3-STAGE COUNTERCURRENT EXTRACTION OF NICKEL FROM SPENT NICKEL-CATALYST

This paper presents the extraction of nickel using nitric acid from wa ste nickel catalyst used in hydrogenation of oils and fats. The compou nds of sulphur, phosphorus, nitrogen, etc., poisoning agents of cataly st and other acid insoluble fractions, are removed in order to utilize the waste catalyst. The extraction process has been optimized. It has been observed that countercurrent extraction up to three-stage with t hree normal acid and one hour duration are the best process conditions .