World Distribution Of Niobium

Niobium is estimated to have an abundance of 20% in the Earth's crust, ranking 33rd among all elements. Some scientists believe that niobium is much more abundant throughout the Earth, but is mainly concentrated in the Earth's core due to its high density. Niobium does not occur in a pure state in nature, but combines with other elements to form minerals. These minerals generally also contain the element tantalum, i.e. columbite (Fe,Mn)(Nb,Ta)2O6) and coltan ((Fe,Mn)(Ta,Nb)2O6). Minerals containing niobium and tantalum are usually by-products in pegmatites and alkaline intrusive rocks. Other minerals are calcium, uranium and thorium as well as niobates of rare earth elements, such as pyrochlore ((Na,Ca)2Nb2O6(OH,F)) and black rare gold ore ((Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6).

This Brazil and Canada have the largest deposits of pyrochlore. Both countries discovered these deposits in the 1950s and are still the largest producers of niobium concentrates. The world's largest deposits are located in a zone of carbonate intrusive rocks in Arasha, Minas Gerais, Brazil, belonging to CBMM (Companhia Brasileira de Minerais e Metallurgia); the other deposit is located in Goiás and belongs to Anglo American Resources, also in carbonate intrusive rocks. These two mines account for 75% of the world's total production. The third largest mine is located near Saguenay, Quebec, Canada, and accounts for 7% of world production.