Process mineralogy analysis of waste residue from ilmenite by acid hydrolysis

Comprehensive process mineralogy analysis of waste residue from incomplete reaction of titanium concentrate and sulfuric acid in sulfate process of titanium dioxide industry was made with Mastersizer 2000, XRD, XRF, ICP-AES, SEM-EDS, specific gravity method and screening, to provide guidance to recycling ilmenite. The residue had wet surface with about 45%(mass) soluble substance, including 4.06%(mass)Ti ion which could be hydrolyzed easily. The insoluble particles with various appearances contained 17.14%(mass) TiO2, 10.78% (mass) Fe2O3, and 46.94%(mass) SiO2. Its particle size distribution was between 1 μm and 100 μm. Its density was 3.21 g·cm-3. From screening, there were different particle sizes and densities between ilmenite and other impurities. Particles above 120 μm with average density about 3.4 g·cm-3 were mainly anhydrite. Particles between 18 μm and 75 μm with average density greater than 3.5 g·cm-3 were mainly ilmenite. Particles below 18 μm with average density about 2.9 g·cm-3 mainly contained silicon sludge, and became viscous and difficult to separate in water. © All rights reserved.