Gold and arsenic recovery from calcinates of rebellious pyrite–arsenopyrite concentrates

The products of stepped calcination of pyrite–arsenopyrite concentrates contain ferric arsenate phases FeAsO4, Fe4As2O11, Fe3(AsO4)2. The article reports the research data on leaching of calcines in alkaline medium including caustic soda and hydrogen peroxide used as an oxidizer. The experiments prove the efficiency of alkaline leaching with H2O2 for dissociation of gold associated with ferric arsenates (II) and (III) and for reduction of arsenic content from 1.2–1.4 to 0.006–0.15%. Preliminary leaching of calcinates enhances gold cyanidation yield from 91–92.9 to 97.3–97.9%.