to the same level, use the same charge of pebbles and the range of sizes of the pebbles should be controlled (the pebbles wear down over time). There are many finer pointsto know about using ball mills and industry uses the term "mill practice" to embody them. Variation caused by poor mill practice can create a number of significant fired glaze faults and affect slurry and application properties. To learn more check the book 'Ceramics Glaze Technology'. You should be able to find a copy at one of the used ceramic book vendors or information online.

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ball mill - an overview | sciencedirect topics

The ball mill accepts the SAG or AG mill product. Ball mills give a controlled final grind and produce flotation feed of a uniform size. Ball mills tumble iron or steel balls with the ore. The balls are initially 510 cm diameter but gradually wear away as grinding of the ore proceeds. The feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel.

The ball mill is operated in closed circuit with a particle-size measurement device and size-control cyclones. The cyclones send correct-size material on to flotation and direct oversize material back to the ball mill for further grinding.

Grinding elements in ball mills travel at different velocities. Therefore, collision force, direction and kinetic energy between two or more elements vary greatly within the ball charge. Frictional wear or rubbing forces act on the particles, as well as collision energy. These forces are derived from the rotational motion of the balls and movement of particles within the mill and contact zones of colliding balls.

By rotation of the mill body, due to friction between mill wall and balls, the latter rise in the direction of rotation till a helix angle does not exceed the angle of repose, whereupon, the balls roll down. Increasing of rotation rate leads to growth of the centrifugal force and the helix angle increases, correspondingly, till the component of weight strength of balls become larger than the centrifugal force. From this moment the balls are beginning to fall down, describing during falling certain parabolic curves (Figure 2.7). With the further increase of rotation rate, the centrifugal force may become so large that balls will turn together with the mill body without falling down. The critical speed n (rpm) when the balls are attached to the wall due to centrifugation:

where Dm is the mill diameter in meters. The optimum rotational speed is usually set at 6580% of the critical speed. These data are approximate and may not be valid for metal particles that tend to agglomerate by welding.

The degree of filling the mill with balls also influences productivity of the mill and milling efficiency. With excessive filling, the rising balls collide with falling ones. Generally, filling the mill by balls must not exceed 3035% of its volume.

The mill productivity also depends on many other factors: physical-chemical properties of feed material, filling of the mill by balls and their sizes, armor surface shape, speed of rotation, milling fineness and timely moving off of ground product.

where b.ap is the apparent density of the balls; l is the degree of filling of the mill by balls; n is revolutions per minute; 1, and 2 are coefficients of efficiency of electric engine and drive, respectively.

A feature of ball mills is their high specific energy consumption; a mill filled with balls, working idle, consumes approximately as much energy as at full-scale capacity, i.e. during grinding of material. Therefore, it is most disadvantageous to use a ball mill at less than full capacity.

The ball mill is a tumbling mill that uses steel balls as the grinding media. The length of the cylindrical shell is usually 11.5 times the shell diameter (Figure 8.11). The feed can be dry, with less than 3% moisture to minimize ball coating, or slurry containing 2040% water by weight. Ball mills are employed in either primary or secondary grinding applications. In primary applications, they receive their feed from crushers, and in secondary applications, they receive their feed from rod mills, AG mills, or SAG mills.

Ball mills are filled up to 40% with steel balls (with 3080mm diameter), which effectively grind the ore. The material that is to be ground fills the voids between the balls. The tumbling balls capture the particles in ball/ball or ball/liner events and load them to the point of fracture.

When hard pebbles rather than steel balls are used for the grinding media, the mills are known as pebble mills. As mentioned earlier, pebble mills are widely used in the North American taconite iron ore operations. Since the weight of pebbles per unit volume is 3555% of that of steel balls, and as the power input is directly proportional to the volume weight of the grinding medium, the power input and capacity of pebble mills are correspondingly lower. Thus, in a given grinding circuit, for a certain feed rate, a pebble mill would be much larger than a ball mill, with correspondingly a higher capital cost. However, the increase in capital cost is justified economically by a reduction in operating cost attributed to the elimination of steel grinding media.

In general, ball mills can be operated either wet or dry and are capable of producing products in the order of 100m. This represents reduction ratios of as great as 100. Very large tonnages can be ground with these ball mills because they are very effective material handling devices. Ball mills are rated by power rather than capacity. Today, the largest ball mill in operation is 8.53m diameter and 13.41m long with a corresponding motor power of 22MW (Toromocho, private communications).

Planetary ball mills. A planetary ball mill consists of at least one grinding jar, which is arranged eccentrically on a so-called sun wheel. The direction of movement of the sun wheel is opposite to that of the grinding jars according to a fixed ratio. The grinding balls in the grinding jars are subjected to superimposed rotational movements. The jars are moved around their own axis and, in the opposite direction, around the axis of the sun wheel at uniform speed and uniform rotation ratios. The result is that the superimposition of the centrifugal forces changes constantly (Coriolis motion). The grinding balls describe a semicircular movement, separate from the inside wall, and collide with the opposite surface at high impact energy. The difference in speeds produces an interaction between frictional and impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill. Planetary ball mills are smaller than common ball mills, and are mainly used in laboratories for grinding sample material down to very small sizes.

Vibration mill. Twin- and three-tube vibrating mills are driven by an unbalanced drive. The entire filling of the grinding cylinders, which comprises the grinding media and the feed material, constantly receives impulses from the circular vibrations in the body of the mill. The grinding action itself is produced by the rotation of the grinding media in the opposite direction to the driving rotation and by continuous head-on collisions of the grinding media. The residence time of the material contained in the grinding cylinders is determined by the quantity of the flowing material. The residence time can also be influenced by using damming devices. The sample passes through the grinding cylinders in a helical curve and slides down from the inflow to the outflow. The high degree of fineness achieved is the result of this long grinding procedure. Continuous feeding is carried out by vibrating feeders, rotary valves, or conveyor screws. The product is subsequently conveyed either pneumatically or mechanically. They are basically used to homogenize food and feed.

CryoGrinder. As small samples (100 mg or <20 ml) are difficult to recover from a standard mortar and pestle, the CryoGrinder serves as an alternative. The CryoGrinder is a miniature mortar shaped as a small well and a tightly fitting pestle. The CryoGrinder is prechilled, then samples are added to the well and ground by a handheld cordless screwdriver. The homogenization and collection of the sample is highly efficient. In environmental analysis, this system is used when very small samples are available, such as small organisms or organs (brains, hepatopancreas, etc.).

The vibratory ball mill is another kind of high-energy ball mill that is used mainly for preparing amorphous alloys. The vials capacities in the vibratory mills are smaller (about 10 ml in volume) compared to the previous types of mills. In this mill, the charge of the powder and milling tools are agitated in three perpendicular directions (Fig. 1.6) at very high speed, as high as 1200 rpm.

Another type of the vibratory ball mill, which is used at the van der Waals-Zeeman Laboratory, consists of a stainless steel vial with a hardened steel bottom, and a single hardened steel ball of 6 cm in diameter (Fig. 1.7).

The mill is evacuated during milling to a pressure of 106 Torr, in order to avoid reactions with a gas atmosphere.[44] Subsequently, this mill is suitable for mechanical alloying of some special systems that are highly reactive with the surrounding atmosphere, such as rare earth elements.

A ball mill is a relatively simple apparatus in which the motion of the reactor, or of a part of it, induces a series of collisions of balls with each other and with the reactor walls (Suryanarayana, 2001). At each collision, a fraction of the powder inside the reactor is trapped between the colliding surfaces of the milling tools and submitted to a mechanical load at relatively high strain rates (Suryanarayana, 2001). This load generates a local nonhydrostatic mechanical stress at every point of contact between any pair of powder particles. The specific features of the deformation processes induced by these stresses depend on the intensity of the mechanical stresses themselves, on the details of the powder particle arrangement, that is on the topology of the contact network, and on the physical and chemical properties of powders (Martin et al., 2003; Delogu, 2008a). At the end of any given collision event, the powder that has been trapped is remixed with the powder that has not undergone this process. Correspondingly, at any instant in the mechanical processing, the whole powder charge includes fractions of powder that have undergone a different number of collisions.

The individual reactive processes at the perturbed interface between metallic elements are expected to occur on timescales that are, at most, comparable with the collision duration (Hammerberg et al., 1998; Urakaev and Boldyrev, 2000; Lund and Schuh, 2003; Delogu and Cocco, 2005a,b). Therefore, unless the ball mill is characterized by unusually high rates of powder mixing and frequency of collisions, reactive events initiated by local deformation processes at a given collision are not affected by a successive collision. Indeed, the time interval between successive collisions is significantly longer than the time period required by local structural perturbations for full relaxation (Hammerberg et al., 1998; Urakaev and Boldyrev, 2000; Lund and Schuh, 2003; Delogu and Cocco, 2005a,b).

These few considerations suffice to point out the two fundamental features of powder processing by ball milling, which in turn govern the MA processes in ball mills. First, mechanical processing by ball milling is a discrete processing method. Second, it has statistical character. All of this has important consequences for the study of the kinetics of MA processes. The fact that local deformation events are connected to individual collisions suggests that absolute time is not an appropriate reference quantity to describe mechanically induced phase transformations. Such a description should rather be made as a function of the number of collisions (Delogu et al., 2004). A satisfactory description of the MA kinetics must also account for the intrinsic statistical character of powder processing by ball milling. The amount of powder trapped in any given collision, at the end of collision is indeed substantially remixed with the other powder in the reactor. It follows that the same amount, or a fraction of it, could at least in principle be trapped again in the successive collision.

This is undoubtedly a difficult aspect to take into account in a mathematical description of MA kinetics. There are at least two extreme cases to consider. On the one hand, it could be assumed that the powder trapped in a given collision cannot be trapped in the successive one. On the other, it could be assumed that powder mixing is ideal and that the amount of powder trapped at a given collision has the same probability of being processed in the successive collision. Both these cases allow the development of a mathematical model able to describe the relationship between apparent kinetics and individual collision events. However, the latter assumption seems to be more reliable than the former one, at least for commercial mills characterized by relatively complex displacement in the reactor (Manai et al., 2001, 2004).

A further obvious condition for the successful development of a mathematical description of MA processes is the one related to the uniformity of collision regimes. More specifically, it is highly desirable that the powders trapped at impact always experience the same conditions. This requires the control of the ball dynamics inside the reactor, which can be approximately obtained by using a single milling ball and an amount of powder large enough to assure inelastic impact conditions (Manai et al., 2001, 2004; Delogu et al., 2004). In fact, the use of a single milling ball avoids impacts between balls, which have a remarkable disordering effect on the ball dynamics, whereas inelastic impact conditions permit the establishment of regular and periodic ball dynamics (Manai et al., 2001, 2004; Delogu et al., 2004).

All of the above assumptions and observations represent the basis and guidelines for the development of the mathematical model briefly outlined in the following. It has been successfully applied to the case of a Spex Mixer/ Mill mod. 8000, but the same approach can, in principle, be used for other ball mills.

The Planetary ball mills are the most popular mills used in MM, MA, and MD scientific researches for synthesizing almost all of the materials presented in Figure 1.1. In this type of mill, the milling media have considerably high energy, because milling stock and balls come off the inner wall of the vial (milling bowl or vial) and the effective centrifugal force reaches up to 20 times gravitational acceleration.

The centrifugal forces caused by the rotation of the supporting disc and autonomous turning of the vial act on the milling charge (balls and powders). Since the turning directions of the supporting disc and the vial are opposite, the centrifugal forces alternately are synchronized and opposite. Therefore, the milling media and the charged powders alternatively roll on the inner wall of the vial, and are lifted and thrown off across the bowl at high speed, as schematically presented in Figure 2.17.

However, there are some companies in the world who manufacture and sell number of planetary-type ball mills; Fritsch GmbH (www.fritsch-milling.com) and Retsch (http://www.retsch.com) are considered to be the oldest and principal companies in this area.

Fritsch produces different types of planetary ball mills with different capacities and rotation speeds. Perhaps, Fritsch Pulverisette P5 (Figure 2.18(a)) and Fritsch Pulverisette P6 (Figure 2.18(b)) are the most popular models of Fritsch planetary ball mills. A variety of vials and balls made of different materials with different capacities, starting from 80ml up to 500ml, are available for the Fritsch Pulverisette planetary ball mills; these include tempered steel, stainless steel, tungsten carbide, agate, sintered corundum, silicon nitride, and zirconium oxide. Figure 2.19 presents 80ml-tempered steel vial (a) and 500ml-agate vials (b) together with their milling media that are made of the same materials.

Figure 2.18. Photographs of Fritsch planetary-type high-energy ball mill of (a) Pulverisette P5 and (b) Pulverisette P6. The equipment is housed in the Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR).

Figure 2.19. Photographs of the vials used for Fritsch planetary ball mills with capacity of (a) 80ml and (b) 500ml. The vials and the balls shown in (a) and (b) are made of tempered steel agate materials, respectively (Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR)).

More recently and in year 2011, Fritsch GmbH (http://www.fritsch-milling.com) introduced a new high-speed and versatile planetary ball mill called Planetary Micro Mill PULVERISETTE 7 (Figure 2.20). The company claims this new ball mill will be helpful to enable extreme high-energy ball milling at rotational speed reaching to 1,100rpm. This allows the new mill to achieve sensational centrifugal accelerations up to 95 times Earth gravity. They also mentioned that the energy application resulted from this new machine is about 150% greater than the classic planetary mills. Accordingly, it is expected that this new milling machine will enable the researchers to get their milled powders in short ball-milling time with fine powder particle sizes that can reach to be less than 1m in diameter. The vials available for this new type of mill have sizes of 20, 45, and 80ml. Both the vials and balls can be made of the same materials, which are used in the manufacture of large vials used for the classic Fritsch planetary ball mills, as shown in the previous text.

Retsch has also produced a number of capable high-energy planetary ball mills with different capacities (http://www.retsch.com/products/milling/planetary-ball-mills/); namely Planetary Ball Mill PM 100 (Figure 2.21(a)), Planetary Ball Mill PM 100 CM, Planetary Ball Mill PM 200, and Planetary Ball Mill PM 400 (Figure 2.21(b)). Like Fritsch, Retsch offers high-quality ball-milling vials with different capacities (12, 25, 50, 50, 125, 250, and 500ml) and balls of different diameters (540mm), as exemplified in Figure 2.22. These milling tools can be made of hardened steel as well as other different materials such as carbides, nitrides, and oxides.

Figure 2.21. Photographs of Retsch planetary-type high-energy ball mill of (a) PM 100 and (b) PM 400. The equipment is housed in the Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR).

Figure 2.22. Photographs of the vials used for Retsch planetary ball mills with capacity of (a) 80ml, (b) 250ml, and (c) 500ml. The vials and the balls shown are made of tempered steel (Nanotechnology Laboratory, Energy and Building Research Center (EBRC), Kuwait Institute for Scientific Research (KISR)).

Both Fritsch and Retsch companies have offered special types of vials that allow monitoring and measure the gas pressure and temperature inside the vial during the high-energy planetary ball-milling process. Moreover, these vials allow milling the powders under inert (e.g., argon or helium) or reactive gas (e.g., hydrogen or nitrogen) with a maximum gas pressure of 500kPa (5bar). It is worth mentioning here that such a development made on the vials design allows the users and researchers to monitor the progress tackled during the MA and MD processes by following up the phase transformations and heat realizing upon RBM, where the interaction of the gas used with the freshly created surfaces of the powders during milling (adsorption, absorption, desorption, and decomposition) can be monitored. Furthermore, the data of the temperature and pressure driven upon using this system is very helpful when the ball mills are used for the formation of stable (e.g., intermetallic compounds) and metastable (e.g., amorphous and nanocrystalline materials) phases. In addition, measuring the vial temperature during blank (without samples) high-energy ball mill can be used as an indication to realize the effects of friction, impact, and conversion processes.

More recently, Evico-magnetics (www.evico-magnetics.de) has manufactured an extraordinary high-pressure milling vial with gas-temperature-monitoring (GTM) system. Likewise both system produced by Fritsch and Retsch, the developed system produced by Evico-magnetics, allowing RBM but at very high gas pressure that can reach to 15,000kPa (150bar). In addition, it allows in situ monitoring of temperature and of pressure by incorporating GTM. The vials, which can be used with any planetary mills, are made of hardened steel with capacity up to 220ml. The manufacturer offers also two-channel system for simultaneous use of two milling vials.

Using different ball mills as examples, it has been shown that, on the basis of the theory of glancing collision of rigid bodies, the theoretical calculation of tPT conditions and the kinetics of mechanochemical processes are possible for the reactors that are intended to perform different physicochemical processes during mechanical treatment of solids. According to the calculations, the physicochemical effect of mechanochemical reactors is due to short-time impulses of pressure (P = ~ 10101011 dyn cm2) with shift, and temperature T(x, t). The highest temperature impulse T ~ 103 K are caused by the dry friction phenomenon.

Typical spatial and time parameters of the impactfriction interaction of the particles with a size R ~ 104 cm are as follows: localization region, x ~ 106 cm; time, t ~ 108 s. On the basis of the obtained theoretical results, the effect of short-time contact fusion of particles treated in various comminuting devices can play a key role in the mechanism of activation and chemical reactions for wide range of mechanochemical processes. This role involves several aspects, that is, the very fact of contact fusion transforms the solid phase process onto another qualitative level, judging from the mass transfer coefficients. The spatial and time characteristics of the fused zone are such that quenching of non-equilibrium defects and intermediate products of chemical reactions occurs; solidification of the fused zone near the contact point results in the formation of a nanocrystal or nanoamor- phous state. The calculation models considered above and the kinetic equations obtained using them allow quantitative ab initio estimates of rate constants to be performed for any specific processes of mechanical activation and chemical transformation of the substances in ball mills.

There are two classes of ball mills: planetary and mixer (also called swing) mill. The terms high-speed vibration milling (HSVM), high-speed ball milling (HSBM), and planetary ball mill (PBM) are often used. The commercial apparatus are PBMs Fritsch P-5 and Fritsch Pulverisettes 6 and 7 classic line, the Retsch shaker (or mixer) mills ZM1, MM200, MM400, AS200, the Spex 8000, 6750 freezer/mill SPEX CertiPrep, and the SWH-0.4 vibrational ball mill. In some instances temperature controlled apparatus were used (58MI1); freezer/mills were used in some rare cases (13MOP1824).

The balls are made of stainless steel, agate (SiO2), zirconium oxide (ZrO2), or silicon nitride (Si3N). The use of stainless steel will contaminate the samples with steel particles and this is a problem both for solid-state NMR and for drug purity.

However, there are many types of ball mills (see Chapter 2 for more details), such as drum ball mills, jet ball mills, bead-mills, roller ball mills, vibration ball mills, and planetary ball mills, they can be grouped or classified into two types according to their rotation speed, as follows: (i) high-energy ball mills and (ii) low-energy ball mills. Table 3.1 presents characteristics and comparison between three types of ball mills (attritors, vibratory mills, planetary ball mills and roller mills) that are intensively used on MA, MD, and MM techniques.

In fact, choosing the right ball mill depends on the objectives of the process and the sort of materials (hard, brittle, ductile, etc.) that will be subjecting to the ball-milling process. For example, the characteristics and properties of those ball mills used for reduction in the particle size of the starting materials via top-down approach, or so-called mechanical milling (MM process), or for mechanically induced solid-state mixing for fabrications of composite and nanocomposite powders may differ widely from those mills used for achieving mechanically induced solid-state reaction (MISSR) between the starting reactant materials of elemental powders (MA process), or for tackling dramatic phase transformation changes on the structure of the starting materials (MD). Most of the ball mills in the market can be employed for different purposes and for preparing of wide range of new materials.

Martinez-Sanchez et al. [4] have pointed out that employing of high-energy ball mills not only contaminates the milled amorphous powders with significant volume fractions of impurities that come from milling media that move at high velocity, but it also affects the stability and crystallization properties of the formed amorphous phase. They have proved that the properties of the formed amorphous phase (Mo53Ni47) powder depends on the type of the ball-mill equipment (SPEX 8000D Mixer/Mill and Zoz Simoloter mill) used in their important investigations. This was indicated by the high contamination content of oxygen on the amorphous powders prepared by SPEX 8000D Mixer/Mill, when compared with the corresponding amorphous powders prepared by Zoz Simoloter mill. Accordingly, they have attributed the poor stabilities, indexed by the crystallization temperature of the amorphous phase formed by SPEX 8000D Mixer/Mill to the presence of foreign matter (impurities).

grinding cylpebs

Our automatic production line for the grinding cylpebs is the unique. With stable quality, high production efficiency, high hardness, wear-resistant, the volumetric hardness of the grinding cylpebs is between 60-63HRC,the breakage is less than 0.5%. The organization of the grinding cylpebs is compact, the hardness is constant from the inner to the surface. Now has extensively used in the cement industry, the wear rate is about 30g-60g per Ton cement.

Grinding Cylpebs are made from low-alloy chilled cast iron. The molten metal leaves the furnace at approximately 1500 C and is transferred to a continuous casting machine where the selected size Cylpebs are created; by changing the moulds the full range of cylindrical media can be manufactured via one simple process. The Cylpebs are demoulded while still red hot and placed in a cooling section for several hours to relieve internal stress. Solidification takes place in seconds and is formed from the external surface inward to the centre of the media. It has been claimed that this manufacturing process contributes to the cost effectiveness of the media, by being more efficient and requiring less energy than the conventional forging method.

Because of their cylindrical geometry, Cylpebs have greater surface area and higher bulk density compared with balls of similar mass and size. Cylpebs of equal diameter and length have 14.5% greater surface area than balls of the same mass, and 9% higher bulk density than steel balls, or 12% higher than cast balls. As a result, for a given charge volume, about 25% more grinding media surface area is available for size reduction when charged with Cylpebs, but the mill would also draw more power.

balls - steel, ceramic, plastic & glass by boca bearings :: ceramic bearing specialists

The Boca Bearing Company offers and extensive line of miniature, metric and inch, industrial grade balls. Sizes range from as small as .5 millimetersto as big as 3 inches. Different materials like steel, ceramic, plastic or glass can be used as outlined below. If you cannot find what you are looking for please feel free to contact us directly.

Metal balls are rolling, spherical elements that are used in check and ball valves, bearings, and other mechanical devices that provide rotary or linear motion. They are usually made from alloy steel, carbon steel or stainless steel. Metal balls are characterized by the Outer Diameter, Permissible Deviation, Surface Roughness and Tolerance. The Outer Diameter (OD) is the overall width or average diameter of the ball. Permissible Deviation is the greatest radial distance in a radial plane between a sphere around the metal ball surface and any point on the ball surface. Surface Roughness measures the irregularities that form on the surface, but are not significant deviations. Basic diameter Tolerance is the maximum allowable deviation average diameter from the diameter specified. Boca Bearings stocks a wide assortment of 52100 Chrome Steel Balls, 440C Stainless Steel Balls and Carbon Steel Balls.

Ceramic balls are rolling, spherical elements that are used in check and ball valves, bearings, and other mechanical devices that provide rotary or linear motion. They are made from inorganic, nonmetallic materials that are processed at high temperatures. Many ceramic balls are capable of achieving an extremely smooth surface finish to a high degree of tolerance. As a result Ceramic Balls have an extremely low coefficient of friction as compared to Metal Balls. Grinding removes cuts, scratches, scuffs, and other irregularities. Many ceramic balls exhibit much greater hardness than steel balls and are capable of handling much higher operating temperatures, resulting in longer life and improved reliability. Ceramic balls can also provide high stiffness, low thermal expansion, light weight, increased corrosion resistance, and electrical resistance. Boca Bearings stocks a wide assortment of Silicon Nitride Ceramic Balls, Alumina Oxide Ceramic Balls and Zirconia Ceramic Balls.

Silicon Nitride (Si3N4) Ceramic Balls are formed from a new material suitable for applications where high loads, high speeds and extreme temperatures are factors. Long life and the need for minimal lubrication make this material appropriate for extreme applications. Silicon Nitride is non-porous, non-magnetic, non corrosive, lighter than steel and, in ball form, is harder than steel. Because ceramic balls are non-porous they are virtually frictionless and are capable of spinning faster than steel balls.

The C-HIP Ceramic Balls are similar to our Si3N4 Ceramic Ball series, but these C-HIP ballsare made with by Hot Isostatic Pressing (HIP). These ceramic ballshave an even greater density and hardness than a standard ceramic ball. Ceramic balls are suitable for applications where high loads, high speeds and extreme temperatures are factors. Long life and the need for minimal lubrication make this material appropriate for extreme applications. Ceramic is non-porous, non-magnetic, non corrosive and lighter than steel. In ball form, ceramic balls are also harder than steel and because ceramic balls are non-porous they are virtually frictionless and capable of spinning faster than steel balls.

Alumina Oxide (Al2O3) Ceramic Balls are resistant to most corrosive materials except for hydrochloric and hydrofluoric acids or strong alkaline solutions. Alumina Oxide is non-porous, lighter than steel and, in ball form, harder than steel. Because ceramic balls are non-porous they are virtually frictionless and are capable of spinning faster than steel balls.

Stainless Steel 440C Series Balls containa martensitic-type stainless steel used extensively in bearing applications that require hardness, dimensional stability, corrosion resistance and toughness. Stainless Steel 440C Balls are resistant to corrosion from fresh water, steam, crude oil, gasoline, perspiration, alcohol, blood and food stuffs. Stainless Steel does contain some carbon so it is still slightly magnetic.

316 Stainless Steel contains chromium, nickel and small amounts of manganese and molybdenum which make it more resistant to chlorides and saline environments. 316 Stainless Steel is resistant to most forms of oxidation. It is used in industrial applications where chemical exposure is high. 316 is also frequently used in saltwater environments and in medical and surgical equipment.

304 Stainless Steel contains chromium, nickel and small amounts of manganese. 304 Stainless Steel is resistant to most forms of oxidation. The durability makes 304 easy to sanitize, and therefore ideal for kitchen and food applications and environments. 304 Stainless Steel is susceptible to corrosion from chloride solutions, and from saline environments like the coast, those conditions would warrant a different material need.

302Stainless Steel contains chromium andnickel. 302 Stainless Steel is resistant to most forms of oxidation. The primary difference between 302 stainless and 304 or 316 is that in addition to being corrosion resistant, it is also non-magnetic.

Chrome Steel 52100 Series Balls contain chromium and, due to thorough hardening, has excellent surface quality and high load capability. 52100 Chrome Steel is a universal material for many applications. Chrome Steel is magnetic.

Plastic Balls are made from a white hardened plastic. Plastic balls are often used in industrial applications for sizing, for non-crush applications, as rollers for tracks, among many other applications. Plastic balls are able to be graded in precision from 1-100.

Hollow Stainless Steel Balls can be made from several different types of stainless steel. These hollow metal balls are used in a variety of industrial and commercial applications. They are often used as float valves, also they are used as mechanisms for weight measurement. These are also popular among various commercial entities they are used as flag pole toppers. They are often times used by mixed media artists in their outdoor sculptures, kinetic art pieces,and in other artistic endeavors.

Zirconia is inert to corrosive materials, with the exception of hydrofluoric acid and hot concentrated sulfuric acid. Zirconia is lighter than steel, non-magnetic and has a maximum useful temperature of 1800F or 968C.

Metallic alloy balls such as brass balls and bronze balls exhibit excellent corrosion resistance to chemicals, water, gas and oil. Brass balls are used in measurement devices, flow meters, pumps and valves. Brass balls are also ideal for electrical conductivity, electrical appliances and electrical contacts. Due to the low friction properties of brass balls gasoline rollover valves and fire equipment hose couplings are also common applications.

Brass balls are very hard, very salt water stable, water resistant. Due to its unique properties, which include corrosion resistance, common uses for Brass include applications which require low friction. These applications can include fittings (fasteners and connectors), tools, appliance parts, and ammunition components. It is good for electroplating and any electrical conductivity requirements. The metal has both good heat and electrical conductivity (its electrical conductivity can be from 23% to 44% that of pure copper), and it is wear and spark resistant (energy exploration).

Soft Carbon Steel Balls are used in applications where the ball would need to be welded, modified, or drilled. The softer carbon steel allows these balls to be modified more easily than a standard chrome steel or stainless steel ball.

S-2 Rockbit Steel balls are hardened steel balls often used in mining and drilling applications. The steel has been hardened to withstand the heavy loads and abrasive conditions associated with drilling into the ground. The S-2 Rockbit Balls are resistant to wear associated with the most extreme conditions.

grinding media - milling balls - ceramic grinding media | norstone inc

Grinding Media Grinding media are the means used to crush or grind material in a mill. It comes in different forms such as alumina oxide balls, ceramic cylinders, or soda lime glass. At Norstone Inc., we offer all types of medias used for grinding, deagglomeration, polishing, deburring, fillers, proppants, spacers, refractory beds and shot peening. Below, youll find a variety of ceramic grinding media specifically formulated to ensure reliable, consistent performance for your bulk material preparation. We also offer technical expertise on current and expanded uses for these medias; Call us to ensure that you are using the right media for your current product and process! Our specialists will recommend the best suited media, shape, size and alloy. The choice of media can depend upon the material to be ground, the grinding process, and the wear mechanisms involved. Toll/Screening services are available for sizing worn media.

Non-abrasive, cube shape, high chemical resistance, non-toxic, dust free. Smallest size available is 0.5mm x 0.5mm x 0.87mm diagonal. Density: 1.20 gm/cc. Bulk Density: 0.68 kg/l; 1.50 #/l; 2.50 kg/gal; 5.50 #/gal

Non-abrasive, spherical in shape, non-toxic and dust free. A variety of levels of cross linked polymers are available in sizes as small as 100 microns. Low in density but tough and wear resistant. Standard and Toughened Polystyrene beads have a strong odor from free styrene but this can be eliminated with a warm water wash. Also available in food grade, porous, toughened and narrow particle distributions. Density: 1.05 gm/cc. Bulk Density: 0.63 kg/l; 1.40 #/l; 2.30 kg/gal; 5.00 #/gal

Non-abrasive, spherical in shape, non-toxic, no odor and dust free. Available in sizes under 150 microns. Not solvent resistant. Density: 1.05 gm/cc. Bulk Density: 0.63 kg/l; 1.40 #/l; 2.30 kg/gal; 5.00 #/gal

Smallest size available is 2.0 mm. Good solvent resistance. Can swell with use in water. Nylon also stains if used with pigments. Density: 1.13 gm/cc. Bulk Density: 0.68 kg/l; 1.50 #/l; 2.50 kg/gal; 5.50 #/gal

High density, non-toxic balls used for delumping, mixing and blending of powders. Certain sizes are available with steel cores. Very long wearing and gentle on the mill. Density: 1.20 gm/cc. Bulk Density: 0.72 kg/l; 1.60 #/l; 2.60 kg/gal; 5.80 #/gal.

High density, non-toxic balls used for delumping, mixing and blending of powders. Certain sizes are available with steel cores. Very long wearing and gentle on the mill. Density: 1.20 gm/cc. Bulk Density: 0.72 kg/l; 1.60 #/l; 2.60 kg/gal; 5.80 #/gal.

This media is still used because of its low price but can be costly in the long run. It is abrasive to the mill due to its irregular shape as it is more needle-like than spherical and the tips tend to break off. Waste disposal of this short term media can also be expensive. Alternative medias are glass and mullite. Density: 2.50 gm/cc. Bulk Density: 1.50 kg/l; 3.30 #/l; 5.50 kg/gal; 120 #/gal

This is the most popular glass sphere used for grinding media. The larger beads are molded. Some brands are produced from virgin glass while others are produced from recycled glass. Air inclusions also vary which can determine the life span of the bead as it determines the strength of the bead. This is an excellent bead for low viscosity material or low heat processes. Density 2.50 gm/cc. Bulk Density: 1.50 kg/l; 3.30 #/l.; 5.50 kg/gal; 12.00 #/gal

This is the most popular glass sphere used for grinding media. The larger beads are molded. Some brands are produced from virgin glass while others are produced from recycled glass. Air inclusions also vary which can determine the life span of the bead as it determines the strength of the bead. This is an excellent bead for low viscosity material or low heat processes. Density 2.50 gm/cc. Bulk Density: 1.50 kg/l; 3.30 #/l.; 5.50 kg/gal; 12.00 #/gal

There are several grades of borosilicate glass beads. This bead is used for low alkali applications as well as food and pharmaceutical. There is also a high crush strength bead which is more abrasion resistant than the soda lime glass. It is more expensive than the soda lime but the value is there. Density 2.60 gm/cc. Bulk Density: 1.60 kg/l; 3.50 #/l.; 6.00 kg/gal; 13.30 #/gal

A natural resource that is getting harder to find in its natural state. It is basically quartz having similar density to glass but harder with irregular shapes and surfaces. The benefit of the pebble is the aspect ratio thus giving it a lot of surface area for contact in the mill. They are still available but getting to be expensive. A good alternative is Steatite. Density: 2.60 gm/cc. Bulk Density: 1.60 kg/l; 3.50 #/l; 6.00 kg/gal; 13.30 #/gal

This media is a fused magnesium silicate composite made up of 62% SiO2. The minimum size is 6.0 mm available in satellite balls, cylinders and spheres. This is an excellent alternative to flint pebbles or large glass balls. It lasts longer than glass but is the same density. Density 2.60 gm/cc. Bulk Density: 1.60 kg/l; 3.50 #/l; 6.00 kg/gal; 13.30 #/gal

Generally available in 92% and higher, balls tend to have less wear issues than satellites. Balls & satellites are much easier to use than cylinders and are commonly found in liquid grinding applications. Density: 3.60 gm/cc. Bulk Density: 2.20 kg/l; 4.90 #/l; 8.20 kg/gal; 18.00 #/gal

Available in percentages of 92% and lower. They are easier to use than cylinders and one of the most popular medias for ball milling. Density: 3.60 gm/cc. Bulk Density: 2.20 kg/l; 4.90 #/l; 8.20 kg/gal; 18.00 #/gal

Available in the same alumina percentages as balls and satellites but larger sizes are more limited in options. Cylinders are used for both liquid and powder processing when fines are needed. They can also be susceptible to chipping around the edges. Density: 3.60 gm/cc. Bulk Density: 2.20 kg/l; 4.90 #/l; 8.20 kg/gal; 18.00 #/gal

This is still the most common range of alumina media used for particle size reduction in both powder and liquid grinding. Beads are available as well as balls, satellites and cylinders. Some sizes are available in both dry pressed and iso pressed. The beads can be abrasive. Density: 3.60 gm/cc. Bulk Density: 2.20 kg/l; 4.90 #/l; 8.20 kg/gal; 19.00 #/gal.

Alumina with this higher purity is used in grinding materials which cannot tolerate contamination other than alumina. It can be dramatically more expensive and is also more brittle than other alumina formulations. It is available in spheres, satellites and cylinders. Density: 3.80 gm/cc. Bulk Density: 2.40 kg/l; 5.30 #/l; 8.60 kg/gal; 19.00 #/gal.

This is a low density ceramic available in limited sizes. The balls and satellites are usually custom made. It is very expensive but used where limited contamination is required. Density: 2.90/3.20 gm/cc.

This is a low density ceramic available in limited sizes. The balls and satellites are usually custom made. It is very expensive but used where limited contamination is required. Density: 2.90/3.20 gm/cc.

This alumina media is most often referred to as MULLITE with approximately 35% SiO2. It has the advantage of being higher in density than glass and lower density than other aluminas. Beads are available in several different alumina concentrations and densities, with or without bauxite. It is available in small beads, satellites and cylinders. It lasts longer than glass and is not as abrasive as other aluminas. Density: 3.25 gm/cc. Bulk Density: 1.74 kg/l; 3.80 #/l; 6.70 kg/gal; 14.50 #/gal

This bead is also a popular medium density bead which looks almost identical to the Zirconia Silicate but they can NEVER be mixed. This bead is FUSED and is consistent from the crust to the core. It lasts longer than a sintered bead but should not be used in sizes above 2.0 mm because of the inherent air inclusions known as hollows in the bead. This bead can crack and break and cause abrasion problems in the mill. Preconditioning the beads is strongly recommended. Density: 3.80 gm/cc. Bulk Density: 2.40 kg/l; 5.00 #/l; 8.60 kg/gal; 19.00 #/gal

This is a popular, medium density, bead which is SINTERED. This bead has a hard outer crust and a soft inner core so it should be used in less aggressive types of small media mills. Sizes above 3.0 mm are not practical because of the inherent structure which weakens the bead and causes it to crack and break. This bead can be abrasive to the mill. Density: 4.00 gm/cc. Bulk Density: 2.45 kg/l; 5.30 #/l; 9.27 kg/gal; 20.40 #/gal.

Zirconia Toughened Alumina: This product is relatively new and has proven to be an excellent media in the medium density range. It is solid, white, round, has high fracture resistance with lower amounts of zirconia and no radioactivity. Sizes start at 0.6 mm and can be made up to 2 in balls and cylinders. Density: 4.20 gm/cc Bulk Density: 2.60 kg/l; 5.70 #/l; 9.60 kg/gal; 21.00 #/gal.

This is a relatively new bead which is aFUSED zirconia silica containing a higher amount of zirconia than the more common formulation. Customers have been impressed with its ability to last much longer than standard zirconia silica and silicate, its lower wear on the equipment and faster grinds. Density: 4.60 gm/cc. Bulk Density: 2.80 kg/l; 10.60 kg/gal; 23.30 #/gal; 6.20 #/l.

A very popular high density ceramic satellite or cylinder for all types of milling. While this form of the media is excellent, the bead is very poor in that it is abrasive to both the mill and itself. Density: 5.50 gm/cc. Bulk Density: 3.20 kg/l; 7.00 #/l; 11.80 kg/gal; 26.00 #/gal

A very popular high density ceramic satellite or cylinder for all types of milling. While this form of the media is excellent, the bead is very poor in that it is abrasive to both the mill and itself. Density: 5.50 gm/cc. Bulk Density: 3.20 kg/l; 7.00 #/l; 11.80 kg/gal; 26.00 #/gal

A very popular high density ceramic satellite or cylinder for all types of milling. While this form of the media is excellent, the bead is very poor in that it is abrasive to both the mill and itself. Density: 5.50 gm/cc. Bulk Density: 3.20 kg/l; 7.00 #/l; 11.80 kg/gal; 26.00 #/gal

This is a relatively new high density mediathat has grown in popularitydue to its durability and value pricing. The bead will not crackor break unless the mill was not put together properly. The media is available in beads, satellites, cylinders and spheres. Density: 6.00/6.25 gm/cc. Bulk Density: 3.60/4.00 kg/l; 7.90/8.80 #/l; 12.70/15.10 kg/gal; 28.00/33.00 #/gal

This is a relatively new high density mediathat has grown in popularitydue to its durability and value pricing. The bead will not crackor break unless the mill was not put together properly. The media is available in beads, satellites, cylinders and spheres. Density: 6.20 gm/cc. Bulk Density: 3.60/4.00 kg/l; 7.90/8.80 #/l; 12.70/15.10 kg/gal; 28.00/33.00 #/gal

This is a relatively new high density mediathat has grown in popularitydue to its durability and value pricing. The bead will not crackor break unless the mill was not put together properly. The media is available in beads, satellites, cylinders and spheres. Density: 6.00/6.25 gm/cc. Bulk Density: 3.60/4.00 kg/l; 7.90/8.80 #/l; 12.70/15.10 kg/gal; 28.00/33.00 #/gal

This is the highest, longest lasting and toughest high density media. This media is very hard and non-porous so that it will not break or crack, cleans easily, and is available in several grades. Beads, spheres and cylinders are available in a wide range of sizes. Density: 6.00 gm/cc. Bulk Density: 3.70 kg/l; 8.10 #/l; 14.00 kg/gal; 30.10 #/gal

This is the highest, longest lasting and toughest high density media. This media is very hard and non-porous so that it will not break or crack, cleans easily, and is available in several grades. Beads, spheres and cylinders are available in a wide range of sizes. Density: 6.00 gm/cc. Bulk Density: 3.70 kg/l; 8.10 #/l; 14.00 kg/gal; 30.10 #/gal

This is the highest, longest lasting and toughest high density media. This media is very hard and non-porous so that it will not break or crack, cleans easily, and is available in several grades. Beads, spheres and cylinders are available in a wide range of sizes. Density: 6.00 gm/cc. Bulk Density: 3.70 kg/l; 8.10 #/l; 14.00 kg/gal; 30.10 #/gal

Case and through hardened steel balls which can rust. They are available in a wide range of alloys and sizes as large as 8" diameters. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

This is a through hardened chrome alloy steel ball. It is highly polished and mono-sized with a hardness of 63-65 Rockwell C. The pricing is reasonable for an almost ball bearing quality media. It is slow to rust and is a long lasting steel media. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

Through hardened carbon steel balls that have a flat 180 degrees apart. They are commonly used in steel ball mills starting at 1/2" diameter. They can rust. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

Through hardened balls which are available in various types of stainless. These balls can be expensive but generally used when other types are not acceptable. Stainless steel is softer than other forms of steel. It can also work harden and become brittle. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

This is cut wire which can then be used as cylinders or conditioned so that it is somewhat round in shape. It is available in various types of stainless. Stainless steel is softer than other forms of steel. It can also work harden and become brittle. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

Not typically a popular media but still available. Stainless steel is softer than other forms of steel. It can also work harden and become brittle. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

There are many sources for steel shot but all are not equal since much of the steel shot is used for shot peening. Make sure that the shot is designed as a grinding media or it could tear up the mill. Steel shot is one of the least expensive grinding medias with the benefit of high density and the availability of a wide range of sizes for small media. The more narrow size ranges of shot will last longer. Density: 7.60 gm/cc. Bulk Density: 4.50 kg/l; 9.90 #/l; 17.80 kg/gal; 38.00 #/gal

This media continues to grow in interest due to its high density. Beads and satellites are available in limited sizes. The mills using this media must be built to handle the high density. Density: 15.00 gm/cc. Bulk Density: 8.20 kg/l; 18.00 #/l; 30.00 kg/gal; 66.00 #/gal

This media continues to grow in interest due to its high density. Beads and satellites are available in limited sizes. The mills using this media must be built to handle the high density. Density: 15.00 gm/cc. Bulk Density: 8.20 kg/l; 18.00 #/l; 30.00 kg/gal; 66.00 #/gal

NORSTONE, INC. PRIVACY POLICY Grinding Media Depot , Blade Depot, Deco Bead Depot and Polyblade-Norblade are Registered Trademarks of Norstone, Inc. Polyblade Patent No. 5,888,440 and Patent No. 8,028,944 B2