Study on Removing As(III) by Oxidation and Precipitation from Acid-leaching Solution of Pyrite Cinder

Abstract

Arsenic removal from acid-leaching solution of pyrite cinder which contains a lot of As3+, and some of Fe3+, Fe2+, Cu2+ through an oxidation and precipitation processed by ferric ions has been studied in this work. In order to reuse the acid solution and recycle the cooper in the following process, ICP-MAS was employed to determine the content of As, Fe, Cu of acid-leaching solution and the solution after precipitation. Experiments used hydrogen peroxide as pre-oxidant, which was performed under different temperature, reaction time and at various pH levels. The formation process of insoluble ferric arsenate was analyzed by thermodynamic The results showed that the maximum extractions of arsenic and iron in leaching solution reached 99.89% and 99.77% respectively, and the maximum loss rate of copper was 3.35% when the end point pH value is 3 and reaction lasts for 10min at room temperature. Copper and arsenic in the leaching solution are respectively turned into copper sulfate solution and ferric arsenate slag to separate copper and arsenic.