Ball mill MSh 9001800 (6007) with central discharge for wet material grinding of mediumhardnessBall mill SM6007 with central discharge is designed for wet grinding of various types of ores and...
Strommashina Corp. offers a variety of ballmills types. Our in-house manufacturing facilities enable us to design ball mills to the exact needs and specifications of our customers, as well as provide customers with all necessary spare parts for ball milling machines.
A ball mill is a type of grinding mill, it is an aggregate for grinding and crushing (grinder) of hard materials that has the same goal as other grinding machinery and crushing machinery. Ball mills are used for crushing and mixing of raw materials. While rotating, the grinding media (balls, beads, pulps, etc.) and the raw material rotate along with the mill drum. The feed material is grinded as a result of the grinding media shifts and mill drum`s rotation.
There are several construction types for the ball mills. The ball mills can vary by the number of compartments (units). The most common are single (one) compartment ball mills (single unit ball mills) and two compartment ball mills (multiple compartment ball mills). The main gear of the construction is a rotary mill drum. The grinding media migrates during the ball mill`s operation and turns the entered material into a powder-like substance. The ball mills are included in various technological complexes and milling complexes. Open circuit milling and closed circuit milling can be used while grinding the feed material. Moreover, both dry milling and wet milling are possible (dry grind processing and wet grind processing). Also, the ball mills may vary by operation type. There are continuous ball mills: that operate continuously, and there are batch ball mills. Various ball mills have different capacity rate and material feed and discharge size.
The ball mills are used for grinding and crushing of ore and non-ore materials, grinding and crushing of medium (average) hardness building materials. The ball mills are used in the production of building materials (gypsum production, Portland cement production, silica brick production, dry mixtures production, etc.), in the asphalt production (asphalt filler production), as well as in the production of micro marble, microcalcite (microspar) production, in the mining and other industries.
Strommashina Corp. supplies ball mills and ball mill grinders for industrial grinding and milling processing in all of the following areas: Mining & Minerals, Oil & Gas, Power Generation, Environment & Recycling, Agglomeration, etc.
Strommashina offers a wide range of equipment for export. Our main objective is to introduce state-of-the-art equipment for effective optimization and improvement of production quality. looking for bal mills for sale? Now we are ready to give our best price for grinding mill! (to get price just fill the form)
We are the leading manufacturer and supplier of high-quality equipment for mining, metallurgical, road, building, and other industries. Weve been custom building high quality ball mill machine since 1942. Our engineering services excel at developing new equipment and complete plant solution, optimizing existing equipment and production lines, as well as turning process by-products into value added products. With over 70 years of experience, we can find a solution to your problem! Whether you know exactly what you need, or are in need of some guidance, we are here to help.
We know your goal when choosing a filter bag is to meet the unique needs of your business and industry. In 2000, FLSmidth began manufacturing filter bags from our facility in Evans, Georgia. We have since expanded to a second manufacturing facility in Chennai, India to meet the filtration needs of customers across Asia and the Middle East.
FLSmidth provides the three main types of baghouse filter bags and maintains the high standards of quality you expect. Whether you have a pulse-jet, reverse-air or shaker baghouse that needs replacement filters, we can help. We put all our bag filters through a litany of physical and chemical tests to ensure they are free from defects. The review process we put our filter bags through ensures your bags will always fit your cages.
Pulse-jet filter bags can be manufactured from most available felt or woven filter medias. A pulse-jet baghouse is the most versatile type of baghouse, because it can use filter bags with a variety of media and finishes.
When you make a commitment to a filter bag manufacturer, you expect a certain level of care and customer service. Thats why we review every individual customer order to make sure the bag will fit your baghouse cage perfectly. We always take into account the specific features and requirements of the filter media. And your unique equipment specifications. When your filter bags fit properly, you will be better able to:
We know reduced bag life in high temperature pulse-jet baghouse is a major problem for our customers. Thats why weve developed the combination of the AFTm ePTFE membrane with the MettaClean fabric option. Youll receive a product that operates at its best in high temperatures. Now you can extend the life of your filter bags while operating at peak efficiency.
With plants increasing capacity, and being forced to reduce emissions, we have heard your requests for a new and improved membrane filter bag. ePTFE membrane filter bags improve overall baghouse operation and deliver higher throughput and energy savings.
We test cleaning efficiency at our United States and Denmark laboratories to ensure our newest technology improves on current baghouse cleaning standards. ePTFE membrane filter bags improve on the cleaning efficiency of other bag types.
FLSmidth AFT ePTFE filter bags are designed to meet the environmental standards of your unique industry and location. FLSmidth engineers work with you to develop a filtration strategy to ensure compliance with the following environmental requirements:
FLSmidths AFT baghouse filter bags come in various filter media and finishes. Each fiber type has unique advantages and disadvantages. For example, if your needs are high maximum temperature and acid resistance, fiberglass would the right choice. If your temperature requirements are low and you value flex resistance, cotton would be a better option.There are many considerations that go into choosing filter media:
The combination of optimised design, improved mechanical construction, and advanced filter control results in reduced and easier maintenance, compared to other types of fabric filters on the market. The SmartBag coupled with the SmartPulse Controller EVO II meets the needs of modern-day cement mills.
FLSmidth provides sustainable productivity to the global mining and cement industries. We deliver market-leading engineering, equipment and service solutions that enable our customers to improve performance, drive down costs and reduce environmental impact. Our operations span the globe and we are close to 10,200 employees, present in more than 60 countries. In 2020, FLSmidth generated revenue of DKK 16.4 billion. MissionZero is our sustainability ambition towards zero emissions in mining and cement by 2030.
All Grinding Mill & Ball Mill Manufacturers understand the object of the grinding process is a mechanical reduction in size of crushable material. Grinding can be undertaken in many ways. The most common way for high capacity industrial purposes is to use a tumbling charge of grinding media in a rotating cylinder or drum. The fragmentation of the material in that charge occurs through pressure, impact, and abrasion.
The choice of mill design depends on the particle size distribution in the feed and in the product wanted. Often the grinding is more economic when executed in a primary step, followed by a secondary step, giving a fine size product.
C=central trunnion discharge P=peripheral discharge R=spherical roller trunnion bearing, feed end H=hydrostatic shoe bearing, feed end R=spherical roller trunnion bearing, discharge end K=ring gear and pinion drive
Type CHRK is designed for primary autogenous grinding, where the large feed opening requires a hydrostatic trunnion shoe bearing. Small and batch grinding mills, with a diameter of 700 mm and more, are available. These mills are of a special design and described on special request by allBall Mill Manufacturers.
The different types of grinding mills are based on the different types of tumbling media that can be used: steel rods (rod mills), steel balls (ball mills), and rock material (autogenous mills, pebble mills).
The grinding charge in a rod mill consists of straight steel rods with an initial diameter of 50-100 mm. The length of the rods is equal to the shell length inside the head linings minus about 150 mm. The rods are fed through the discharge trunnion opening. On bigger mills, which need heavy rods, the rod charging is made with a pneumatic or manual operated rod charging device. The mill must be stopped every day or every second day for a few minutes in order to add new rods and at the same time pick out broken rod pieces.
As the heavy rod charge transmits a considerable force to each rod, a rod mill can not be built too big. A shell length above 6100 mm can not be recommended. As the length to diameter ratio of the mill should be in the range of 1,2-1,5, the biggest rod mill will convert maximum 1500 kW.
Rod mills are used for primary grinding of materials with a top size of 20-30 mm (somewhat higher for soft materials). The production of fines is low and consequently a rod mill is the right machine when a steep particle size distribution curve is desired. A product with 80% minus 500 microns can be obtained in an economical manner.
The grinding charge in a ball mill consist of cast or forged steel balls. These balls are fed together with the feed and consequently ball mills can be in operation for months without stopping. The ball size is often in the diameter range of 20-75 mm.
The biggest size is chosen when the mill is used as a primary grinding mill. For fine grinding of e.g. sands, balls can be replaced by cylpebs, which are heat treated steel cylinders with a diameter of 12-40 mm and with the same length as the diameter.
Ball mills are often used as secondary grinding mills and for regrinding of middlings in concentrators. Ball mills can be of the overflow or of the grate discharge type. Overflow discharge mills are used when a product with high specific surface is wanted, without any respect to the particle size distribution curve. Overflow discharge mills give a final product in an open circuit. Grate discharge mills are used when the grinding energy shall be concentrated to the coarse particles without production of slimes. In order to get a steep particle size distribution curve, the mill is used in closed circuit with some kind of classifier and the coarse particles known as classifier underflow are recycled. Furthermore, it should be observed that a grate discharge ball mill converts about 20% more energy than an overflow discharge mill with the same shell dimensions.
Ball mill shells are often furnished with two manholes. Ball mills with small balls or cylpebs can produce the finest product of all tumbling mills. 80% minus 74 microns is a normal requirement from the concentrators.The CRRK series of wet grinding ball mills are tabulatedbelow.
No steel grinding media is used in a fully autogenous mill. When choosing primary autogenous grinding, run of mine ore up to 200-300 mm in size is fed to the mill. When using a crushing step before the grinding, the crusher setting should be 150-200 mm. The feed trunnion opening must be large enough to avoid plugging. The biggest pieces in the mill are important for the size reduction of middle size pieces, which in their turn are important for the finer grinding. Thus the tendency of the material to be reduced in size by pressure, impact, and abrasion is a very important question when primary autogenous grinding is proposed.
When autogenous grinding is used in the second grinding step, the grinding media is size-controlled and often in the range of 30-70 mm. This size is called pebbles and screened out in the crushing station and fed to the mill in controlled proportion to the mill power. The pebble weight is 5-25% of the total feed to the plant, depending on the strength of the pebbles. Sometimes waste rock of high strength is used as pebbles.
Pebble mills should always be of the grate discharge type. The energy that can be converted in a mill depends on the total weight of the grinding charge. Consequently, pebble mills convert less power per mill volume unit than rod and ball mills.
High quality steel rods and balls are a considerable part of the operating costs. Autogenous grinding should, therefore, be considered and tested when a new plant shall be designed. As a grinding mill is built to last for decades, it is more important to watch the operation costs than the price of the mill installation. The CRRK series of wet grinding pebble mills are tabulated below.
Wet grinding is definitely the most usual method of grinding minerals as it incorporates many advantages compared to dry grinding. A requirement is, however, that water is available and that waste water, that can not be recirculated, can be removed from the plant without any environmental problems. Generally, the choice depends on whether the following processing is wet or dry.
When grinding to a certain specific surface area, wet grinding has a lower power demand than dry grinding. On the other hand, the wear of mill lining and grinding media is lower in dry grinding. Thus dry grinding can be less costly.
The feed to a dry grinding system must be dried if the moisture content is high. A ball mill is more sensitive to clogging than a rod mill. An air stream through the mill can reduce the moisture content and thus make a dry grinding possible in certain applications.
Due to the hindering effect that the ball charge gives to the material flow in dry grinding, the ball charge is not more than 28-35% of the mill volume. This should be compared with 40-45% in wet grinding. The expression used for this phenomenon is that the charge in a dry grinding mill is swollen.
Big dry grinding ball mills are often two-compartment mills, with big balls in the first compartment and small balls or cylpebs in the second one. An extra grate wall is used to separate the two charges.
The efficiency of wet grinding is affected by the percentage of solids. If the pulp is too thick, the grinding media becomes covered by too thick a layer of material, which hinders grinding. The opposite effect may be obtained if the dilution is too high, and this may also reduce the grinding efficiency. A high degree of dilution may sometimes be desirable in order to suppress excessive slime formation.
The specific power required for a certain grinding operation, usually expressed in kWh/ton, is a function of both the increase in the specific surface of the material (expressed in cm/cm or cm/g) and of the grinding resistance of the material. This can be expressed by the formula
where c is a material constant representing the grinding resistance, and So and S are the specific surfaces of the material before and after the grinding operation respectively. The formula is an expression of Rittingers Law which is shown by tests to be reasonably accurate up to a specific surface of 10,000 cm/cm.
When the grinding resistance c has been determined by trial grinding to laboratory scale, the net power E required for each grinding stage desired may be determined by the formula, at least as long as Rittingers Law is valid. If grinding is to be carried out not to a certain specific surface S but to a certain particle size k, the correlation between S and k must be determined. The particle size is often expressed in terms of particle size at e.g. 95, 90 or 80% quantity passing and is denoted k95, k90 or k80.
where E =the specific power consumption expressed in kWh/short ton. Eo = a proportionality and work factor called work index k80p = particle size of the product at 80% passage (micron) k80f =the corresponding value for the raw material (micron)
The value of Eo is a function of the physical properties of the raw material, the screen analyses of the product and raw material respectively, and the size of the mill. The value for easily-ground materials is around 7, while for materials that have a high grinding resistance the value is around 17.
Eo is correlated to a certain reduction ratio, mill diameter etc. Corrections must be made for each case. The simplest method of calculating the specific power consumption is test grinding in a laboratory mill, and comparison of the results with a known reference material. The sample is ground in batches for 3, 6,12 minutes, a screen analysis is carried out after each period, after which the specific surface is determined. A good estimate of the grinding characteristics of the sample can be obtained by comparison of the specific surfaces with corresponding values for the reference material.
When the net power required has been determined, an allowance is made for mechanical losses. The gross power requirement thus arrived at, should with a satisfactory margin be utilised by the mill selected.
The critical speed of a rotating mill is the RPM at which a grinding medium will begin to centrifuge, namely will start rotating with the mill and therefore cease to carry out useful work. This will occur at an RPM of ncr, which may be determined by the formula
where D is the inside diameter in meters of the mill. Mills are driven in practice at a speed corresponding to 60-80% of the critical speed, the choice of speed being influenced by economical considerations. Within that range the power is nearly proportional to the speed.
The charge volume in the case of rod and ball mills is a measure of the proportion of the mill body that is filled by rods or balls. When the mill is stationary, raw material and liquid should fill the voids between the grinding media, in order that these should be fully utilized.
Maximum mill efficiency is reached at a charge volume of approximately 55%, but for a number of reasons 45-50% is seldom exceeded. The efficiency curve is in any case quite flat about the maximum. In overflow mills the charge volume is usually 40%, while there is a greater choice in the case of grate discharge mills.
For coarse grinding in rod mills, the rods used have a diameter of 50-100 mm and their lengths are approx. 150 mm below the effective inside shell length. Rods will break when they have been worn down to about 20 mm and broken rods must from time to time be taken out of the mill since otherwise they will reduce the mill capacity and may cause blockage through piling up. The first rod charge should also contain a number of rods of smaller diameter.
It may be necessary to charge the mill with rods of smaller diameter when fine grinding is to be carried out in a rod mill. Experience shows that the size of the grinding media should bear a definite relationship to the size of both the raw material and the finished product in order that optimum grinding may be achieved. The largest grinding media must be able to crush and grind the largest pieces of rock, while on the other hand the grinding media should be as small as possible since the total active surface increases in inverse proportion to the diameter.
A crushed mineral whose largest particles pass a screen with 25 x 25 mm apertures shall be ground to approx. 95% passing 0.1 mm in a 2.9 x 3.2 m ball mill of 35 ton charge weight. In accordance with Olewskis formula
Grinding media wear away because of the attrition they are subjected to in the course of the grinding operation, and in addition a continuous reduction in weight takes place owing to corrosion. The rate of wear will in the first place depend on the abrasive properties of the mineral being ground and naturally also on the hardness of the grinding media themselves.
The wear of rods and balls is usually quoted in grammes per ton of material processed (dry weight) and normal values may lie between 100 and 1500 g/ton. Considerably higher wear figures may however be experienced in fine wet grinding of e.g. very hard siliceous sand.
A somewhat more accurate way of expressing wear is to state the amount of gross kWh of grinding power required to consume 1 kg of grinding media. A normal value in wet grinding is 15 kWh/kg.The wear figures in dry grinding are only 10-30 % of the above.
where c is a constant which, inter alia, takes into consideration the mean slope a of the charge, W is the weight in kp of the charge n is the RPM Rg is the distance in metres of the centre of gravity from the mill centre
W for rod and ball mills shall be taken as the weight of the rod or ball charge, i.e. the weight of the pulp is to be ignored. For pebble mills therefore W is to be calculated on the basis of the bulk weight of the pebbles.
It should be pointed out that factor c in the formula is a function of both the shape of the inner lining (lifter height etc.) and the RPM. The formula is however valid with sufficient accuracy for normal speeds and types of lining.
The diagram gives the values of the quantity Rg/d as a function of the charge volume, the assumption being that the charge has a plane surface and is homogeneous, d is the inside diameter of the mill in metres. The variation of the quantity a/d, where a is the distance between the surface of the charge and the mill centre, is also shown in the same figure.
In order to keep manufacturing costs at a minimum level, Morgardshammar has a series of standard mill diameters up to and including 6.5 m. Shell length, however, can be varied and tailor made for each application. The sizes selected are shown on the tables on page 12-13 and cover the power range of 200-5000 kW.
Shells with a diameter of up to about 4 m are made in one piece. Above this dimension, the shell is divided into a number of identical pieces, bolted together at site, in order to facilitate the transport. The shell is rolled and welded from steel plate and is fitted with welded flanges of the same material. The flanges are machined in order to provide them with locating surfaces fitting into the respective heads. The shells of ball and pebble mills are provided with 2 manholes with closely fitting covers. The shells have drilled holes for different types of linings.
Heads with a diameter of up to about 4 m are integral cast with the trunnion in one piece. Above this diameter the trunnion is made as a separate part bolted to the head. The head can then be divided in 2 or 4 pieces for easy transport and the pieces are bolted together at site. The material is cast steel or nodular iron. The heads and the trunnions have drilled holes for the lining.
Spherical roller (antifriction) bearings are normally used. They offer the most modern and reliable technology and have been used for many years. They are delivered with housings in a new design with ample labyrinth seals.
For very large trunnions or heavy mills, i.e. for primary autogenous grinding mills. Morgardshammar uses hydrostatic shoe bearings. They have many of the same advantages as roller bearings. They work with circulating oil under pressure.
The spherical roller bearing and the hydrostatic shoe bearing take a very limited axial space compared to a conventional sleeve bearing. This means that the lever of the bearing load is short. Furthermore, the bending moment on the head is small and as a result of this, the stress and deformation of the head are reduced. Ask Morgardshammar for special literature on trunnion bearings.
Ring gears are often supplied with spur gears. They are always split in 2 or 4 pieces in order to facilitate the assembly. Furthermore, they are symmetrical and can be turned round in order to make use of both tooth flanks. The material is cast steel or nodular iron. They are designed in accordance with AGMA.The ring gear may be mounted on either the feed or the discharge head. It is fitted with a welded plate guard.
The pinion and the counter shaft are integral forged and heat treated of high quality steel. For mill power exceeding about 2500 kW two pinions are used, one on each side of the mill (double-drive). The pinion is supported on two spherical roller bearings.
The trunnion bearings are lubricated by means of a small motor- driven grease lubricator. The gear ring is lubricated through a spray lubricating system, connected to the electric and pneumatic lines. The spray nozzles are mounted on a panel on the gear ring guard.
In order to protect the parts of the mill that come into contact with the material being ground, a replaceable lining of wear-resistant material is fitted. This may take the form of unalloyed or alloyed rolled or cast steel, heat treated if required, or rubber of the appropriate wear resistant quality. White cast iron, unalloyed or alloyed with nickel (Ni-hard), may also be used.
The shape of the mill lining is often of Lorain-type, consisting of plates held in place between lifter bars (or key bars) of suitable height bolted on to the shell. This system is used i.e. of all well-known manufacturers of rubber linings. Ball mills and autogenous mills with metal lining also can be provided with single or double waved plates without lifter bars.
In grate discharge mills the grate and the discharge lifters are a part of the lining. The grate plates with tapered slots or holes are of metal or rubber design. The discharge lifters are fabricated steel with thick rubber coating. Rubber layer for metal linings and heavy corner pieces of rubber are included in a Morgardshammar delivery as well as attaching bolts, washers, seal rings, and self-locking nuts. A Morgardshammar overflow mill can be converted into a grate discharge mill only by changing some liner parts and without any change of the mill. Trunnion liners are rubber coated fabricated steel or cast steel. In grate discharge mills the center cone and the trunnion liner form one piece.
Scoop feeders in combination with drum feeders are used when retaining oversize from a spiral or rake classifier. As hydrocyclones are used in most closed grinding circuits the spout feeders are used most frequently.
Vibrating feeders or screw feeders are used when charging feed to dry grinding mills. Trommel screens are used to protect slurry pumps and other transport equipment from tramp iron. Screens can have perforated rubber sheets or wire mesh. The trommel screens are bolted to the discharge trunnion lining.
Inching units for slow rotation of the mills are also furnished. Rods to the rod mills are charged by means of manual or automatic rod charges. Erection cradles on hydraulic jacks are used when erecting medium or big size mills at site.
A symbol of dependable quality ore milling machinery manufacturing, industrial and mining equipment, ball mills and rod mills as well as supplies created for your specific needs. During this period thousands of operators have experienced continuous economical and unequalled service through their use.As anindustrial ball mill manufacturer and supplier, we havecontinuously accumulated knowledge on grinding applications. It has contributed greatly to the grinding process through the development and improvement of such equipment.
Just what is grinding? It is the reduction of lump solid materials to smaller particles by the application of shearing forces, pressure, attrition, impact and abrasion. The primary consideration, then, has been to develop some mechanical means for applying these forces. The modern grinding mill applies power to rotate the mill shell and thus transmits energy to some form of media which, in turn, fractures individual particles.
Through constant and extensive research, in the field of grinding as well as in the field of manufacturing. Constantly changing conditions provide a challenge for the future. Meeting this challenge keeps our company young and progressive. This progressive spirit, with the knowledge gained through the years, assures top quality equipment for the users of our mills.
You are urged to study the following pages which present a detailed picture of our facilities and discuss the technical aspects of grinding. You will find this data helpful when considering the selection of the grinding equipment.
It is quite understandable that wetakes pride in the quality of our mills.Complementing the human craftsmanship built into these mills, our plants are equipped with modern machines of advanced design which permit accurate manufacturing of each constituent part. Competent supervision encourages close inspection of each mill both as to quality and proper fabrication. Each mill produced is assured of meeting the high required standards. New and higher speed machines have replaced former pieces of equipment to provide up-to-date procedures. The use of high speed cutting and drilling tools has stepped up production, thereby reducing costs and permitting us to add other refinements and pass these savings on to you, the consumer.
Each foundry heat is checked metallurgically prior to pouring. All first castings of any new design are carefully examined by the use of an X-ray machine to be certain of uniformity of structure. The X -ray is also used to check welding work, mill heads, and other castings.
Each Mills, regardless of size, is designed to meet the specific grinding conditions under which it will be used. The speed of the mill type of liner, discharge arrangement, size of feeder, size of bearings, mill diameter and length, and other factors are all considered to take care of the size of feed, tonnage, circulating sand load, selection of balls or rods, and the final size of grind.
All Mills are built with jigs and templates so that any part may be duplicated. A full set of detailed drawings is made for each mill and its parts. This record is kept up to date during the life of the mill. This assures accurate duplication for the replacement of wearing parts during the future years.
As a part of our service our staff includes experienced engineers, trained in the field of metallurgy with special emphasis on grinding work. This knowledge, as well as a background gained from intimate contact with various operating companies throughout the world, provides a sound basis for consultation on your grinding problems. We take pride in manufacturing rod mills and ball millsfor the metallurgical, rock products, cement, process, and chemical industries.
As an additional service we offer our testing laboratories to check your material for grindability. Since all grinding problems are different some basis must be established for recommending the size and type of grinding equipment required. Experience plays a great part in this phase however, to establish more direct relationships it is often essential to conduct individual grindability tests on the specific material involved. To do this we have established certain definite procedures of laboratory grinding work to correlate data obtained on any new specific material for comparison against certain standards. Such standards have been established from conducting similar work on material which is actually being ground in Mills throughout the world. The correlation between the results we obtain in our laboratory against these standards, coupled with the broad experience and our companys background, insures the proper selection and recommendation of the required grinding equipment.
When selecting a grinding mill there are many factors to be taken into consideration. First let us consider just what constitutes a grinding mill. Essentially it is a revolving, cylindrical shaded machine, the internal volume of which is approximately one-half filled with some form of grinding media such as steel balls, rods or non-ferrous pebbles.
Feed may be classified as hard, average or soft. It may be tough, brittle, spongy, or ductile. It may have a high specific gravity or a low specific gravity. The desired product from a mill may range in size from a 4 mesh down to 200 mesh, or into the fine micron sizes. For each of these properties a different mill would be indicated.
The Mill has been designed to carry out specific grinding work requirements with emphasis on economic factors. Consideration has been given to minimizing shut-down time and to provide long, dependable trouble-free operation. Wherever wear takes place renewable parts have been designed to provide maximum life. A Mill, given proper care, will last indefinitely.
Mills have been manufactured in a wide variety of sizes ranging from laboratory units to mills 12 in diameter, with any suitable length. Each of these mills, based on the principles of grinding, provides the most economical grinding apparatus.
For a number of years ball mill grinding was the only step in size reduction between crushing and subsequent treatment. Subsequently smaller rod mills have altered this situation, providing in some instances a more economical means of size reduction in the coarser fractions. The principal field of rod mill usage is the preparation of products in the 4-mesh to 35-mesh range. Under some conditions it may be recommended for grinding to about 48 mesh. Within these limits a rod mill is often superior to and more efficient than a ball mill. It is frequently used for such size reduction followed by ball milling to produce a finished fine grind. It makes a product uniform in size with only a minimum amount of tramp oversize.
The basic principle by which grinding is done is reduction by line contact between rods extending the full length of the mill. Such line contact results in selective grinding carried out on the largest particle sizes. As a result of this selective grinding work the inherent tendency is to make size reduction with the minimum production of extreme fines or slimes.
The small rod mill has been found advantageous for use as a fine crusher on damp or sticky materials. Under wet grinding conditions this feed characteristic has no drawback for rod milling whereas under crushing conditions those characteristics do cause difficulty. This asset is of particular importance in the manufacture of sand, brick, or lime where such material is ground and mixed with just sufficient water to dampen, but not to produce a pulp. The rod mill has been extensively used for the reduction of coke breeze in the 8-mesh to 20-mesh size range containing about 10% moisture to be used for sintering ores.
Grinding by use of nearly spherical shaped grinding media is termed ball milling. Strictly speaking, such media are made of steel or iron. When iron contamination is detrimental, porcelain or natural non-metallic materials are used and are referred to as pebbles. When ore particles are used as grinding media this is known as autogenous grinding.
Other shapes of media such as short cylinders, cubes, cones, or irregular shapes have been used for grinding work but today the nearly true spherical shape is predominant and has been found to provide the most economic form.
In contrast to rod milling the grinding action results from point contact rather than line contact. Such point contacts take place between the balls and the shell liners, and between the individual balls themselves. The material at those points of contact is ground to extremely fine sizes. The present day practice in ball milling is generally to reduce material to 35 mesh or finer. Grinding in a ball mill is not selective as it is in a rod mill and as a result more extreme fines and tramp oversize are produced.
Small Ball mills are generally recommended not only for single stage fine grinding but also have wide application in regrind work. The Small Ball millwith its low pulp level is especially adapted to single stage grinding as evidenced by hundreds of installations throughout the world. There are many applications in specialized industrial work for either continuous or batch grinding.
Wet grinding may be considered as the grinding of material in the presence of water or other liquids in sufficient quantity to produce a fluid pulp (generally 60% to 80% solids). Dry grinding on the other hand is carried out where moisture is restricted to a very limited amount (generally less than 5%). Most materials may be ground by use of either method in either ball mills or rod mills. Selection is determined by the condition of feed to the mill and the requirements of the ground product for subsequent treatment. When grinding dry some provision must be made to permit material to flow through the mill. Mills provide this necessary gradient from the point of feeding to point of discharge and thereby expedites flow.
The fineness to which material must be ground is determined by the individual material and the subsequent treatment of that ground material Where actual physical separation of constituent particles is to be realized grinding must be carried to the fineness where the individual components are separated. Some materials are liberated in coarse sizes whereas others are not liberated until extremely fine sizes are reached.
Occasionally a sufficient amount of valuable particles are liberated in coarser sizes to justify separate treatment at that grind. This treatment is usually followed by regrinding for further liberation. Where chemical treatment is involved, the reaction between a solid and a liquid, or a solid and a gas, will generally proceed more rapidly as the particle sizes are reduced. The point of most rapid and economical change would determine the fineness of grind required.
Laboratory examinations and grinding tests on specific materials should be conducted to determine not only the fineness of grind required, but also to indicate the size of commercial equipment to handle any specific problem.
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cnc milling machine 4 axis vmc850 Product Description related products Related products Our Services Company Information Exhibition FAQ 1 . Q:Howcan i choose right machine and how to assure quality? A :You can c...
XK7126 cnc metal milling machine Product Description Packaging & Shipping Our Services Company Information Exhibition FAQ 1 . Q:Howcan i choose right machine and how to assure quality? A :You can choose machine ...
Product Description X6126 Universal MIlling Machine Packaging & Shipping Rust-proof oil + plasticbag + fumigation-free wooden boxes+ wooden pallets/iron pallets; The packing similar as below pictures Our Services...
Product Description Universal Vertical Drilling and milling machine for metal ZX6350C 1. Complete with automatic table feed in x- and y-axis including rapid feed 2. Surface treated, large table includes T-slots 3...
Product Description ZX6332ZW Universal radial milling machine, drill and milling machine Packaging & Shipping Rust-proof oil + plasticbag + fumigation-free wooden boxes+ wooden pallets/iron pallets; The packing s...
Product Description Drilling and Milling Machine ,Universal Milling Machine ZX6332ZA Packaging & Shipping Rust-proof oil + plasticbag + fumigation-free wooden boxes+ wooden pallets/iron pallets; The packing simil...
Our alumina ball is made of alumina ( aluminium oxide, the most thermodynamically stable form) by cool isostatic pressing and fired at a very high temperature in the tunnel kiln. Our alumina ball product series include: alumina grinding ball for ball mill grinding media and inert alumina ball for tower packing, catalyst bed support, column internals and catalyst carrier.read more
Alumina grinding ball of high alumina content is one ideal ball mill grinding media, it can improve grinding efficiency and keep your product clean! Alumina grinding ball is high-density and ultra-high fired. It is ideal for both wet and dry milling. Also, high density mill linings alumina brick is available.read more
We are one leading manufacturer and top exporter of alumina ball, alumina grinding ball and inert alumina ball in China. Our products have been exported to USA, Canada, England, France, India, Thailand, Indonesia and several other countries and regions. Our annual production capacity exceeds 25,000 tons, reliable quality, competitive pricing and prompt shipment is guaranteed.
We have 2 up-to-date full automatic production lines including the 1700C high temperature tunnel kiln, cool isostatic pressing ball forming machine and the ISO9001:2000 quality management and control system, all this guarantee the stable quality of the alumina ball.
Neumann Machinery Company (NMC) is headquartered in West Jordan, Utah, in the USA just 14 miles south of Salt Lake City. The area is steeped in a rich history in the supply of mining and heavy industrial machinery.
The original EIMCO products have been operating in many parts of the world since 1932. NMC has updated designs and added the most state of the art features, automation and techniques to its most recent ball mill designs.
... Upgradeable With Cail & Fletcher heavy duty in-line shredder the existing carrier can be used when upgrading. Mills are protected from rocks and metal. Mill roll wear is significantly less than with ...
Concrete crusher for recycling / concrete pulverizer for floors, walls, panels, runways Top Plate for bolt on bracket. 2 versions : B = without rotation. R = continuous 360 hydraulic rotation. Reversed cylinder, protected ...
Third component of the Selmi Bean to Bar range, this machine has the specific task of grinding the cocoa nibs in particles of size between 200 and 250 microns. The product, once inserted into the hopper, is crushed by stainless steel ...
... Impact Hammer Mill, series PHPH ''Grizzly'' was developed for the economical size reduction of residual- and waste wood of any kind. Not only pre-broken waste wood but also non precut, long recycling wood can be introduced ...
... Chamber size up to 8"x18" (20.3cm x 45.7cm) Throughput: 123 lbs/hr to 221 lbs/hr (58kg/hr to 100 kg/hr) 3 knife open rotor design for efficient size reduction Rotating end discs for minimized friction and ...
Now with a 515 hp (384 kW) Tier 4 Final engine, the HG4000 has more power to meet your requirements. With proven performance and cost of operation top of mind, the HG4000 from Vermeer offers the features to help keep you working day-in ...
The benefits Your added value Easy to charge materials High throughput Easy to clean Short setup times EXTREM COMBINED THREE IN ONE The new, horizontal grinder Vecoplan solution for long-length plastic parts combines guillotine, shredder ...
Specification Unit MSHP 2000H MSHP 2000CT MSHP 3000H MSHP 3000CT Weight Kg 1750 1950 2500 2770 Cylinder Pressure bar 320 320 320 320 Blade Length mm 175 175 175 175 Dimension A mm 1936 1938 2065 2045 B mm 1466 ...
The MCP-IT fixed Pulveriser is the ideal attachment for secondary demolition or rather for the work of reduction and fragmentation of the demolished material making disposal and recycling easier by separating the reinforced iron from ...
Gericke's Nibbler features comprehensive size reduction functions, used for a wide range of applications such as re-work, de-agglomeration, and lumpy component size reduction. This unit showcases up to a 150-mm standard bulk feed product ...
The Rapid RG Series is specifically designed for beside-the-press recycling of hard and brittle materials. The ultra-slow rotor speed and screenless operation provide low noise level and very low dust level even with ...
GEA Nu-Con manufactures lump breakers for dry powder de-agglomeration, reducing scrap product, or compacted, lumpy, and hard friable materials from silos, bags or bulk sacks. The GEA Nu-Con rotary lump breaker ...
BCM2.5-BL is a unique machine for many lab applications. If you have a laboratory and want to develop different recipes, BCM2.5-BL is probably one of the best options because; - Thanks to its mono phase power supply, it can be used ...
The new compact mills have finally entered in production for all those who need a small production: from 50 to 1.000 Kg/h. The MINI Cogelme glass crushers get the same concept of robustness and performance as the biggest ...
... Another application is the grinding of PE. P Pulverizer is used in the production process to create the powder needed in the process. The material is fed into the Pulverizer by a vibrating dosing channel, ...
RELIABLE QUALITY and ADVANCED TECHNOLOGY TOPA is providing a variety of demolition attachments to fit customers need, Today this commitment is represented by complete line of industry-leading attachments for shearing, crushing and ...
... continuity in the feeding of the mill avoiding oscillations at the motors chain. Count with magnetic sheets that withdraw ferrous bodies avoiding the entrance in the grinding chamber and protecting the equipment of damage; Rotor ...
... Roller Grinding Mill According to accumulation and experimental analyses of on-site test data for more than thirty years, SBM, a Chinese grinding mill manufacturer, has researched and developed the fifth-generation ...
... Bauer Mill has long been recommended by the U.S. Department of Agriculture for the preparation of cottonseed samples (this sampling requires Bauer Plate No. 8503 and a mill speed of 3600 RPM). The American ...
A fleeting glimpse on the 6 m wide feed hopper is enough to find out that the AK 635 SA EcoPower is destined for greater things. But not just in this respect the largest machine of the series stands out there are numerous other features ...
Features Very little dust The cutters do not re-cut sprues and runners in the same place so that the cutters can minimize dust, static electricity, and heat generation. Very few miscuts The cutters have the mechanism to cut the ...
RotaCut RCX handles extreme applications The Next Generation Grinder for Primary Sludge, Digester Cleanout & Biogas Applications The RCX is the newest iteration of the RotaCut line. It is a complete redesign of the inline grinder concept ...
Sagitta Band Granulators have been used for more than 50 years in various production processes by the most important industries. The feedback is very positive. In the Compounding Technology, for instance, it has been verified a cost cutting ...
The addition ratio of the ball mill grinding steel ball size shall be determined according to factors such as the diameter of the ball mill, the hardness of the ore, the particle size of the ball mill, the hardness (mass) of the abrasive steel balls, and also the speed of the ball mill. When the model of the ball mill is determined, the speed of the ball mill is also determined. The hardness of the ore is measurable. The ore particle size of the steel ball mill is determined by changing the size of the grid screen. Generally, the newly installed steel ball mill has a running-in process. During the running-in process, the amount of steel balls is added for the first time, accounting for 80% of the maximum steel ball loading capacity of the ball mill. 100, 80, 60, 40). The added weight of the abrasive steel ball is based on the quality of the steel ball, which determines the amount of ore added per ton. It is best to use new wear-resistant steel balls. The best (good quality) steel ball addition is calculated based on the amount of ore processed per ton (that is, 0.8 per ton of ore i
DOVE Ball Mills are supplied in a wide variety of capacities and specifications. DOVE small Ball Mills designed for laboratories ball milling process are supplied in 4 models, capacity range of (200g/h-1000 g/h). For small to large scale operations, DOVE Ball Mills are supplied in 17 models, capacity range of (0.3 TPH 80 TPH).
With over 50 years experience in Grinding Mill Machine fabrication, DOVE Ball Mills as critical component of DOVE Crushing plants are designed with highest quality of material for long life and minimum maintenance, to grind ores to 35 mesh or finer.
DOVE Grinding Mills are supplied in a wide range of capacities and specifications, for reliable and effective grinding, size reduction applications and for diverse applications of either dry or wet ore.
DOVE Ball Mills have extended history in the Mining and Mineral Processing Industry, Construction, Solid Waste Processing, Food Processing Industry, Chemical and Biochemical Industry, for Pyrotechnics and Ceramics.
DOVE Ball Mills are designed to operate with various types of grinding media, including Ball Mills Balls. DOVE supply Steel Balls in Various sizes and specifications. Cast Iron steel Balls, Forged grinding steel balls, High Chrome cast steel bars, with hardness of 60-68 HRC. We also supply Grinding Cylpebs with surface hard ness of 60-68 HRC, and grinding Rod with surface hardness of 55-60 HRC.
DOVE Ball Mills are made of high grade cast and carbon steel for extra strength, long and trouble-free operations. The inner lining plate designed with high manganese steel for long life and minimum wear off.
DOVE Ball Mill can be integrated in a Complete Plant designed by DOVE Engineering Services, provided for our Clients application and supplied with all components of the plant for efficient processing, smooth operation and efficient integration with the balance of the Processing Plant.
DOVE Ball mills, also known as Grinding mill, Mining mill, Pebble mill, Ball & Pebble mill, is an important machinery in the mining and various other industries, which would require grinding different material.
They are highly efficient Grinding mill machines, designed for grinding applications, where fine material is required. DOVE Ball Mills are used in supplied and applicable for wet and dry grinding applications within the following branches of industries:
DOVE ball mills is a rotating horizontal cylinder that tumbles the material to grind with a certain media. The standard media that we use in our ball milling process are the steel grinding balls, however depending on the specific application, we can configure the grinding mill with different media.
DOVE supplies various types and sizes of Ball Mill Balls, including; Cast Iron steel Balls, Forged grinding steel balls, High Chrome cast steel bars, with surface hardness of 60-68 HRC. DOVE Ball Mills achieves size reduction by impact and attrition. When the cylinder rotates, the balls are dragged to almost the top of the shell, and from there, they fall unto the material, which lead to the material breaking due to the impact.
DOVE Ball Mills are used in hard rock mineral processing plants as an ore-dressing step to grind the rocks into fine powder size, liberating the mineral particles from the rocks. This will ensure that the ore is well prepared for the next stage of processing and optimize the recovery of the minerals.
DOVE ball mill is integrated and used in DOVE Portable and Semi-Stationary Hard Rock plants (Hard Rock processing plants) to efficiently grind the ore from primary deposit until the liberation size of valuable minerals is reached. DOVE ball mill is the key grinding equipment after material is crushed. It is used to grind and blend bulk material into powder form using different sized balls. The working principle is simple, impact and attrition size reduction take place as the ball drops from near the top of the rotating hollow cylindrical shell of the Ball Mill. The output materials will be feed to the processing and recovery machines.
DOVE Ball Mills are deigned for either wet or dry grinding of materials, in various models, and in accordance to the processing and the crushing plant design, to cater to the liberation size of the minerals and the hardness of the ore.
DOVE supplies two different kinds of ball mills Grate type, and Overfall type. The difference between the two type is according to their ways of discharging material, and the plant flow design specifications.
The Grinding Balls will grind the material into powder size of 20 to 75 micron. In mining operations, this will allow for the liberation of gold and other precious metals that are hosted by the rocks. Many types of grinding media are suitable for use in a ball mill, each material having its own specific properties, specification and advantages.
Media Size: The grinding media particles should be substantially larger than the largest pieces of final material after grinding. The smaller the media particles, the smaller the particle size of the final product.
Composition: Each ball mill application has different requirements. Some of these requirements are relates to the grinding media being in the finished product, while others are based on how the media will react with the material being milled. Therefor, grinding media selection plays major factor on the final milled product.
Contamination: In certain grinding mill process, low contamination is important, the grinding media may be selected for ease of separation from the finished product, for example steel dust produced from steel balls can be magnetically separated from non-ferrous products. An alternative to separation is to use media of the same material as the product being milled.
Corrosive:Certain type of media, such as steel balls, may react with corrosive materials. For this reason, stainless steel balls, or ceramic balls, and flint grinding media may each be used when corrosive substances are present during grinding.