Mineral processing copper extraction

V. H. Aprahamian and D. G. Demopoulos, The Solution Chemistry and Solvent Extraction Behaviour of copper, iron, nickel, zinc, lead, tin, Ag, arsenic, antimony, bismuth, selenium and tellurium in Acid Chloride Solutions Reviewed from the Standpoint of PGM Refining, Mineral Processing and Extractive Metallurgy Review, Vol. 14, p. 143,1995. 

Iron [7439-89-6J, Fe, from the Latin ferrum, atomic number 26, is the fourth most abundant element in the earth s cmst, outranked only by aluminum, sihcon, and oxygen. It is the world s least expensive and most useful metal. Although gold, silver, copper, brass, and bron2e were in common use before iron, it was not until humans discovered how to extract iron from its ores that civilization developed rapidly (see Mineral processing and recovery). 

Duyvesteyn, W. P. C. Sabacky, B. J. Ammonia Leaching Process for Escondida Copper Concentrates (Reprinted from Extractive Metallurgy of Copper, Nickel, and Cobalt. Vol. 1, 1993). Trans. Inst. Min. Metall. Sect. C-Miner. Process. Extr. Metall. 1995, 104, C125-C140. 

Cuprex [Copper extraction] A process for extracting copper from sulfide ores, combining chloride leaching, electro-winning, and solvent extraction. Piloted by a consortium consisting of ICI, Nerco Minerals Company, and Tecnicas Reunidas. 

In most industrial processes, copper is produced from the ore chalcopyrite, a mixed copper-iron sulfide mineral, or from the carbonate ores azurite and malachite. The extraction process depends on the chemical compositions of the ore. The ore is crushed and copper is separated by flotation. It then is roasted at high temperatures to remove volatile impurities. In air, chalcopyrite is oxidized to iron(ll) oxide and copper(ll) oxide ... 

The first process ore undergoes is called classification or ore dressing. The purpose here is to separate the richer components of a mixture from the unuseful soils. Mineral processing may be used to produce a single stream, as is the case with taconite circuits, where iron extraction is the main activity. It may also create two streams, such as copper concentrate and gold concentrate, when both minerals are found in the same ore body. ... 

ACTIVOX A hydrometaUurgical process for extracting copper from sulfide ores, also suitable for nickel and gold. It involves fine grinding, low temperature, and low pressure. Developed in Australia by Western Minerals Technology, now Norilsk Process Technology. Piloted but not yet licensed. 

The abundance in the earth s crust of metals that are used in electronic products is shown in Table 7 [16]. Extracting metals contained in seawater is not economically feasible. The major supply of metals is extracted from mineral ore in the earth s continental crust. There is considerable variation in the cost of extracting the ore and processing it into elemental metals. As the readily available resources become depleted, the process of extracting metals from mineral ores is increasingly more difficult and expensive. For example, in 1900 in the U.S. the copper content in rich ore was more than 4% by weight. By 1950, the available ore contained less than 1 % copper and has continued to decline such that the yield is currently less than 0.5%. 

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). 

Nonferrous Metal Production. Nonferrous metal production, which includes the leaching of copper and uranium ores with sulfuric acid, accounts for about 6% of U.S. sulfur consumption and probably about the same in other developed countries. In the case of copper, sulfuric acid is used for the extraction of the metal from deposits, mine dumps, and wastes, in which the copper contents are too low to justify concentration by conventional flotation techniques or the recovery of copper from ores containing copper carbonate and siUcate minerals that caimot be readily treated by flotation (qv) processes. The sulfuric acid required for copper leaching is usually the by-product acid produced by copper smelters (see Metallurgy, extractive Minerals RECOVERY AND PROCESSING). 

Copper ore minerals maybe classified as primary, secondary, oxidized, and native copper. Primaryrninerals were concentrated in ore bodies by hydrothermal processes secondary minerals formed when copper sulfide deposits exposed at the surface were leached by weathering and groundwater, and the copper reprecipitated near the water table (see Metallurgy, extractive). The important copper minerals are Hsted in Table 1. Of the sulfide ores, bornite, chalcopyrite, and tetrahedrite—teimantite are primary minerals and coveUite, chalcocite, and digenite are more commonly secondary minerals. The oxide minerals, such as chrysocoUa, malachite, and azurite, were formed by oxidation of surface sulfides. Native copper is usually found in the oxidized zone. However, the principal native copper deposits in Michigan are considered primary (5). 

The present description pertaining to copper refers to solvent extraction of copper at the Bluebird Mine, Miami. When the plant became operational in the first quarter of 1968 it used L1X 64, but L1X 64N was introduced in to its operation from late 1968. The ore consists of the oxidized minerals, chrysocolla and lesser amounts of azurite and malachite. A heap leaching process is adopted for this copper resource. Heap-leached copper solution is subjected to solvent extraction operation, the extractant being a solution of 7-8% L1X 64N incorporated in kerosene diluent. The extraction process flowsheet is shown in Figure 5.20. The extraction equilibrium diagram portrayed in Figure 5.21 (A) shows the condi-... 

Dalton, R. F. Diaz, G. Price, R. Zunkel, A. D. The cuprex metal extraction process—recovering copper from sulfide ores. JOM-J. Miner. Met. Mater. Soc. 1991, 43, 51-56. 

One important application of electrolytic treatment is the removal of harmful anions, such as chloride and sulphide, from the mineralized archaeological artifacts. The negative polarization of the system repels the negatively charged species out of the cathode. The process is often accompanied by the formation of either gas or soluble species in the electrolyte. This kind of treatment was carried out to increase the rate of extraction of chlorides from iron (see Fig. 6.1) [295], copper [296], and aluminium [297] mineralized objects. 

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