Research On The Process Of Titanium Leaching And Extracting From Titanium-Bearing Blast Furnace Slag

This paper takes the titanium-bearing blast furnace slag from Pangang and Chenggang as raw material, leaching Ti out with ammonium sulfate method, preparing TiO2with titanium liquid hydrolysis method and recycling the flux with evaporation crystallization method. This paper discusses the related factors impacting the leaching rate of Ti and preparation of TiO2, and finally determines optimum parameters in this process. This research develops a green way for comprehensive utilization of titanium-bearing blast furnace slag, which is our unique resource, and lays a foundation for further researches.(1) Leaching Ti out with ammonium sulfate methodThe optimum parameters of leaching Ti out from titanium-bearing blast furnace slag from Pangang are:when the mass ratio of slag to fluxing anents and (NH4)2SO4is3:2:24, holding for60min at450℃, the leaching rate of Ti from the slag is78.14%. The leaching rate of Ti can increase to82.87%with adding a little of HCl in the leaching process.The optimum parameters of leaching Ti out from titanium-bearing blast furnace slag from Chenggang are:when the mass ratio of slag to fluxing anents and (NH4)2SO4is3:2:24, holding for60min at350℃, the leaching rate of Ti from the slag is83.66%. The leaching rate of Ti can increase to89.85%with adding a little of HCl in the leaching process.The changes in phase compositions of the titanium-bearing blast furnace slag after water quenching, may affect the reaction between (NH4)2SO4and slag, which can increase the leaching rate of Ti. Therefore, water quenching treatment has done on the titanium-bearing blast slag and the phase compositions change greatly, but the leaching rate of Ti doesn’t increase.The residue after leaching includes CaSO4, SiO2, and the Ti content is very low. The residue can be used as cement additives.(2) Preparing TiO2with titanium liquid hydrolysis methodThe optimum parameters of preparing TiO2with titanium liquid hydrolysis method from Panggang slag are:when the molar ratio of EDTA to Fe is3:1, CA to Si is2:1, pH is1.3, and holding for60min at80℃, the TiO2content in the production TiO(OH)2(roasted at650℃for60min) is98.54%. The optimum parameters of preparing TiO2with titanium liquid hydrolysis method from Chenggang slag are:when the molar ratio of EDTA to Fe is4:1, CA to Si is1:8, pH is1.3, and holding for60min at80℃, the TiO2content in the production TiO(OH)2(roasted at650℃for60min) is95.50%.After treatment at650℃for60min, the TiO(OH)2becomes pure TiO2. Some anatase type TiO2has transformed to rutile type.(3) Recycling of the fluxThe paper also studies the feasibility of recycling flux. The testing results show that the recycling flux mainly contains (NH4)2SO4, K2SO4, MgSO4and CaSO4and so on.When the mass ratio of the slag from Pangang to recycling flux is1:14, the final leaching rate of Ti is66.87%after reaction.When the mass ratio of the slag from Chenggang to recycling flux is1:10, the final leaching rate of Ti is74.33%after reaction.