Method for comprehensively recovering valuable metals and arsenic trioxide from copper ash and arsenic sulfide slag

The invention discloses a method for comprehensively recovering valuable metals and arsenic trioxide from copper ash and arsenic sulfide slag. The method comprises the following steps that (1) two-stage leaching is performed on the copper ash; (2) second-stage copper deposition is performed by the aid of the arsenic sulfide slag; (3) SO2 is used for reduction and arsenic removal; and (4) evaporative crystallization is performed. According to the method, the valuable metals and the arsenic trioxide are comprehensively recovered through interaction of components in the two different kinds of waste, namely the copper ash and the arsenic sulfide slag. The method specifically comprises the steps that two-stage leaching is adopted, valuable metals copper, zinc, arsenic and the like in the copper ash enter a solution, metals such as lead, bismuth and the like enter slag, and lead-bismuth slag can serve as a raw material for lead smelting; the acid leaching solution adopts arsenic sulfide slag for two-stage copper de