EP 0265736 A3 19900124 - PROCESS FOR LEACHING NOBLE METALS FROM ORES OR THEIR CONCENTRATES USING CYANIDIC SOLUTIONS WITH ADDITIONS OF HYDROGEN PEROXIDE
Title (en)
PROCESS FOR LEACHING NOBLE METALS FROM ORES OR THEIR CONCENTRATES USING CYANIDIC SOLUTIONS WITH ADDITIONS OF HYDROGEN PEROXIDE
Publication
Application
Priority
DE 3637082 A 19861031
Abstract (en)
[origin: EP0265736A2] Leaching of gold and/or silver from ores or ore concentrates in an aqueous alkaline cyanide solution with added hydrogen peroxide has so far not been used industrially, because it is uneconomical, i.e. the consumption of H2O2 and NaCN was unduly high. It has been found that the process can be made very economical and disadvantages of the conventional leaching technology can be avoided if the addition of the aqueous H2O2 solution is controlled via the concentration of the oxygen dissolved in the leaching solution, which contains 2 to 20 mg of O2 and preferably 7 to 13 mg of O2 per litre. Preferably, 0.5 to 5% by weight of H2O2 solutions are added under control. The process is applicable to agitation leaching and heap leaching, the H2O2 addition being controlled via measuring the O2 concentration in a measuring stream. At low consumption of H2O2 and NaCN, sometimes the gold yield is even increased and the leaching time is shortened.
IPC 1-7
IPC 8 full level
C22B 11/08 (2006.01)
CPC (source: EP US)
C22B 11/08 (2013.01 - EP US)
Citation (search report)
- [AD] US 3826723 A 19740730 - WOODS J, et al
- [A] US 4578163 A 19860325 - KUNTER RICHARD S [US], et al
- [AD] CANADIAN MINING JOURNAL, Band 88, August 1967, Seiten 55-60, National Business Publications Ltd, Gardenvale, CA; E.L. DAY: "Some factors influencing the rate of dissolution of gold in sodium cyanide solutions"
- [A] HYDROMETALLURGY, Band 16, Nr. 3, August 1986, Seiten 395-400, Elsevier Science Publishers B.V., Amsterdam, NL; R.M. GARCIA: "The recovery of silver from photographic film: a study of the leaching reaction with cyanide solution for industrial use"
Designated contracting state (EPC)
ES FR GB
DOCDB simple family (publication)
EP 0265736 A2 19880504; EP 0265736 A3 19900124; EP 0265736 B1 19920115; AR 240177 A1 19900228; AU 589818 B2 19891019; AU 8053387 A 19880505; BR 8705756 A 19880531; CA 1331518 C 19940823; DE 3637082 C1 19880519; DO P1987004572 A 19981205; ES 2027674 T3 19920616; MX 169904 B 19930730; NZ 222354 A 19890927; PH 24130 A 19900305; PT 86035 A 19871101; PT 86035 B 19900831; US 5275791 A 19940104; ZA 876329 B 19880329
DOCDB simple family (application)
EP 87114714 A 19871008; AR 30912487 A 19871027; AU 8053387 A 19871030; BR 8705756 A 19871028; CA 550705 A 19871030; DE 3637082 A 19861031; DO 1987004572 A 19871009; ES 87114714 T 19871008; MX 895987 A 19871023; NZ 22235487 A 19871029; PH 36007 A 19871030; PT 8603587 A 19871029; US 89906092 A 19920616; ZA 876329 A 19870825