Hydrometallurgical recovery of manganese, gold and silver from refractory Au-Ag ore by two-stage reductive acid and cyanidation leaching

•A refractory Au-Ag ore from Beiya (Yunnan, China) is characterised.•The occurrence states of Au and Ag are clarified.•Most of Ag occurring as isomorphs in manganese oxide ore cannot be leached via direct cyanidation.•A hydrometallurgical recovery process of two-stage reductive acid and cyanidation leaching is proposed.•70.13% Mn, 87.37% Au, and 80.19% Ag are recovered.