PROCEDURE FOR EXTRACTION OF MERCURY OUT OF MERCURY-SELENIUM FINAL TAILINGS Russian patent published in 2011 - IPC C22B43/00 C22B61/00 C22B7/00 C22B1/02 

FIELD: metallurgy.

SUBSTANCE: procedure for extraction of mercury out of mercury-selenium final tailings consists in introduction of mercury selenium final tailings into pulp of calcium hydroxide and in re-pulping produced mixture, in burning in tubular furnace and in withdrawing process gases of burning containing vapours of mercury into condenser, in condensing mercury out of process gases, in production of stupp and in removing mercury from stupp. Also, mixture re-pulping is performed at ratio of hydroxide of calcium and selenium in final tailings Ca(OH)₂:Se final tailings=(3.0-3.5):1. First, there is burned re-pulped mixture producing process gases not containing elementary selenium, further there is burned stupp upon its removal. Burning is carried out in a rotating tubular furnace at excess of oxygen. Output of mercury comes to 99 %. There is produced mercury-less ash with maximal content of bound selenium suitable for successive extraction of selenium.

EFFECT: increased output of mercury facilitating further extraction of selenium due to elimination of mercury losses owing to complete selenium binding with excess of calcium hydroxide at oxidising burning.

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