Dewatering of Coal Mine Tailings Using Electrokinetics

Abstract

Increasing quantities of finer wastes often contain reactive sulphide minerals and high water contents that pose stability and environmental concerns. This study investigates how electrokinetic process can be improved, to make it more viable towards dewatering finer coal slurries. In the electrokinetic process, a direct current induces the movement of water out of a porous material. A wooden test box was filled up to two-thirds with fine coal slurries. Electrokinetic Geotextiles (EKGs) and brass were used as electrodes. The conducting wires were attached to each electrode and connected to a DC source to form an electro-osmosis cell. Current was passed through the cell and water moved to the cathode where it was withdrawn. The dewatering efficiencies ranged from 13.13 to 109.84 ml/Ah. The energy consumptions ranged from 5.23 to 14.03 kWh/m3 and are in line with those recorded by Johns (2005). Conductivity and pH measurements were taken. EKGs performed better than brass electrodes.