tertiary crushers crushing

rubble master

RUBBLE MASTER was founded in 1991 with the idea to enable contractors to recycle materials on-site without needing the same material processing experience as aggregate producers. The machines had to be compact with high throughput, easy to use and safe, so that on-site crushing became an attractive business to the contractor market. Since then, we have grown with our customers and today RUBBLE MASTER is the global market leader in mobile Compact Crushers.

RM NEXT elevates the most easy to use material processing equipment to a new level of simplicity, safety and performance. RM's refined machine controls are designed to give you the most out of your crusher or screen. Make light work out of daily maintenance. Troubleshoot issues faster and with confidence. And put more product on the ground.

RM Compact Crushers with the iconic low-mount engine design set the standard in mobile on-site crushing. Today's jobsites and workforce change rapidly. RUBBLE MASTER keeps thinking of new ways to make your life easier, so that you can achieve a high output without the hassle - growing your business.

portable crushing & screening - astec

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secondary & tertiary crushing circuits

In this sectoron Secondary and Tertiary crushing, we will continue the practice of talkingabout different equipment, the work it does, and the effects of what I call operating variables. These variables are anything that affect the performance of the equipment.

Lets begin with an over view of these two crushing stages. Then describe various flow sheets, and discuss the variables that influenced their design. After the whys have been given we will discuss the equipment and the operating techniques required to operate a modern crushing plant. The two major variables that determine the size of the crusher and the design of the flow-sheet are the tonnage through put required and the hardness of the ore. The tonnage will be determined by economic factors, namely what tonnage is required to make the mine profitable? The hardness of the ore is determined by what is known as the WORK INDEX. This measurement is determined by the resistance of the ore to breakage. It is discovered by the energy output required to reduce the ore to a specific predetermined size. It is measured by the KILOWATT PER HOUR usage of electricity required. Lets start with a very simple flow sheet. This one is designed for very soft rock, or where the product size isnt important.

The feed comes from the primary crusher and will have a certain amount of rock that doesnt need further crushing. To run this ore through the crusher will be a waste of energy and crushing space. Ideally it should be removed.

To remove it requires a procedure called SCALPING. This is when the ore is allowed to flow over a set of SCREENS or GRIZZLIES. The large ore wont be able to pass through the mesh, but the fine material will, this effectively separates the two sizes.

The ore is a little harder and the sizing more critical however, this means the positioning of the equipment has to change a little. The ore is still discharged from the primary crusher to the scalping equipment. For this type of application this is usually a screen. Again the fine material is removed from the circuit while the course gets crushed. But now, instead of continuing, the crushed product is directed back to the screen for further sizing. Any rock that isnt small enough will have to go through the crusher once more. Designing the circuit this way insures that the crushed rock has a uniform size.

Just for interest sake, the first circuit we looked at is called an OPEN CIRCUIT. This is because of the constant forward movement of ore. The second one is referred to as a closed circuit. That is because the ore must meet the circuits objective, in this case the correct size, before it is allowed to escape the closed loop of the crushing circuit.

Our last schematic represents a CLOSED CIRCUIT. This one involves both SECONDARY and TERTIARY crushing. This circuit is employed where either the tonnage or the work index of the ore is high enough to require that the crushing be done in stages.

Again the ore will come from a Primary crusher and be scalped. The coarse material will be crushed by the secondary crusher. The fines will be taken out of the circuit. Once the secondary has finished with the ore it will be reclassified by a second set of screens with the oversize going to the tertiary crusher. The discharge of the tertiary is reintroduced to the screen deck to ensure that the ore size is uniform. These three schematics are samples of crushing circuits. There are many other varieties, each one dictated by the requirements of the ore, and the economics involved. Although each mine has its own individual problems, and the resulting unique design, they do usually have one thing in common. Almost all secondary and tertiary crushing circuits use the same type of crusher, the cone crusher.

tertiary impact crushers - meka crushing & screening plants

Crusher main body is fabricated from low carbon steel. Crushing chamber is completely lined with thick, interchangeable, bolt-on abrasion resistant (AR) liners. Sensors on the frame make maintenance interventions safer by preventing machine start up. Inspection doors located all around the frame make it possible to reach the interior of the Crusher.

Three independent breaker plates ensure highly efficient control of gradation. The upper and lower breaker plates are hydraulically adjustable, and have a security system that prevents blocking.

The rotors in our MTI Series crushers can be operated in both directions, so when the wear parts are worn out for one direction of the crusher, the operators can change the rotors operating direction to the other direction. This method decreases inventory costs for clients by reducing maintenance requirement time and parts cost.

The entire range of MTI Series crushers have been designed to gain the trust and confidence of our customers. The rotor is the heart of the crusher, so ours are manufactured as precisely machined welded construction rotors with proven quality, ensuring long-term use. In addition, all components are of premium quality in order to give our customers a trouble-free operation experience.

MTI Series crushers have maintenance gates on both sides, which can be opened manually without using any other equipment to provide easy access to the crusher rotor and wear parts during maintenance. Also, MTI Series crushers come standard-equipped with an automatic lubrication system.

MTI Series crushers come with four blow bars for better productivity. Discharge Gap can be adjusted via three hydraulic setting rods to easily obtain the size of end product required. The crushing chamber design is optimised to increase the impact effect on the material for a higher capacity, enabling the crusher to produce fine materials up to 50 percent of feed size.

The liners and breaker parts of the crusher do not wear out at the same pace, so some of the parts may need to be replaced earlier than others. Most of the wear parts and breaker plates are designed to be interchangeable, giving the customer great savings on inventory costs by reducing inventory space requirements.

secondary tertiary crusher saves energy 20% than common crusher - ftm machinery

Tertiary stone crusher, manufactured from Henan Fote Machinery Ltd., is especially suitable for making abrasive, refractory, cement and crushing quartz sand, steel sand, slag powder, copper ore, etc. There are different types of tertiary crushers like tertiary impact crushers and tertiary cone crushers.

Mining tertiary crusher is an efficient, energy-saving crushing equipment that can save energy 50% than traditional crushers. The tertiary stone crusher is also be called fine crusher. As the name suggests, it is a crusher for fine crushing and always used after coarse crushers like concrete jaw crushers and secondary crushers like impact crushers and cone crushers.

Compared with traditional stone crushers, fine crusher saves 20% energy, works stably. In terms of production capacity, the tertiary crusher no matter what tertiary roll crushers or tertiary impact crushers can improve by 30% compared to the traditional crusher of the same size.

The materials discharged from the tertiary crusher are finer. However, its capacity is lower than common crusher. Therefore, customers can choose the suitable equipment according to different demands on the production line.

The tertiary stone crusher is a kind of heavy machinery which works cyclically. When the tertiary crusher is working, the rotor driven by the motor rotates at a high speed. And the raw materials are put into the first crushing cavity and impact with the hammer on the rotor.

Then, the materials impacted in the first chamber will be put into the second cavity, and be discharged from the outlet. In a world, the tertiary crusher repeats the operating above all to crush the stone materials.

The hammer of the tertiary crusher is an indispensable part of the stone crusher, including the wear-resistant parts. Most of the hammer parts produced by FTM Machinery use high-manganese steel. When the Henan Fote company is processing crushing equipment, the element is added to the high-manganese steel. The hammer of the tertiary crusher can be greatly strengthened. When crushing iron ore with a tertiary crusher, the service life of the China Fote Machinery hammer is higher than that of ordinary high manganese steel.

Although powerful performances of the tertiary crushers, it still need to team up with other crushers like primary jaw crushers, secondary cone crushers and impact crushers to implment the whole crushing process.

China Fote has high-quality mining equipment but cheap price. And the machines have a long life. Our experts will offer you a professional plan according to your needs. We will arrange workers to install and train the precautions for you at the site. We also have remote online service. If you want to know more, please leave your message on our website and our manager will contact you within 24hours and send you the latest quotation.

tertiary crushing | article about tertiary crushing by the free dictionary

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what is primary, secondary, and tertiary crushing? - eagle crusher

The crushing market caters to a wide range of material processing industries, like aggregate, asphalt, and concrete and demolition recycling, that handle an even wider range of materials, including limestone, concrete, and gravel, among many others. Yet, all crusher...

As the summer months arrive in North America, operating portable crushing and screening plants on a job site outdoors can become more demanding as exposure to high temperatures introduce new safety hazards to team members. Dangers that are inherent to hot weather like...

From horizontal shaft impactors to jaw crushers, Eagle Crusher manufactures some of the toughest and most powerful crushing equipment on the market, empowering producers to conquer any size crushing project. Not only that, but Eagle Crushers team of engineers...

On a crushing job, every machine and piece of crushing equipment works together to contribute to the success of production. However, it is necessary to recognize that certain components of equipment like portable plants should require extra care to achieve that...

Striking the right balance between producing a quality aggregate product and maximizing operational efficiency is a familiar challenge on any crushing site. To achieve harmony, the right equipment needs to be set up and configured to account for any variables that...

Eagle Crusher Launches New Company Website Eagle Crusher is pleased to announce the launch of our new company website that is designed to better help users find the right crushing and screening products for their operations. An industry leader for more than 100 years,...

Portable crushing and screening plants are engineered with the safety of its operators and others in mind. Just as well, potential safety hazards like pinch points and finger injuries can be prevented on the job site by properly training team members and following...

The most effective crushing operations are often complemented by an appropriate configuration of screening plants and systems that can best sort and stockpile the material being processed as efficiently possible. Eagle Crusher manufactures a comprehensive range of...

In the crushing business, abrasive materials like aggregate, concrete, and asphalt can wear away at vital components across the production line. While these components are manufactured to withstand steady wear, they will require upkeep. As the entry point for the flow...

Portable plants and other crushing equipment can come in many shapes and sizes depending on the needs of a producer. Just as integral to a crushing operation as an impactor or jaw crusher are the screens being utilized to sort product. With so many options and...

There are many ways to crush a rockand depending on your industry, your location, and the project specifications, the equipment that you use and the layout by which it crushes that rock is often rather unique, especially when it comes to product size.

The degree to which material is reduced through stages of primary, secondary, and tertiary crushing can depend on the type of material, like aggregate, concrete, and asphalt, and can also depend on the variety of output sizes needing produced.

Primary crushing is the first stage of material reduction and can sometimes be the only stage needed to generate the desired product for a job. Depending on the setup, primary crushing will take the larger material that has been blasted, excavated, or reclaimed and process it through an impactor, jaw, or gyratory crusher to generate a range of product sizes.

For many aggregate producers, utilizing a closed-circuit portable crusher plant with scalping and screening capabilities can be all they need to create the product they need. But when a wider variety of product is desired and certain material is being processed, like concrete and asphalt, it can be valuable to rely on additional stages of crushing, like secondary and tertiary.

Secondary crushing, as you can imagine, is the second stage of material processing following its initial reduction. At this stage, material will flow through perhaps a second impactor or even a cone crusher, which is effective at breaking down these types of material.

There are also tertiary and even quaternary stages of crushing that exist to achieve the finer levels of material reduction. These stages in addition to secondary crushing can often be laid out utilizing an open-circuit portable crusher plant system where processed material is screened and conveyed from one crusher to the next.

Relying on these many stages of crushing beyond only primary can add great value to a crushing operation. Not only can multiple sizes of product be generated, but often in an open-circuit crushing layout, the flow and processing of material is streamlined and can increase output when compared to a closed-circuit crushing layout.

Eagle Crusher offers a comprehensive portfolio of closed-circuit and open-circuit portable crusher plants alike, manufacturing powerful equipment like horizontal-shaft impactors, jaw crushers, and cone crushers that are critical for any stage of crushing. When you speak with a Team Eagle representative, we can help you determine which crushing equipment will be best for your next project.

The crushing market caters to a wide range of material processing industries, like aggregate, asphalt, and concrete and demolition recycling, that handle an even wider range of materials, including limestone, concrete, and gravel, among many others. Yet, all crusher...

As the summer months arrive in North America, operating portable crushing and screening plants on a job site outdoors can become more demanding as exposure to high temperatures introduce new safety hazards to team members. Dangers that are inherent to hot weather like...

From horizontal shaft impactors to jaw crushers, Eagle Crusher manufactures some of the toughest and most powerful crushing equipment on the market, empowering producers to conquer any size crushing project. Not only that, but Eagle Crushers team of engineers...

On a crushing job, every machine and piece of crushing equipment works together to contribute to the success of production. However, it is necessary to recognize that certain components of equipment like portable plants should require extra care to achieve that...

Striking the right balance between producing a quality aggregate product and maximizing operational efficiency is a familiar challenge on any crushing site. To achieve harmony, the right equipment needs to be set up and configured to account for any variables that...

Eagle Crusher Launches New Company Website Eagle Crusher is pleased to announce the launch of our new company website that is designed to better help users find the right crushing and screening products for their operations. An industry leader for more than 100 years,...

Portable crushing and screening plants are engineered with the safety of its operators and others in mind. Just as well, potential safety hazards like pinch points and finger injuries can be prevented on the job site by properly training team members and following...

The most effective crushing operations are often complemented by an appropriate configuration of screening plants and systems that can best sort and stockpile the material being processed as efficiently possible. Eagle Crusher manufactures a comprehensive range of...

In the crushing business, abrasive materials like aggregate, concrete, and asphalt can wear away at vital components across the production line. While these components are manufactured to withstand steady wear, they will require upkeep. As the entry point for the flow...

Portable plants and other crushing equipment can come in many shapes and sizes depending on the needs of a producer. Just as integral to a crushing operation as an impactor or jaw crusher are the screens being utilized to sort product. With so many options and...

kleemann products | kleemann

The crushing plants of the MOBICAT series are used for the precrushing of almost all natural rock and in recycling. However, the output of the MOBICAT crushing plants is determined not only by the jaw crusher alone - in fact, the optimal interaction of all components plays a decisive role. The focus is increasingly on cost and environmental awareness, availability of the plants, versatility, and quality of the final product.

The mobile cone crushers MOBICONE are used in medium-hard to hard and abrasive natural rock, as well as for raw materials processing in mining applications. The cone crushers deliver excellent cubic final grains in the secondary and tertiary crushing stages. The MOBICONE plants are available in different sizes and versions and for different applications. The cone crusher is suitable mainly in the linking with primary crushers and screening plants.

The mobile MOBIREX impact crushers are used in soft to medium-hard natural stone and in recycling. The performance of the plants is impressive not just in terms of pure volume reduction. The focus today is on cost and environmental awareness, availability, versatility and, above all, the quality of the end-product to be achieved. The MOBIREX plants crush stone so efficiently that the grain shape, grain size distribution and cleanness comply with the strict standards for concrete and asphalt aggregates.

The mobile screening plants MOBISCREEN are used for screening almost all types of natural rock and in recycling. The classifying and coarse screens are available in a double- or triple-deck version, with hydraulic or diesel-electric drives. The applications of the MOBISCREEN plants are diverse. There is a variety of appropriate screen media available for obtaining different grain sizes and for different feed material.

The mobile stackers MOBIBELT are used to improve tipping onto conical or kidney-shaped stockpiles. The direct material transport from the crushing or screening plant to the dedicated stockpile means that additional material movements with the wheel loader can be avoided. This reduces operating costs, increases operational reliability and efficiency.

universal worm gearmotors : bonfiglioli

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tertiary impact crushers

After secondary crushing stage, oversize material is directed either back to the secondary stage or to be crushed and shaped further at the tertiary stage to get much finer high-quality products. Since the materials are reduced to smaller size, specially designed, strong and faster machineries should be used for tertiary crushing stage.Material size and output gradations are affected by the type of tertiary crushers selected and used. Thats why we recommend our customers to get a professional aid when they have to select a tertiary crusher for their plants.

calibration secondary and tertiary crushers - crushing, screening & conveying - metallurgist & mineral processing engineer

How does the size setting of secondary and tertiary crushers is related.we do have Hp 200 and Hp300 cone crushers, for a better throughput how do I have to calibrate them related to each other and the feed material which has size of 80mm and should be communited to 10mm size finally

The settings are based on the crushing characteristic of the material being fed and the desired final product size and size distribution. There are no hard and fast rules. But in general (very very generally, with many exceptions) crushers will do a 4 to 1 up to a 10 to 1 reduction (mostly dependent on the hardness and friability).

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crusher - an overview | sciencedirect topics

Roll crushers are generally not used as primary crushers for hard ores. Even for softer ores, like chalcocite and chalcopyrite they have been used as secondary crushers. Choke feeding is not advisable as it tends to produce particles of irregular size. Both open and closed circuit crushing are employed. For close circuit the product is screened with a mesh size much less than the set.

Fig. 6.4 is a typical set up where ore crushed in primary and secondary crushers are further reduced in size by a rough roll crusher in open circuit followed by finer size reduction in a closed circuit by roll crusher. Such circuits are chosen as the feed size to standard roll crushers normally do not exceed 50mm.

Cone crushers were originally designed and developed by Symons around 1920 and therefore are often described as Symons cone crushers. As the mechanism of crushing in these crushers are similar to gyratory crushers their designs are similar, but in this case the spindle is supported at the bottom of the gyrating cone instead of being suspended as in larger gyratory crushers. Fig. 5.3 is a schematic diagram of a cone crusher. The breaking head gyrates inside an inverted truncated cone. These crushers are designed so that the head to depth ratio is larger than the standard gyratory crusher and the cone angles are much flatter and the slope of the mantle and the concaves are parallel to each other. The flatter cone angles helps to retain the particles longer between the crushing surfaces and therefore produce much finer particles. To prevent damage to the crushing surfaces, the concave or shell of the crushers are held in place by strong springs or hydraulics which yield to permit uncrushable tramp material to pass through.

The secondary crushers are designated as Standard cone crushers having stepped liners and tertiary Short Head cone crushers, which have smoother crushing faces and steeper cone angles of the breaking head. The approximate distance of the annular space at the discharge end designates the size of the cone crushers. A brief summary of the design characteristics is given in Table 5.4 for crusher operation in open circuit and closed circuit situations.

The Standard cone crushers are for normal use. The Short Head cone crushers are designed for tertiary or quaternary crushing where finer product is required. These crushers are invariably operated in closed circuit. The final product sizes are fine, medium or coarse depending on the closed set spacing, the configuration of the crushing chamber and classifier performance, which is always installed in parallel.

For finer product sizes, i.e. less than 6mm, special cone crushers known as Gyradisc crushers are available. The operation is similar to the standard cone crushers except that the size reduction is caused more by attrition than by impact, [5]. The reduction ratio is around 8:1 and as the product size is relatively small the feed size is limited to less than 50mm with a nip angle between 25 and 30. The Gyradisc crushers have head diameters from around 900-2100mm. These crushers are always operated in choke feed conditions. The feed size is less than 50mm and therefore the product size is usually less than 6-9mm.

Crushing is accomplished by compression of the ore against a rigid surface or by impact against a surface in a rigidly constrained motion path. Crushing is usually a dry process and carried out on ROM ore in succession of two or three stages, namely, by (1) primary, (2) secondary, and (3) tertiary crushers.

Primary crushers are heavy-duty rugged machines used to crush ROM ore of () 1.5m size. These large-sized ores are reduced at the primary crushing stage for an output product dimension of 1020cm. The common primary crushers are of jaw and gyratory types.

The jaw crusher reduces the size of large rocks by dropping them into a V-shaped mouth at the top of the crusher chamber. This is created between one fixed rigid jaw and a pivoting swing jaw set at acute angles to each other. Compression is created by forcing the rock against the stationary plate in the crushing chamber as shown in Fig.13.9. The opening at the bottom of the jaw plates is adjustable to the desired aperture for product size. The rocks remain in between the jaws until they are small enough to be set free through this opening for further size reduction by feeding to the secondary crusher.

The type of jaw crusher depends on input feed and output product size, rock/ore strength, volume of operation, cost, and other related parameters. Heavy-duty primary jaw crushers are installed underground for uniform size reduction before transferring the ore to the main centralized hoisting system. Medium-duty jaw crushers are useful in underground mines with low production (Fig.13.10) and in process plants. Small-sized jaw crushers (refer to Fig.7.32) are installed in laboratories for the preparation of representative samples for chemical analysis.

The gyratory crusher consists of a long, conical, hard steel crushing element suspended from the top. It rotates and sweeps out in a conical path within the round, hard, fixed crushing chamber (Fig.13.11). The maximum crushing action is created by closing the gap between the hard crushing surface attached to the spindle and the concave fixed liners mounted on the main frame of the crusher. The gap opens and closes by an eccentric drive on the bottom of the spindle that causes the central vertical spindle to gyrate.

The secondary crusher is mainly used to reclaim the primary crusher product. The crushed material, which is around 15cm in diameter obtained from the ore storage, is disposed as the final crusher product. The size is usually between 0.5 and 2cm in diameter so that it is suitable for grinding. Secondary crushers are comparatively lighter in weight and smaller in size. They generally operate with dry clean feed devoid of harmful elements like metal splinters, wood, clay, etc. separated during primary crushing. The common secondary crushers are cone, roll, and impact types.

The cone crusher (Fig.13.12) is very similar to the gyratory type, except that it has a much shorter spindle with a larger-diameter crushing surface relative to its vertical dimension. The spindle is not suspended as in the gyratory crusher. The eccentric motion of the inner crushing cone is similar to that of the gyratory crusher.

The roll crusher consists of a pair of horizontal cylindrical manganese steel spring rolls (Fig.13.14), which rotate in opposite directions. The falling feed material is squeezed and crushed between the rollers. The final product passes through the discharge point. This type of crusher is used in secondary or tertiary crushing applications. Advanced roll crushers are designed with one rotating cylinder that rotates toward a fix plate or rollers with differing diameters and speeds. It improves the liberation of minerals in the crushed product. Roll crushers are very often used in limestone, coal, phosphate, chalk, and other friable soft ores.

The impact crusher (Fig.13.15) employs high-speed impact or sharp blows to the free-falling feed rather than compression or abrasion. It utilizes hinged or fixed heavy metal hammers (hammer mill) or bars attached to the edges of horizontal rotating discs. The hammers, bars, and discs are made of manganese steel or cast iron containing chromium carbide. The hammers repeatedly strike the material to be crushed against a rugged solid surface of the crushing chamber breaking the particles to uniform size. The final fine products drop down through the discharge grate, while the oversized particles are swept around for another crushing cycle until they are fine enough to fall through the discharge gate. Impact crushers are widely used in stone quarrying industry for making chips as road and building material. These crushers are normally employed for secondary or tertiary crushing.

If size reduction is not completed after secondary crushing because of extra-hard ore or in special cases where it is important to minimize the production of fines, tertiary recrushing is recommended using secondary crushers in a close circuit. The screen overflow of the secondary crusher is collected in a bin (Fig.13.16) and transferred to the tertiary crusher through a conveyer belt in close circuit.

Primary jaw crushers typically operate in open circuit under dry conditions. Depending on the size reduction required, the primary jaw crushers are followed by secondary and tertiary crushing. The last crusher in the line of operation operates in closed circuit. That is, the crushed product is screened and the oversize returned to the crusher for further size reduction while the undersize is accepted as the product. Flow sheets showing two such set-ups are shown in Figs. 3.1 and 3.2.

Jaw crushers are installed underground in mines as well as on the surface. When used underground, jaw crushers are commonly used in open circuit. This is followed by further size reduction in crushers located on the surface.

When the run of mine product is conveyed directly from the mine to the crusher, the feed to the primary crusher passes under a magnet to remove tramp steel collected during the mining operation. A grizzly screen is placed between the magnet and the receiving hopper of the crusher to scalp (remove) boulders larger than the size of the gape. Some mines deliver product direct to storage bins or stockpiles, which then feed the crushers mechanically by apron feeders, Ross feeders or similar devices to regulate the feed rate to the crusher. Alternately haulage trucks, front-end loaders, bottom discharge railroad cars or tipping wagons are used. In such cases, the feed rate to the crusher is intermittent which is a situation generally avoided. In such cases of intermittent feed, storage areas are installed and the feed rate regulated by bulldozers, front loaders or bin or stockpile hoppers and feeders. It is necessary that the feed to jaw crushers be carefully designed to balance with the throughput rate of the crusher. When the feed rate is regulated to keep the receiving hopper of the crusher full at all times so that the volume rate of rock entering any point in the crusher is greater than the rate of rock leaving, it is referred to as choke feeding. During choke feeding the crushing action takes place between the jaw plates and particles as well as by inter-particle compression. Choke feeding necessarily produces more fines and requires careful feed control. For mineral liberation, choked feeding is desirable.

When installed above ground, the object of the crushing circuit is to crush the ore to achieve the required size for down stream use. In some industries, for example, iron ore or coal, where a specific product size is required (iron ore 30+6mm), careful choice of jaw settings and screen sizes are required to produce the minimum amount of fines (i.e. 6mm) and maximum the amount of lump ore within the specified size range. For hard mineral bearing rocks like gold or nickel ores where liberation of minerals from the host rock is the main objective, further stages of size reduction are required.

A gold ore was crushed in a secondary crusher and screened dry on an 1180micron square aperture screen. The screen was constructed with 0.12mm diameter uniform stainless steel wire. The size analysis of the feed, oversize and undersize streams are given in the following table. The gold content in the feed, undersize and oversize streams were; 5ppm, 1.5ppm and 7ppm respectively. Calculate:

The self tuning control algorithm has been developed and applied on crusher circuits and flotation circuits [22-24] where PID controllers seem to be less effective due to immeasurable change in parameters like the hardness of the ore and wear in crusher linings. STC is applicable to non-linear time varying systems. It however permits the inclusion of feed forward compensation when a disturbance can be measured at different times. The STC control system is therefore attractive. The basis of the system is:

The disadvantage of the set up is that it is not very stable and therefore in the control model a balance has to be selected between stability and performance. A control law is adopted. It includes a cost function CF, and penalty on control action. The control law has been defined as:

A block diagram showing the self tuning set-up is illustrated in Fig. 18.27. The disadvantage of STC controllers is that they are less stable and therefore in its application a balance has to be derived between stability and performance.

Bone recycling is a simple process where useful products can be extracted. Minerals such as calcium powder for animal; feed are extracted from the bone itself. The base material for cosmetics and some detergent manufacturing needs are extracted from the bone marrow.

The bone recycling process passes through seven stages starting from crushing and ending with packing. Figure 13.14 gives a schematic diagram showing the bone recycling process which goes through the following steps:

Following the standard procedures in the Beijing SHRIMP Center, zircons were separated using a jaw crusher, disc mill, panning, and a magnetic separator, followed by handpicking using a binocular microscope. The grains were mounted together with the standard zircon TEM (417Ma, Black etal., 2003) and then polished to expose the internal structure of the zircons. Cathodoluminescence (CL) imaging was conducted using a Hitachi SEM S-3000N equipped with a Gatan Chroma CL detector in the Beijing SHRIMP Center. The zircon analysis was performed using the SHRIMP II also in the Beijing SHRIMP Centre. The analytical procedures and conditions were similar to those described by Williams (1998). Analytical spots with 25m diameter were bombarded by a 3nA, 10kV O2 primary ion beam to sputter secondary ions. Five scans were performed on every analysis, and the mass resolution was 5000 (at 1%). M257 standard zircon (561.3Ma, U=840ppm) was used as the reference value for the U concentration, and TEM standard zircons were used for Pb/U ratio correction (Black etal., 2003). Common Pb was corrected using the measured 204Pb. Data processing was performed using the SQUID/Isoplot programs (Ludwig, 2001a,b). Errors for individual analyses are at 1, but the errors for weighted average ages are at 2.

A stockpile can be used to blend ore from different sources. This is useful for flotation circuits where fluctuations ingrade can change the mass balance and circulating loads around the plant. Blending can also be done on the ROMpad.

The lowest cost alternative is to have no surge at all, but rather to have a crushing plant on line. This is workable for small-scale plant with single-stage jaw crushers as the availability of these simple plant is very high provided control over ROM size is maintained.

The second alternative is to use a small live surge bin after the primary crusher with a secondary reclaim feeder. Crushed ore feeds this bin continuously and the bin overflows to a small conveyor feeding a dead stockpile. In the event of a primary crusher failure, the crusher loader is used to reclaim the stockpile via the surge bin, which doubles as an emergency hopper.

For coarse ore, the next alternative is a coarse ore stockpile. Stockpiles of this type are generally 1525% live and require a tunnel (concrete or Armco) and a number of reclaim feeders to feed the milling circuit.

Multi-stage crushing circuits usually require surge capacity as the availability of each unit process is cumulative. A fine-ore bin is usually required. Smaller bins are usually fabricated from steel as this is cheaper. Live capacity of bins is higher than stockpiles but they also require a reclaim tunnel and feeders.

hussmach asphalt and concrete technologies | poland

Each order is carefully designed and produced according to the customers specifications and requirements by the experts and is carefully handled by the quality control department before shipping. Thanks to the modular structure, we meet and even exceeded customers requirements in a short space of time.

Our asphalt and concrete plants are equipped with a high-tech automation system, including top-class SIEMENS & SCHNEIDER brands electronic components and PLC. The whole system is controlled through advanced software which has sophisticated features and a user-friendly interface.

Our products are complemented by additional logistics services such as international transport, freight insurance, warehousing as well as customs clearance provided by our company. We, therefore, enable economical transport and assembly. Besides, we speak English, German, Polish, Russian and Turkish.

All our products are a suitable solution for small, middle, big, and temporary term or long-term projects in dedicated areas, and delivered under the guarantee of the production capability of any asphalt and concrete, spare parts, technical service, and also compliance with ISO 9001, TSE, and CE norms.

The dust collection system which is perfectly tailored to the mixing plant capacity includes supporting feet for easy installation and implementation. The vertical layout of the filter bags guarantees maximum utilization of the surface area with an efficient filter function.

They provide the industrys best solution designed to get your asphalt plant running and profitable as quickly as possible and producing the top quality mastic and colored asphalt from the first operation with the least amount of hassle.

They provide the industrys best solution designed to get your concrete batch plant running and profitable as quickly as possible and producing the top quality concrete from the first concrete batch with the least amount of hassle.

Both our stationary cement silos and mobile cement silos with their capacities as well as easy-to-use design provide easy flow and they can be used for several years without wearing off even in the worst weather conditions.

We offer crushers such as jaw crushers, mobile limestone crushers, primary impact crushers, secondary impact crushers and vertical shaft impact crushers, produced according to our customers needs and requirements.

Mobile limestone crushers are a special type of mobile crushers which are generally preferred for crushing relatively softer stones such as limestone. A limestone crusher can be defined also as a crushing machine that is mainly used to process all kinds of limestones.

Vertical shaft impact crushers are also known as sand making machines and are used as tertiary stage crusher to achieve a high ratio of fine materials and give cubic shape to products which pass through secondary crushers.

Belt conveyors are used in concrete batching and stone crushing and screening plants to weigh, feed, transfer and stock the materials. Our belt conveyors are equipped with high-quality and heavy-duty electric motors and gearboxes.

Our aggregate feeding conveyors are classified as stationary and mobile types which can be used in all types of concrete plants. Mobile type aggregate feeding conveyors can be moved by a vehicle just like our mobile concrete plants. Aggregate feeding conveyors are equipped with a remote controller and also a CCTV system which is integrated into the control system of the concrete plant so that the system can be controlled and operated by concrete plant operator easily.

Our vibrating grizzly feeders which are designed and produced to take heavy shock loads from trucks, shovels and loaders provide a continuous feed rate under a variety of loading and material conditions and are generally used in quarries, recycling, mining, sand and gravel operations.

Twin Shaft Mixer is ideal for use in the ready mix precast, block, paver, and dam applications. Depending on the type of application, the mixers can be equipped with several accessories and options to optimize their productivity. The gearboxes of the mixing group are epicyclical types. The mixer tank is lined with Ni-Hard Cast Iron of 530HB minimum hardness. The mixing arms, with a low profile to avoid material build-up, are made in Spheroidal Cast Iron. The mixing blades are made in Ni-Hard Cast Iron with 530HB minimum hardness.

All our truck mixers perfectly designed and equipped to transport the ready-mix concrete in the highest quality to the site have a great contribution to the construction companies in constructing high-quality concrete structures.

Our wet system truck mixers in 6 CBM, 8 CBM, 9 CBM, 10 CBM, and 12 CBM capacities designed for the special requirements of ready-mix concrete and construction companies are the most commonly preferred concrete truck mixers.

The production of our truck mixers is made on an area of a total of 11.000 m2 in which 6.000 m2 open and 5.000 m2 closed parts, in where total 10 pcs are in the production line at the same time. Annually, more than 600 of our Truck Mixers are delivered to various countries in the Middle East, Europe and Latin America.

Besides, we make a difference by offering many companies, especially from the construction sector, the opportunity to purchase products they need in the domestic market in the fastest and safest way without the need to import.

cone crushers - for demanding crushing needs - metso outotec

Cone crushers are very suitable for size reduction and shaping in the downstream of a crushing circuit. They reduce the material in a crushing cavity by continuous compression between a fixed element (bowl liner) and a moving element (mantle).

Our cone crusher offering consists of four different product families that utilize the same crushing principle but vary in features and optimal applications. In addition to stationary crushers, many cone crusher models are also available as mobile andportable versions.

Engineered for all rock types, Nordberg GP Series cone crushers can be utilized as secondary, tertiary, and quaternary crushers in aggregates production plants and in mining operations. Nordberg GP Series cone crushers are all-round crushing machines enabling smooth crushing process adaptation and full automation.

Nordberg HP Series cone crushers are well performing and reliable rock crushing machines for all aggregates production, quarrying and mining applications. They are normally utilized in secondary, tertiary and quaternary crushing stages.

Nordberg MP Series cone crushers have a high capacity and the highest crushing force of any cone crusher of similar size. Thanks to their crushing force, Nordberg MP Series cone crushers are widely used in the secondary and tertiary crushing stages in mining operations that process very large amounts of material.

Metso MX Series cone crushers are the latest addition to the cone crushers portfolio. MX Series cone crushers utilize a revolutionary technology that combines a rotating bowl with piston into one crusher.

Known for lower operating costs, high uptime and consistent high-quality output, Metso MX Series cone crushers are ideal for secondary, tertiary and quaternary stages in hard and soft rock applications.

p&q university lesson 7- crushing & secondary breaking : pit & quarry

In the quarry, crushing is handled in four potential stages: primary, secondary, tertiary and quaternary. The reduction of aggregate is spread over these stages to better control the product size and quality, while minimizing waste.

The primary stage was once viewed merely as a means to further reduce stone following the blast or excavation prior to secondary crushing. Today, primary crushing is viewed as more important within the balance of production and proper sizing needs. The size and type of the primary crusher should be coordinated with the type of stone, drilling and blasting patterns, and the size of the loading machine. Most operations will use a gyratory, jaw or impact crusher for primary crushing.

In the secondary and subsequent stages, the stone is further reduced and refined for proper size and shape, mostly based on specifications to produce concrete and asphalt. Between stages, screens with two or three decks separate the material that already is the proper size. Most secondary crushers are cone crushers or horizontal-shaft impact crushers. Tertiary and quaternary crushers are usually cone crushers, although some applications can call for vertical-shaft impact crushers in these stages.

A gyratory crusher uses a mantle that gyrates, or rotates, within a concave bowl. As the mantle makes contact with the bowl during gyration, it creates compressive force, which fractures the rock. The gyratory crusher is mainly used in rock that is abrasive and/or has high compressive strength. Gyratory crushers often are built into a cavity in the ground to aid in the loading process, as large haul trucks can access the hopper directly.

Jaw crushers are also compression crushers that allow stone into an opening at the top of the crusher, between two jaws. One jaw is stationary while the other is moveable. The gap between the jaws becomes narrower farther down into the crusher. As the moveable jaw pushes against the stone in the chamber, the stone is fractured and reduced, moving down the chamber to the opening at the bottom.

The reduction ratio for a jaw crusher is typically 6-to-1, although it can be as high as 8-to-1. Jaw crushers can process shot rock and gravel. They can work with a range of stone from softer rock, such as limestone, to harder granite or basalt.

As the name implies, the horizontal-shaft impact (HSI) crusher has a shaft that runs horizontally through the crushing chamber, with a rotor that turns hammers or blow bars. It uses the high-speed impacting force of the turning blow bars hitting and throwing the stone to break the rock. It also uses the secondary force of the stone hitting the aprons (liners) in the chamber, as well as stone hitting stone.

With impact crushing, the stone breaks along its natural cleavage lines, resulting in a more cubical product, which is desirable for many of todays specifications. HSI crushers can be primary or secondary crushers. In the primary stage, HSIs are better suited for softer rock, such as limestone, and less abrasive stone. In the secondary stage, the HSI can process more abrasive and harder stone.

Cone crushers are similar to gyratory crushers in that they have a mantle that rotates within a bowl, but the chamber is not as steep. They are compression crushers that generally provide reduction ratios of 6-to-1 to 4-to-1. Cone crushers are used in secondary, tertiary and quaternary stages.

With proper choke-feed, cone-speed and reduction-ratio settings, cone crushers will efficiently produce material that is high quality and cubical in nature. In secondary stages, a standard-head cone is usually specified. A short-head cone is typically used in tertiary and quaternary stages. Cone crushers can crush stone of medium to very hard compressive strength as well as abrasive stone.

The vertical shaft impact crusher (or VSI) has a rotating shaft that runs vertically through the crushing chamber. In a standard configuration, the VSIs shaft is outfitted with wear-resistant shoes that catch and throw the feed stone against anvils that line the outside of the crushing chamber. The force of the impact, from the stone striking the shoes and anvils, fractures it along its natural fault lines.

VSIs also can be configured to use the rotor as a means of throwing the rock against other rock lining the outside of the chamber through centrifugal force. Known as autogenous crushing, the action of stone striking stone fractures the material. In shoe-and-anvil configurations, VSIs are suitable for medium to very hard stone that is not very abrasive. Autogenous VSIs are suitable for stone of any hardness and abrasion factor.

Roll crushers are a compression-type reduction crusher with a long history of success in a broad range of applications. The crushing chamber is formed by massive drums, revolving toward one another. The gap between the drums is adjustable, and the outer surface of the drum is composed of heavy manganese steel castings known as roll shells that are available with either a smooth or corrugated crushing surface.

Double roll crushers offer up to a 3-to-1 reduction ratio in some applications depending on the characteristics of the material. Triple roll crushers offer up to a 6-to-1 reduction. As a compressive crusher, the roll crusher is well suited for extremely hard and abrasive materials. Automatic welders are available to maintain the roll shell surface and minimize labor expense and wear costs.

These are rugged, dependable crushers, but not as productive as cone crushers with respect to volume. However, roll crushers provide very close product distribution and are excellent for chip stone, particularly when avoiding fines.

Hammermills are similar to impact crushers in the upper chamber where the hammer impacts the in-feed of material. The difference is that the rotor of a hammermill carries a number of swing type or pivoting hammers. Hammermills also incorporate a grate circle in the lower chamber of the crusher. Grates are available in a variety of configurations. The product must pass through the grate circle as it exits the machine, insuring controlled product sizing.

Hammermills crush or pulverize materials that have low abrasion. The rotor speed, hammer type and grate configuration can be converted for different applications. They can be used in a variety of applications, including primary and secondary reduction of aggregates, as well as numerous industrial applications.

Virgin or natural stone processing uses a multi-stage crushing and screening process for producing defined aggregate sizes from large lumps of rock. Such classified final fractions are used as aggregates for concrete, asphalt base, binder and surface course layers in road construction, as well as in building construction. The rock is quarried by means of drilling and blasting. There are then two options for processing the bulk material after it has been reduced to feeding size of the crushing plant: mobile or stationary plants.

When stone is processed in mobile primary crushing plants, excavators or wheel loaders feed the rock into the crusher that is set up at the quarry face, gravel pit or in a recycling yard or demolition site. The crushed material is then either sent to the secondary/tertiary processing stage via stacking conveyors or transported by trucks. Some mobile crushers have an independent secondary screen mounted on the unit, effectively replacing a standalone screen.

The higher the compressive strength of rock, the higher also is its quality, which plays an important role particularly in road construction. A materials compressive strength is delineated into hard, medium-hard or soft rock, which also determines the crushing techniques used for processing to obtain the desired particle sizes.

The materials quality is influenced significantly by particle shape. The more cubic-shaped the individual aggregate particles are, the better the resulting particle interlock. Final grains of pronounced cubic shape are achieved by using several crushing stages. A cubicity showing an edge ratio of better than 1-to-3 is typical of high-quality final aggregate.

As the earths natural resources are becoming ever more scarce, recycling is becoming ever more important. In the building industry, recycling and reuse of demolition concrete or reclaimed asphalt pavement help to reduce the requirements for primary raw materials. Mobile impact and jaw plants are uniquely positioned to produce high-quality reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA) for reuse in pavements, road bases, fill and foundations.

Use of RAP and RCA is growing dramatically as road agencies accept them more and more in their specs. But because RAP and RCA come from a variety of sources, to be specified for use by most departments of transportation they must be processed or fractionated and characterized into an engineered, value-added product. RCA or RAP are very commonly crushed and screened to usable sizes often by impact crushers and stored in blended stockpiles that can be characterized by lab testing for use in engineered applications.

Impact crushers are increasingly used for crushing recycling material. Impact crushers are capable of producing mineral aggregate mixes in one single crushing stage in a closed-cycle operation, making them particularly cost-effective. Different crusher units can alternatively be combined to process recycling material. A highly efficient method of processing recycling material combines crushing, screening and separation of metals. To produce an end product of even higher quality, the additional steps of washing to remove light materials such as plastics or paper by air classification and via electromagnetic metal separator are incorporated into the recycling process.

Mobile impact crushers with integrated secondary screens or without integrated screen used in conjunction with an independent mobile screen are ideal for producing large volumes of processed, fractionated RAP or RCA on a relatively small footprint in the plant. Mobile impactors are especially suited for RAP because they break up chunks of asphalt pavement or agglomerations of RAP, rather than downsize the aggregate gradation. Compression-type crushers such as jaws and cones can clog due to packing (caking) of RAP when the RAP is warm or wet.

Contaminants such as soil are part of processing demolition concrete. Mobile impact and jaw crushers when possessing integrated, independent prescreens removing dirt and fines before they ever enter the crushing circuit reduce equipment wear, save fuel, and with some customers, create a salable fill byproduct. A lined, heavy-duty vibrating feeder below the crusher can eliminate belt wear from rebar or dowel or tie bar damage. If present beneath the crusher, this deflector plate can keep tramp metal from degrading the conveyor belt. That way, the feeder below the crusher not the belt absorbs impact of rebar dropping through the crusher.

These mobile jaw and impact crushers may feature a diesel and electric-drive option. In this configuration, the crusher is directly diesel-driven, with the conveyor troughs, belts and prescreen electric-driven via power from the diesel generator. This concept not only reduces diesel fuel consumption, but also results in significantly reduced exhaust emissions and noise levels. This permits extremely efficient operation with low fuel consumption, allowing optimal loading of the crusher.

Jaw crushers operate according to the principle of pressure crushing. The raw feed is crushed in the wedge-shaped pit created between the fixed crusher jaw, and the crusher jaw articulated on an eccentric shaft. The feed material is crushed by the elliptic course of movement and transported downwards. This occurs until the material is smaller than the set crushing size.

Jaw crushers can be used in a wide range of applications. In the weight class up to 77 tons (70 metric tons), they can be used for both virgin stone and recycled concrete and asphalt aggregates processing as a classic primary crusher for natural stone with an active double-deck grizzly, or as a recycling crusher with vibrating discharge chute and the crusher outlet and magnetic separator.

Output for mobile jaw crushers ranges from 100 to 1,500 tph depending on the model size and consistency of the feed material. While larger mobile crushers produce more aggregate faster, transport weights and dimensions may limit how easily the crusher can be shipped long distances. Mobile jaw crushers can have either a vibratory feeder with integrated grizzly, or a vibrating feeder with an independent, double-deck, heavy-duty prescreen. Either way, wear in the system is reduced because medium and smaller gradations bypass the crusher, with an increase in end-product quality because a side-discharge conveyor removes fines. A bypass flap may provide easy diversion of the material flow, eliminating the need for a blind deck.

Jaw crusher units with extra-long, articulated crusher jaws prevent coarse material from blocking while moving all mounting elements of the crusher jaw from the wear area. A more even material flow may be affected if the transfer from the prescreen or the feeder trough is designed so material simply tilts into the crushing jaw.

Mobile jaw and impact crushers alike can be controlled by one operator using a handheld remote. The remote also can be used to move or relocate the crusher within a plant. In other words, the crusher can be run by one worker in the cab of an excavator or loader as he feeds material into the crusher. If he sees something deleterious going into the hopper, he can stop the crusher.

Impact crushing is totally different from pressure crushing. In impact crushing, feed material is picked up by a fast moving rotor, greatly accelerated and smashed against an impact plate (impact toggle). From there, it falls back within range of the rotor. The crushed material is broken again and again until it can pass through the gap between the rotor and impact toggle.

A correctly configured mobile jaw or impact crusher will enhance material flow through the plant and optimize productivity. New-design mobile jaw and impact crushers incorporate a highly efficient flow concept, which eliminates all restriction to the flow of the material throughout the entire plant. With this continuous-feed system, each step the material goes through in the plant is wider than the width of the one before it, eliminating choke or wear points.

For example, a grizzly feeder can be wider than the hopper, and the crusher inlet wider than the feeder. The discharge chute under the crusher is 4 inches wider than the inner width of the crusher, and the subsequent discharge belt is another 4 inches wider than the discharge chute. This configuration permits rapid flow of crushed material through the crusher. Also, performance can be significantly increased if the conveying frequencies of the feeder trough and the prescreen are adapted independently to the level of the crusher, permitting a more equal loading of the crushing area. This flow concept keeps a choke feed to the crusher, eliminating stops/starts of the feed system, which improves production, material shape and wear.

Users are focused on cost, the environment, availability, versatility and, above all, the quality of the end product. Simple crushing is a relatively easy process. But crushing material so that the particle size, distribution and cleanliness meet the high standards for concrete and asphalt requires effective primary screening, intelligent control for optimal loading, an adjustable crusher with high drive output, and a screening unit with oversize return feed.

This starts with continuous flow of material to the crusher through a variable-speed control feeder. Having hopper walls that hydraulically fold integrated into the chassis makes for quick erection of hopper sides on mobile units. If available, a fully independent prescreen for either jaw or impact models offers the ability to effectively prescreen material prior to crushing this allows for product to be sized prior to crushing, as opposed to using a conventional vibrating grizzly. This has the added value of increasing production, reducing wear costs and decreasing fuel consumption.

This independent double-deck vibrating screen affects primary screening of fines and contaminated material via a top-deck interchangeable punched sheet or grizzly, bottom-deck wire mesh or rubber blank. Discharged material might be conveyed either to the left or to the right for ease of positioning. The independent double-deck vibrating prescreen improves flow of material to the crusher, reducing blockages and feed surges.

Modern electrical systems will include effective guards against dust and moisture through double-protective housings, vibration isolation and an overpressure system in which higher air pressure in the electrical box keeps dust out. Simple and logical control of all functions via touch panel, simple error diagnostics by text indicator and remote maintenance system all are things to look for. For crushing demolition concrete, look for a high-performance electro- or permanent magnet with maximum discharge capacity, and hydraulic lifting and lowering function by means of radio remote control.

For impact crushers, a fully hydraulic crusher gap setting with automatic zero-point calculation can speed daily set-up. Featured only on certain mobile impact crushers, a fully hydraulic adjustment capability of the crushing gap permits greater plant uptime, while improving quality of end product.

Not only can the crushing gap be completely adjusted via the touch panel electronic control unit, but the zero point can be calculated while the rotor is running. This ability to accurately set the crusher aprons from the control panel with automatic detection of zero-point and target-value setting saves time, and improves the overall efficiency and handling of the crusher. On these mobile impact crushers, the zero point is the distance between the ledges of the rotor and the impact plates of the lower impact toggle, plus a defined safety distance. The desired crushing gap is approached from this zero point.

While the upper impact toggle is adjusted via simple hydraulic cylinders, the lower impact toggle has a hydraulic crushing gap adjustment device, which is secured electronically and mechanically against collision with the rotor. The crushing gap is set via the touch screen and approached hydraulically. Prior to setting of the crushing gap, the zero point is determined automatically.

For automatic zero-point determination with the rotor running, the impact toggle moves slowly onto the rotor ledges until it makes contact, which is detected by a sensor. The impact toggle then retracts to the defined safe distance. During this procedure, a stop ring slides on the piston rod. When the zero point is reached, the locking chamber is locked hydraulically and the stop ring is thus fixed in position. The stop ring now serves as a mechanical detent for the piston rod. During the stop ring check, which is carried out for every crusher restart, the saved zero point is compared to the actual value via the electronic limit switch. If the value deviates, a zero-point determination is carried out once again.

These impact crushers may feature a new inlet geometry that allows even better penetration of the material into the range of the rotor. Also, the wear behavior of the new C-form impact ledges has been improved to such an extent that the edges remain sharper longer, leading to improved material shape.

The machines come equipped with an efficient direct drive that improves performance. A latest-generation diesel engine transmits its power almost loss-free directly to the crushers flywheel, via a fluid coupling and V-belts. This drive concept enables versatility, as the rotor speed can be adjusted in four stages to suit different processing applications.

Secondary impact crushers and cone crushers are used to further process primary-crushed aggregate, and can be operated with or without attached screening units. These crushers can be used as either secondary or tertiary crushers depending on the application. When interlinked to other mobile units such as a primary or screen, complicated technical processing can be achieved.

Mobile cone crushers have been on the market for many years. These machines can be specially designed for secondary and tertiary crushing in hard-stone applications. They are extraordinarily efficient, diverse in application and very economical to use. To meet the diverse requirements in processing technology, mobile cone crushing plants are available in different sizes and configurations. Whether its a solo cone crusher, one used in addition to a triple-deck screen for closed-loop operation, or various-size cone crushers with a double-deck screen and oversize return conveyor, a suitable plant will be available for almost every task.

Mobile cone crushers may be available with or without integrated screen units. With the latter, an extremely efficient triple-deck screen unit may be used, which allows for closed-loop operation and produces three final products. Here the screen areas must be large so material quantities can be screened efficiently and ensure that the cone crusher always has the correct fill level, which is particularly important for the quality of the end product.

Mobile, tracked crushers and screen plants are advancing into output ranges that were recently only possible using stationary plants. Previously, only stationary plants were used for complicated aggregate processing applications. But thanks to the advancements made in machine technology, it is becoming increasingly possible to employ mobile technology for traditional stationary applications.

Mobile crushers are used in quarries, in mining, on jobsites, and in the recycling industry. These plants are mounted on crawler tracks and can process rock and recycling material, producing mineral aggregate and recycled building materials respectively for the construction industry. A major advantage of mobile crushers is their flexibility to move from one location to the next. They are suitable for transport, but can also cover short distances within the boundaries of their operating site, whether in a quarry or on the jobsite. When operating in quarries, they usually follow the quarry face, processing the stone directly on site.

For transport over long distances to a new location or different quarry, mobile crushers are loaded on low trailers. No more than 20 minutes to an hour is needed for setting the plant up for operation. Their flexibility enables the mobile crushers to process even small quantities of material with economic efficiency.

Mobile plants allow the combination of prescreening that prepares the rock for the crushing process and grading, which precisely separates defined aggregate particle sizes into different end products to be integrated with the crushing unit into one single machine. In the first stage, the material is screened using an active prescreen. After prescreening, it is transferred to the crusher, from where it is either stockpiled via a discharge conveyor or forwarded to a final screen or a secondary crushing stage. Depending on the specified end product, particles are then either graded by screening units or transported to additional crushing stages by secondary or tertiary impact crushers or cone crushers. Further downstream screening units are used for grading the final aggregate fractions.

The process of prescreening, crushing and grading is a common operation in mobile materials processing and can be varied in a number of ways. Mobile crushers with up to three crushing stages are increasingly used in modern quarries. Different mobile crushing and screening plants can be combined for managing more complex crushing and screening jobs that would previously have required a stationary crushing and screening plant.

Interlinked mobile plants incorporate crushers and screens that work in conjunction with each other, and are coordinated in terms of performance and function. Mining permits are under time constraints and mobile plants provide faster setup times. They provide better resale value and reusability, as mobile plants can also be used individually. They also reduce operating costs in terms of fewer haul trucks and less personnel.

With a so-equipped mobile crusher, the feed operator can shut the machine down or change the size of the material, all using the remote control, or use it to walk the crusher from one part of the site to the other, or onto a flat bed trailer for relocation to a different quarry or recycling yard. This reduces personnel and hauling costs compared to a stationary plant. With the mobile jaw or impact primary crusher, the only additional personnel needed would be a skid-steer operator to remove scrap steel, and someone to move the stockpiles.

Thanks to better technology, mobile plants can achieve final aggregate fractions, which previously only were possible with stationary plants. Production availability is on par with stationary plants. Theyre applicable in all quarries, but can be used for small deposits if the owner has several quarries or various operation sites. For example, an operator of several stone quarries can use the plants in changing market situations at different excavation sites. In addition, they also can be used as individual machines. A further factor is that mobile plants, in general, require simpler and shorter licensing procedures.

The high cost of labor keeps going up. A stationary crusher might be able to produce multiple times the amount of product, but also would require about seven or eight workers. Aggregate producers can benefit when producing material with the minimized crew used for mobile jaw and impact crushers.

Using correct maintenance practices, mobile crushers will remain dependable throughout their working life. Crushing and processing material can result in excessive wear on certain components, excessive vibration throughout the plant, and excessive dust in the working environment. Some applications are more aggressive than others. A hard rock application is going to require more maintenance on top of standard maintenance, as there will be more vibration, more dust and more wear than from a softer aggregate.

Due to the nature of its purpose, from the moment a mobile crusher starts, the machine is wearing itself out and breaking itself down. Without routine, regular maintenance and repair, a mobile crusher will not be reliable nor provide the material customers demand.

The first area of wear on any machine is the feed system. Whether its a feeder with an integrated grizzly, or a feeder with an independent prescreen, how the machine is fed contributes to wear. When setting up and maintaining a machine, the machine must be level. A machine that is unlevel left to right will experience increased wear on all components, including the feeder, the screens, the crushing chambers and the conveyor belts. In addition, it reduces production and screening efficiency, as the whole area of the machine is not being effectively used. Also, having the machine sit high at the discharge end will have the effect of feeding the material uphill in the feeder and reducing its efficiency, thus reducing production.

Another area for consideration is the equipment used to feed the machine. The operator using a loader to feed the crusher will have no control over the feed size, as he cannot see whats in the bucket. Whereas with an excavator, the operator can see whats inside and has more control over the feed into the hopper. That is, the operator is not feeding so much material all at once and is controlling the size of the feed. This reduces wear in the feed hoppers impact zones and eliminates material blockages due to feed size being too large to enter the chamber.

Dust is a problem in its own right, especially for the power plant of the mobile crusher. In a very dusty application, it is easy to plug the radiator and have engine-overheating problems. High dust levels cause increased maintenance intervals on air filters, and if not controlled properly, can enter the diesel tank and cause problems with the fuel system. Also, dust that gets inside the crusher increases wear. But if systems are put in place to remove the dust, it should keep it from going into the machine in the first place.

Dust also is a hazard on walkways and a problem for conveyors. If maintained, side-skirting and sealing the conveyors keeps dust from spilling out, building up underneath the conveyor, or building up in rollers, pulleys, bearings, and causing wear on shafts. Its important to maintain the sealing rubbers on the conveyor belts to avoid those issues. Routine maintenance calls for removing accumulated dust from inside and under the machine.

Dust also is a problem for circuit boards and programmable controllers. Dust causes electrical switches to malfunction because it stops the contacts from correctly seating. Electrical systems under positive air pressure dont permit dust to penetrate the control system. In control panels with a correctly maintained positive pressure system, filters remove dust from air that is being pumped into the cabinets. If the filters are plugged, the system will not pull as much air through, allowing dust, moisture and heat to build in the cabinet.

There are also impact aprons against which the rock is thrown, which also see high wear. There are side plates or wear sheets on the sides of the machine. The highest wear area is around the impact crusher itself, around the circumference of the rotor. If not maintained, the wear items will wear through and compromise the structure of the crusher box.

Conduct a daily visual check of the machine. The jaw is simple; just stand up on the walkway and take a look down inside. A crushers jaw plate can be flipped so there are two sides of wear on them. Once half the jaw is worn out, flip it; once that side is worn, change it.

The impact crusher will have an inspection hatch to see inside. Check to see how much material is left on the blow bars and how much is left on the wear sheets on the side of the crusher box. If half the bar is worn out after one week, change the blow bars in another week.The frequency of changes depends entirely on the application and the rock that is being crushed.

They have to be user serviceable, user friendly, and able to be changed in a short time. The best way to change these parts is a service truck with a crane; some use excavators but thats not recommended by any means.

After initial blasting, breakers are used to break down aggregate that typically is not only too large to be hauled in dump trucks, but also too large for crushers that size rock to meet asphalt, drainage system, concrete and landscaping specifications. Breakers can be mounted to a mobile carrier, such as an excavator, or to stationary boom systems that can be attached to a crusher. The total number of hydraulic breakers can vary from site to site depending on production levels, the type of aggregate materials and the entire scope of the operation.

Without hydraulic breakers, workers rely on alternative practices that can quickly affect production rates. For instance, blasting mandates shutting down operations and moving workers to a safe location. And when you consider how many times oversize aggregate might need to be reduced, this can lead to a significant amount of downtime and substantially lower production rates.

Aggregate operations can use hydraulic breakers to attack oversize without having to clear the quarry. But with an ever-growing variety of manufacturers, sizes and models to choose from, narrowing the decision to one hydraulic breaker can be overwhelming with all of the stats and speculation. Thats why its important to know what factors to consider before investing in a new hydraulic breaker.

In most cases, heavy equipment dealers are very knowledgeable about quarry equipment, including breakers, so they are a good resource for finding the best model for a carrier, usually an excavator or stationary boom system. More than likely, they will have specifications and information about various breaker sizes to help gauge what model is best. But being familiar with what to look for in a breaker can streamline the selection process.

The best places to look for breaker information are in the manufacturers brochure, website, owners manual or catalogue. First, carefully review the carrier weight ranges. A breaker that is too big for the carrier can create unsafe working conditions and cause excessive wear to the carrier. An oversized breaker also transmits energy in two directions, toward the aggregate and through the equipment. This produces wasted energy and can damage the carrier. But using a breaker thats too small puts excessive force on the tool steel, which transmits percussive energy from the breaker to the material. Using breakers that are too small also can damage mounting adapters and internal components, which considerably decreases their life.

Once you find a breaker that meets the carriers capacity, check its output power, which is typically measured in foot-pounds. Foot-pound classes are generalizations and are not based on any physical test. Often the breakers output will be documented in one of two ways: as the manufacturers calculated foot-pound class or as an Association of Equipment Manufacturers measured foot-pound rating. Foot-pound class ratings can be deceiving since they are loosely based on the breakers service weight and not the result of any physical test. The AEM rating, on the other hand, measures the force a breaker exerts in a single blow through repeatable and certified testing methods. The AEM rating, which was developed by the Mounted Breaker Manufacturers Bureau, makes it easier to compare breaker models by reviewing true figures collected during an actual test procedure.

For instance, three breaker manufacturers might claim their breakers belong in a 1,000-lb. breaker class. But AEM testing standards could reveal all three actually have less foot-pound impact. You can tell if a breaker has been AEM tested if a manufacturer provides a disclosure statement or if the breaker is labeled with an AEM Tool Energy seal. If you cannot find this information, contact the manufacturer. In addition to output energy specifications, manufacturers often supply estimates for production rates on different types of aggregate material. Make sure to get the right measurements to make the best decision.

In addition to weight and output power, look at the breakers mounting package. Two things are crucial for mounting a breaker to a carrier: a hydraulic installation kit and mounting components. Breakers need hydraulic plumbing with unidirectional flow to move oil from the carrier to the breaker and back again. A one-way flow hydraulic kit is sufficient to power the breaker as long as the components are sized to properly handle the required flows and pressures. But, consider a bidirectional flow hydraulic kit if you plan to use the same carrier with other attachments that require two-way flow. Check with the dealer or breaker manufacturer to determine which hydraulic package best fits current and future needs.

Hydraulic flow and pressure specifications also need to be considered when pairing a breaker to a hydraulic system. If the carrier cannot provide enough flow at the right pressure, the breaker wont perform with maximum output, which lowers productivity and can damage the breaker. Additionally, a breaker receiving too much flow can wear quickly, which reduces its service life. For the best results, follow the hydraulic breaker specifications found in owners manuals, catalogs and brochures. Youll find out if a breaker has additional systems that might require additional servicing. For instance, some breakers feature nitrogen gas-assist systems that work with the hydraulic oil to accelerate the breakers piston. The nitrogen systems specifications need to be followed for consistent breaker power output.

Brackets or pin and bushing kits are commonly required to attach the breaker to the carrier. Typically they are bolted to the top of a breaker and are configured to match a specific carrier. Some manufacturers make universal mounting brackets that can accommodate two or three different sizes of carriers. With the adjustable pins, bushings or other components inside these universal brackets, the breaker can fit a range of carriers. However, varying distances between pin centers can complicate hookups to quick coupling systems. In addition, loose components, such as spacers, can become lost when the breaker is not in use and detached from the carrier.

Some carriers are equipped with quick-coupling systems, which require a breakers mounting interface to be configured like the carriers original attachment. Some manufacturers produce top-mount brackets that pair extremely well with couplers. This allows an operator to use the original bucket pins from the carrier to attach the breaker, and eliminates the need for new pins. This pairing also ensures a fast pickup with the quick coupler.

Its also a good idea to check which breaker tools are available through the dealer and manufacturer. The most common for aggregate mining are chisels and blunts. There are two kinds of chisels commonly used in aggregate mines: crosscut and inline. Both chisels resemble a flat head screwdriver, but the crosscut chisels are used when carrier operators want to direct force in a left-to-right concentration; whereas, inline chisels direct force fore and aft. With chisel tools, operators can concentrate a breakers energy to develop cracks, break open seams or define scribe lines.

If a chisel cant access or develop a crack or seam, a blunt can be used. Blunts have a flattened head that spreads the energy equally in all directions. This creates a shattering effect that promotes cracks and seam separation. Ask your dealer if the tools you are considering are suited for the application. Using non-original equipment manufacturer tool steel can damage the percussive piston in the breaker, seize into the wear bushings, or cause excessive wear.

Regular breaker maintenance is necessary, yet its one of the biggest challenges for aggregate operations. It not only extends the life of the breaker, but also can keep minor inconveniences from turning into expensive problems. Some manufacturers recommend operators inspect breakers daily to check grease levels and make sure there are no worn or damaged parts or hydraulic leaks.

Breakers need to be lubricated with adequate amounts of grease to keep the tool bushing area clear and reduce friction, but follow the manufacturers recommendations. For example, adding grease before properly positioning the breaker can lead to seal damage or even catastrophic failure. And too little grease could cause the bushings to overheat, seize and damage tools. Also, manufacturers advise using high-moly grease that withstands working temperatures greater than 500 degrees. Some breakers have automatic lube systems that manage grease levels, but those systems still need inspections to ensure there is adequate grease in their vessels. Shiny marks on the tool are a good indication the breaker is not properly lubricated.

Little has changed in basic crusher design over past decades, other than that of improvements in speed and chamber design. Rebuilding and keeping the same crusher in operation year after year has long been the typical approach. However, recent developments have brought about the advent of new hydraulic systems in modern crusher designs innovations stimulated by the need for greater productivity as well as a safer working environment. Importantly, the hydraulic systems in modern crusher designs are engineered to deliver greater plant uptime and eliminate the safety risks associated with manual intervention.

Indeed the crushing arena is a hazardous environment. Large material and debris can jam inside the crusher, damaging components and causing costly downtime. Importantly, manually digging out the crusher before repairs or restarts puts workers in extremely dangerous positions.

The Mine Safety and Health Administration has reported numerous injuries and fatalities incurred when climbing in or under the jaw to manually clear, repair or adjust the typical older-style jaw crusher. Consider that fatalities and injuries can occur even when the machine is locked out and tagged out. Recent examples include a foreman injured while attempting to dislodge a piece of steel caught in the primary jaw crusher. Another incident involved a fatality when a maintenance man was removing the toggle plate seat from the pitman on a jaw crusher. The worker was standing on a temporary platform when the bolts holding the toggle seat were removed, causing the pitman to move and strike him.

The hydraulic systems on modern crusher designs eliminate the need for workers to place themselves in or under the crusher. An overview of hydraulic system technology points to these three key elements:

A hydraulic chamber-clearing system that automatically opens the crusher to a safe position, allowing materials to pass. A hydraulic overload relief that protects parts and components against overload damage. A hydraulic adjustment that eliminates the maintenance downtime associated with manual crusher adjustments, and maintains safe, consistent crusher output without the need for worker intervention.

Whether a crusher is jammed by large material, tramp iron or uncrushable debris; or is stalled by a power failure the chamber must be cleared before restarting. Manual clearing is a lengthy and risky task, especially since material can be wedged inside the crusher with tremendous pressure, and dislodging poses much danger to workers placed in harms way inside the crusher.

Unlike that of the older-style jaw, the modern jaw will clear itself automatically with hydraulics that open the crusher to a safe position, and allow materials to pass again, without the need for manual intervention. If a feeder or deflector plate is installed under the crusher, uncrushable material will transfer smoothly onto the conveyor without slicing the belt.

To prevent crusher damage, downtime and difficult maintenance procedures, the hydraulic overload relief system opens the crusher when internal forces become too high, protecting the unit against costly component failure. After relief, the system automatically returns the crusher to the previous setting for continued crushing.

The modern crusher is engineered with oversized hydraulic cylinders and a traveling toggle beam to achieve reliable overload protection and simple crusher adjustment. All closed-side setting adjustments are made with push-button controls, with no shims being needed at any time (to shim is the act of inserting a timber or other materials under equipment). This is a key development as many accidents and injuries have occurred during shim adjustment, a process which has no less than 15 steps as described in the primary crusher shim adjustment training program offered by MSHA.

secondary crushing simulation

The crushing plant simulator was utilized to evaluate the influence of major variables on the following responses: plant reduction ratio , weight % of - inch material in screen undersize, circulating load ratio and secondary screen efficiency. Variables manipulated were: weight % of +1 inch material in secondary crusher feed (73.3 to 92.9%), secondary crusher feed rate (1255 to 1578.8 STPH), secondary crusher close side set (2.54 to 3.785 cm), tertiary crusher close side set (.65 to 1.08 cm), and secondary screen opening (1.27 to 1.59 cm).

Unless stated otherwise, standard settings were: % +1 inch in secondary crusher feed = 83.6, secondary crusher close side set = 3.16 cm, secondary screen opening = 1.43 cm, tertiary crusher close side set = .788 cm and secondary crusher feed rate = 1417.1 STPH for two crushers. Output information(1) was obtained in accord with an experimental design.

The reduction ratio, the screen efficiency , and the % - inch material in screen undersize are virtually independent of feed rate over the range investigated. On the other hand, at higher feed rates the curculating load increases slightly. This may be attributed to a crowding effect associated with higher feed rates to the secondary crusher. Secondary crusher product becomes coarser, so that the circulating load rises correspondingly.

Figure 3-B shows how the % +1 inch in plant feed will influence responses at standard settings. Note that the % - inch material in the screen undersize (final product) goes through a slight minimum. As might be expected, screen efficiency tends to increase a small amount at coarser feeds.

Coarsening the feed to the secondary crushers causes a decrease in the amount of fines discharged, so that the circulating load increases. The discharge rate of secondary crusher fines, at some point, becomes more or less constant and the circulating load levels off.

At standard settings, the effect of an increase in secondary crusher close side set is depicted in Figure 3-C. The % - inch material in the screen undersize decreases slightly as the set increases. Plant reduction ratio decreases. Screen efficiency increases slightly, because the screen feed has coarsened. The circulating load ratio increases dramatically. As long as the tertiary crusher has not reached maximum capacity, the increase in circulating load does not profoundly influence fines production (screen undersize).

Figure 3-D shows the effect of an increase in secondary screen opening on responses at standard settings. Screen efficiency goes through a very slight minimum, an effect that may be associated with the proportion of near mesh material produced by the crushers. In contrast, the % - inch material in the screen undersize, the plant reduction ratio and the circulating load ratio decrease substantially. This is not unexpected.

Screen efficiency exhibits a very slight rise, while reduction ratio decreases from 6 to about 5.3 over the range investigated. The circulating load ratio tends to remain constant, then rises abruptly and levels off. For smaller close side sets (less than about .6 cm), the simulator suggests that reduction ratios and circulating loads may fall off. Samples acquired in this region around the tertiary crusher are being checked and, if necessary, the model parameters will be re-evaluated.

In Figure 4-B current draw is plotted against the reciprocal of the crusher set. If W ci is held constant at 0.3 times V, where V is a multiplier, a 10% increase in W ci feed rate causes the current to increase by 1.2 amp. The effect of a 10% increase in W ci is not as large (current increases by aboutamp).

The methodology employed to simulate the Brenda Mines limited secondary crushing plant has been described. This includes selection of responses and independent variables, selection of mathematical models, acquisition of raw data, statistical adjustment of raw data, fitting models to data, assessing the adequacy of fitted functions and constructing a simulator for study.

In general, trends in simulator output are consistent with practice. For example, when screen efficiency is calculated as percent recovery to undersize and plotted against plant feed rate, a slight maximum is observed around 1420 STPH. Such effects have been observed by Flavel for various modes of operation. The current draw expressions (Equations 6 and 8) are consistent. Thus, at constant voltage, current is proportional to power. Hence Equations 6 and 8 show that power is directly proportional to crusher feed rate and inversely proportional to close side setting. This agrees with graphical observations by Flavel.

The simulator suggests that more horsepower installed on tertiary crushers may be beneficial, depending upon site objectives such as a finer crushing plant discharge. A similar conclusion was reached, independently and in a different manner, by Burkhardt.

Although trends appear to be consistent, alternative crusher models are being explored to avoid the complexity of those described in the APPENDIX. Current efforts are directed towards the development of more general crusher/screen models, since those herein reported are specific to the Brenda operation.

The Brenda crushing plant subroutines have been incorporated into a structure that will simulate the crushing and grinding circuits. The resulting simulator will serve as a subroutine for an offline optimization study to obtain an indication of the best crusher sets and screen opening for a given objective.

tertiary crusher, tertiary crushing plant - all industrial manufacturers - videos

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