Developments and innovations in bacterial oxidation of refractory ores

Abstract

The Bacterial Oxidation (BIOX) process for the pre-treatment of refractory ores for gold recovery developed by Genmin, the mining division of Gencor, has been operating successfully at the Fairview Mine since October 1986. The continuous operation of a pilot plant at Genmin Process Research has resulted in further process developments to improve plant operating efficiencies. These new developments, which include a higher solids content of the pulp feed to BIOX, lower retention times, higher operating temperatures, lower power utilization for oxygen dispersion and reduced nutrient addition, have all been successfully implemented on the Fairview plant. It has furthermore been confirmed that the arsenic precipitate formed in the neutralization of effluent solutions complies to the United States of America EPA standards. Continuous cyanidation pilot plant work conducted on BIOX product has indicated that cyanide consumption can be drastically decreased if a continuous flowsheet is implemented in preference to a batch leaching system.