Study On Separation Of Rutile Phase From Modified Titanium-bearing Slag

A lot of titanium-bearing blast furnace slag is discharged every year in China. A good deal of slag is dumped, which not only pollutes environment, but also wastes titanium resources. At present, the comprehensive utilization of titanium-bearing blast furnace slag has not yet been resolved, thus the enrichment of titanium in titanium-bearing slag is fully of theoretical significance and application value.Based on the process mineralogy characteristics of the Ti-bearing slag, a method of which was a combination of " increasing rutile content by high temperature modification-shaker sorting-hydrometallurgy" was proposed. The following content was studied in this paper:(1) Technological mineralogy of modified Ti-bearing blast furnace slag was studied. The result showed that the phase composition of the Ti-bearing blast furnace slag after modification was simpler than before modifcation. There were only phases in the modified slag, rutile and pyroxene. Rutile was the main Ti-bearing mineral phase.(2) Particle size distribution curve and grinding curve were obtained of different scale of modification experiment, absolute grindability monomer dissociation degree were calculated.(3)The best parameters of shaking table separation were:the stroke was 12mm, the vibration frequency was 360times/min. Single particle size experiment, choiceness experiment and scavenging experiment were done by shaking table separation which laid the foundation for the expansion experiment.(4) Modified slag of different scale of modification experiment was used in the shaking table separation process, the content of TiO2 in the concentrate were 40.51%,42.53%,45.36%,48.14% respectively when the particle size of the slag was 74-150μm. The content of TiO2 in the concentrate was 44.36%,46.52%,48.74%,52.35% respectively when the particle size of the slag was 48-74μm.(5)When it was in the shaking table separation 300kg modified slag, the content of TiO2 in the concentrate was 54.54% and 45.79%, the content of TiO2 in the tailings were 15.65% and 13.69%.It was necessary to improve the TiO2 content of concentrate and reduce the TiO2 content of the tailings.(6)Acid leaching process of the modified slag was also been studied. The impacts of concentration of leaching solution, temperature, reaction time, particle size, liquid-solid ratio and stirring speed were observed. The appropriate conditions were CHCI=25%, T=100℃, t= 5h, L/S=6:1,48-74μm titanium particle, and 400rpm of stirring speed(7) The results of kinetics showed that acid leaching reactions could be fitted by the "reducing unreacted nuclear"model. The leaching process was controlled by the chemical reaction, the apparent activated energy of this process was 47.73kJ/mol.(8)The TiO2 content of synthetic rutile is 93.75% which was abstained by combining of shaking table separation and hydrometallurgy, the recoveray rate in the leaching process is 90.27%.