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Machine translation
1. (WO1981002569) A METHOD OF PURIFYING WASTE AQUEOUS SOLUTIONS FROM HEAVY METALS
Latest bibliographic data on file with the International Bureau   

Pub. No.:    WO/1981/002569    International Application No.:    PCT/SE1981/000060
Publication Date: 17.09.1981 International Filing Date: 04.03.1981
IPC:
C02F 1/52 (2006.01), C02F 9/00 (2006.01), C22B 3/44 (2006.01)
Applicants:
Inventors:
Priority Data:
8001720 05.03.1980 SE
Title (EN) A METHOD OF PURIFYING WASTE AQUEOUS SOLUTIONS FROM HEAVY METALS
(FR) PROCEDE DE PURIFICATION DE SOLUTIONS DE RECUPERATION CONTENANT DES METAUX LOURDS
Abstract: front page image
(EN)A method for purifying acid waste solutions containing heavy metals, of which at least one of the elements arsenic, antimony, mercury and tin is present in considerable amounts, by chemical precipitation with sulphide ions. The sulphide ions are charged to the solution at at least two separate acidity ranges and adjustment between said acidity ranges is effected by adding a suitable base, whereafter the resultant precipitates are removed from the solution. The first sulphide ion charge made at a ph of at least lower than 3.4, preferably within the range 1.0-2.5. The second sulphide ion charge is made at a ph of at least higher than 4.0, preferably beneath 4.3, subsequent to regulating the ph with a suitable base.
(FR)Procede de purification de solutions de recuperation acides contenant des metaux lourds, l"un au moins des elements contenus, l"arsenic, l"antimoine, le mercure et l"etain etant presents en quantites considerables, par precipitation chimique d"ions sulfure. La solution est chargee en ions sulfure selon deux plages d"acidite separees et le reglage entre ces plages d"acidite est effectue par addition d"une base convenable, puis les precipites resultants sont separes de la solution. La premiere charge en ions sulfure est effectuee a un pH n"excedant pas 3,4, de preference dans la gamme 1,0-2,5. La seconde charge en ions sulfure est effectuee a un pH d"au moins 4 mais de preference inferieur a 4,3 apres ajustement du pH a l"aide d"une base appropriee.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)