PROCESSING METHOD OF WASTE OF ELECTRONIC AND ELECTRICAL INDUSTRY Russian patent published in 2013 - IPC C22B7/00 C22B11/00 C22B25/06 C22B3/04 

FIELD: metallurgy.

SUBSTANCE: dilution of tin solder is performed with 5-20% solution of methanesulfonic acid with oxidiser additives at the temperature of 70-90°C during two hours. Then, plastic mass is removed, and flushed and supplied for further utilisation. After that, suspended and frameless parts, microcircuits are separated on a grid, cleaned from methanesulfonic acid solution, dried, crushed to the particle size of -0.5 mm, separated on a magnetic separator into two fractions and processed fraction by fraction by means of hydrometallurgical methods. Besides, magnetic fraction is processed by means of an iodine-iodide method, and non-magnetic fraction is processed by means of a nitrohydrochloric acid method. The rest suspension of metastannic acid in solution of methanesulfonic acid with gold and lead impurities are coagulated at boiling during 30-40 minutes and filtered. Filtered deposit is flushed with hot water, dried and annealed till gold-bearing stannic oxide with further removal of gold from it is obtained.

EFFECT: reduction of reagent consumptions, losses of gold together with stannum and lead, reduction of power consumption and losses of palladium and platinum.

6 cl, 1 ex