Impact Crusher Research Articles

The Rotor’s Modal Analysis of the Vertical Shaft Impact Crusher

Used the Solidedge to bulid the solid model of the Vertical Shaft Impact crusher’s rotor, then it is imported into Ansys for modal analysis, get the former twenty frequency and vibration model, through the twenty color vibration models and vibration animations attained from analysis, the rotor’s dynamic properties and weakness area could be detected directly, to set up the foundmental theory for the structure design.

Study on Wet Treatment Process of Waste Printed Circuit Boards

The dry crushing of wasted printed circuit boards (PCBs) can make secondary contamination. In this paper, a wet comminution process is put forward to solve the difficulties. For the comminution product, the distributions of particle size, liberation degree and metal grade are analyzed, and for the product below 1mm, a wet metal beneficiation process combined with shaking table and flotation is employed. The results show that the Whole PCBs could be comminuted by the MX wet impact crusher, and the cumulative yield, liberation degree, total metal content and its copper grade of the product below 1mm is 83.49%, 97%, 83.46% and 20.50%respectively, and that metal concentrates could be beneficiated by XZY wet shaking table, and the yield, total metal weight, copper grade of the metal concentrate, the recovery of total metal and copper is 34.87%, 88.99%, 50.73%,79.90% and 78.07% respectively keeping the feeding concentration at 20% and water consumption in 1100L/h. For these metals included by shaking-table middling, the separation of both flotation and shaking table is carried out, and the total metal content and its copper grade, recovery in metal concentrate 2′ is 72.07% , 31.59% and62.04% respectively, meanwhile the copper grade of tailings in flotation and shaking table are decreased to 1.26% and 2.94%. The wet treatment process can effectively concentrate these valuable metals from waste PCBs.

Optimization of Abrasive Wear Behavior of High Chromium Cast Iron and Hadfield Steel

Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin on disk wear test. The wear test was carried out with different loads on a pin. Abrasive wear behavior of two crushers made of Hadfield steel and high chromium cast iron was evaluated by comparing weight loss, wear resistance, microhardness and friction coefficient. The results showed that abrasive wear of high chromium cast iron was lower than Hadfield steel because of the larger amount of carbides and higher work hardening in the steel at the higher applied loads. Increase in surface hardness of Hadfield steel was more noticeable compare to high chromium cast iron due to the work hardening and formation of the twining sites during the wear test. Owing to the presence of M7C3 carbides in high chromium cast iron matrix, impact crushers exhibited higher friction coefficient. In addition, a wear loss equation was derived based on a real crushing condition. However, a new approach in optimization of the wear parameters was developed and wear behavior of the materials was predicted based on the maximum number of the effective factors. The optimization of the parameters by genetic algorithm showed that optimum wear loss for hammer and impact crushers under real condition is 5.2958 mg and 3.8449 mg, respectively. Results of the numerical simulation show that the genetic algorithm optimization is effective and very useful in designing the hammer and impact crushers. In addition, some recent patents on abrasive wear behavior of the high chromium cast iron and Hadfield steel are discussed in details. Keywords: Abrasive wear, genetic algorithm, Hadfield steel, hammer crusher, high chromium cast iron, impact crusher, optimization, wear resistance

Production of recycled sand from construction and demolition waste

Existing construction waste recycling technologies and standards have long been applied in construction and demolition waste recycling. However, they have been essentially focused on the production and use of coarse recycled aggregates. This paper presents a technology that permits the production of high quality recycled sand. The selective removal with a vertical impact crusher of the cement paste attached to recycled aggregates and the potential improvements in the quality of the recycled sand that is produced were investigated. The results showed that the proposed method permitted the production of low-porosity sand from construction and demolition waste and may contributes to changing the construction recycling model.

Wear of Throwing End of Vertical Shaft Impact Crusher

Statistics show that China currently applied in the vertical shaft impact crusher, the intensity itself is not a major problem affecting the life, the most critical issue is the main material throw head wear . Vertical shaft impact crusher rotor system based on virtual prototyping, combined with the actual working conditions and research objectives, in ADAMS dynamic simulation of the rotor system, a spindle speed at 1600r/min obtained when different materials on the first intermediate principal cast material suffered impact relationships

Vertical Shaft Impact Crusher Wear Analysis and Research on Antiwear Measures

Analysing the wear characteristics and features of vertical shaft impact crusher in the use of the principles of Tribology. Obtain the wear types and mechanism. Summarizes the factors which impact wear and tear, life and reliability. By selecting appropriate material and structure to optimize two respects its anti-wear measures were studied. Put forward to solve the method of reducing the wear problem.

Analysis of technical-technological parameters of secondary impact rotary crusher in limestone processing

This paper deals with the production of limestone at the stable plant separation of the open pit 'Duboki potok-Bijela rijeka'. Besides that, the effects of different levels of production and material flows were researched. Research was carried out in a fixed plant separation of the open pit limestone 'Duboki potok-Bijela rijeka' in Duboki Potok. Positions of research were on the secondary part of separation (impact crusher, routers materials, funnels, rubber conveyors, vibrating screens, etc). In the course of using different methods of measuring material flow, calculating capacity conveyors, laboratory methods where used in measuring size and distribution obtained material, and particle shape. The research results were reported in: - particle size distribution diagrams of the obtained aggregate stone with the best bands of particle size distribution - defining the functional dependence of impact crusher gap size distribution and structure of the obtained materials.

The New Rotor Diameter Selection of Vertical Shaft Impact Crusher Based on EDEM

The five rotor models of traditional 850mm, 200*400,200*500,250*500,300*500 and 300*600 were imported into EDEM for dynamic simulation, indicated that the acceleration efficiency of new rotor was better than the traditional. In the new rotor, when the subject rotor radius was the constant, the greater the impact plate installation radius, the better the acceleration efficiency; when the impact plate installation radius was the constant, the greater the subject rotor radius, the better the acceleration efficiency.

Size distribution of wet crushed waste printed circuit boards

A wet impact crusher was used to breakdown waste printed circuit boards (PCB’s) in a water medium. The relationship between the yield of crushed product and the operating parameters was established. The crushing mechanism was analyzed and the effects of hammerhead style, rotation speed, and inlet water volume on particle size distribution were investigated. The results show that the highest yield of −1 + 0.75 mm sized product was obtained with an inlet water volume flow rate of 5.97 m 3/h and a smooth hammerhead turning at 1246.15 r/min. Cumulative undersize-product yield curves were fitted to a nonlinear function: the fitting correlation coefficient was greater than 0.998. These research results provide a theoretical basis for the highly effective wet crushing of PCB’s.

Failure Analysis of Flail Knife on Aluminum Scrap Impact Crusher

Flail knife is one consumable part of aluminum scrap impact crusher made in Germany. In order to lower production cost, localized production of flail knife has been researched. Flail knife in steel 42CrMo has been developed instead of that of Germany. In course of using, neck of the self-developed flail knife has been broke up and fractured. For seeking the reason of failure, microstructure and mechanical properties of new flail knife has been analyzed, and force condition has been calculated by finite element analysis, heat treatment process and installation technology has been investigated. The reason of failure in flail knife has been summarized, and the heat treatment process optimized has been designed and took good effect.

Analysis of Particle Motion in Vertical Shaft Impact Crusher Rotor

The rotor of vertical shaft impact crusher was modeled by SolidWorks and imported into EDEM for dynamic simulation. The average speed, maximum speed, average force, maximum force with time were analyzed in rotor, so the true law of particles motion in rotor would be revealed, indicated that the speed of particle field in rotor increased with the rotor radius at the time of rotor work steady, about 80% of the particles were accelerated to the maximum speed, and the change of speed affected significantly the particle interactions.

Effect of Different Crushing Methods on Gradation and Particle Shape of Recycled Aggregate

Based on the current production line of artificial aggregate, the waste concrete derived from the same source was crushed by different crushing machine, jaw crusher and impact crusher. This paper focuses on the effect of different crushing machine on gradation and particle shape of recycled aggregate. As is shown by the results, recycled aggregate produced by two crushing methods can satisfy the requirements of specifications. Compared with the recycled aggregate produced by impact crusher, the coarse recycled aggregate produced by jaw crusher have less length/breadth ratio and higher thickness/breadth ratio; particle shape can come closer to round.

A new size distribution model by t-family curves for comminution of limestones in an impact crusher

In the evaluation of crushers, t-family curves obtained from single particle test methods are frequently used. It is known that there are many difficulties and problems in these tests. In this study the breakage behaviour of three different limestones in an impact crusher was investigated. A new size distribution model was developed by t-family value evaluation and Bond work index approach. As a result, the validity of the equation was proved by a high regression value ( r 2 = 0.88).

Simulation Analysis for Rotor’s Strength of Impact Crusher

The impact process of the hammer and the rock in impact crusher has been simulated with the software MSC.Dytran. Through the analysis of stress distribution in hammer and square plate, the region which stress is greater and the maximum stress loaction was founded. The result of the simulation will provides the basis for the improvement of the crusher’s performance.

The Influence of Rotor Bar Wear of Impact Crusher on Impact Effect

The influence of the wear of the rotor bar on its impact effect was investigated with FEM simulation. The effectiveness of FEM simulation on the research of impact force was verified through the comparison of experiment and simulation data. Simulation results showed that the wear of rotor bar has not so large influence on impact force. In its initial stage, the bar is worn easily, and the wear becomes slow with the wear increasing.

Research on the Load Distribution of Throwing Ends in Vertical Shaft Impact Crusher

With ADAMS dynamics software to simulate the stone movement in the vertical shaft impact crusher rotor, the law of an impact frequency and load on the throwing ends with the variation of feed size and rotor speed is studied, the reasons that the middle throwing end is most vulnerable to wear failure and the rotor speed is not as high as possible are explained.

Breaking Convention

Victor Prochazka Victor Prochazka, Funvesa, Peru, provides details of a situation where plant and foundry worked together to solve a wear problem on an impact crusher.

Modelling of output and power consumption in vertical shaft impact crushers

The vertical shaft impact (VSI) crusher is a commonly-used machine in aggregate production. A comprehensive understanding of the physical phenomena that influence the power consumption and the particle output of the device are essential to enable development of protocols that minimize energy consumption during rock crushing. While natural gravel has traditionally been the main choice of material for Swedish concrete manufacturers, the number of deposits is limited due to its role as a fresh water filter. It is therefore essential to achieve a product size distribution of aggregate that is on the same order as that of natural gravel to enable its use in concrete production. This work aims to present a model that predicts capacity, power and particle size distribution in a VSI crusher.

Minimization of fines generation in size reduction of coals by impact crusher

In Bubbling Fluidized Bed Combustors (BFBC) utilizing coal, efficient combustion requires that feed size of coal particles be in the maximum size range of 2 to 6 mm. This requires that the comminution process be effective. In this work, various types of coals have been comminuted in an impact crusher. The size reduction process is characterized by four process parameters and relevant properties of the coal samples. Taguchi's design of experiment was used to minimize the number of experiments done to obtain meaningful results. It was concluded from the experiments that among process parameters, RPM has a more prominent effect on generation of fines compared to feed rate, feed size and gap setting. Among coal properties, volatile matter, ash content and fixed carbon have significant effect, followed by moisture content. RPM has relatively less influence on coarse particle (> 6 mm) content. An empirical correlation has been formulated based on the data to predict the generation of fines for a given set of process parameters and physical properties of coals. The results obtained using the model was within the acceptable accuracy when compared to the experimental data. The same correlation has also been applied successfully to fit the cement production from a plant, indicating that it has merit beyond the laboratory and that the specific type of crusher is immaterial, provided the mechanism of size reduction remains the same.

Energy considerations in compressive and impact crushing of rock

A cone crusher and a vertical shaft impact (VSI) crusher were operated in closed circuit to compare the performance of the two different crushing machines. The crushers were operated in closed circuit with a 9 mm final screen aperture size. A comparison of capacity, size reduction and power draw shows that the VSI crusher is significantly more energy efficient than the cone crusher, and it produces significantly more fine material. The study also shows that the recirculating load is higher with the VSI than with the cone crusher. Compared to the cone crusher, the VSI product contained 65% more material smaller than 1 mm while at the same time consuming less power. An alternative energy measure was introduced to assess the value of feeding a finer product to a grinding mill. This measure suggests that a VSI can save 2–14% of the energy consumed in grinding, depending on the energy model used and the final product size. This estimate is in agreement with an energy saving of 11.8% observed in an iron ore application where VSI’s were introduced as a crushing step preceding the grinding circuit.