Beneficiation of titaniferous ores by selective separation of iron oxide, impurities and rare earth oxides for the production of high grade synthetic rutile

摘要

A new process for the production of synthetic rutile which includes high temperature alkali roasting process and the ensuing hydrometallurgical leaching steps has been developed. It was found that the various complex phases of Na-Ti-Fe-Al-REE formed during roasting reaction were responsible for the removal of impurities. Evidences for selective separation are presented based on the chemical (X-ray diffraction, X-ray fluorescence, atomic absorption) and microstructural analysis (SEM, EDX) of roasted mass and leached product. The paper highlights the various physical inorganic and thermodynamic aspects of reaction equilibrium in Fe-Ti-O-Na system, and the effect of Eh-pH diagram in determining the pH required for better removal of iron and sodium. The efficiency of selective separation is reported based on chemicals analysis of the materials derived after leaching.