METHOD OF RE-WORKING OF LEAD-CONTAINING INDUSTRIAL WASTES Russian patent published in 2007 - IPC C22B7/02 C22B13/02 

FIELD: non-ferrous metallurgy; re-working of lead-containing wastes.

SUBSTANCE: proposed method is used for re-working of lead-containing wastes including tin, antimony, copper, iron, zinc, bismuth, arsenic, silver, calcium, sodium, potassium, magnesium in form of oxides, chlorides, sulfites and sulfates. Size of wastes shall not exceed 0.07 mm. Wastes are mixed with potassium carbonate at weight ratio of 1 : (0.3-0.35) at subsequent addition of water to solid-to-liquid ratio of 1 : (2.5-3.0) at temperature not higher than 30°C. Solution of pulp thus obtained is filtered for separation of lead carbonate from potassium chloride and sulfate solution; then, potassium chloride and sulfate solution is directed for evaporation of water followed by crystallization. Mixture of potassium chloride and potassium sulfate salts is extracted as commercial product; released lead carbonate is subjected to molding for obtaining briquettes at mechanical strength no less than 60% and subsequent melting at temperature not above 1000°C, thus obtaining master alloy on base of lead and commercial quality product.

EFFECT: enhanced ecological efficiency; increased extraction of valuable components.

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