This study aims to demonstrate the selective removal of iron from acidic leach solutions using an effective purification method and to convert nickel into a usable form. The method of removing iron by using CaCO3, which is a better precipitation reagent, was optimized using Response Surface Methodology. A further evaluation was carried out on the complexation of Ni(II) ions with dimethylglyoxime to obtain a high-yield nickel-dimethylglyoxime complex from nickel remaining in the solution after iron precipitation. Taking into account nickel losses to remove iron, pH should be within the range of 3-4, and low temperatures around 25 degrees C should be used.