HEAP BIOLEACHING OF LOW-GRADE CHALCOPYRITE ORE FROM THE DAREHZARE DEPOSIT

摘要

The heap bioleaching of low grade chalcopyrite ore has been the topic of much research, both in the form of theoretical models and pilot plant trials. Mintek is evaluating a heap bioleach design approach consisting of a combination of heap construction features, leach operating parameters, in-heap instrumentation and a control package developed in-house. This technology is currently being demonstrated by Mintek/NICICO on 20,000 tonne test heaps treating low-grade chalcopyritic ore from the Darehzare deposit in Iran. The test heap material contains 0.6 percent copper, of which about 50 percent is in the form of chalcopyrite. Temperatures of around 40 deg C were maintained in the test heaps, with maxima of around 45 deg C having been observed. An acceptable rate of copper extraction could be maintained, while the formation of jarosite remains under control. The control package could also find application in the administration of heaps and solutions on oxide and secondary sulphide heap leach plants. The use of 'Smart' columns to simulate real heap behaviour proved invaluable in the specification of the design parameters of the pilot plant.