Nickel production from lateritic/sulfidic ores

Cobalt is produced as a coproduct of nickel or copper refining. Copper-cobalt sulfide concentrates can be processed by the RLE process. Mixed cobalt-nickel sulfides can be precipitated from ammoniacal leach solutions and as mixed nickel-cobalt hydroxide or carbonate from acid sulfate leach processes. From chloride leach solutions, cobalt can be separated by solvent extraction. Most cobalt production is associated with nickel production from sulfide and laterite ores. Pressure leaching, solvent extraction followed by the electrowinning of... 

Primary nickel is produced from both lateritic and sulfidic ores. Although currently the majority of nickel is produced from sulfidic ores, the production of nickel from lateritic ores is increasing and may overtake nickel production from sulfidic ores [1]. Lateritic ores are formed by prolonged weathering of ultramafic rocks. Typical mineralogical profile of nickel laterite ore bodies is as follows [2, 3] ... 

It has been mentioned in an earlier chapter that nickel deposits are basically of two types sulfidic and lateritic (oxide). The scenario of nickel extraction from nickel sulfide concentrates and nickeliferrous pyrrho tite (these two are the two products of physical beneficiation of nickel sulfide ores), and from limonitics and gamieritics (these are the common lateritic ores) has been presented in Figure 5.6. It can be seen that nickel is extracted from its various sources by pyro, pyro-hydro and hydroprocessing. The account given here pertains to the latter two processes applied to the various nickel sources. 

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. 

These topics are discussed in detail in monographs and reviews (NAS 1975, IPCS 1991, Barceloux 1999, Mastromatteo 1986, Sunderman 1984, 2001a). Nickel constitutes less than 0.008% of the Earth s crust. The world s nickel production is obtained primarily from sulfide ores (e.g., pentlandite and nickeliferous pyrrhotite) and, to lesser extent, from oxides ores (e.g., laterite). Nickel sulfide ores, usually mined underground, are crushed and ground, concentrated by physical methods, converted to nickel subsulfide matte, and roasted to nickel oxide. The nickel oxide may be refined electrolytically to yield nickel cathodes or refined by the Mond process, which involves reduction with hydrogen, reaction with carbon monoxide to yield nickel carbonyl, and thermal decomposition to deposit pure nickel. Nickel oxide ores, usually mined in open pits, are smelted to produce ferronickel for use in stainless steel. 

In Russia, nickel-laterite ores are mined in South Africa, cobalt is obtained as a significant by-product from platinum mines. 

Production The methods for the extraction and refining of nickel minerals depend on the mineralogical and geological characteristics of the ore. Nickel has mainly been extracted from sulfide and laterite ores. 

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