The Copper Concentrator at Mount Isa Mines Limited treats approximately 6 Mt of chalcopyrite ore annually.
The ore is currently sourced from the 1100 and 3000 orebodies at Mount Isa. Chalcopyrite is the only significant
copper bearing mineral, with pyrite, quartz and dolomite being major gangue minerals. Ore is typically 10%
chalcopyrite, 11% iron sulphides and 79% non-sulphide gangue. Copper ore is treated through two autogenous
mills, two ball mills and a flotation circuit. The autogenous mills replaced a crushing plant, two rod mills and two
primary ball mills during 1991. For routine analysis of concentrator performance, composite samples of mill feed, final concentrate and tailings
are generated every 4 week period. All samples are sized and size fractions are assayed. Recovery of mineral
species to the concentrate are then calculated for each size fraction. Sometimes liberation analysis was also
performed by QEM*SEM (Quantitative Evaluation of Material by Scanning Electron Microscope).