ZKR Linear Vibrating Screen, crusher,jaw crusher,cone crusher,sand maker,crusher for sell.,
Usage:
ZKR series linear vibrating screen is new vibrating screen equipment, with vibration motor as vibration source. It is widely used in metallurgy, mines, coal, chemical industry, building materials, food processing, mechanical manufacturing and other industries.
We have light and efficient heavy-duty two series, of which light screen generally adopts horizontal installation and woven screen, widely used for classification, dehydration, medium drainage of medium, small particle materials and powder material in various industries, with small processing capacity; efficient heavy-duty screen is general installed with 5°～15°angle, and use screen plate, widely used for classification, dehydration, medium drainage of large, medium particle materials in various industries.
characteristics；
Compared with rocker screen and electromagnetic vibrating screen, this series vibrating screen has the following characteristics
1. Simple structure, low failure rate, convenient installation, operation and maintenance;
2. Good screening precision and high efficiency.
3. Low energy consumption, remarkable energy saving effect.
4. Low noise, advantageous to improve working environment.
This series vibrating screen belongs to the single mass forced vibration system, and the vibration source is the two sets vibrating motor of identical model. when two sets vibration motor do the synchronized reverse movement, at every moment of the eccentric block rotating, the component centrifugal force along the throwing direction always stack, and the component force along the normal direction always cancel out, form the single vibrating force along the throwing direction. Under action of the force, the material is to be continuously screened obliquely upward according to the screen box vibration frequency, a part of material is to be delivered through the screen while vibrating, so as to achieve the purpose of screening.
Selection Explanation
1. Choose screen: The screen mesh of this series light vibrating screen is usually divided into the ordinary carbon steel woven and the carbon steel welded, according to the requirements of users, uses the polyurethane fine screen, stainless steel overbraided wire net, sew net and other special materials nets. Efficient heavy-duty vibrating screen (mining vibrating screen), usually adopts the polyurethane screen plate, cast steel screen plate, rubber wear-resisting screen plate or Q235 steel plate, 16Mn steel drilling screen plate.
2. Determination of the production
The production output of this series light and heavy-duty vibrating screen (i.e. mining screen) is the processing capacity, that is the output for productivity, and that is the sum of the screening and screened materials. The basic calculating conditions of this series screen output are: material stack density 1.6 t/m3, accounted for 25% grain content in which the feeding size is greater than the screen hole, 40% in which less than 1/2 screen hole, screen surface opening rate is 50%. The screen hole is square, screening efficiency is 90%. And the capacity of the heavy-duty screen is determined under the condition of the screen descending 15°angle. When the customer specifically choose this series vibrating screen, the production output can only refer to the sample, and according to the concrete characteristics( such as bulk density, feed size, each content level, moisture content and screening frequency) and screen hole size to finally determination.
3. If the customer need us help to choose model, please provide: material name, bulk density, feed size, each content level, moisture content, screening frequency, output, screen model and screen hole size, and explain the screen mesh is single layer or multi-layer, light or heavy-duty, sealed or open type, so as to convenient us to accurate selection.
4. Our company can undertake to design and manufacture every types of screen with screen leaning body in 5 to 15 at any angle.
5. We also undertake the design and manufacture of all types of nonstandard vibrating screen with customer’s special requirements. Also undertake the nonstandard design shown in figure 5 to figure 10. If choose one, please provide the corresponding size according to the size code in the figure, if no special requirements, please indicate, then our company will design at our own.
6. This series vibrating screen should be equipped with corresponding control box, its main functions are: open brake to be stable and reliable, and can make the vibrating machine with bigger inertial oscillation sht down quickly in 0~5 seconds. It can effectively prevent the vibration machine and surrounding building from and improve the service life of equipment. And the braking time can be adjusted within 0 ~ 5 seconds.
Mobile construction waste recycling , crusher,mobile crusher,sand maker,
Mobile construction waste recycling is designed by Zoonyee company absoring advanced construction waste recycling technology. It is widely used in construction waste, industrial waste, coal, coal rock, slag, and building materials, etc.
After the solid waste application process, it can produce all kinds of new building material which meet quality inspection standard. The utilization ratio of construction waste can reach 80-100% according to the different equipmeny configuration. There is no second pollution, and it can achieve almost zero pollution and zero emissions.
The construction waste is sent to feed bin by the loader, then the material go into vibrating feeder from feed bin. At the same time, the raw material is sent to construction waste crusher by vibrating feeder. The broken material is sent to vibrating screen by belt conveyor. The crushed material is divided into three materials, 0-10mm is final material to be sent to finished area. Wood and mud by belt conveyor transported to the waste field. Big material by belt conveyor sent to the crusher for broken again
GZT-series vibrating feeder, crusher,stone crusher,jaw crusher.,
GZT series vibrating feeder is a new type and energy-saving feeding equipment. It adopts the vibrating motor to produce vibration force which can make sure to feed material homogeneously and continuously .The GZT-series vibrating feeder has simple structure which is much easier for maintenance, usually it is used together with vibrating conveyor ,vibrating screens ,bucket elevator, crusher etc , and widely applied in metallurgical , mining , hydropower , building material .
Operating principle & structural features:
GZT series Vibrating feeder is drived by new type vibrating motors, which makes the frame feeding homogeneously and quantified by doing periodic straight vibration. It consists of feeding frame, vibrating motors and damping device .
Installation& commissioning, usage& maintenance :
Features:
a.In order to ensure the materials be fed homogeneously , and avoid flow automatically , the vibrating feeder shall be installed horizontally . meanwhile , it can be declined 10°or 15°if the materials are stickiness or moist.
b.It shall be horizontally and have 20mm gap after installation .For the swing device, it shall use flexibility connection .
make sure to fasten all the bolts before air test , especially the foundation bolts of vibrating motor ; after 3-5 hours working , please refasten all the bolts .
c.Check the stability of amplitude, current and noisy during working , if problem , please stop immediately .
d.Refuel the lubrication oil of motor bearing every 2 months , or each month if the temperature is very high .
ZSW Vibrating Feeder, ,
ZSW Vibrating Feeder
ZSW Series Vibrating Feeder is mainly used for coarse crushing, continuously and evenly feeding before the crusher, while screening fines, to increase crushing capacity. Especially in the feeding of heavy crushing construction equipment, it has been used greatly! Features and Advantages: liner trajectory, stable vibration, special rack design, adjustable to prevent trash material clogging rack space.
LX Series High efficiency Spiral Stone Washing Machine, crusher,jaw crusher,cone crusher,sand maker.,
LX Series High efficiency Spiral Stone Washing Machine
LX series high efficiency spiral stone washing machine can wash and separate the soil and impurities. It has the advantage of new seal structure, adjustable overflow weir plate, reliable transmission device which can ensure the washing efficiency. It is applied to industries， such as highway, water power, mixing plant, cement, construction etc.
Supplying you with better products, economic and reasonable solutions are the tenet of Zhengzhou Zhongyi Mining Machinery Co.Ltd. Our engineers will supply technology support at any time. We sincerely hope to build the long term cooperative relationship with you to pursue higher value together.
XS Bucket Wheel Sand Washer, crusher,jaw crusher,stone crusher.,
XS series sand washer is widely used in construction sites, gravel plants, concrete hydropower dam site and many other industries. It has such advantages of high washing cleanliness, reasonable structure, large capacity, low power consumption, less loss of sand during washing process. Especially, the transmission part of sand washer isolates to water and sand, so the failure rate is much lower than the common sand washer. XS series sand washer is the best choice for upgrading the domestic sand washing industry.
YK Series Circular Vibrating Screen, crusher,stoen cruser,jaw crusher.,
The circular vibrating screen manufactured by our company is a new screening equipment, with elliptical vibrating trajectory, designed to screen stone material in the quarry, also to grade products in coal preparation, mineral processing, building materials, electricity, chemical and other sectors. The screen has a feature of advanced structure, powerful vibrating forces, low vibration noise, easy maintenance, high durability and etc. Our vibrating screen has the output energy consumption up to national standards, domestic and international advanced level, which has high reputation in the industries of consumers.
Operation Features:
1.Adopted eccentric as exciting force, and the force is strong.
2.The screen beam and screen box adopt high strength spiral, simple structure and convenient maintenance.
3.Adopted type couplings, flexible connection and smooth operation.
4.The small amplitude, high frequency and big angle structure make the screen high screening efficiency, big capacity, long life, low power consumption and low noise.
Cylinder Stone Washing Machine, crusher,stone crushe,crushing equipment.,
Cylinder stone washing machine is design by Zhengzhou ZhongYi Mining Machinery Co. Ltd., in order to meet the high crushing requirement of China Railway Bureau and China Construction Bureau. It has the advantage of high cleaning rate, high efficiency and energy saving. Compared with other similar machines, it has the advantages of high throughput, low operating noise, and easy maintenance.
This machine can effectively remove the soil, stone powder and other impurities on the crushed stone surface. It is good for the graduation of the mixing plant and the improvement of construction quality. We have build long term cooperation relationship with China Railway Bureau and China Construction Bureau Sine we developed the stone washing machine, and open professional service channel for them. Our machines are widely used in several national key projects, such as Zhengzhou-Xi’an High speed rail, Beijing-Shanghai High speed rail and the second Lan-Xin’ Railway.
Our standard models are as follows. Our machines can be are customized according to the actual demand.
Instruction: Check the tightness of bolts before using. Power-on sequence: 1st. discharging conveyor; 2nd.Main engine; 3rd.Feeding conveyor.
In addition to this, our company also produce spiral stone washing machine, which is mainly used in the stone washing and selecting of high standard project. It is low power consumption, and can effectively improve the grade and quality of various sand & stone material. These two machines can be collocated as required.
Fine sand recovery system , crusher,sand maker,jaw crusher,crushing equipment.,
Present artificially sand production line, the majority use wet production process, no matter what type of washing sand by machine, its the biggest drawback is fine sand (0.16 mm below particles) erosion, some even loss 20 % above, this not only damage output, but also seriously affect the gradation of the sand, killing the gradation unreasonable, fineness modulus partial coarse, and greatly reduce the mechanism of product quality. Sand Too much fine sand discharge, still can cause environmental pollution.
In order to solve the above questions, we research and manufacture the HZ series sand collecting system. This system is designed on the base of absorbing the foreign advanced technology, together with our real condition and come up to the advanced world standard.
They are utilized widely in the sandstone aggregate processing system of water and electricity station, the processing system of original glass material, the production line of manufactured sand, recovery of the coarse slime of the coal cleaning factory, and the protection environment project ( the mud cleaning etc.) and so on, they can solve the fine sand recovery questions. It solves the artificial aggregate processing system appears high finished sand fineness modulus, low power content questions.
Product Feature:
1. Effectively reduce the fine sand losing quantity, and make it in the scope of 5-10%.
2. The vibrating screen utilizes polyurethane screen cloth, which has longer life compared with others and uneasy to be blocked.
3. Inner the polyurethane, strengthen the whole device service life, it can smoothly finished the
Work of condensing slime and clearing the liquid etc.
4. The maximum fine grain materials quantity recovered from the total effluent is 95%, so it has
Unsurpassed technology and economic advantage compared with other equipments.
5. The find sand are recovered sufficiently, you can reduce the sedimentation basin workload and Low its clean cost.
6. Reducing nature stock time of the fine material, they can be transferred directly and supplied to the market
7. We can design corresponding solve project according to our consumers, different requirements.
PF Series Impact Crusher , crusher,stone crusher,jaw crusher,impact crusher,mobile crusher.,
PF Series Impact Crusher Products introduction
PF series impact crusher is mainly used secondary crushing,and can crush material its crushing compression strength not more than 320 Mpa.
It has the large throughput,discharging fine features.
Excellent shape of product,mainly the products shape is cubic with small fraction of elongated flaky particle shape,no inner crack.
It is the prefered crusher to produce aggregate for highway, hydroelectric, airport and building material industry.
Features:
1. Many cavity to crusher,suitable for crushing hard rock.
2. Reasonable design of leveling plate making charge finer and cubic without interior cracks.
3. Low and rig feed opening makes the production line easy to arrange and increase the size of feeding material.
4. New anti-abrasive material makes longer service life of impact bar,impact plate and liner.
PL series Vertical (Shaping) Impact crusher, crusher,jaw crusher,cone crusher,sand maker.,
PL series Vertical (Shaping) Impact crusher is widely applied to the medium crushing and fine crushing (sand making) of various hard and brittle materials, such as rock, grinding material, refractory material, cement clinker, quartz stone, iron ore, concrete aggregate.
PL series Vertical (Shaping) Impact crusher consists of feeder, divider, vortex crushing chamber, impeller, main shaft assembly, base transmission device and motor.
PL series Vertical (Shaping) Impact crusher working principle:
After being sent into the crusher by feeder, the materials will be divided into two parts by the divider. One part goes into the rapidly rotating impeller through the middle of the divider, and then is speeded up promptly by the impeller, with the acceleration hundreds times of the acceleration of gravity. Then they will be casted through the impeller’s three uniform distributed flow channels at the speed of 40-100 m/s. Firstly, they will be impacted with the material dropping from all round of divider, and then they will be stroke to the material layer in vortex crushing chamber, and then be rebounded to the top of this chamber, then move downward. Materials launched from the impeller’s flow channel forms a material screen. In this way, after being impacted, rubbed and grinding several times in vortex crushing chamber, a block of material will be discharged from the discharge opening at the bottom. It forms a closed circuit with the recycling and screening systems. Generally, material will be crushed under 20 Meshes after three recycling. In the process of crushing, materials impact, rub and grind with the material layer without directly touching the metal parts. That lengthens wear parts’ service life. Airflow’s self-circulation inside the vortex crushing chamber eliminates the dust pollution.
Working Feature of PL series Vertical (Shaping) Impact crusher:
1:Simple structure,low cost.
2:Energy saving and high crushing efficiency.
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3:With fine crushing and coarse grinding function.
4:high passing rate of non-crushing material, influenced lightly by the material moisture. The moisture content can reach 8%.
5:Used for crushing of medium hard and ultra-hard materials (such as corundum and sintered bauxite).
6:with shaping function, cubical product, needle plate content is less than 5%. This machine is mainly used for crushing and construction quarry shaping. It has the advantage of fine material particle size, small fineness modulus, less machine wear.
7:materials in the impeller and vortex crushing chamber forms liner by themselves. That greatly reduce the wear parts cost and the maintenance amount.
8:easy to operate, maintain and install.
9:working noise is less than 75 decibel (dB level)
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10:light Machine Body; Multiple installation method.
Perfect Control System
PL series Vertical (Shaping) Impact crusher is equipped with overload, over-current and short-circuit protection device which can monitor the oil temperature, oil return amount of the lubrication system. When the oil temperature is too high or the oil return amount is little, the system will give an alarm and automatically turn off the crusher. That not only ensures the equipment’s normal operation, but also the personal safety.
Cone crusher, crusher,stone crusher,crusher for sell,jaw crusher.,
Cone crusher used for crushing metallurgy, construction, road construction, chemical and silicate industry raw materials, it is suitable for crushing mid hard and above mid hard ores and rocks. It’s adopt advanced technology, increasing the service life of the wearing parts. Cone crusher crushing the material through the motor drive change the crushing cavity gap by big and small cone gear driving spindle do spiral motion .This machine has a big reduction ratio, high efficiency, low energy consumption, particle size uniformity ,it is suitable for of all kinds of ores and rock’s medium crushing and fine crushing.
Due to the smooth operation, reliable, large capacity, particle size uniformity the cone crusher was widely used in metallurgy, chemical industry, building materials, electricity, transportation and other industrial sectors, as all the hard ores and rocks medium and fine crushing equipment.
Cone crusher working principle is identical with the gyratory crusher, the basic structure is also very similar. Their biggest difference in the crushing chamber, gyratory crusher is steeply inclined, cone crusher is gently inclined; according to the difference of crushing chamber, cone crusher has three type : the standard, medium and short head type, use a spring or hydraulic systems to adjusted and iron protection the discharging mouth
Jaw Crusher , crusher,jaw crusher,cone crusher,sand maker,sand production.,
Jaw Crusher is mainly used for middle crushing and fine crushing the medium hard ores and rocks in metallurgy, mining, chemical, cement, construction, refractories , ceramics and other industrial sectors.
This series jaw crusher has the characteristics of large crushing ratio, even particle size, simple structure, reliable operation, easy maintenance, economic operating costs.
Motor drives belt and pulley, the eccentric shaft movable jaw up and down, when the movable jaw rises, the angle between movable jaw become large, thus pushing jaw plate close to the fixed jaw plate, while the material is to be crushed or split into pieces, achieve the purpose of crushing; when the movable jaw descends, the angle between elbow plate and movable jaw becomes small, under the action of bar and spring, movable jaw plate leaves the fixed jaw plate, then the crushed material discharge from the crushing chamber mouth. With the electric motor rotating continously, the movable jaw crushes and discharges the material periodically, to achieve continuous operation.
The jaw crusher is composed of frame, eccentric shaft, large pulley, flywheel, moving jaw, side guards, elbow board, elbow board backseat, adjust gap screw, return spring, fixed jaw plate and active jaw plates, of which elbow board plays a role as insurance.
Jaw Crusher composition
PFC Series Compound Energy Saving Fine Crusher, crusher,crusher for sell,jaw crusher,buy crusher.,
PFC series compound energy saving fine crusher is the latest generation high efficiency fine crusher. It is developed by our company by absorbing the domestic and overseas advanced technology and integrating the real working condition of the cement industry. It integrates the advantages of hammer type, reaction type, impact type fine crusher, and designed with special chamber, especially that its hammer head is made of “2021” special wear-resistance material. That brings this machine the advantages of fine discharging product and long service life of wear parts. It has achieved obvious economic benefit after the promotion.
In China, people from cement industries are searching for a good solution to solve the problem existing in stone fine crushing process. The majorities use PEX fine jaw crusher of 20-30mm discharging size. However once such big size material feeding into the cement mill, it will cause low efficient and high power consumption to the cement grinding system. If the average feeding size declines to P80≤5mm, the output capacity of grinding mill will be improved greatly, with the reasonable adjustment of the grinding mill technical parameter. In recent years, although most fine crushers in China have reach this standard, those crushers service life is short, and their benefits are getting worse. Fortunately, the PFC series compound energy saving fine crusher developed by our companies solves the problem of fine crushing and service life, and it has been the preferred equipment for the cement plant to increase the production capacity, lower down the energy consumption and improve their benefits.
Working Principle
As shown on the following drawing, the big material will be crushed immediately, and then fly to the impact plate to go through the second collision crushing. The rebounded material will hit with the follow-up flying material and crush each other. After being crushed in the first chamber, crushed material will go through repeated crushing in the second chamber. Finally, the material will be screened by the discharging grate, qualified product will be discharged from the grate seam, and coarser materials will be returned to the first chamber for repeated crushing.
The feeding size of this machine is 20-50mm; its max rated feeding size shall not be surpassed.
It is better to place it on the road side to avoid affecting manufacturing in the process of maintaining. The feeding material’s temperature shall be under 150 ℃, for the high temperature will short the service life of wear parts and bearings.
Structure Feature:
1: Adopt three-chamber curved surface crushing chamber, to increase the material’s hitting times and reducing compressing, rubbing and the consumption of hammer head.
2: Interval between impact plate and the hammer head is adjustable, so the discharging size can be effectively controlled.
3:Adopt deflectable structure to avoid the hammer head cracking if the material is too hard.
4: PFC50-300 opening equipment is equipped with hydraulic device, which makes the maintenance easier.
5:Installation iron discharging door at the grate’s outlet. If the iron block or the material is too hard to be crushed, they can be discharged from this door. That can protect the machine parts from breaking, but can not substitute the iron separator.
6；Intervals between left liner and lower impact plate is adjustable, just as that between the grate and the hammer head. When the particle size surpasses the rated valve, the intervals can be adjusted inward in different ways.
he DPX series single stage hammer crusher , crusher,jaw crusher,sand maker,sand production line,
he DPX series single stage hammer crusher is one of our leading products. It is used for crushing raw materials that have compressive strength less than 150MPa such as limestone, marl, sandstone, gypsum, coal, etc. This hammer crusher can crush the lump ore into the required granularity at a time , meanwhile, it can replace the traditional Multi-stage crusher and help simplify process flow, save infrastructure investment and production costs.
DPX series single stage hammer crusher has big crushing cavity and feeding opening, which can ensure lump ore be feeded smoothly. The special designed rotor can break the material easily for increasing the crushing efficiency . The forward way grid plate improves the conditions of passing materials, so the grid plate will not jam even if the materials contain clay. Structure of the frame is very strong, although iron been feeded , it will not damage the working parts .and the iron will be discharged from the discharging opening at the bottom of rotor .
Features:
1∶Three-cavity curved designed , which increased the breaking times of materials .The “rock-on-rock” principle indeed reduce the friction , wear of hammers and also consumption of energy.
2；High crushing ratio , small granularity (D80≤8mm)
3∶Easy adjusting for the gap between liner plate and hammers. The discharging size of final products can also been adjusted from 3-30mm.
4∶Energy saving over 40% than multi-stage crushers.
Long service life ,lower cost of operating, easy maintenance.
5∶Easy adjusting of discharging grid plate.
6∶20 mins can finished the complete checkup for the equipment by one person.
Working principle :
The special designed “rock-on-rock” design makes the intensive materials suspended in the cavity, materials will be feeded into the chamber just like the rain of bullets. After high speed crushed, the qualified material will be discharged from the grid plate .
60%-70% materials will be broken during the rock-on-rock processes, just 20%-30% materials will be crushed by hammers ,so compare with other crushers , there are three advantages as bellow :
1∶The feeded lump ore will pile up at the middle of special designed bracket, hammers rotating in the gaps of bracket , lump ore will fall down after continuous crushing , the crushed small materials will grided again by high speed rotated hammers ,then discharging from the grid plate.
2∶Oversized discharging cavity and crystallize of several patent technology .
3∶DPX series single stage hammer crusher has oversized discharging cavity which is designed by computer. The head-on crushed materials will like the rain of bullets in the crushing chamber. It is highly increased the working efficiency and decreased the hard friction. This is one of the secret weapons special designed hammers and grid plate is another secret weapon .
4∶Security
The stability of heavy bob bar linkage of discharging gate , the performance of rotation hammers and adjustment of grid plate have been proved by many users by years works.
5:Simplicity, stability
Discharging grid plate can be adjusted easily outside the frame, which can make sure the wear parts have long service life and always work in good conditions.
6:Furthermore, this type of crusher has access door , which can replace the hammers and do daily maintenance without opening the cover,meanwhile it also very convenient to check the status of the wears parts to make sure all the parts working normally during daily work.
PJ Construction Waste Crusher, crusher,jaw crusher,cone crusher,crusher for sell.,
PJ Construction Waste Crusher is developed and manufactured by our company based on our company’s years of experience, with absorbing the advanced technology of the domestic and overseas similar machines, considering the specific working conditions of the domestic related industries. It is specially used for construction waste crushing.
This machine has the advantages of big feeding size, high compression strength. It can be widely for the medium crushing of various coarse material of less than 250 Mpa in industries of cement, building material, mining, water power etc. especially for crushing of construction aggregate, such as basalt, granite, pebble in the special industries of highway, railway, irrigation project etc.
Design with particular vortex crushing chamber and three chambers of curved surface; the interval between tooth liner and plate hammer in the medium and fine crushing chamber is adjustable, so the discharging size can be effectively controlled; the high wear-resistance plate hammer adopts plug-in installation; the multi-azimuth doors of frame, screw rod or hydraulic opening device make the wearing parts replacement and the maintenance more easier.
PCX High Efficiency Fine Crusher, crusher,jaw crusher,crusher for sell,jaw crusher.,
When raw materials are fed into the fine crusher, they will be hit by the rapidly contrarotating hammer head.
The big material will be crushed immediately, and then fly to the impact plate to go through the second collision crushing. The rebounded material will hit with the follow-up flying material and crush each other.
After being crushed in the first chamber, crushed material will go through repeated crushing in the second chamber.
Finally, the material will be screened by the discharging grate, qualified product will be discharged from the grate seam, and coarser materials will be returned to the first chamber for repeated crushing.
The material layer floats intensively in the crushing chamber. The following fed material rip into the intensive material layer, the rapidly flying materials hit with each other and cleavage crushing happens. The crushed small particles rub and grind with each other and produce plenty of fine powder. Finally, the qualified fine powder will discharge from the grate seam.
In the “Rock-on-Rock” Crusher, 70%-80% crushing are caused by the mutual hit among the materials. Hence, the wear load of its hammer head and liner are only 20%-30% of the common crusher.
The former harmful functions which wear down the hammer head and liner are converted into useful function for material crushing. In this way, the “Rock-on-Rock” cleavage crushing is truly realized.
Compared with the common crushers, our PCX high efficiency fine crusher has the advantages of lower consumption, longer service life of wear-resistant parts and higher reduction ratio. It is widely applied in industries， such as sand making, stone crushing, cement, refractory material, metallurgy etc.
