Electrocoagulation in a packed aluminium scraps anode reactor for mineral processing wastewater treatment

Abstract

Efficient treatment and purification of mineral processing wastewater (MPW) have not been sufficiently investigated in the past though they are of great importance for sustainable mineral processing. Herein, a unique electrocoagulation (EC) reactor with aluminium scraps as anode material was developed for the treatment of real industrial MPW containing residual flotation reagents (major contributor to chemical oxygen demand, COD) and suspended particles. It was found that the active coagulants produced from the dissolution of aluminium scraps can play a key role in the purification of MPW. Under the conditions of initial pH 9, current 1 A, and processing time 90 min, the removal rate of COD was 74% while the turbidity can be almost completely removed. The mechanism lies in that most of the flotation reagents was adsorbed on the surfaces of suspended mineral particles, namely, montmorillonite, quartz, garnet, chlorite and mica, and then precipitated with the mineral particles. This innovative technology of utilizing wasted aluminium scraps to treat MPW is in line with the green development.