China Nonferrous Metallurgy

The total iron （TFe） content of carbide slag is 2. 0%-3. 5%， when used in the low-temperature chlorination process to produce titanium dioxide， the iron in the slag reacts with chlorine gas to form ferric chloride， which blocks the low-temperature chlorination rinsing system and affects the stability and smooth operation of the system. Therefore， this paper conducted process mineralogy and iron removal experiments on carbide slag to provide a reference for the control of iron content in slag. Through the study of process mineralogy， it was found that carbide slag is mainly composed of silicate glass （85. 71%）， titanium carbide （11. 53%）， metallic iron （0. 87%）， and iron oxide （0. 53%）. Metallic iron is embedded in silicate glass in a spherical or ellipsoidal shape. Its particle size distribution is uneven， more than half distributed between 0. 08 mm and 0. 32 mm； TiC is mainly distributed in the silicate glass phase and coexists with metal iron and other substances. Its particle size is primarily below 0. 01 mm； The particle size of iron oxide is primarily below 0. 04 mm. Wet magnetic separation experiments were conducted to remove iron from carbide slag. The results showed that increasing the magnetic field intensity and grinding time was beneficial for the removal of TFe from the slag， but also resulted in a decrease in the recovery of TiC. When the magnetic field intensity reaches 3 000 Gs and the grinding time is more than 15 min， the TFe content in the tailings is reduced to less than 1. 50%， which meets the requirements for low temperature chlorination raw materials. In the actual production， different magnetic field intensities and grinding times can be selected according to the production needs to control the TFe content in the slag while minimizing the TiC loss.