Glencore (Canada)

Rockbursting around underground excavations continues to be a core risk for many deep mining operations. Numerous advancements in mine design, preconditioning, monitoring, mining equipment, exclusion zones, and ground support have significantly lowered the risk to mine workers. As mining continues in deeper, more challenging environments, a multi-tiered approach to rockburst risk mitigation, starting with mine design, is required. Both the overall mine sequence, for example, avoiding converging mining fronts, and local design "stick handling" can play an important role in risk reduction. Rockburst case studies dating back to the late 1990s up until 2024 are used to highlight risk factors and risk mitigation (tactical and strategic). Examples from several deep hard rock mines are used, generally in high horizontal stress fields (k ratios 1.5 to 2), and strong brittle rock (> 200 MPa unconfined compressive strength). Mining induced stresses as well as high in situ stress due to depth are discussed. The context is Canadian mining, which typically has highly mechanised operations, large openings and equipment. Examples from a narrow vein mine and shaft sinking are also given because neither environment is simple to mechanise, highlighting the need for other risk mitigations. A "sieve" analysis based on mine incident reports is used to show how a multi-tiered risk management plan can lower exposure to violent ground failures. A few incidents still make their way through the "sieve," indicating a need for further improvements. Thoughts on future/ current developments, and their strategic importance are given. Ground support is the last line of defence. The proliferation of multiple styles of yielding tendons and support systems has made many choices available to rock engineering professionals. Despite the increased availability of dynamic ground support components, there are still difficulties getting clean load transfer to bolts, determining support demand, monitoring loss of capacity over time/mining, and evaluating true system capacity. Virgin development in deep high stress brittle rock can result in high strainburst exposure prior to any stoping operations. The mining process must reduce worker exposure to unsupported rockmasses. Successful preconditioning in a shaft sinking operation, the use of high early strength shotcrete, and mechanised equipment are also discussed.

In skeletally immature patients, medial patellofemoral ligament (MPFL) reconstruction must consider the femoral physis while also trying to reproduce the ligament as anatomically as possible. There is currently no gold-standard surgical approach. Previous surgical techniques for MPFL reconstruction in skeletally immature patients have described methods to avoid the physis, but it is difficult to accomplish this and still place the tunnel at Shottle's point. The technique described in this video allows the surgeon to find Shottle's point while still placing a tunnel that is all-epiphyseal. Following MPFL attachment to the patella, the guide pin is placed at Schottle's point under fluoroscopic guidance, and the scope is placed facing the posterior cruciate ligament (PCL) footprint. With the knee at 90° of flexion or greater, the guide pin is passed through the femoral condyle, aiming directly at the scope such that the pin enters the notch through the PCL footprint. The pin can then be passed anteriorly through the knee and the anterolateral soft tissues without endangering the lateral femoral condyle or the patellar tendon. A blind-ended tunnel is then drilled through the epiphysis to the level of the cortex making up the PCL footprint. Care is taken to ensure appropriate graft length such that the graft does not "bottom out" in the tunnel. The graft is passed into the tunnel and secured with an interference screw while the knee is in 45° to 60° of flexion. Expected outcomes for this all-epiphyseal MPFL reconstruction are very good. Patients begin physical therapy immediately after surgery and are allowed full weightbearing and full range of motion without a brace. The MPFL attachment is very near the medial femoral physis. Due to the undulating physis, placing the start of the femoral tunnel at the femoral MPFL attachment point requires that the tunnel trajectory be directed toward the center of the knee. The technique described in this video allows for all-epiphyseal femoral tunnel drilling with a starting point at the MPFL femoral attachment, allowing the graft to be placed as anatomically as possible. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Abstract In mine wastewaters, three microbial sulfur oxidation pathways have the potential to cause different water quality outcomes that can differ from abiotic model sulfate and acidity predictions, currently used to monitor potential sulfur risks. However, studies integrating microbiology and geochemistry in active mine tailings impoundments, are very limited. Here, we developed a novel diagnostic approach to detect microbially driven sulfur pathways. Within this 28-day study, eight, on-site, 500 L mesocosms were filled with water extracted directly from the water cap of an active Ni/Cu mine tailings impoundment. Diverse combinations of tailings, sulfur compound and nitrate amendments were added to the environmental mesocosms simulating common operational variations experienced by active tailings impoundments. Mesocosm results linked SOx, S4I, and incomplete SOx + rDSR pathway occurrence (metagenomes, inferred from the identity, i.e. 16S rRNA) and activity (mRNA) to physico-chemistry and S geochemistry. By integrating the three lines of evidence, the diagnostic approach was able to identify which S pathways were active under varying physico-chemical conditions and how sulfur geochemical outcomes were affected. A relationship emerged between acid generation and SoxCD occurrence, indicating complete SOx pathway activity. However, observed proton yields and sulfate concentrations were lower than those predicted by SOx pathway activity alone, indicating other pathways, e.g., SOx and the partial S4I pathways (within Thiomonas and Halothiobacillus), and/or activity of the incomplete SOx pathway (within Thiobacillus and Desulfurivibrio), when not coupled to rDSR and/or paired with use of nitrate, were influencing overall S outcomes.

The worldwide move to introduce more automation into underground metal ore mining is currently aimed at improving both operational productivity and safety. We have used a comparative life cycle assessment (LCA) as a novel approach for the industry to determine the beneficial impacts automation can also have on environmental performance using data collected on mine site productivity and energy consumption. The LCA looked at four impact categories: global warming potential, acidification, eutrophication, and human toxicity. When comparing key automated equipment to their traditional manual counterpart, all four impact categories experienced a reduction with automation and a subsequent improvement in sustainability performance. Global warming potential, for example, decreased by 18.3% over the mine life period, or 3.7 kg of carbon dioxide equivalent (CO2 eq.) per tonne of ore extracted. Environmental impact reductions were due primarily to lower diesel fuel consumption in the loading and haulage processes as well as a 27% shorter operational mine life leading to less years of mine and mine camp maintenance.

The consumption of energy contributes significantly to the overall cost of operations and the environmental impact of the mining and mineral processing industry. However, despite a few notable exceptions, most of the resulting waste heat produced is dissipated, without recovery, into the environment. There is also a lot of stored heat in mine water which can be tapped into long after a mine has closed. There is, therefore, significant opportunity to improve the industry's sustainability through increasing the amount of waste heat recovered and repurposed.