METHOD OF EXTRACTION OF SLUDGE CONTAINING METALS OF PLATINUM GROUP Russian patent published in 2004 - IPC

FIELD: chemical technology; extraction of sludge containing metals of platinum group. SUBSTANCE: proposed method uses catalysts on base of metals of platinum group and includes treatment of surfaces with aqueous solutions of chemicals or their mixtures: caustic soda, caustic potash, ammonium nitrate, tripolyphosphate, hydrochloric, sulfuric, phosphoric, oxalic, formic, acetic acids and amines at concentration of chemical compounds no more than 5% at temperature of 35-95^oC followed by extraction of sludge by machining the surface with cutting tools at specific pressure exerted on surface of 5•10³-2•10⁵ N/sq m. Treatment with aqueous solution of chemicals is performed after machining with cutting tools at rate not exceeding 0.015 m/s. EFFECT: increased degree of extraction of sludge; enhanced safety of process; reduced corrosion of surface. 3 cl, 2 tbl, 10 ex