Preparation of Ti-rich material from titanium slag by activation roasting followed by acid leaching
(School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract: A method of activation roasting followed by acid leaching using titanium slag was introduced to prepare Ti-rich material. The effects of H3PO4 dosage, roasting temperature, and roasting time on TiO2 grade were investigated. A Ti-rich material containing 88.54% TiO2, 0.42% (CaO+MgO) was obtained when ?nely ground titanium slag was roasted with 7.5% H3PO4 at 1000 °C for 2 h, followed by a two-stage leaching in boiling dilute sulfuric acid for 2 h. The XRD patterns show that the product is titanium dioxide with a rutile structure. Mechanism studies show that structures of anosovite solid solution and silicate minerals are destroyed in the roasting process. As a result, titanium components in titanium slag are transformed into TiO2 (rutile) while impurities are transformed into acid-soluble phosphate and quartz.
Key words: titanium slag; activation roasting; acid leaching; Ti-rich material; rutile