METHOD OF DRESSING TIN-CONTAINING POLYMETALLIC STOCK Russian patent published in 1997 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: method may be used for producing high-quality tin concentrates from difficultly concentrated tin ores and under-grade tin stock: for example, products of dressing sulfide-cassiterite ores with high arsenic and sulfur content, sulfide and quartz tails of dressing and finishing plants. Proposed method enables, with retaining high level of extraction of tin and other valuable components (lead, bismuth, indium), elimination of possible formation in system of capture of sublimates of strongly toxic arsenic hydride, reduction in equipment cost, and improvement of operational safety. According to invention, in a method of dressing under-grade tin-containing stock, including preparation of slurry, chloride-sublimation burning, capture of sublimates, and their hydrometallurgical processing, capture of sublimates is effected with aqueous suspension of an alkali calcium compound. In neutral and alkaline media, formation of arsenic hydrogen is completely impossible. Slurry is brought out of capture system and leached with hydrochloric acid solution. Arsenic sulfide and elementary arsenic are separated with dust through filtration, and tin concentrate is precipitated from filtrate by calcium-containing suspension. EFFECT: enhanced efficiency of process and reduced cost. 1 dwg