Separation of Titanium Component from Treated Slag by Gravity Separation /Flotation

"In the blast furnace slag, titanium disseminated in various mineral phases Titanium could be concentrated mainly in perovskite, which could be selectively precipitated and grown by optimizing the operation factors like the slag composition, temperature of heat treatment and additive agents. This study aims at establishing the titanium slag mineralogy and its distribution in the treated slag and the as-received slag, as well as the methods of perovskite separation. After heat treatment, the grain size was grown from 5 - 20µm to 80 - 200µm, the distribution of Ti02 in perovskite was increased from 48% to 81 %, the morphology was changed from snow-shaped grain to coarsening dendrites or equiaxed crystals. A concentrate were produced by gravity separation analyzing 35.25% Ti02 with a recovery of 68.28% and a tailing analyzing 9.53% Ti02 , and a possibility of flotation upgrading was discussed. I INTRODUCTION CHINA is rich in mineral resources of titanium, 92.4% of which is vanadium-titanium bearing magnetite. About 53% titanium were in iron concentrate after mineral processing, by which the blast furnace slag containing about 25% TiO2 were produced[11 • The content of TiO2 in such slag is too low to separate titanium dioxide, and it is also too high to produce slag cement[21. It has been accumulated to 50 million tons so far, which is still increasing at a rate of 3 million tons per year, and results in a waste of titanium resources and pollution of environment. Due to the dispersed distribution of titanium component in various mineral phases, very fine grain(<10µm) and complex interfacial combination, it is very difficult to recovery titanium component from the slag by traditional separating technique. In this paper, a novel technique to recovery titanium from the waste slags was proposed [3H4l, on which three continuous processes were involved: selective concentrating, selective growing and selective separating. Perovskite was designed as a titanium-rich phase, in which the most titanium was concentrated promptly, then perovskite could be selectively grown and coarsened by optimizing the heat treatment and the appropriate additives [ 5l[6l. The grain size of perovskite phase was larger than 80 µm, and the crystals appeared as coarsening dendrites or equiaxial grains like lump."