The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 24, 1981
Filed:
Dec. 29, 1978
Armand L Davister, Liege, BE;
Wilhem E Pavonet, Flemalle-Haute, BE;
Renaud F Quatpers, Stockay Saint Georges, BE;
Societe de Prayon, Prayon-Foret, BE;
Abstract
The present invention relates to a process for treating residues from a primary leaching of ferriferous zinc ores by sulphuric acid, with a view to recover a leadbearing by-product, such process comprising a secondary leaching of said residues, by sulphuric acid, within several countercurrent stages, at a temperature comprised between 85.degree. and 100.degree. C., the solid residues of the successive stages being circulated from the first to the last stage, the residue of this last stage being the said lead bearing by-product, whereas the various solutions separated from the second to the last stage are each recycled within the leaching operation of the respectively foregoing stage, and the dual zinc and iron sulphates solution, as separated from the first stage, being the principal product of the treatment. The primary leaching consists essentially of the chemical attack of the zinc oxide of the ore (naturally oxidized ore or roasted sulphur-based ore) by sulphuric acid and yields, as product, the zinc sulphate solution, which after purification, is used for the electrowinning of the zinc contained, whereas the solid residue from this primary leaching, when ferriferous ores are involved, is subject to the above said secondary leaching, in order to recover separately its zinc as sulphate solution, its iron as a precipitate and its lead as final residue of lead sulphate.