REDUCTION CARBURISATION OF COLUMBITE CONCENTRATE/

The carbothermic reduction of columbite has been investigated at 1400 degrees C utilising coal and graphite as alternative sources of carbon . Reduction to an iron-carbon matrix and NbC and TaC carbides occurs r eadily with complete reduction being achieved in 45 min with coal and 100 min with graphite. The reduction occurs by the intermediate format ion of iron-niobium-tantalum suboxides. Reduction with CO is slow comp ared to the reduction with carbon. Reduction of the ilmenite component of the columbite concentrate studied yields titanium oxy-carbide in a n iron-carbon matrix. The feasibility of utilising carbothermic reduct ion as a means of exploiting columbite is discussed.