Effect of Temperature Conditions and Additives on Selective Precipitation Process of Perovskite Crystals

In order to further realize the effective recovery of titanium components from the titanium-containing blast furnace slag,the effect of temperature conditions and additives on the selective precipitation behavior of perovskite crystals were studied in this paper.By analyzing the chemical components and mineral compositions of titanium-bearing blast furnace slag,the selective precipitation technology was used to explore the effects of the Fe₂O₃ addition amount,the temperature holding range,the cooling rate and the additives on the perovskite precipitation and growth.Based on the investigation,the most favorable temperature range for perovskite crystallization was found around 1 350～1 320 ℃.With 3.2% CaO and 0.5% Fe₂O₃ added to the slag,and the temperature decreasing at a temperature reduction rate of 0.5 ℃/min in the range of 1 350 ℃ to 1 320 ℃,the crystal size and volume fraction of the perovskite phase precipitated reached the maximum values at the same time,respectively at 58.83 μm and 20.17%.Adding 4% CaF₂,2% Al₂O₃ or 2% MnO under the same temperature conditions can gradually increase the crystal size and volume fraction of perovskite in the slag,and thus realize the effective enrichment of TiO₂ in the titanium-containing blast furnace slag,which has created favorable conditions for the separation of perovskite phase.