Abstract:Arsenic-containing copper ore is an important copper resource. During the process of bioleaching, the passivation film formed on the surface of the ore significantly reduces the leaching rate of Cu. Using XRD, XPS, etc., the morphology, composition, and phase changes on the mineral surface during the bacterial leaching of arsenic-containing copper ore are studied. The results show that in the early stage of leaching (1~5 d), the main substances produced on the surface of the ore are Fe(Ⅲ)—OOH, Fe(Ⅲ)—oxide, Sn2-, and S0; in the middle stage of leaching (5~9 d), the content of Fe(Ⅲ)—OOH, Fe(Ⅲ)—oxide, Sn2-, and S0 on the surface of the ore increases; in the late stage of leaching (9~15 d), jarosite and amorphous ferric arsenate are produced on the surface of the ore. Combined with the curve of Cu leaching rate over time, it is analyzed that there is no passivation phenomenon in the early stage of leaching; the main hindrance in the middle stage of leaching is the effect of S0 and Sn2-; the main passivation effect in the late stage of leaching is due to jarosite.