Recovery of dimethylglyoxime (DMG) from Ni-DMG complexes

Dimethylglyoxime (DMG) is an analytical reagent used to precipitate Ni from its aqueous solution. The process is very efficient for Ni recovery in terms of selectivity and completeness but hardly adopted industrially. The reason is attributed to the loss of the reagent when calcined. The paper outlines extraction of DMG from Ni-DMG complex by sulphuric acid treatment in two methods i.e. leaching and dissolution-recrystallization. In leaching the Ni-DMG is just treated with sulphuric acid and DMG is recovered. In the second case the Ni-DMG complex is completely dissolved in sulphuric acid and recrystallized through refrigeration.