Electrochemical conditioning of recycled flotation wastewater for flotation results improving

Abstract

Flotation of minerals, an important part of the chain of metals production for our society, needs huge amounts of water. This industry can contribute to the sustainable use of water and circular economy development by utilizing its own production wastewater. However, reuse of clarified water without additional treatment may cause worsening of flotation results. Electrocoagulation of this water with mild steel sacrificial anodes, complemented by electroflotation is able to decrease the chemical oxygen demand (COD) and dissolved organic carbon (DOC) of the treated water, i.e. to remove at least partially the residual organic reagents. For the studied case 66 % of COD and nearly 32 % of DOC were removed by electrocoagulation with mild steel electrodes at energy consumption of 0, 458 kWh/m3. This warrants better results of lead-zinc flotation carried out with treated water, in comparison to the case of use of untreated water, and contributes to freshwater saving. Treated water ensured outcomes of lead-zinc flotation comparable to the results found at use of fresh tap water.