温度制度和添加剂对钙钛矿晶体选择性析出过程的影响

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

为了进一步实现攀钢含钛高炉渣中钛组分的有效回收,探究了温度制度和添加剂对钙钛矿晶体选择性析出行为的影响。通过分析含钛高炉渣化学组分及矿物组成特点,采用选择性析出技术,探究了Fe2O3加入量、保温区间、降温速度及添加剂对钙钛矿析出和长大的影响,找到了最有利于钙钛矿结晶的温度区间为1350~1320℃;并且向炉渣中加入3.2%的CaO和0.5%的Fe2O3,在1350~1320℃以0.5℃/min的降温速率降温,此时钙钛矿相析出的晶体粒度和体积分数同时达到最大值,分别为58.83μm和20.17%;在相同温度制度条件下添加4%CaF2、2%Al2O3或2%MnO都可使炉渣中钙钛矿的结晶粒度和体积分数进一步增大,实现了含钛高炉渣中TiO2的有效富集,为钙钛矿相的分离创造了有利条件。

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 1350~1320℃.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 1350℃to 1320℃,the crystal size and volume fraction of the perovskite phase precipitated reached the maximum values at the same time,respectively at 58.83μm 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.