Ph-controlled selective leaching of Co and W from hardmetal waste using lactic acid

The recovery of Critical Raw Materials (CRMs) is a strategic priority for the metallurgical industry. Hardmetal (HM, WC–Co) production is particularly vulnerable to tungsten (W) and cobalt (Co) supply shortages and price volatility, as these elements constitute its primary feedstocks. This study investigates valorization strategies for HM waste through a combined thermal–chemical approach. Oxidized powders (WO₃/CoWO₄) obtained from WC–Co scraps were subjected to leaching using lactic acid solutions at different pH values, with particular focus on the dissolution behavior of W and Co. The systematic evaluation of pH-dependent leaching performance provides key insights into metal selectivity and process optimization. The results contribute to the development of a smart and sustainable recycling strategy for efficient W and Co recovery from industrial HM waste streams.