Use of Geometallurgy to Predict Tailings Leach Acid Consumption at Olympic Dam

摘要

For any processing plant there will be deleterious elements or minerals which affect production orrnquality, and a strategy to predict their occurrence and mitigate their impact is required. An earlyrnobjective of the Olympic Dam geometallurgy program was prediction of the acid consumptionrnand gelling behaviour of the ore, which affects leach recovery, throughput and circuit availability.rnThe geometallurgical test program measured the response of a wide range of ore types, and thenrnrelationships between mineralogy, metallurgy and chemistry were developed. Thus the drivers ofrnacid consumption and triggers for gelling events could be described in ways that were meaningfulrnto plant operations.rnTo enable optimisation of the mine planning and ore blending processes, the parameters drivingrnmetallurgical response must be translated to the block model. Data support is critical in populatingrna block model. Assay information is easily obtained, but mineralogical and metallurgicalrninformation is more expensive and time consuming to collect. Hence population of a block modelrnwith mineralogical and metallurgical values using a conventional geostatistical approach is notrnalways possible.rnAn alternative approach employed at Olympic Dam was the development of a suite of assay-tomineralrnalgorithms. These algorithms were calibrated using all available mineralogical information,rnand this enabled the calculation of mineral abundances for more than 1.5 million assayed samples.rnEstimation of the minerals in the block model, and the generation of acid consumption values forrneach block could subsequently occur.rnThe use of back-calculated mineralogy from assays as part of process model generation is anrninnovative tool which can be used for mine planning and optimisation and to ensure the plantrndoes not receive any unwelcome surprises. Ultimately, one purpose of geometallurgy is to predictrnpotential processing issues and their drivers so that these can be mitigated. A strategy to achievernthis is outlined hereafter.