LEAD ION REMOVAL METHOD (OPTIONS) Russian patent published in 2001 - IPC

FIELD: inorganic chemistry methods. SUBSTANCE: method involves bringing nickel chloride solution into contact with organic solvent having thiophosphinic acid structure and subsequent removal of lead ion. Method comprises following operations: (i) first stage: at least single contact of nickel chloride solution containing lead ion with aforesaid solvent to extract and remove lead ion; (ii) second stage: contacting spent organic solvent with acid solution having pH value below pH in extraction and lead ion removal stage and, more particularly, lying within the range 0.5 to 3.0 to return valuable metal extracted with lead ion back into nickel chloride solution; and (iii) distilling off lead ion contained in extract solution in the form of lead sulfate formed in presence of sulfuric acid to regenerate extractant solution. EFFECT: enhanced lead ion removal efficiency. 10 cl, 4 tbl, 4 ex