METHOD OF PROCESSING OF SPENT CATALYTIC AGENTS CONTAINING METALS OF PLATINUM GROUP Russian patent published in 1999 - IPC

FIELD: metallurgy of noble metals, extraction of metals of platinum group from spent catalytic agents based on aluminum oxide and carrying platinum or palladium. SUBSTANCE: method of processing of spent catalytic agents containing platinum metals based on aluminum oxide consists in milling, in blending with hydroxide of alkaline metal, in caking, in water leaching of cake with transfer of sodium aluminate to solution, in filtration and acidic treatment of solid cake with winning of concentrate of platinum metals. In correspondence with invention milling is conducted to reduce mixture to size of - 3.0 mm, blending is performed with ratio of hydroxide of alkaline metal-catalytic agent (0.8-1.2): 1.0, caking is carried out at temperature of 400-700 C in the course of 1.0-2.0 h, water leaching is conducted in presence of alkaline reagent, acidic treatment at pH=1.5-2.0 is carried out with injection of inorganic reductant. Sodium or potassium hydroxide is used as hydroxide of alkaline metal. Sodium or potassium hydroxide with concentration 10.0-20.0 g/l is used as hydroxide of alkaline reagent. Compounds of copper (I), for example, copper oxide (I) with grain size -0.05 mm with proportion of metals of platinum group 0.2-0.5 from stoichiometry of reducing reaction is used as inorganic reductant. Solution after water leaching is directed for neutralization with winning of commodity compounds of aluminum. Water leaching is conducted with S:L=1:(3-5) in the course of 1.0-2.0 h, acidic treatment is carried out with S:L=1:(3-5) at temperature of 50-90 C and mixing. EFFECT: reduced losses of platinum metals, increased quality of end product-concentrate of platinum metals. 7 cl, 3 tbl