Thermal oxidation of covellite (CuS)

Single Phase Formation of CuInS2 Nanoparticles: Structural, Morphological, Thermal Studies with Annealing Effect

“…Sample B-CIS1 exhibits two broad peaks at 130 cm -1 and 302 cm -1 whereas single peak is obtained in sample B-CIS3 at 285 cm -1 . An intense mode at ~302 cm -1 in sample B-CIS1 has been previously noticed for indium rich CuInS 2 samples [15,[16][17] and β-In 2 S 3 presents a strong peak close to 302 cm -1 with A 1 symmetry [18]. Raman peak is observed at 285 cm -1 corresponds to the symmetric A 1 mode (pure anion vibration) of the sulphur lattice and found to be dominating Raman mode in device-quality CuInS 2 material [19].…”

Thermal Oxidation Strategy towards Porous Metal Oxide Hollow Architectures

“…In general, the thermal oxidation of natural and precipitated CuS includes four steps: [20] a) formation of lower sulfur content sulfides (Cu 1.8 S and/or Cu 2 S) associated with oxidation of the evolved sulfur to SO 2 , b) oxidation of the existing sulfides either to oxides (Cu 2 O and CuO, the latter can be formed also by Cu 2 O oxidation), or two copper sulfates (Cu 2 SO 4 , CuSO 4 , the latter is formed either by direct oxidation of Cu 2 O, or by the reaction between liberated SO 2 and Cu 2 O), c) oxysulfate formation (CuSO 4 , and CuO Á CuSO 4 ) by reaction between CuO, Cu 2 O, oxygen, and liberated SO 2 , d) decomposition of oxysulfates with CuO formation.…”

Cathodic processes in the leaching and electrochemistry of covellite in mixed sulfate–chloride media

“…5 and is due to re-oxidation of a reduced copper sulfide, Cu 2-x S, formed at potentials below about 0.35 V in the presence of copper(II) ions. The reduced amount of this species in the presence of increasing concentration of chloride ions can be attributed to the fact that the concentration of copper(II) ions available for reaction (2) is reduced at the surface of the covellite due to reduction to copper(I) ions at the masstransport controlled rate. The potential required for reaction (2) is thereby reduced to more negative potentials.…”

“…Synthetic covellite is produced by precipitating cupric ion with gaseous H 2 S or sulfide ion [1]. The mineral covellite is generally associated with other copper sulfides such as chalcopyrite, bornite and chalcocite [2]. Covellite can be formed as an intermediate during the leaching of chalcocite, copper matte and other complex copper sulfide materials [3].…”