Effect of injection of different gases on removal of arsenic in form of dust from molten copper smelting slag prior to recovery process

Abstract

In order to reduce the environmental risks caused by arsenic in copper smelting slag, a method of dearsenisation from molten slag based on gas injection was proposed. It was expected to enrich arsenic in the form of dust prior to copper recovery process. The effects of inert, oxidising, and reducing gas on the removal of arsenic from molten slag were compared. When CO2 was injected, the removal of arsenic was mainly attributed to the oxidation of Cu—As inclusions and arsenic sulphide in the slag. Based on the injection of CO, the removal rate of arsenic reached more than 60%. Based on the injection of reducing gas, arsenic oxide in the FeOx—SiO2 slag was reduced and volatilised into the gas phase, resulting in the removal of arsenic. This study provides a reference with respect to the establishment of strategies for the mitigation of arsenic pollution caused by smelting slag.