Hydrogen peroxide leaching of hydrolyzed titania residue prepared from mechanically activated Panzhihua ilmenite leached by hydrochloric acid

摘要

The hydrolyzed titania residue with mainly precipitated hydrated TiO_2 is prepared from mechanically activated Panzhihua ilmenite leached by hydrochloric acid. We use H_2O_2 as a coordination agent to leach Ti from the hydrolyzed titania residue. The effects of H_2O_2 to-hydrolyzed titania residue mass ratio, leaching pH value, leaching temperature, leaching time, and H_2O_2 concentration on leaching of hydrolyzed titania residue by H_2O_2 are investigated. The recovery of Ti is above 98% under the optimal conditions. XRD shows that the peroxo-titania powder prepared by boiling the aqueous titanium peroxide solution is crystalline anatase phase. A well-crystallized anatase TiO_2 and rutile TiO_2 can be obtained through calcining at the temperature of 800 and 1000 °C, respectively. EDS shows that the impurities including silicon are enriched in the leaching slag. Little Si is detected as the only impurity in the synthetic TiO_2 due to the weak alkaline condition of leaching.