Chalcopyrite in the context of "Camp Bird Mine"

Copper extraction is the multi-stage process of obtaining copper from its ores. The conversion of copper ores consists of a series of physical, chemical, and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations, and other factors. The copper smelters with the highest production capacity (metric tons of copper yearly) lie in China, Chile, India, Germany, Japan, Peru and Russia. China alone has over half of the world's production capacity and is also the world's largest consumer of refined copper.

Precious metals and sulfuric acid are often valuable by-products of copper refining. Arsenic is the main type of impurity found in copper concentrates to enter smelting facilities. There has been an increase in arsenic in copper concentrates over the years since shallow, low-arsenic copper deposits have been progressively depleted.

Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO₄. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5, and the specific gravity is 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO₄·2H₂O) by the absorption of water. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C (400 °F) under normal atmospheric conditions. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite, and pyrite in vein deposits.

Sphalerite is a sulfide mineral with the chemical formula (Zn, Fe)S. It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite, dolomite, quartz, rhodochrosite, and fluorite.

German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on the Greek word sphaleros, meaning "deceiving", due to the difficulty of identifying the mineral.

11°01′00″S 76°26′00″W / 11.01667°S 76.43333°W / -11.01667; -76.43333

The Huarón Mining District is one of the richest polymetallic (Zn-Pb-Ag-Cu-(Au)) deposit clusters in Peru. It is located 20 km SSW of Cerro de Pasco, in the Huayllay District, Pasco Province, Pasco Department, between 4500 and 4700 m.a.s.l. The Huarón Mining District belongs to the Miocene polymetallic belt of the Central Andes. Hydrothermal mineralization occurs as predominantly in N-S to NNW-SSW and E-W veins as well as in "mantos" replacing favorable sedimentary rock. Epithermal hydrothermal fluids are thought to be derived from quartz-monzonitic intrusions tentatively dated at 7.4 Ma (K-Ar on adularia). The most important economic minerals are tennantite‐tetrahedrite (containing most of the silver), sphalerite, galena, and chalcopyrite. Silver is also found in pyrargyrite, proustite, polybasite, and pearceite. In the central copper core of the Huarón deposit, enargite occurs. Main gangue minerals are pyrite, quartz, rhodochrosite, and calcite.

The Stillwater igneous complex is a large layered mafic intrusion (LMI) located in southern Montana in Stillwater, Sweet Grass and Park Counties. The complex is exposed across 30 miles (48 km) of the north flank of the Beartooth Mountain Range. The complex has extensive reserves of chromium ore and has a history of being mined for chromium. More recent mining activity has produced palladium and other platinum group elements.

Sedimentary exhalative deposits (SEDEX or SedEx deposits) are zinc-lead deposits originally interpreted to have been formed by discharge of metal-bearing basinal fluids onto the seafloor resulting in the precipitation of mainly stratiform ore, often with thin laminations of sulfide minerals. SEDEX deposits are hosted largely by clastic rocks deposited in intracontinental rifts or failed rift basins and passive continental margins. Since these ore deposits frequently form massive sulfide lenses, they are also named sediment-hosted massive sulfide deposits, as opposed to volcanic-hosted massive sulfide (VHMS) deposits. The sedimentary appearance of the thin laminations led to early interpretations that the deposits formed exclusively or mainly by exhalative processes onto the seafloor, hence the term SEDEX. However, recent study of numerous deposits indicates that shallow subsurface replacement is also an important process, in several deposits the predominant one, with only local if any exhalations onto the seafloor. For this reason, some authors prefer the term clastic-dominated zinc-lead deposits. As used today, therefore, the term SEDEX is not to be taken to mean that hydrothermal fluids actually vented into the overlying water column, although this may have occurred in some cases.

Main ore minerals in SEDEX deposits are fine-grained sphalerite and galena, chalcopyrite is significant in some deposits; silver-bearing sulfosalts are frequent minor constituents; pyrite is always present and can be a minor component or the dominant sulfide, as it is the case in massive sulfide bodies; barite content is common to absent, locally economic.