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

Abstract

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 deposition, so that copper sulfide with low arsenic content is obtained, and meanwhile, a part of hazardous waste arsenic sulfide slag is also utilized; the percentage content of As2O3 in refined As2O3 obtained after SO2 is added into the copper deposition liquid for reduction and arsenic removal is larger than 95%; the content of copper in refined zinc sulfate heptahydrate obtained by evaporative crystallization of the arsenic-removed zinc liquid is less than 0.05%, and the content of arsenic is less than 2%.

Description

technical field [0001] The invention relates to comprehensive recovery of metal copper, zinc, lead, bismuth and arsenic, in particular to a method for comprehensive recovery of valuable metals and preparation of arsenic trioxide from copper soot and arsenic sulfide slag. [0002] technical background [0003] The raw material for copper smelting is mainly copper sulfide concentrate, which contains a certain amount of arsenic. In the process of pyrometallurgy, a large amount of arsenic in copper sulfide concentrate will volatilize into the flue gas, and then into the copper fume and waste acid. In addition, in addition to arsenic, soot also contains a large amount of valuable metals such as copper, lead, zinc, bismuth, gold, silver, etc. Therefore, the harmless and resourceful utilization of copper soot has always been the focus of enterprises. After the arsenic in the flue gas enters the purified waste acid, it will first go through the sulfidation process, and then enter th...

AI Technical Summary

Problems solved by technology

There are mainly three processes of water leaching, acid leaching and alkali leaching in wet separation. CN105567983A discloses a water leaching-alkali leaching treatment process for copper smelting dust, which separates arsenic from metal, and the prepared arsenic products are not marketable; CN104357668A publishes A method of leaching smoke dust with dirty acid and removing arsenic by electrodeposition, however, arsine hydrogen is easily produced in the process of acid leaching and electrodeposition to cause poisoning; CN201210534763.5 discloses a multi-metal comprehensive recovery process for copper smelting soot , part of the chemical reagent sodium sulfide needs to be added in the process, and the product arsenic trioxide does not indicate whether it meets the national standard GB-26721-2011 for arsenic trioxide

Images