Nickel Ores

Nickel Ores 

mineral deposits containing nickel in quantities that make its extraction economically feasible. Industrial nickel ores are divided into cupronickel sulfide and silicate ores.

The cupronickel sulfide ores contain the following principal minerals: pentlandite, millerite, chalcopyrite, cubanite, pyrrhotine, magnetite, and frequently sperrylite. Deposits of these ores belong to magmatic formations, which are associated with crystalline shields and ancient platforms. They are located in the lower and outer portions of intrusions of norites, peridotites, gabbrodiabases, and other formations of basic magma. They form beds, lentils and veins of rich ores, as well as zones of less rich disseminated ores, which are characterized by varying ratios of pentlandite to copper sulfides and pyrrhotine. Disseminated, brecciated, and massive ores are widespread. The nickel content in sulfide ores ranges from 0.3 to 4.0 percent and more. The Cu:Ni ratio varies from 0.5 to 0.8 in low-copper ores and from 2 to 4 in high-copper ores. In addition to nickel and copper, considerable quantities of cobalt, as well as gold, platinum, palladium, rhodium, selenium, tellurium, and sulfur, are extracted from such ores. Deposits of cupronickel ores are found in the USSR in the region of Noril’sk and in Murmansk Oblast (the Pechengi region), as well as abroad (in Canada and South Africa).

Silicate nickel ores are friable and claylike formations of the crust of weathering of ultrabasites, containing nickel (usually not less than 1 percent). Ores associated with the crust of weathering of serpentinites of the areal type contain the nickel minerals kerolite, serpentine, goethite, and asbolane. These nickel ores are usually characterized by a moderate nickel content, but their reserves are significant. Crusts of weathering of the interstitial, contact-karst, and linear-areal types, which are formed under complex geological-tectonic and hydrogeological conditions, are associated with richer ores. The principal minerals in these ores are garnierite, nepouite, nickel kerolite, and ferrihalloysite. The silicate ores include varieties containing iron, magnesia, silica, and alumina, which are usually blended in fixed proportions for purposes of metallurgical processing.

Nickel ores are not susceptible to mechanical enrichment. The silicate nickel ores contain cobalt with the Co:Ni ratio of the order of 1:20–1:30. In some deposits, the silicate nickel ores are accompanied by iron-nickel ores with high proportions of iron (50–60 percent) and Ni (1.0–1.5 percent). Nickel deposits of the weathered type are known in the USSR in the middle and southern Urals and in the Ukraine.

Among the capitalist countries that are notable for the extent of nickel ore production are Canada and New Caledonia (1972 production, 232, 600 and 115, 300 tons, respectively). (For processing and use of nickel ores, see.)

REFERENCES

Otsenka mestorozhdenii pri poiskakh i razvedkakh. Fasc. 20: A. A. Glazkovskii, Nikel’. Moscow, 1963.
Smirnov, V. I. Geologiia poleznykh iskopaemykh, 2nd ed. Moscow, 1969.

A. A. GLAZKOVSKII