Material flow in active mining faces

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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.**