公开(公告)号：EP2683840B1

公开(公告)日：2016-03-02

申请号：EP12731764.2

申请日：2012-03-08

申请人： Malusel, Viorel, Alexandru

发明人： POPA, Ioan, Florentin ,  GOLDSTEIN, Jack ,  OSANU, Liana, Rozica ,  MALUSEL, Viorel Alexandru

IPC分类号： C22B11/00

CPC分类号： C25C1/20 ,  C22B11/04

公开(公告)号：EP2683840A1

公开(公告)日：2014-01-15

申请号：EP12731764.2

申请日：2012-03-08

申请人： Malusel, Viorel Alexandru

发明人： POPA, Ioan, Florentin ,  GOLDSTEIN, Jack ,  OSANU, Liana, Rozica

IPC分类号： C22B11/00

CPC分类号： C25C1/20 ,  C22B11/04

摘要： The present invention relates to a process for chemical extraction of gold and silver from low grade and refractory pyritic concentrates containing minimum 1 ppm Au, by their leaching in enamelled cast iron reactors, steel plated lead or plastic coated steel, at room temperature, in ammoniac solutions (pH 8-10) of sodium thiosulfate (50-60 g/l Na
2 S
2 0
3 • 5 H
2 O) with a divalent copper salt as catalyst (3-4 g/l Cu).The suspension resulting after 2- 4 hours of reaction is filtered. The thiosulfate solution containing minimum 5 mg /l undergoes an electrolysis process with insoluble anodes. Copper, gold and silver is deposited in the cell as a sludge, and the electrolyte having a maximum content of Au of l mg/l, is recycled to the leaching operation of raw material, after correction of copper content and alkalinity to the baseline values. The copper, gold and silver deposit, separated as a sludge, is purified by leaching copper in a solution of 30-40% sulphuric acid at a solid: liquid ratio of 1:5 - 1:10, at a temperature of 85 - 90°C for 2-4 hours under air bubbling. The suspension is filtered. The copper leached as CuSO
4 •5H
2 O returns to the extraction process of gold and silver.