Treatment of iron ore beneficiation plant process water by electrocoagulation

Process water collected from the iron ore beneficiation plant was treated by electrocoagulation (EC) process to make it suitable for reuse or safe for discharge. Experimental studies were carried out towards efficient removal of the various metal ions such as iron (Fe), chromium (Cr), copper (Cu), zinc (Zn), manganese (Mn), lead (Pb), aluminum (Al) from process water along with monitoring of total dissolved solids (TDS), turbidity, conductivity, salinity. The influence of various operating parameters of EC, such as electrode material, electrode configuration, current density, inter-electrode distance, and solution conductivity, were explored for effective treatment of process water. Experimental results showed that aluminum electrodes at monopolar mode with a current density of 68.50 A/m², an inter-electrode distance of 1 cm, and solution conductivity of 1033 µS/cm were the ideal operating conditions to get treated water with a removal efficiency of 99.95%, 99.46%, 99.33%, 97.99%, 73.44% for Fe, Cr, Pb, Mn, and Cu ions respectively after 60 min of EC with electric energy consumption of 3.93 kWh/m³ and operating cost of 0.6115 US$/m³. X Ray Diffraction analysis of EC generated sludge confirmed the exclusion of major elements like Fe, Cr, Cu, Zn, Mn, Pb, Al as well as trace elements such as Nickel, Cobalt, Magnesium, Titanium, Vanadium, Zinc, Neodymium, Samarium, Yttrium, etc. from process water.