Copper matte

The washed slime is dried and melted to produce slag and metal. The slag is usually purified by selective reduction and smelted to produce antimonial lead. The metal is treated ia the molten state by selective oxidation for the removal of arsenic, antimony, and some of the lead. It is then transferred to a cupel furnace, where the oxidation is continued until only the silver—gold alloy (dorn) remains. The bismuth-rich cupel slags are cmshed, mixed with a small amount of sulfur, and reduced with carbon to a copper matte and impure bismuth metal the latter is transferred to the bismuth refining plant. 

Calcining, sintering or smelting of nickel copper matte or acid leaching or electrorefining of roasted matte Coal soots, coal tar, pitch and coal tar fumes Hardwood dusts... 

The conversion process for the copper matte removes iron, sulfur and other impurities from matte, thereby yielding liquid metallic copper of about 99% purity (blister copper). The slags which come out of converters contain from 2 to 15% copper and must go through treatment for copper recovery, usually by froth flotation of the copper from solidified and slowly cooled slag. 

Following smelting, the copper matte is fed into a converter. During this process the copper matte is poured into a horizontal cylindrical vessel (approximately 10 x 4 m) fitted with a row of... 

Copper conversion Copper matte, scrap copper, siliceous flux Sulfur dioxide, particulate matter containing arsenic, antimony, cadmium, lead, mercury, and zinc Acid plant blowdown slurry/sludge, slag containing iron sulfides, silica... 

Hybinette A process for extracting nickel from sulfide ores. The nickel ore that occurs in Canada is a mixture of the sulfides of nickel, copper, and iron. Several methods have been used to separate these metals. In the Hybinette process, the ore is first smelted in a blast furnace, yielding a nickel-copper matte (i.e., a mixture of their lower sulfides). This is roasted to remove sulfur and leached with dilute sulfuric acid to remove copper. The resulting crude nickel oxide is used as the anode of an electrochemical cell. The nickel deposits on the cathode, which is contained in a cloth bag. Precious metals collect in the anode slime. The process was invented by N. V Hybinette in 1904 and operated at the Kristiansand refinery, Norway, from 1910. 

Manhes A metallurgical process for removing sulfur from copper matte by blowing air through the molten material. Invented by P. Manhes in France in 1880. 

The melt copper (matte) is further processed in a converter, where the remaining sulfur and iron is removed by underbath injection of oxygen-enriched air. The resulting so-called blister copper has a copper content of 98%. 

Preparation. High purity nickel can be produced through electrolytic process or by the carbonyl process. In the latter case carbon monoxide reacts at 50°C with impure Ni (or nickel-copper matte) to give the volatile tetracarbonyl from which the metal (99.9-99.99% purity) is obtained by decomposition at 200-230°C through the reaction ... 

For the treatment of zinc blende roaster gases for use in the Contact Process, soe Robson, Trans. Canad. Inst. Min. and Met., 1927, 30, 950 and for the use of gases produced in the bessemerising of nickel-copper matte, see De Blois, ibid., p. 929. 

A very important alloy containing 25 per cent, of nickel and 75 per cent, of copper finds extensive application in the manufacture of currency both in Europe and in the New World. Reference has already been made to this in previous pages.1 Monel metal is an alloy of nickel and copper made by the Orford Copper Company by direct reduction of the nickel-copper matte obtained from the Sudbury ores (see p. 82). It is therefore termed a natural alloy. It contains from 60-72 per cent, of nickel, the remainder consisting mainly of copper with iron ranging from 0-5 to 6-5 per cent. The United States Government specification, issued in July 1910, for monel metal requires 8... 

The practical application of the pyritic smelting principle to suitable raw ores, and to practically all copper mattes. 

Several processes for the extraction of copper by electrometallurgical methods have been devised. The Marchese patent2 aimed at the decomposition of copper matte and deposition of the copper simultaneously in a sulphuric-acid electrolyte with a copper-matte anode and a copper cathode. In Siemens and Halske s patent3 the copper of the ore was oxidized to the cupric state by an acid solution of ferric sulphate, and the copper deposited electrolytically in a second vessel with a diaphragm separating the cathode and the anode. Neither process has been commercially successful. 

The Ziervogel process can be worked with argentiferous copper mattes free from lead, arsenic, antimony, and bismuth. By roasting the matte in an oxidizing atmosphere, the iron is converted into sulphate. About 700° C. this substance is decomposed, the copper being converted into sulphate. At 840° to 850° C. the copper salt is converted into cupric oxide,8 and silver sulphate simultaneously formed. At this point the roasting is stopped, the silver sulphate is extracted with hot water, and the silver precipitated by means of metallic copper. These mattes are now usually worked for copper, and the silver separated electrolytically. 

The application of ammonia pressure leaching as a method of refining nickel-cobalt matte has been studied (Bll, P3) and is considered an economically attractive process. Nickel-copper mattes with low cobalt content have been found to be readily leached with ammonia (P3). A high-nickel matte with a composition of 77% Ni, 0.1% Cu, 1.8% Co, 0.7% Fe, and 20% S is amenable to both acid and ammonia leach, but the sulfur deficiency can be made up more economically by circulation of ammonium sulfate solution within the process than by providing the sulfur through addition of sulfuric acid. 

A matte with a higher copper content is more commonly encountered in practice because of the natural association of copper and nickel in most of the sulfide ores. A nickel-copper matte with 54% Ni, 12.5% Cu, 0.5% Co, 6.8% Fe, and 22.4% S was leached in a series of laboratory experiments followed by a continuous pilot plant campaign of over three months (P3). The matte was ground to 99.5% —100 mesh without giving problems in the filtration of the residue. The flow sheet followed in this test together with analytical data from the process streams, are shown in Fig. 2. The extractions for nickel, cobalt, and copper were 98.5, 95, and 98.5% respectively. 

Fig. 2. Ammonia leach and preferential hydrogen reduction for a nickel-copper matte. Pearce et al. (P3).

Copper electrorefining plays a major role in the production and recycling of copper. In the production of copper, copper-bearing sulfide concentrates are first smelted to copper matte. The molten matte is oxidized to blister copper by a Peirce-Smith converter and the blister copper is fire refined and cast to copper anodes. Blister copper contains about 99% copper and impurities such as arsenic, bismuth, iron, nickel, lead, antimony, selenium, tellurium, and precious metals. It is cast into flat anodes, most often on a rotating horizontal wheel. The mold shape includes lugs by which the anodes are... 

World nickel metal production in 2002 was 678000 tons [39]. Hydrometallurgy has typically been applied to the treatment of nickel-copper mattes, anode nickel, and reduced laterite ore. The sulfide concentrates are usually oxidized by roasting and then smelted to copper-iron-nickel sulfide matte (75-80% Cu-Ni), which is refined or used directly to make M onel metal. Cathode nickel can be produced from a variety of electrolytes, including chloride, sulfate, or a mixed chloride-sulfate. The former two are acid systems used in leaching and electrowinning. Mixed chloride-sulfate electrolytes are used for electrorefining the nickel sulfide matte from the traditional matte-smelting operations. 

Derivation Varies with the type of ore. With sulfide ores, the steps may be (1) concentration (of low-grade ores) by flotation and leaching, (2) roasting, (3) formation of copper matte (40-50% Cu), (4) reduction of matte to blister copper (96-98%), (5) electrolytic refining to 99.9+% copper. 

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