Copper hydrometallurgical

Copper. The recovery of copper [7440-50-8] Cu, from ore leach Hquors as a stage in the hydrometallurgical route to the pure metal is one of the... 

D. H. Jennings, R. T. McAndrew, and E. S. Stratigakos, A Hydrometallurgical Methodfor Recovering Selenium and Tellurium from Copper Refinery Slimes, paper no. A 68-69, TMS, Warrendale, Pa., 1968. 

In the most common hydrometallurgical process, the ore is leached with ammonia or sulfuric acid to extract the copper. These processes can operate at atmospheric pressure or as pressure leach circuits. Copper is recovered from solution by electrowinning, a process similar to electrolytic refining. The process is most commonly used for leaching low-grade deposits in situ or as heaps. 

The copper product is known as blister copper because of the appearance of air bubbles in the solidified metal. In the hydrometallurgical process, soluble Cu2+ ions are formed by the action of sulfuric acid on the ores. Then the metal is obtained by reducing these ions in aqueous solution either electrolytically or chemically, by using an inexpensive reducing agent that has a more negative standard potential than that of copper, such as hydrogen or iron (see Section 14.3) ... 

Heap leaching of copper oxides and transition ores and acid/neutral leaching of zinc calcine are well-established processes to generate the feed solutions for the hydrometallurgical recovery of these metals.2... 

Anatread A hydrometallurgical process for extracting copper from a sulfide ore with ferric chloride solution. 

Most of the oxide copper deposits are located in the former Republic of Zaire (Katanga) and Zambia. Only a few deposits are located in Chile, Peru, Canada and the United States. From most of the south and North American deposits, oxide copper is recovered using a hydrometallurgical method. 

In the deposits where oxide cobalt is present, it is common to have oxide copper minerals. The cobalt is, therefore, recovered in a bulk copper-cobalt concentrate that is processed using a hydrometallurgical technique to produce separate copper and cobalt metals. Oxide... 

Hydrometallurgical methods can be applied when low-grade oxidized (oxide) or mixed (oxidized and sulphidic) ores are available. These methods have advantages of high selectivity disadvantages are the relative slowness of leaching and the large volume of solution per unit mass of copper. 

The first step in the hydrometallurgical treatment is leaching the feed material with an ammoniacal solution. Metals such as copper, nickel, and zinc form metal ammonium complexes and will therefore dissolve in the leach solution. Other metals like iron and chromium form insoluble hydroxides and will be found in the residue. This residue is dried and treated in the induction converter. Copper and nickel are separated from the filtered leach... 

Solubility data (pA sp) for two dozen hexacyanoferrate(II) and hexacyanoferrate(III) salts, and Pourbaix (pe/pH) diagrams for iron-cyanide-water, iron-sulfide-cyanide-(hydr)oxide, iron-arsenate-cyanide-(hydr)oxide, and iron-copper-cyanide-sulfide-(hydr)oxide, are given in a review ostensibly dedicated to hydrometallurgical extraction of gold and silver. " The electrochemistry of Prussian Blue and related complexes, in the form of thin films on electrodes, has been reviewed. ... 

Two other refining processes are also frequently employed. One involves hydrometallurgical refining in which sulfide concentrates are leached with ammonia solution to convert the copper, nickel, and cobalt sulfides into their complex amines. Copper is precipitated from this solution upon heating. Under such conditions, the sulfide-amine mixture of nickel and cobalt are oxidized to their sulfates. The sulfates then are reduced to metalhc nickel and cobalt by heating with hydrogen at elevated temperatures under pressure. The metals are obtained in their powder form. 

Japan, Canada, and the United States accounted for 70% of the 1995 estimated world production of 20001 (Table 5). At least 100 t of selenium was also available to Western markets from the former Soviet bloc. Selenium production is expected to rise in South America, particulady Chile, as the copper industry continues rapid expansion. A considerable amount of unrefined selenium is also shipped to Chile and the Philippines for conversion to final commercial product by either hydrometallurgical or distillation processes. 

Hydrometallurgical methods4,5 use reactions in aqueous solution (often involving metal complex formation) to concentrate and/or separate the metal ions of interest. A commercially important example is the heap leaching of low-grade copper ores with acid. 

Related hydrometallurgic methods may allow the use of bacteria to release copper from low-grade ores, or the use of algae to concentrate precious metals such as gold (see Chapter 19). ... 

About a third of the hydrogen manufactured is used in mining for the hydrometallurgical extraction of copper and other metals, the extraction of the metals from their ores by reduction in aqueous solution ... 

In the hydrometallurgical processes for extracting copper, soluble Cu2+ ions are formed by the action of sulfuric acid on the ores. Then the... 

Metals in Groups 11 and 12 are easily reduced from their compounds and have low reactivity as a result of poor shielding of the nuclear charge by the d-electrons. Copper is extracted from its ores either by pyrometallurgical or hydrometallurgical processes. 

The development of hydrometallurgical processes for the extraction of copper from ores and concentrates has been a widespread major research activity for the past 20 years. Coordination chemistry has been applied in many ingenious ways in attempts to devise novel and energy-efficient processes to replace the conventional smelting—electrorefining approach. Several of these processes... 

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