Invisible gold; comparison of Au deposition on pyrite and arsenopyrite

Abstract

Other| December 01, 1998 Invisible gold; comparison of Au deposition on pyrite and arsenopyrite L. M. Maddox; L. M. Maddox Flinders University, Department of Chemistry, Adelaide, South Aust., Australia Search for other works by this author on: GSW Google Scholar G. Michael Bancroft; G. Michael Bancroft Search for other works by this author on: GSW Google Scholar M. J. Scaini; M. J. Scaini Search for other works by this author on: GSW Google Scholar J. W. Lorimer J. W. Lorimer Search for other works by this author on: GSW Google Scholar American Mineralogist (1998) 83 (11-12_Part_1): 1240–1245. https://doi.org/10.2138/am-1998-11-1212 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation L. M. Maddox, G. Michael Bancroft, M. J. Scaini, J. W. Lorimer; Invisible gold; comparison of Au deposition on pyrite and arsenopyrite. American Mineralogist 1998;; 83 (11-12_Part_1): 1240–1245. doi: https://doi.org/10.2138/am-1998-11-1212 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and open circuit potentials were used to compare the size, chemical state, and distribution of adsorbed and reduced gold from Au (super 3+) chloride solution on pyrite and arsenopyrite. Many small Au 0 particles grow on the arsenopyrite surface, whereas few, much larger, gold particles appear on pyrite. These results mimic the differences in distribution of gold in some coexisting natural pyrites and arsenopyrites. The rate-limiting step in deposition of gold from Au (super 3+) chloride solutions is the reduction of Au (super 3+) to Au (super -) , whereas the open-circuit potential for deposition is determined by the reduction of Au (super -) to Au 0 . The open-circuit potential of pyrite or arsenopyrite is a corrosion potential. Presence of Au (super 3+) shifts the corrosion potential to a value that depends on the relative rates of the reduction of Au (super 3+) and the oxidation of the mineral. Open-circuit potential measurements indicate that the rate of deposition of gold on pyrite is controlled almost entirely by the rate of reduction of Au (super 3-) . By contrast, the rate of reduction of gold on arsenopyrite is controlled significantly by the rate of oxidation of arsenopyrite. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.