Mount Isa Mines Copper Concentrator – An Insight into Current and Historical Practice

摘要

The Mount Isa Mines (MIM) copper concentrator at Mount Isa processes both chalcopyrite ore fromrnthe MIM underground mine and rotary holding furnace (RHF) slag from the MIM copper smelter.rnThere have been numerous changes to the processing practices since commissioning this concentratorrnin 1973. Current management of the concentrator extends from grinding and flotation to concentraternhandling (thickening and filtration) and tailings disposal (fill plants, tailings thickeners and processrnwater systems).rnPredominant mill feed through the concentrator is chalcopyrite ore. RHF slag is processed whenrnconcentrator production exceeds mined ore production. The chalcopyrite circuit has two stages ofrngrinding in parallel lines (Line 1 and Line 2). Each line has parallel preflotation and rougher banks,rncombining into a common scavenger/retreat circuit (including regrinding) and common cleanerrncircuit. RHF slag may be milled in parallel with chalcopyrite, utilising Line 2 flotation roughers and arnJameson cell cleaner.rnAll final concentrate produced is combined and pumped to the concentrate handling plant. Thernconcentrate is thickened, pre-fluxed and filtered in hyperbaric disc filters. Fluxing specification is setrnby the copper smelter, and filtered product transferred via conveyor belt to the smelter concentraternstorage facility.rnWet fill and paste fill plants utilise flotation final tailings as hydraulic or cemented hydraulic fill forrnstopes underground. Cement ratios and fill plant utilisation are varied depending on undergroundrnstope fill requirements. Tailings from the adjacent lead-zinc concentrator are also processed at wetrnfill. All tailings that are not utilised for backfill are pumped via wet fill to three parallel tailingsrnthickeners. Thickener underflows are gravity fed to the tailings dams with thickener overflowsrnrecycled for site process water use.rnIn addition to summarising historical operations, this paper will provide a detailed outline of morernrecent changes in the concentrator flotation circuit, equipment upgrades, reagent optimisation as wellrnas product and process optimisation at the final concentrate handling and fill plants.