PROCEDURE FOR PROCESSING SILVER CONTAINING LEAD WASTES AT EXTRACTION OF SILVER AND LEAD AS PRODUCTS Russian patent published in 2010 - IPC C22B11/00 C22B13/00 C22B7/00 C22B3/10 

FIELD: metallurgy.

SUBSTANCE: invention refers to procedures for extracting valuable metals from wastes including wastes of refining production. The procedure for processing silver containing lead wastes for extracting silver and lead in form of products consists in leaching wastes with solution containing hydrochloric acid to transit lead into solution and silver to sedimentation. Also leaching is carried out in three stages. At the first stage leaching is peformed with solution of lead chloride (PbCl₂) at temperature 0°-25°C in concentrated hydrochloric acid (HCl) by placing wastes in this solution heated to temperature 40°-80°C. Major part of lead transits into solution. During the second and the third stages non-dissolved wastes are leached in 30-42% HCl and successively filtered till pure powder-like silver is produced in a non-soluble residue. Upon the first stage solution is cooled to 0°-25°C, crystals of PbCl₂ are extracted out of it and combined with solutions of HCl after leaching at the first and the third stages; a new portion of wastes is directed to leaching. Implementation of this procedure at a lead plant of average output can collect yearly income of approximately 100 million dollars from sale of lead chloride.

EFFECT: raised efficiency of wastes processing, additional economic profit from implementation of this procedure at various metallurgical productions.

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