Electrochemical leaching of nickel from low-grade laterites

A new method for extracting nickel from low-grade laterites containing less than 2 wt.% nickel is proposed. The method employs an electrochemical treatment and was used to extract the nickel from four Indonesian low-grade laterites. Electrochemical leaching of the nickel was conducted in an electrolytic cell that was divided into two compartments by using a PVC separator. The cell had a current density of 3.2–32 mA/cm2. Nickel in the laterites was leached together with iron via electrolytic reduction in the presence of sulfur dioxide. It is believed that extraction of nickel from laterites by electrochemical leaching treatment could be related to the reductive dissolution of iron during electrolysis. oposed method allows for the low cost recovery of nickel from low-grade laterites regardless of the magnesium and/or iron content, and at ambient temperature.