Selective Separation Of Rutile Phase In Modified High Titanium Slag

The high-titanium slag produced by low-grade ilmenite ore or vanadium-titanium magnetite concentrate through EAF reduction or direct reduction is low, which cannot be used as raw materials for titanium dioxide of direct chlor-ination or titanium sponge, so it needs enrichment, the modification technology for making the low-grade titanium slag to be rutile was statement by Northeastern University. The Ti components in furnace titanium slag achieved selective enrichment and growth through modification. After modification the phase of slag was simple, only including rutile phase and silicate glass phase (TiO2<5%).In this paper, modified high-titanium slag is used as raw material, the calculation of thermodynamic and kinetic analysis on alkali leaching combining acid system.were studied Through gravity separation and chemical leaching method, the third stage selective separation of rutile in modified titanium slag is completed. It is found that the alkali leaching process control steps is chemical reaction.In alkali leaching process, the experiment studies on the effects of concentration, temperature, reaction time, particle size, liquid ratio and stirring speed on TiO2content and the recovery rate. It comes to the appropriate conditions:CNaOH=15%, T=100℃, t=6h, L/S=20mL/g,-38μm titanium particle, stirring speed being500rpm. The leaching product is:TiO2content51.86%and TiO2recovery95.05%.It is obvious for the calculation of E that modified slag is suitable for gravity separation. The titanium-rich material with grade of55.66%can be obtained, when the particle size of the slag is between200and300mesh.Three ways were showed to get high-grade synthetic rutile:(1) twice gravity separation combining alkali leaching and acid washing method, TiO2content90.89%, recovery:60.03%;(2) three times gravity separation combining alkali leaching and acid washing, TiO2content93.16%, recovery:16.57%;(3) three times alkali leaching combining acid washing method, TiO2content91.42%, TiO2recovery:78.47%.