Production of niobium

Niobium metal can be produced by electrolysis of molten potassium niobium heptafluoride, or by reduction of potassium niobium heptafluoride with sodium metal or niobium pentoxide with aluminum metal. Pure niobium is used in electron tubes to remove residual gases, and niobium doping in steel can improve the oxidation resistance of steel at high temperatures and improve the welding properties of steel. Niobium is also used in the manufacture of high-temperature cermets.

The ore obtained from mining is subjected to a separation process that separates tantalum pentoxide (Ta2O5) and niobium pentoxide (Nb2O5) from the other minerals.

Jean-Charles Galisa de Marinha invented industrial-scale separation methods that take advantage of the differences in water solubility possessed by the fluoride complexes of niobium and tantalum. The new method then uses an organic solvent similar to cyclohexanone to extract the fluoride from an aqueous solution, and then water to extract the niobium and tantalum complexes separately from the organic solvent. The addition of potassium fluoride precipitates the niobium into the potassium fluoride complex, while the addition of ammonia precipitates niobium pentoxide.

There are several methods of reduction from the compounds to the metallic state. One is the electrolysis of a molten mixture of K2[NbOF5] and sodium chloride, and the other is the reduction of niobium fluoride with sodium. The niobium metal derived from this method has a high purity.

As of 2013, the Brazilian Metallurgical and Mining Company Ltd. controls 85% of the world's niobium production. The United States Geological Survey estimates that niobium production rose from 38,700 tons in 2005 to 44,500 tons in 2006. The global inventory of niobium resources is estimated at 4.4 million tons. Between 1995 and 2005, production more than doubled from 17,800 tons, and between 2009 and 2011, production remained steady at 63,000 tons per year.