Behavior of Gaseous Reduction of Molten Slag Containing Niobium Oxide

The behavior of gaseous reduction of molten slag containing niobium oxide was examined for the purpose of making ferro-niobium alloy of good quality. The molten slag containing niobium oxide was reduced in the crucibles made of high purity magnesia or pure iron with H2 gas, CO gas and H2-CO gas mixtures. The results are as follows; (1) Iron oxide and P2O5 in the slag were easily reduced with H2 gas while they were slightly reduced with CO gas at 1 450°C. (2) The slag elements except FeO, Fe2O3 and P2O5 were scarcely reduced with H2 or CO gas in the temperature range from 1 350 to 1 550°C. (3) The reduction of FeO with H2 gas was accelerated by the increase in MgO content in slag. (4) The relation between (%FeO) and (%P2O5) in reduced slags is expressed in the following equation: (%P2O5)=0.037(%FeO)+ 0.04