Material flow in active mining faces

***本提案将建立新型矿用挖掘机运行性能分析、测量和测试系统以及挖掘机铲斗设计指南，支持低能耗、低成本、高生产率的目标。这项研究将支持采矿业实现更低的操作和维护成本，并支持挖掘机制造商在替代设计方面的考虑。******绳铲和液压挖掘机铲斗的设计和操作使用分别保持了100多年和50多年的基本相同。在挖掘过程中有效填满的铲斗体积的比例，称为“填满系数”；生产性挖掘能影响爆破岩土的挖掘难易程度；高地啮合工具（斗齿）磨料磨损；而对挖掘机机械可用性的总体影响仍未得到采矿业的答复。这些都会导致操作和维护时间和费用的损失。挖掘机脚垫稳定性问题；此外，移动采矿设备的燃料使用过剩也是令人担忧的问题。******建议通过实地测量、比例实验室测试和数值模拟，对3名主要的全日制HQP和至多12名额外的短期HQP （BSc合作社）进行培训；主要评价破碎岩土与不同配置挖机铲斗相互作用的基本流动机制（使用方式和挖机类型的函数）。为了更好地理解磨料磨损和生产率作为比能量（每单位体积挖掘所消耗的能量）的函数的平行问题，将建议替代铲斗操作模式、磨损保护材料的选择以及新颖的铲斗几何形状作为挖掘条件的函数。******方法，新颖的测量技术和分析***一种新型的(1)实验室规模的挖斗面相互作用“透视罐”测试系统，配备高速和应变相机测量系统，补充了更传统的反作用力测量；(2)将主要使用改进的“现场模拟”（力载荷和挖掘速率）可编程磨损测试系统。***计划在此工作期间测试多达10个桶设计，以及数百个磨损样品。分析将评估挖掘路径、挖掘和磨损能量、填充因素、边坡稳定性和破坏/流动机制；作为铲斗形状和操作运动的函数。分析还将与现场挖掘机燃料使用（排放反射）和挖掘机履带下的地面稳定性相关联，从而对挖掘机底盘进行新的性能分析，评估需要高维护的损坏可能性。另外，更常规的岩土强度、材料密度和地面粒度表征测试也将用于确定挖掘条件。**

Summary, justification and objectives***This proposal will establish novel mining excavator operational performance analyses, measurement and test systems and excavator bucket design guidelines, supporting a low energy, low cost, higher productivity goal. This research will support mining industry operations in achieving lower operating and maintenance costs, and excavator manufacturers in alternative design considerations.******Rope shovel and hydraulic excavator bucket designs and operational use have remained essentially the same for over 100 years and 50 years respectively. The proportion of a bucket volume that efficiently fills during excavation, termed ‘fill factor'; productive dig energy impacting the ease that blasted rock or soil can be excavated; high ground engaging tool (bucket teeth) abrasive wear; and overall impacts on excavator mechanical availability remain unanswered mining industry concerns. These all result in operational and maintenance lost time and expense. Issues of excavator pad stability; and mobile mining equipment excess fuel use are additional concerns. ******It is proposed that three principal full time HQP and up to a dozen additional short term HQP (BSc co-op) will receive training through field measurements, scaled laboratory tests and numerical modeling; to principally evaluate the fundamental flow mechanisms of fragmented rock and soils interacting with excavator buckets of different configuration (a function of mode of use and excavator type). To better understand parallel issues of abrasive wear and productivity as a function of specific energy (the energy expended per unit volume excavated), alternative bucket operational modes, wear protection materials selection, and novel bucket geometries as a function of the dig conditions will be suggested.******Approach, novel measurement techniques and analysis***A novel (1) laboratory scale bucket-dig face interaction ‘see through tank' test system, equipped with high speed and strain camera measurement systems, complimenting more conventional reaction force measurement; and (2) modified ‘field mimicking' (force loading and dig rate) programmable abrasion wear test system, will be principally used. *** It is planned that up to ten bucket designs, plus several hundred wear samples will be tested during this work. Analyses will evaluate dig path, dig and wear energies, fill factors, slope stability and failure/flow mechanisms; as a function of bucket shape and operational motions. Analyses will also be correlated to field excavator fuel use (reflective of emissions) and ground stability beneath excavator tracks, leading to a novel performance analysis of excavator undercarriage evaluating the likelihood of damage requiring high maintenance. Additional more conventional geotechnical strength, material density and ground particle size characterization tests will also be used to establish dig conditions.**