Analysis of thermal decomposition of acidified sediments in gold plants and harmless disposal of it.

In the present work, thermal decomposition of ASs in air was characterized by a combination of TG-DSC, XRD, and TG-FTIR. The treatment of generated toxic (CN) gas was investigated as well. The result showed that the decomposition of ZnFe(CN) in ASs preferentially reacted with CuSCN leading to the early decomposition of ASs, in which a part of CuSCN decomposed into CuFeS or CuS followed by being oxidized to sulfates and oxides as the temperature increased to 420 °C.