Vanadium ores

VANADIUM ORES (EN: vanadium ores; DE: Vanadienerze; FR: minerais de vanadium; ES: minerales de vanadio; RU: ванадиевые руды) are the natural mineral formations, which are containing vanadium in such quantities, for which there is economically feasible the extraction of the vanadium. Vanadium is located within the ore as the impurity (0.1-4.9% of the V2O5 compound) within magnetite and its varieties, within ilmenite, rutile, or in the form of its own minerals: vanadinite (11-19% of the V2O5 compound), descloizite (16-23%), cuprodescloizite (17-22%), carnotite (16-21%), roscoelite (9-29%), tyuyamunite (19%), and others. The majority of the deposits, from the ores of which they extract vanadium, are complex; together with vanadium, they obtain from them iron, titanium, uranium, lead, zinc, copper, aluminium, and phosphorus.

The industrial deposits of the vanadium ores are divided into magmatic, contact-metasomatic, exogenous (sedimentary, and of the oxidation zone), and metamorphogenic. The magmatic deposits are spatially and genetically associated with the regions of the distribution of the ultrabasic, basic, and alkaline rocks. The massifs of the vanadium-bearing rocks may be found on the ancient cratons, within the marginal parts of the pre-Cambrian shields, and within the folded regions. The ore bodies of the magmatic deposits represent by themselves the depositions of the interspersed or schlieren-interspersed ores, which are having the shape of the lenses, and also the vein, layer, and tubular shapes; there may be found the tabular separations of the massive magnetite. Among them, there are distinguished: the titanomagnetite, ilmenite-titanium-magnetite, and ilmenite-hematite ore bodies within the pyroxenites, hornblendites, olivinites, gabbros, norites, anorthosites, and gabbro-diabases; they are characterized by the low content of the V2O5 compound (0.1-1%), but by the very large reserves of vanadium. The most known deposits of this type: Gusevo-Gorskoe (USSR), Mapahs (Republic of South Africa), Tegavus (USA), Rodsend (Norway), Lac Tio (Canada), and Barrambi (Australia). Among the contact-metasomatic deposits, within the skarned rocks, there may be found the magnetite ores, which are containing up to 0.25% of the V2O5 compound. The examples of the deposits of this class are the Osokino-Aleksandrovskoe (USSR), and Algarrobo (Chile). There are distinguished among the vanadium ores of the exogenous deposits: the descloizite, cuprodescloizite, and vanadinite oxidation zones of the lead-zinc and copper ores (they contain 2-10% of the V2O5 compound); the carnotite, tyuyamunite, and roscoelite ores within the variegated sedimentary depositions (1-5% of the V2O5 compound); the vanadium-bearing phosphorites (0.1-1% of the V2O5 compound), the vanadium-bearing petroleum (up to 0.1% of the V2O5 compound), the patronite deposits within asphaltites (11% of the V2O5 compound); the titanomagnetite placers, prevalently of the coastal-marine type (approximately 0.3% of the V2O5 compound). The exogenous deposits of the vanadium ores are known within the USA (the Colorado plateau), Namibia (Berg Aukas), and Zambia (Kabwe). The metamorphogenic deposits of the vanadium ores are represented by the clayish formations of the argillic zone within the ancient crystalline schists (approximately 1% of the V2O5 compound), and by the ilmenite-magnetite formations within the gabbro-amphibolites (0.4-0.5% of the V2O5 compound). The large deposits of this type are known within the USA (Wilson Springs), and within Finland (Otanmäki, and Mustavaara). The most important, according to the reserves, and to the scale of the extraction, are the magmatic deposits with titanomagnetite; they are usually developed with the usage of the opencast method.

The major methods for the obtainment of vanadium are associated with the processing of the iron ore raw materials. Within the USSR, there is used the duplex-process (the blast-furnace smelting, and the converter), after which there remains the slag, which is containing 10-16% of the V2O5 compound. They roast the slag with the sodium salts, and leach this substance. There is isolated the technical vanadium oxide (the V2O5 compound), from which they obtain the ferrovanadium (the alloy of iron with 35% of vanadium). Abroad, they use the immediate leaching of vanadium from the ores, or from the ore concentrates, by the solutions of acids and alkalis. There is used also the roasting of the raw materials with the sodium salts, with the subsequent leaching by the water, and later, by the diluted sulfuric acid, with the deposition of the V2O5 compound from the solution; they obtain from this compound the alloys: korvan, solvan, nitrovan, and ferrovanadium, which are containing 35-86% of vanadium.

The total resources of vanadium (in terms of the V2O5 compound) are being determined at 56.2 million tonnes (1980); the reserves of vanadium within the industrial ores within the industrially developed capitalistic and developing countries amount to 8.7 million tonnes, of which approximately 92% are accounted for the Republic of South Africa. The production of vanadium abroad during the 1960-79 has increased by 3.3 times, and has reached 24 thousand tonnes, including (thousand tonnes) 12.7 within the Republic of South Africa, 4.3 within the USA, approximately 3.0 within Finland, 0.36 within Chile.

There holds the leading position among the producers of the V2O5 compound the "Highveld Steel and Vanadium Corp. Ltd." South African corporation, which accounts for approximately 40% of the issue of the vanadium produce by the industrially developed capitalistic and developing countries. During the 1965-80, the consumption of vanadium abroad has doubled, and has reached 37 thousand tonnes in terms of the V2O5 compound. There consume the major amount of vanadium the enterprises of the ferrous metallurgy. There grows with the especially high tempos the usage of this metal as the alloying element for the manufacturing of the high-strength low-alloy steels, which are used for the construction of pipelines, building structures, storage tanks, and similar products. There deals with the problems of the further expansion for the spheres of usage for vanadium the International Technical Committee for vanadium.

The difference between the regions for the production and consumption of vanadium has made this product the important article for the international commerce. At the expense of the import, there are satisfied approximately 2/3 of the needs of the capitalistic countries for this type of the industrial raw materials. The largest exporters are the Republic of South Africa and Finland. As the importers, there act practically all the industrially developed capitalistic countries. Under the influence of the growing demand for vanadium, and of the growth of the expenditures for the production, the prices for the vanadium raw materials and its products have the tendency toward the increase.

There are the promising sources for the extraction of vanadium the petroleum (up to 0.1% of the V2O5 compound); the oolitic limonites (the iron-phosphorous ores), which are characterized by the low contents of vanadium (0.07-0.2%), but by the large reserves; the carbonaceous-siliceous schists (0.2-1.5%), and bauxites (0.02-0.4%); the ashes of the coals, and of the petroleum shales (0.2%).