Ferroniobium
Ferroniobium is an important iron niobium alloy, with a niobium content of 60-70%. It is the main source for niobium alloying of HSLA steel and covers more than 80% of the world wide niobium production. The niobium is mined from pyrochlore deposits and is subsequently transformed into the niobium pentoxide Nb2O5. This oxide is mixed with iron oxide and aluminium and is reduced in an aluminothermic reaction to niobium and iron. The ferroniobium can be purified by electron beam melting or used as it is. For alloying with steel the ferroniobium is added to molten steel before casting. The largest producers of ferroniobium are the same as for niobium and are located in Brazil and Canada.