Abstract:The phosphorus behavior of Nb-bearing iron ore powder in Bayan Obo was studied through the experiment of hydrogen selective reduction-melting-separation-Nb-bearing iron smelting. Under the experimental conditions, niobium-bearing iron ore powder containing 0.100% phosphorus was reduced by hydrogen and then melted, the niobium enriched slag which contained 2.00% niobium was yielded and contained phosphorus less than 0.010%. Meanwhile the iron contained niobium of 0.008% and phosphorus of 0.230%. And niobium concentration in the niobium enriched slag was 3.5 times in the niobium-bearing iron ore powder. The experimental results indicated that Ca3P2O8 can also be reduced by hydrogen when iron oxides were reduced by hydrogen. So the aim that phosphorus and iron elements were separated from the niobium enriched slag had been achieved.