China Nonferrous Metallurgy

The titanium middling ore in the separation product of vanadium titanomagnetite contains 28%-36% TiO2, and the titanium can be enriched from titanium middling ore by the coal-based direct reduction technology. In this paper, the effects of reduction temperature, reduction time, carbon/oxygen molar ratio, raw material particle size and other parameters on the content of TiO2 in non-magnetic products were investigated through coal-based direct reduction experiments. The effects of magnetic field intensity and particle size of non-magnetic products on the content and recovery of TiO2 in products were investigated by magnetic separation experiments. The conclusions drawn are as follows: the optimal process parameters for the coal-based direct reduction process are: binder addition of 3%, molding pressure of 15MPa, reduction temperature of 1350℃, reduction time of 45min, raw ore particle size of 180-200 mesh, carbon ratio nC/nO=1.1; the optimal process parameters of the magnetic separation process are the magnetic field strength of 160mT and the particle size of the reduction product of 180-200 mesh; under this process condition, a non-magnetic product with a TiO2 content of 58.64% and a yield of 63.94% can be obtained. X-ray diffraction was used to analyze the physical images of titanium middles, magnetic products and non-magnetic products. The results show that coal-based direct reduction technology can reduce iron elements in titanium middles into elemental iron, and separate magnetic products and non-magnetic products under the action of magnetic field, so as to realize the separation of titanium iron.