外文翻译-颚式破碎机在花岗岩采掘中受岩石强度性能的影响

Influence of some rock strength properties on jaw crusher

performance in granite quarry

Abstract：The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks．Investigation was conducted on four different rock samples namely marble．dolomite．1imestone and granite which were representatively selected from fragmented lumps in quarries．Unconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysis．The results of the strength parameters of each sample were correlated with the crushing time and the grain size distribution of the rock types。The results of the strength tests show that granite has the highest mean value of 101.67 MPa for Unconfined Compressive Strength(UCS)test．6.43 MPa for Point Load test while dolomite has the least mean value of 30.56 MPa for UCS test and 0.95MPa for Point Load test。According to the International Society for Rock Mechanic OSRM)standard．the granite rock sample maybe classified as having very high strength and dolomite rock sample，low strength．Also，the granite rock has the highest crushing time(2 1．O s)and dolomite rock has the least value(5．0 s)．Based on the results of the investigation，it was found out that there is a great influence of strength properties on crushing time of rock types．

1 Introduction

The strength of a material refers to the materials ability to resist an applied force．Strength property of rock is the ability of the rock

material to resist failure when load is applied without yielding or fracture．The mechanical properties of rock depend upon the interaction between the crystals，particles and cementation material of which it is composed．The yield strength of a material is an adequate indicator of the material’s mechanical strength and is the parameter that predicts plastic deformation in the material．from which one can make informed decisions on how to increase the strength of a material depending on its micro-structural properties and the desired end effect．Strength is considered in terms of compressive strength，tensile strength，and shear strength，namely the limit states of compressive stress，tensile stress and shear stress， respectively．According to Reference，the effect of dynamic loading is probably the most important practical part of the strength of materials，especially the problem of fatigue．Repeated loading often initiates brittle cracks，which grow slowly until failure occurs．It is of paramount importance to first carryout size reduction of an ore or rock material on a laboratory scale for the ore or rock material to be profitably andeconomically processed industrially．This permits the determination of parameters such as liberation size，grindability，coarse to medium to fine proportion in any product of the crushing and grinding equipment and the proportion of values of gangues in the fines．Jaw Crusher is used for crushing rock material in mines and quarries。It provides the latest technology in heavy duty crusher design that delivers high production，infinite setting adjustment，larger feed opening bolted mainframe，cast swing，jaw holder and optional positioning of the crusher support feet to suit installation requirement．This crusher is designed for exceptional heavy and continuous application with heavy duty part for optimum operation and long life and this can be influenced by the strength properties of the rock．The influence of rock strength property can result to the loss of capacity to perform the stipulated function for which jaw crusher was designed． The UCS was the main quantitative method for