Some of the more common niobium containing minerals includes columbite, coltan, pyrochlore, and euxenite. The isolation procedures of niobium are especially complicated as niobium occurs in most minerals which contain niobium also contain tantalum. These two elements have extremely similar chemical characteristics, and separating the two is difficult.
Niobium extraction begins with extracting the niobium from ores by fusing the ores with an alkali. The alkali/ore mixture is then treated with hydrofluoric acid. Once the treatment with the acid takes place, tantalum is separated from the acid solution through a liquid-liquid extraction process. During these processes, the tantalum salts that are formed are extracted into MIBK, a ketone. The niobium is left in the hydrofluoric solution. This acidic solution is subject to further extractions of MIBK to remove all of the tantalum that is in the mixture. Niobium is left in an organic solution. Niobium is then converted to its oxide form and reduced to its pure metal form using sodium or carbon.
