Effects of reductants on iron reduction in the direct reduction process of high-phosphorus oolitic hematite

Direct reduction iron was prepared by adding dephosphorization agents during a direct reduction roasting-magnetic separation process,and the effects of reductants on the direct reduction process of high-phosphorus oolitic hematite were studied.Experimental results and SEM analysis show that the aggregation and growth of iron crystals,the increase of iron crystals' amount and the index of the reduced iron with a reductant can be influenced by the contents of fixed carbon and volatile in the reductants.When the reductant is coke or anthracite,iron crystals and gangue minerals are more closely combined in the roasting products,thus it is difficult to achieve monomeric liberation during the grinding process.When lignite is used as a reductant,the obvious connection and growth of iron crystals appear,coarser iron crystals form,and the boundary between iron crystals and gangue minerals is clear in the roasting products.Thus the liberation of iron crystals from gangue minerals is easier and the recovery of iron is higher than that obtained with other reductants.