Copper Sulfides

Copper Sulfides

 

compounds of copper and sulfur, Cu2S and CuS. Cu2S (cuprous sulfide) occurs as the grayish black mineral chalcocite, or copper glance, which has a density of 5.5-5.8 g/cm3; three modifications of this mineral are known. Upon heating, Cu2S oxidizes to form CuO and SO2 (or CuSO4). It is practically insoluble in water, dilute acids, and ammonia solutions but soluble in aqueous solutions of FeSO4, cyanide, and CuCl2. It dissolves in hot HNO3 with the liberation of elemental sulfur.

CuS (cupric sulfide) forms the bluish black mineral covellite, or indigo copper, which has a density of 4.68 g/cm3. When heated to temperatures above 450°C, it decomposes into Cu2S and sulfur. CuS readily undergoes oxidation. Black CuS is precipitated from slightly acidic copper salt solutions by H2S.

The pyrometallurgical methods of copper extraction are based on the marked affinity of Cu for S.

References in periodicals archive ?
The overall thickness of the secondary chalcocite and primary copper sulfides, encountered during this phase of drilling, ranges from a thickness of 120 meters in hole CO-05-05 and down to a thickness of 34.
The shipboard party also discovered lenses of very hard material made of iron and copper sulfides buried in the loose hydrothermal sediments.
6 million mt/year minerals pier in Peru's northern Ancash region by 2016 to handle output from Votorantim Metais unit Milpo's $747 million Magistral copper project, Rio Alto Mining's $300 million La Arena copper sulfides expansion and Newmont's $4.
The newly discovered, polymetallic base and precious metal deposit is characterized by intrusives, oxidized brecciated cappings derived from copper sulfides, intense silicification and sericite alteration, a pyritic halo and peripheral skarn type mineralization.
All holes drilled to date have intersected iron and copper sulfides, which is very encouraging.
A large number of high-grade gold veins and abundant disseminated copper sulfides and massive sulfides led to the discovery of the associated intrusive deposits, mantos and shear zones.
This volcanic breccia contains disseminated copper sulfides and larger blocks (20 x 30 centimetres) of massive sulfides which assayed up to 17.
Mineralization has been derived through an epithermal (high sulfidation) event which has resulted in sugary quartz veins hosting pyrite, free gold, covellite and other copper sulfides.
Copper mineralization associated with oxidation after primary copper sulfides minerals were encountered in virtually all of the holes.