Electroremediation of copper mine tailings

Abstract

Mining activities are a key industry for many countries worldwide and especially in Chile where production and exportation of copper is crucial for the country’s economy. These activities have generated large amounts of solid waste, which have been deposited in mine tailing impoundments. These impoundments cause increased concern to the communities due to dam failures or natural leaching to groundwater and rivers. It seems to be of common interest that mine tailings should be treated in some way to minimize environmental risks. This work shows the laboratory results of three electrodialytic remediation experiments on copper mine tailings. The results showed that an electric current could remove copper. With the addition of sulphuric acid, the pH was lowered to around 4, and the metals were released and dissolved from the solid. The copper remediation efficiency was 31% with 21 days of remediation applying 20 V across the soil and a total charge of 6852 C passed through the mine tailing. Remediation occurs slowly and at a reduced efficiency, without the addition of sulphuric acid.