Leaching of a silver bearing sulphide by-product with cyanide, thiourea and chloride solutions

• Type: Article in International Scientific Journal
• Date: 1995

Authors

M. F. Almeida (Author) FEUP; Maria Manuela Amarante (Author) FEUP

Journal

Title: Minerals Engineering

Vol. 8 No. 3

Pages: 257-271

ISSN: 0892-6875

Publisher: Elsevier

Indexing

Scopus

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Technological sciences > Engineering > Geological engineering

Other information

Abstract (EN): The aim of this research was to increase the value of sulphide tailings assaying 1000-1500 g/ton Ag per tonne and high arsenic (about 13%) content. The sulphides were characterized and it was verified that silver occurs both as mathildite, AgBiS2, and in solid solution in galena. Three alternative routes were assessed: cyanidation, thiourea leaching and chloride leaching. The cyanidation route showed that there was a high consumption of cyanide and led to the formation of an insoluble compound of silver thiocyanate. The leaching with thiourea was achieved without the introduction of Fe 3+ but it is not an economically viable route. Chloride leaching of the product in its original particle grain size showed very good extraction even without addition of Fe 3+. Operating under [Cl-]>_.3 M at 80-90°C for at least 3 h it was possible to dissolve 60-80% of the total silver, and higher recoveries of lead and bismuth were also achieved.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15