GEOCOAT ®

The GEOCOAT ® technology offers a unique approach to the application of bacterial processing; combining the low capital and operating costs of heap leaching with the high recoveries obtained in agitated tank reactors. Both of which are well accepted processes in the minerals industry and are in commercial operation worldwide. In the GEOCOAT ® process, sulfide flotation or gravity concentrate slurry is coated onto crushed and sized support rock which may be barren or may contain sulfide or oxide mineral values. The coated material is stacked on a lined pad for biooxidation. The process is applicable to the biooxidation of refractory sulfide gold concentrates and to the bioleaching of copper, nickel, cobalt, zinc, and polymetallic base metal concentrates. Mesophilic or thermophilic biological systems are used to catalyze the sulfide oxidation reactions. In the processing of chalcopyrite concentrates, the higher temperatures associated with the use of thermophile microorganisms have proven highly beneficial in increasing the rate and extent of copper leaching. In the processing of refractory gold sulfide concentrates, the GEOCOAT® process offers significant cost advantages over the established processes: roasting, pressure oxidation, and agitated tank biooxidation. In base metals operations, the GEOCOAT® process is particularly suited to the treatment of “dirty” concentrates, can reduce transport by allowing the on-site production of metal at remote deposits, and can take advantage of depletion of oxide reserves through the utilization of existing SX/EW equipment. The process is simple, robust, and ideally suited to operation in remote locations.