Processing of the Nickel existing in the mineral waste of a mine in Azerbaijan region, Iran

The raw material used in the present research was the waste of lead and zinc mines of Iran named CFC, stands for cold filter cake. CFC contains considerable amounts of nickel (2.5-4%). Annually, a large amount of CFC residue is produced in Iran’s Lead and Zinc Project. The residue of Ni-Cd purification step can be used as the second source of production of zinc, nickel, and cadmium. First of all, the zinc existing in the waste was separated from CFC in two steps in order to find the ability of purification and conversion into metal. This operation was performed by sodium hydroxide solution. The rest of the waste which was just solid converted into solution by sulfuric acid. Solvent extraction operation with D2EHPA diluted kerosene was done at the optimal pH. The optimal pH for 80% kerosene and 20% D2EHPA was obtained to be 3-3.5. Given the amount of impurities in the solution, solvent extraction operation was done by D2EHPA (Di-2-Ethyl Hexyl Phosphoric Acid) which produced pure solution of cadmium-nickel. In this solution, nickel is in the form of sulfate in an acidic environment. In order to achieve more industrial results, Iranian laboratory materials with purity close to industrial one were used.