Copper ore is a mineral form in which copper element is mainly in the form of compound and a few in the form of simple substance.There are more than 200 kinds of copper ores in nature, and common copper ores can be divided into three types: natural copper, sulfide ore and oxide ore.The gangue of copper ore is mainlyquartz, followed bycalcite、feldspar、mica、Chlorite、Bariteetc.[1]。
Copper mainly exists in the crust in the form of compounds. There are more than 200 kinds of copper bearing minerals in nature. Common copper minerals can be divided intoNative copper, sulfide ore and oxidized ore.Natural copper is rare in nature, mainly sulfide ore and oxide ore.Sulphide ores are widely distributed and are the main raw materials for copper smelting.The distribution of copper sulfide ores is chalcopyrite, bornite and chalcocite in turn.
Malachite is the most widely distributed oxidized ore of copper.In copper sulfide ores, in addition to copper sulfide minerals, there are pyrite, sphalerite, galena, pentlandite, etc.Common others in oxidized copper oresMetallic mineralsThere are limonite, hematite, siderite, etc.Gangues in copper ores are mainly quartz, followed by calcite, feldspar, mica, chlorite, barite, etc.Gangue is mainly composed of SiOtwo、CaO、MgO、AltwoOthreeEtc.Copper ore also contains a small amount of arsenic, antimony, bismuth, cobalt, selenium, tellurium, gold, silver, etc[1]。
Native copper
Announce
edit
Native copper
The main component of native copper is Cu, and the native copper sometimes contains silver and gold.The crystal structure of copper belongs to equiaxed crystal system, and the crystal is cubic, but rare;It is generally in the form of dendritic, flaky or dense massive aggregates.Copper red, the surface is easy to be oxidized to brown black.The streaks are bright copper red.Metallic luster。It has a hardness of 2.5~3, strong ductility, serrated fracture, and is a good conductor of electricity and heat, with a specific gravity of 8.5~8.9.Natural copper is commonly found in the oxidation zone of copper bearing sulfide deposits, which is generally the product of copper sulfide transforming into oxide[2]。
The primary native copper of hydrothermal origin is often disseminated in some hydrothermal deposits, and also occurs in copper bearing sandstone.Natural copper is scarce in nature, mainly distributed on the south bank of Lake Superior in Michigan (420 tons of natural copper was found here in 1857), Tulinsk in Russia and Montecatini in Italy.Natural copper also exists in the oxidation zone of copper deposits in Hubei, Yunnan, Gansu and the middle and lower reaches of the Yangtze River in China[3]。
Composition of chalcopyrite CuFeStwo, containing 34.56% Cu.The most common is the tetragonal variant.The crystal is tetragonal bipyramid or tetragonal tetrahedron, but it is rare;It is often in granular or dense massive aggregate.Brass, the surface is often golden yellow or red purple due to oxidation;Stripes green and black.Hardness 3~4;Specific gravity 4.1~4.3.Mainly produced inCopper nickel sulfide deposit, porphyry copper deposits, contact metasomatic copper deposits and layered copper deposits of some sedimentary origin (including volcanic sedimentary origin).Under weathering, chalcopyrite is transformed into water soluble copper sulfate, which forms malachite and azurite when it reacts with solution containing carbonic acid;It can form secondary bornite, chalcocite and copper blue by interaction with primary copper sulfide minerals, forming secondary enrichment of copper.Chalcopyrite is one of the main mineral raw materials for copper smelting[2]。
Chalcopyrite mainly exists in Rio Tinto, Spain, Cramazu, Arizona, Bingham, Utah, Biute, Montana, Cananeas, Mexico, Chuki Camata, Chile, etc.In China, chalcopyrite also exists in the middle and lower reaches of the Yangtze River, Sichuan and Yunnan, Zhongtiaoshan in southern Shanxi, Hexi Corridor in Gansu and Tibet Plateau.Among them, Dexing Copper Mine in Jiangxi and Yulong Copper Mine in Tibet are the most famous[3]。
Bornite
Chemical composition CufiveFeSfour, a sulfide mineral.Because bornite often contains micro inclusions of chalcopyrite and chalcocite, its composition varies greatly.Porphyrite is an equiaxed system.Single crystals are extremely rare, usually in the form of dense massive or granular irregular aggregates.The fresh section is bronze red, and the surface is often blue purple mottled, hence the name;Stripes are grayish black.haveMetallic luster, opaque, no cleavage;Hardness 3, specific gravity 4.9~5[2]。
Porphyry copper deposits can be formed in Cu Ni sulfide depositsSkarn depositAnd the secondary sulfide enrichment zone of copper sulfide deposits.The bornite is easily decomposed in the oxidation environment to form minerals such as malachite, azurite, hematite, limonite, etc.The bornite mainly exists in Biute, Montana, the United States, Canaea, Mexico and Chuki Camata, Chile.Copper deposits such as Dongchuan in Yunnan Province, China exist in the form of bornite[3]。
Chalcocite
Chemical composition of chalcocite CutwoS，It contains 79.86% Cu and belongs to orthorhombic system.Crystals are rare, usually in the form of soot, granules or dense blocks.Lead gray;Stripes are dark gray.It has metallic luster.Hardness 2~3, specific gravity 5.5~5.8[2]。
Chalcocite can be of endogenic hydrothermal origin or exogenic origin, and is one of the main mineral raw materials for copper smelting.It is mainly distributed in Bristol, Connecticut, Byatt, Montana, Arizona, Bingham Canyon, Utah, Duck City and Tennessee in the United States;Cornwall in England, Chumeb in Namibia, Rio Tinto in Tuscany and Spain in Italy, Ely in Nevada, Moreci, Miami and Clifton in Arizona in the United States, and Biote in Montana.In China, Dongchuan copper mine in Yunnan mainly exists in the form of chalcocite[3]。
The chemical formula of azurite is Cu (OH)two(COthree)twoThe composition is quite stable.It belongs to monoclinic system.The crystals are usually short columnar, columnar or thick plate, and the aggregates are dense block, crystal cluster, radial, earthy or shell, film, etc.Dark blue, earthy block is light blue;Light blue streak;The crystal is glassy and the earthy block is earthy;Transparent to translucent.Complete or moderate cleavage;Conchoidal fracture；Hardness 3.5~4, specific gravity 3.7~3.9, brittle[4]。
It is a secondary mineral occurring in the oxidation zone of copper deposit, gossan and cracks near the ore wall rock. It is often associated with malachite. Its formation is generally later than malachite, but sometimes it is also replaced by malachite.It is mainly distributed in Zambia, Australia, Namibia, Russia, Zaire, the United States and other regions.In China, there are blueprints in Yangchun, Guangdong, Daye, Hubei and northwest Jiangxi[3]。
Cuprite
Cuprite
The chemical formula of hematite is CutwoO，Containing 88.8% Cu.It belongs to equiaxed crystal system.The crystal is in fine octahedral shape, sometimes in needle or hair shape, which is called goethite;The aggregate is granular, dense massive or earthy.Dark red, streaked maroon, withAdamantine lusterOr semi metallic luster.Hardness 3.5~4, specific gravity 6[2]。
Formed under exogenous conditions, hematite is mainly found in the oxidation zone of copper deposits and is the product of oxidation of copper bearing sulfide.It can be used as copper ore in case of massive accumulation.It is mainly distributed in France, Chile, Bolivia, South Australia, the United States and other regions.In China, copper oxide exists in Dongchuan copper mine in Yunnan and copper mine areas in Jiangxi, Gansu and other regions[3]。
Malachite
Malachite
Chemical composition of malachite Cutwo(OH)twoCOthree。It belongs to monoclinic system.The crystals are often columnar.The aggregate is in crystal cluster, kidney, grape, shell, filling vein, powder, soil, etc.There are concentric layers inside the kidney shaped assembly, which are composed of green to white bands of different depths, similar to the patterns on peacock feathers, so it is named.Earthy malachite is called copper green (or stone green), which is generally green, but its tone changes greatly, from dark green, bright green to white;Light green streaks;Glass toAdamantine lusterThe fibrous ones have silk luster.Complete cleavage;Hardness 3.5~4, specific gravity 4.0~4.5[4]。
Malachite can be used to smelt copper when it is produced in large quantities. Malachite with pure quality and beautiful shape can be used as decorations and works of art, and powder can be used as green pigment.Malachite can be used as a prospecting indicator for copper deposits.Malachite occurs in the oxidation zone of copper deposits and is often associated with azurite.It is mainly distributed in Zambia, Australia, Namibia, Russia, Zaire, the United States and other regions.In China, there are blueprints in Yangchun, Guangdong, Daye, Hubei and northwest Jiangxi[3]。
