颚式破碎机在花岗岩采掘中受岩石强度性能的影响外文文献翻译、中英文翻译.doc

Influence of some rock strength properties on jaw crusher performance in granite quarryAbstract：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 rocksInvestigation was conducted on four different rock samples namely marbledolomite1imestone and granite which were representatively selected from fragmented lumps in quarriesUnconfined compressive strength and Point load tests were carried out on each rock sample as well as crushing time and size analysisThe 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)test6.43 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)standardThe granite rock sample maybe classified as having very high strength and dolomite rock sample，low strengthAlso，the granite rock has the highest crushing time(2 1O s)and dolomite rock has the least value(50 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 types1 IntroductionJaw crushers are used for reducing the size of solid material, such as mineral material for example in mining industry. Usually jaw crushers comprise two vertical jaws, where the first jaw is fixedly mounted and the second jaw is arranged movable to and fro relative to the first jaw. The material to be crushed is fed between the jaws and subjected to the pressing and relieving actions of the moving jaw. The jaws are arranged in tapered manner so that they are farther apart at the top than at the bottom, and the material, which is crushed travels at the same time downwards towards the discharge opening.The crushing occurs between the two jaws, whereby the surface of the jaws is subjected to heavy wear and abrasion. The wear surfaces of the jaws are usually made of wear resistant material, such as manganese steel. However, when very abrasive minerals are crushed, the wear surfaces are rapidly eroded and they must be replaced. Replacement of the wear surface requires that the operation of the jaw crusher must be interrupted, which leads to process downtime and losses in operational efficiency. The strength of a material refers to the materials ability to resist an applied forceStrength property of rock is the ability of the rock material to resist failure when load is applied without yielding or fractureThe mechanical properties of rock depend upon the interaction between the crystals，particles and cementation material of which it is composedThe yield strength of a material is an adequate indicator of the materials mechanical strength and is the parameter that predicts plastic deformation in the materialfrom 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 effectStrength is considered in terms of compressive strength，tensile strength，and shear strength，namely the limit states of compressive stress，tensile stress and shear stress，respectivelyAccording to Reference，the effect of dynamic loading is probably the most important practical part of the strength of materials，especially the problem of fatigueRepeated loading often initiates brittle cracks，which grow slowly until failure occursIt 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 industriallyThis 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 finesJaw Crusher is used for crushing rock material in mines and quarries.Replacement of the wear surface requires that the operation of the jaw crusher must be interrupted, which leads to process downtime and losses in operational efficiency. Naturally, the process costs are also increased.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 rockThe 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 characterizing the strength of rock materialsPoint load test is used to determine rock strength indexes in geotechnical practiceRock lithologies were classified into general categories and conversion factors were determined for each categoryThis allows for intact rock strength data to be made available through point load testing for numerical geotechnical analysis and empirical rock mass classification systems such as the Coal Mine Roof Rating(CMRR) Crushing is an integral portion for mineral processing operations and is critical for the preparation of ore for downstream process for mineral processing operationsCrushing of quarried rock is carried out in stages，with the primary crushing stage typically carried out using jaw crusher and subsequent(secondary and tertiary)From field observation，the greater the number of crushing stage，the higher the amount of fine produced as a proportion of total plant throughoutThe type of crusher used also directly controls the amount of fines produced A recent study of quarry fines looked at possible relationship between quarry plant operation and the generation of quarry finesThe conclusion drawn have been critically revealed that hard rock aggregate plant production is directly proportional to the number of crushing stages；it increases with an increase in production stageLow reduction fines generation at each stage especially where the rock or mineral are fragile，however，the cumulative fines production may be higher than a process using fewer stages with higher reduction The panicle size analysis is the method used to determine the particle size distribution or the grain size distribution of rockore materialsIn practice，close size control of feed to mineral processing equipment is required in order to reduce the size effect and make the relative motion of the particles separation dependentThe particle size distribution of a matedal is important in understanding its physical and chemical propeniesIt affects the strength and load bearing properties of rocksThe easiest conventional method of determining mineral particle size is sieve analysis，where grain size is separated on sieve of different sizesapertures using Sieve ShakerThus the particle size distribution is defined in tems of discrete size ranges and measured in micronIt is usually determined over a list of size ranges that covers nearly all the sizes present in the sampleSome methods of determination allow much narrower size ranges to be defined that can be obtained by use of sieves and are applicable to panicle sizes outside the range available in sievesHowever，the idea of notionalsievethatretainsparticles above a certain size andpassespanicles below that size is universally used in presenting panicle size distribution data of all kindsThe size distribution may be expressed as arangeanalysis，in which the amount in each size range is listed in order of fineness of particlesIt may also be presented incumulative formin which the total of all sizesretainedorpassedby a single notionalsieveis given for a range of sizesRange analysis is suitable when a particular ideal midrange panicle size is being sought while cumulative analysis is used where the anlount of under-size orover-sizemust be controlledAccording to one embodiment of the invention the wear surface structure comprises a plurality of wear inserts arranged in a pattern. The wear inserts may be arranged to form a desired pattern on the wear surface structure of the jaw crusher in order to optimise the throughput of crushed material. By proper arrangement and selection of different insert cross sectional forms and sizes and/or heights on different parts of the wear surface of the jaw it is also possible to optimise the wear protection. For example, it is possible to arrange higher number of inserts in the centre part of the wear surface structure. It is also possible to optimise the capacity and jaw wear in the crushing process by using wear surface structures with different insert patterns.Furthermore, an uneven wear of the wear surface structure has been a problem in the known solutions. In earlier solutions the matrix material of the jaw surface structure has been rapidly and unevenly worn out and caused various problems. 2 Materials and methodThe rock samples used for the investigation were obtained from different quarries in NigeriaDolomite，limestone and marble samples were collected from Edo State and granite rock samples from Ondo State. NigeriaFive boulders of each rock type of dimension 90 cm50 cm50 cm were representatively selected from recently blasted portion of the rocks which were ftee from natural defects，that is,discontinuities such as cracks，joints，fractures etc were packed properly to avoid damage during transportationFor the unconfined compressive strength test，the rock sample was cut into square shape with dimension of 60 mm60 mm with masonry saw and Vernier caliper was used to measure the dimensionAlsofor the point load test，the rock samples were broken into irregular shape with sledge hammerVernier caliper was used to measure the diameter and length of irregular shaped rock samples from the different locationsThe mean value for length ad diameter was detemined . The rock samples were prepared and tested in the laboratory to Intemational Society for Rock Mechanics Standard for each strength test carried out using Masonry Saw Machine and Compression Testing Machine and Point Load Tester respectivelyThe readings were taken and recordedThe size reduction of equal weighed of the rock samples was done using Laboratory Jaw crusher and the particle size distribution was carried out in notional set of sieves using Sieve ShakerThe crushing times were taken and recorded and the weights of samples retained on the sieves recorded for size distributionThe rock sample were cut into square shape by using masonry cutting machine，the cut samples were smooth，free of abrupt irregularities and strengthFive specimen of each of the rock samples were tested and the failure load was recorded for each test as the failure was observed axlally in the compressive testing machineSome lumps of the different rock types were then crushed using the Laboratory Jaw crusher and taken record of the crushing timesThe screening of the crushed rock samples was carried out in a set of sieve using the Laboratory Sieve ShakerThe sieve was arranged in the order of decreasing apenure：4700，2000，1700，11 80，850，600，425，and 212 by placing the sieve that has the largest opening at the top and the least opening at the bottomA tight fitting pan or receiver was placed below the bottom sieve to receive the finest grained which is referred to as undersizeThe crushed sample was placed on the top sieve and a lid was used to cover it to prevent escape of the rock sample during me processThe set of the sieve was then placed in a sieve shaker which vibrates the sieve for proper screeningThis operation was carried out on each of the rock sample for five minutesThis was achieved by using the automatic control timer of the sieve shakerAfter the screening analysis，the retained sample on each sieve was measured on weigh balance and recorded to the cotresponding sieve opening size颚式破碎机在花岗岩采掘中受岩石强度性能的影响摘要岩石强度性能的影响在颚式破碎机性能上取决于破碎的时间和岩石粒度分配。调查被分为了四个不同的岩石样品，既是从采掘场支离破碎的块状中挑选出的具有代表性的大理石，白云石，石灰石，和花岗岩样品。对每种样品都做了在相同的破碎时间和粒级分析下的无测限抗压强度和集中载荷试验。每一种样品的受力参数都和它们的破碎时间和各自岩石类型的粒度分配一一的关联起来。强度载荷试验表明花岗岩是最高的达到101.67MP的无测限抗压强度，6.43MP的点载荷试验，然而白云石在无测限抗压强度只达到了30.56，在点载荷试验的为0.95MP。通过国际社会岩石机械强度标准，花岗岩样品被分类为了具有很高的强度白云石为较低的强度。而且，花岗岩具有着最高的破碎时间（21.秒），白云石具有最少的破碎时间值（5.0秒）。基于试验的结果可以看到，各种岩石类型的破碎时间受到很多强度性能的影响。1介绍颚式破碎机用于减少固体材料的尺寸，例如采矿工业中的矿物材料。通常颚式破碎机包括两个垂直钳口，其中第一钳口固定安装，第二钳口相对于第一钳口可前后移动。将被压碎的材料在颚之间进给，并受到动颚的压紧和缓解作用。钳口以锥形方式布置，使得它们在顶部比底部更远离，并且被压碎的材料同时向下朝着排放开口行进。挤压发生在两颚之间，从而颌面受到严重摩擦和磨损。钳口的磨损表面通常由耐磨材料制成，如锰钢。然而，当研磨性矿物被粉碎时，磨损表面被迅速侵蚀并且必须被替换。磨损表面的更换要求颚式破碎机的操作必须中断，这导致加工停机时间和操作效率的损失。材料的强度关系到这种材料抵抗外部压力的能力。岩石的强度性能是当负载没有屈服或者断裂时岩石材料抵抗破坏的能力。岩石的力学性质取决于晶体之间的相互作用，它是由颗粒和胶结物质组成。材料的屈服强度是材料的机械强度的指标参数也是预测材料塑性变形的依据，从此可以从其微观结构特性和期望效果中对如何提高材料的强度做出明智的决定。强度被认为分别是抗压强度，抗拉强度，抗剪强度，即对压应力，拉应力和剪应力极限状态计算。据参考，动态负载效应可能是材料强度的最重要实践部分，尤其是在疲劳问题上。重复载荷常常会产生裂缝，当其增长缓慢直到发生故障。这使得粉碎磨料和非常磨料的材料成为可能，并使破碎过程中的停机时间最小化，从而提高了总吞吐量和生产率。还可以根据被压碎的材料优化磨损表面结构的耐磨性。最为重要的就是在实验室规模的矿石破碎使之工业加工的有利性和经济性。在任何破碎和研磨设备产品中贵重细磨矿石就被限制例如释放大小，可磨性参数测定，由粗中细比例参数。颚式破碎机在矿山和采石场用于破碎岩石材料。它提供了在重型破碎机设计的最新技术，以实现高产量、更大的进料口、分离大型机、回转度、可满足安装要求的颚式破碎机支架和可选支撑脚定位。这种破碎机是为了异常重载连续运行中受岩石强度性能影响达到最佳效果操作和长寿命而设计的。岩石强度性能的影响可能会导致颚式破碎机设计中规定功能的丧失。无测限抗压强度测试的主要特征就是岩石材料强度的定量方法。点载荷试验用于在岩土工程实践中确定岩石强度指数。岩石岩性分为一般类和确定每个类别的转换因子。这使得完整的岩石强度的数据将提供岩土工程数值分析与实证岩体分类系统，例如煤矿顶板点荷载试验。粉碎是矿物加工工程的组成部分，是为下步选矿工艺行动做准备的关键。破碎岩石的开采是分阶段进行，与初级阶段粉碎进行通常使用颚式破碎机和随后的部分（二级和三级）。从野外观察，更大数量的粉碎阶段，在整个生产过程中更高的精细粉碎生产比例。所用破碎机还直接的控制着生产过程中的精细破碎的总额。一个最近的研究看起来可能关联着矿山设备操作和矿场精细生产。得出的结论显示，已精细的坚硬的岩石料