METHOD OF EXTRACTING NICKEL FROM SPENT ACID SOLUTIONS OF CHEMICAL NICKEL PLATING Russian patent published in 2001 - IPC

FIELD: extraction of metallic nickel from spent acid hypophosphite solutions of chemical nickel plating. SUBSTANCE: finely dispersed nickel powder is added as catalyst to spent solution, and stepwise treatment is then carried out with dry sodium carbonate at temperatures from 55 to 65 C and pH of 6-7. Nickel is extracted in the form of finely dispersed power containing 99.5% of nickel. In this case no additional amount of hypophosphite is required, increased extraction of nickel is attained from solution at molar ratio of sodium hypophosphite to nickel ions of 1:1. EFFECT: more efficient extraction method. 1 ex