Raman investigation of chalcopyrite oxidation

Applications of in situ synchrotron XRD in hydrometallurgy: Literature review and investigation of chalcopyrite dissolution

“…By means of ex situ techniques, many authors have detected elemental sulfur on chalcopyrite after oxidation in both ferric sulfate and ferric chloride media under low-temperature conditions (b100°C) (Ammou-Chokroum et al, 1979;Biegler and Swift, 1979;Carneiro and Leão, 2007;Córdoba et al, 2008a;Dutrizac, 1989Dutrizac, , 1990Hirato et al, 1986Hirato et al, , 1987Jones and Peters, 1976;Klauber et al, 2001;Majima et al, 1985;Mikhlin et al, 2004;Muñoz et al, 1979;Parker et al, 2003Parker et al, , 2008Viramontes-Gamboa et al, 2007;Warren et al, 1982;Yin et al, 1995). Most of these authors claim that the formation of elemental sulfur is correlated to the observed hindered dissolution: that is, the product layer inhibits the reaction progress.…”

“…Many authors have assumed that metal-deficient sulfides (Cu 1−x Fe 1−y S 2−z ) are intermediate product phases of chalcopyrite dissolution in acidic, oxidizing media, at low temperatures (Abraitis et al, 2004;Ammou-Chokroum et al, 1979;Arce and González, 2002;Biegler and Horne, 1985;Biegler and Swift, 1979;Ghahremaninezhad et al, 2010;Jones and Peters, 1976;Lázaro and Nicol, 2003;Linge, 1976;Mikhlin et al, 2004;Nava and and González, 2006;Parker et al, 2008;Warren et al, 1982;Yin et al, 1995) and at high temperatures as well (Hackl et al, 1995). The formation of these non-stoichiometric phases (Eq.…”

“…Most of these authors claim that the formation of elemental sulfur is correlated to the observed hindered dissolution: that is, the product layer inhibits the reaction progress. The formation of elemental sulfur on chalcopyrite has been reported to occur at a broad potential range: from approximately 0.50 to 1.50 V vs. the Standard Hydrogen Electrode (SHE) (Ammou-Chokroum et al, 1979;Biegler and Swift, 1979;Córdoba et al, 2008b;Klauber et al, 2001;Majuste et al, 2012a;Parker et al, 2003Parker et al, , 2008Viramontes-Gamboa et al, 2007;Warren et al, 1982;Yin et al, 1995). At high temperatures (100 to 230°C), it has been assumed that the chalcopyrite dissolution rate declines with time due to the formation of molten sulfur, which wets and agglomerates the mineral particles (Hackl et al, 1995;King et al, 1993;McDonald and Muir, 2007a,b).…”

The preferential oxidation of orthorhombic sulfur during batch culture

“…Recent studies examining the microstructure of the solid sulfur phase that forms during bioleaching have focussed mostly on the dissolution of chalcopyrite (Klauber et al 2001, Parker et al 2003, Parker et al 2008, Rodriguez et al 2003. Klauber (2008) recently reviewed the surface chemistry of the oxidation of chalcopyrite and suggested the initial sulfur species formed are S-S dimers or short chain polymers followed by chain extension to form a polymeric allotrope which is finally transformed into the orthorhombic allotrope.…”

Arsenopyrite weathering under conditions of simulated calcareous soil

“…Likewise, the Raman peak located at 470 cm −1 indicates an important formation of polysulfides (S n 2− ) (Fig. 3b, Table 1), which denotes unambiguously the presence of metal-deficient layers in altered SM systems (Mycroft et al 1990;Parker et al 2008). Additionally, the Raman peaks relaxing from 1050 to 1055 cm −1 provide evidence to consider the presence of HCO 3 − species also adsorbed to α, γ-FeOOH Table 1) and the formation of a hematite (Fe 2 O 3 )-like compound arising at 1294 cm −1 (Fig.…”