China Nonferrous Metallurgy

Aiming at the problem of low calcium and high magnesium in titanium concentrate in Panxi area, this paper uses air supplement and no air supplement to pre-oxidize the titanium concentrate. The mineral composition and microstructure of the roasting products of titanium concentrate with different roasting temperature, roasting time and atmosphere were analyzed by MLA mineral analysis system, and the material characteristics were discussed on this basis. The results show that under the condition of no air supplement, the magnetite in the titanium concentrate is oxidized to hematite, which is dissolved with the unoxidizedilmenite to form titanium hematite, which has a solid solution separation structure. With the increase of roasting temperature, the proportion of intergrowth minerals of ilmenite increases, the proportion of monomer decreases, and the degree of dissociation becomes worse. Under the condition of adding air, the rutile formed by the first crystallization is in his shape, and the particle size is about 6μm. The iron-brookite formed by post-crystallization is self-shaped and semi-self-shaped, and the particle size is about 10μm. Iron brookite encapsulates mineral particles such as rutile, with granular embedded crystal structure, and its dissociation effect is poor. After the oxidation roasting of titanium concentrate, the grain boundaries and pores formed between the minerals improve the metallurgical kinetics and thermodynamic conditions. In contrast, the effect of supplementary air oxidation is better than that of non-supplementary air oxidation. The suitable oxidation roasting parameters are roasting temperature of 1200℃ and holding time of 80min.