METHOD OF RECOVERING PLATINUM FROM EXHAUSTED CATALYSTS Russian patent published in 1998 - IPC

FIELD: precious metal recovery. SUBSTANCE: exhausted catalysts are treated at 95-103 C by mixture containing 4-7 mol/l hydrogen chloride, 1-4 mol/l hydrogen peroxide, and 0.5-3.0 mol/l dimethylformamide and reduction of platinum is performed by products of hydrolytic cleavage of dimethylformamide at pH 3-4 and temperature 90-105 C. Solution with washed out base is used in reducing platinum, after which dimethylformamide is regenerated and solution subjected to dimethylformamide regeneration is reused in catalyst treatment process. EFFECT: increased economical efficiency due to using solvent (dimethylformamide) proper to be regenerated.