Utilization of coal sludge as reductant in the direct reduction of titanomagnetite ore

Abstract

a gengchao1988@yeah.net Keywords: coal sludge; direct reduction; titanomagnetite; desulfurization Abstract: Coal-based direct reduction followed by magnetic separation was used to produce direct reduction iron powder (DRIP) from a titanomagnetite (TTM) ore. The residual solid wastes which are called coal sludge in this paper are still discarded as waste in large quantities. To explore the feasibility of using coal sludge as reductant, two types of coal sludge, namely, TJ and SX, with different dosages were investigated. Results showed that this process can realize coal-sludge utilization, and good DRIP products were obtained. The suitable dosage of coal sludge depended on the fixed carbon content of coal sludge. TJ and SX presented a similar result in reducing the TTM ore, i.e., TTM ore was reduced to iron, ilmenite, and ferrous pseudobrookite by both TJ and SX; improved Fe recovery in DRIP was further achieved by increasing the dosages of the two coal sludge, but the increased dosage was unfavorable to Fe grade and TiO 2 content. The sulfur contained in coal sludge occurred in the form of troilite in the reduced ore. Because troilite is a nonmagnetic material, it was removed into tailings after magnetic separation. Thus, the process presented a good ability of desulfurization.