Confronted by failing metal prices and rising costs, progressive resource companies are examining novel methods for metal recovery. Conventional pyrometallurgical methods are subject to increasingly strict, environmental regulations, high smelting charges and regional limitations resulting in potentially high transport charges. Pressure hydrometallurgical methods have several advantages including the ability to produce metal directly at the mine site thus reducing transport costs, closed circuit effluent treatment and reduced impurity penalties. Unfortunately, these processes are capital and maintenance intensive. Certainly other novel processes exist but many suffer from high reagent costs and unproven metal recovery methods. Fortunately low cost treatment alternatives exist in the form of heap biooxidation. GeoBiotics, LLC, together with Kumba Resources Limited, is adapting the GEOCOAT(R) heap biooxidation technology-to treat sphalerite concentrates. GeoBiotics originally developed the GEOCOAT(R) system for the treatment of refractory gold deposits and has since expanded the technology for the treatment of copper, nickel and cobalt. Now, with the industrial support of Kumba, GEOCOAT(R) is being successfully applied for the treatment of sphalerite concentrates. Testing indicates that zinc extractions in excess of 95% can be achieved from the Rosh Pinah concentrate. (C) 2002 Elsevier Science Ltd. All rights reserved.