Impact of silver sulphide on gold cyanidation with conductive sulphide minerals. (4th May 2017)

• Record Type: Journal Article
• Authors: Khalid, Muhammad; Larachi, Faïçal; Adnot, Alain
• Is Part Of: Canadian journal of chemical engineering. Volume 95:Number 10(2017)
• Page Start: 1875
• Page End: 1884
• Publication Date: 2017-05-04
• Subjects: silver sulphide -- gold cyanidation -- sulphide minerals -- passivation -- galvanic interactions; Chemical engineering -- Periodicals; Technology -- Periodicals; 660.05
• DOI: 10.1002/cjce.22870
• Languages: English
• ISSNs: 0008-4034

Abstract

Abstract : Gold is mostly found in metallic form, while silver exists in various mineral forms. Pyrite, chalcopyrite, sphalerite, and stibnite were the sulphidic minerals investigated for the effect of silver sulphide on gold cyanidation. Four sets of mineral systems, pyrite‐silica, chalcopyrite‐silica, sphalerite‐silica, and stibnite‐silica, were established to investigate the effect of silver sulphide. Silver sulphide addition promoted gold dissolution for the pyrite‐silica and sphalerite‐silica systems. The gold dissolution was retarded with the chalcopyrite‐silica and stibnite‐silica systems, irrespective of the dispersion of gold and silver sulphide in the mineral as well as in the quartz layer. The surface characterization of the gold particles was attempted by using X‐ray photoelectron spectroscopy (XPS) in order to identify the surface obstructing species. XPS analysis showed that the passivation layers of silver sulphide (Ag2 S), Cu2 O/Cu(OH)2, and antimony oxide (Sb2 O5 ) might form on the surface of goldparticles by the simultaneous dissolution of silver sulphide as well as sulphide minerals, resulting in the retardation of gold dissolution.