Process for comprehensively recovering nickel, copper and iron from nickel sulfate purification slag

The invention relates to a process for comprehensively recovering nickel, copper and iron from nickel sulfate purification slag, copper, nickel and iron in the nickel sulfate purification slag are comprehensively recovered in the forms of copper sponge, nickel sulfide and iron phosphate, no wastewater is discharged in the whole production process, no valuable hazardous waste is generated, and comprehensive treatment work of the hazardous waste is facilitated. 本发明涉及一种从硫酸镍净化渣中综合回收镍、铜、铁的工艺，是将硫酸镍净化渣中的铜、镍、铁综合以海绵铜、硫化镍、磷酸铁的形式回收，在整个生产过程中无废水外排，也没有无价值的危险废物产生，有利于危险废物的综合治理工作。