Executive Summary : | Objective: To study the microwave reduction of ilmenite at lower temperature to the process of metallization Summary: Rapid depletion of scarcely available high grade ilmenite coupled with increasing demand for suitable titanium feedstock for titanium dioxide pigment industries has necessitated upgradation of the abundantly available ilmenite to rutile or anatase grade TiO2. However, many of the existing industrial processes for the production of TiO2 from ilmenite are bogged with environmental issues related to the disposal of iron containing acidic effluents. In view of the stringent environmental guidelines and other socio economic issues related to effluent disposal, the future industrial processes for the production of TiO2 must be aimed at greener technologies with near zero pollution. At present, industries in India employ the Benelite process or its variant, the Wah Chang process both having serious environmental problems due to generation of large volumes of acidic effluents for which a cost effective way to treat is not available. During reduction of ilmenite in rotary kiln, 10-15% of TiO2 losses due to fines generation that leads to process is not economically feasible. Microwave assisted reduction process is more attractive for many mineral industries and the reaction can proceed more quickly and effectively at a lower bulk temperature, resulting in energy savings and shortening the processing time. Comparing with conventional reaction, microwave-induced reaction has the unique advantages as follows: interior heating, higher heating rates, selective heating, greater control of the heating process, no direct contact between the heating source and heated materials, and reduced equipment size and waste. Present proposal effort is required to study the microwave reduction of ilmenite at lower temperature to the process of metallization. Tests will be conducted to establish a correlation between degree of metallization, fines generation, size reduction, maintaining anatase phases that will be produced. In a nut shell it can be admitted that the process package envisaged is not a path breaking research but a sincere effort towards establishing a technology for anatase grade TiO2 production with less fines generation and maximising iron oxide separation. All these information and data clearly establish the merit of the metallization cum rusting process. CSIR – National Institute for Interdisciplinary Science and Technology (NIIST) has already carried out production of about 7 metric tonnes of metallised ilmenite using an existing electrically heated rotary kiln of 40kg/day capacity. CSIRNIIST has also experience in ilmenite processing technology for production of synthetic rutile and also experienced in carrying out pilot scale trails on producing metallized ilmenite and smelting in arc furnace for over a decade. This project will develop the scientific know-how and innovative microwave based reduction process using continuous kiln for reduction of ilmenite with different alkali additives for formation of anatase phase in metallized ilmenite. Aeration rusting of the metallized product shall be carried out for the selective removal of metallic iron and upgradation of the product theron with respect to anatase grade TiO2 content. The successful application of the knowledge and technology developed through this project will lead to the expansion of manufacturing and utilization of large quantity of low grade ilmenite from beach sands in India, and encourage businesses to invest on such as Anatase based TiO2 manufacturing techniques with environmental. |