METHOD OF RECOVERING PRECIOUS METALS FROM OF SULFURIC ACID PRODUCTION ASH WASTE Russian patent published in 2008 - IPC C22B11/00 C22B3/06 C22B7/00 

FIELD: precious metal technologies.

SUBSTANCE: invention relates to recovery of precious metals from of sulfuric acid production ash waste obtained from sulfuric pyrite firing stage. Method contemplates mixing ashes with a reagent, irradiating resulting mixture by microwave field, and separating it into non-magnetic residue and magnetic fraction. The latter is treated with acid and/or oxidant solution. Precious metals are sorbed from solution and suspension obtained by a sorbent, which is further burned off to give concentrate of precious metals containing notably Pt, Pd, Rh, Au, and Ag. Above-mentioned reagent is selected from potassium hydroxide and mixtures thereof with sodium formate or sodium carbonate, or potassium nitrate, or with oxalic acid, mixtures of oxalic acid with sodium formate, zinc powder with tin dichloride, and sodium peroxide with sodium carbonate. Sorbent is selected from 1,1-bis(perhydro-1,3,5-dithiazinin-5-yl)ethane, 1-hydroxy-2-(perhydro-1,3,5-dithiazinin-5-yl)ethane, 2-(perhydro-1,3,5-dithiazinin-5-yl)acetic acid, and polydithiopropane.

EFFECT: increased degree of Pt, Pd, and Rh recovery from ash pyrites.

6 cl, 1 tbl