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 mm and 100 mm. 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 mm with average density about 3.4 g·cm-3 were mainly anhydrite. Particles between 18 mm and 75 μm with average density greater than 3.5 g·cm-3 were mainly ilmenite. Particles below 18 mm with average density about 2.9 g·cm-3 mainly contained silicon sludge

and became viscous and difficult to separate in water.