摘要
含Ｔｉ高炉渣是还原性渣，其中含有约占总Ｔｉ量１／５—１／４低价Ｔｉ（Ｔｉ~２＋，Ｔｉ~３＋），而钙钛矿主要由Ｔｉ~４＋形成，因此可通过渣氧化使低价Ｔｉ氧化为高价Ｔｉ，以提高钙钛矿结晶量．实验结果表明，在空气中于１０００℃保温约３０ｍｉｎ，渣中的低价Ｔｉ几乎变为高价Ｔｉ．以０．５℃／ｍｉｎ从１４７０ ℃降至１２００℃，而后自然冷却到室温时，约有８５％ ＴｉＯ_２分布于钙钛矿中．由于渣中氧位的提高，熔渣中能使粘度降低的ＦｅＯ转变为Ｆｅ_２Ｏ_３，这使渣的粘度提高，不利于钙钛矿晶粒长大．另外，氧化使渣中高熔点ＴｉＣ和ＴｉＮ固体颗粒减少或消失而导致钙钛矿晶体异质形核数目减少，从而降低了钙钛矿析出温度。
The reducible Ti-bearing slag contains Ti^2+ and Ti^3+ about 1/5-1/4 of total titanium. However, the formation of titanium in perovikite crystal is Ti^4+ mainly. Therefor, it is possible that increasing the precipitation content of perovikite by the slag oxide make Ti^2+ and Ti^3+ into Ti^4+. The experimental results showed that the most part of Ti^2+ and Ti^3+ transformed into Ti^4+ by slag oxide for 0.5 h at 1000 ℃ in air, and the precipitation content increases obviously. There is about 85% TiO_2 distributed in perovikite phase when the oxide slag was cooled from 1470 ℃ to 1200 ℃ with a rate of 0.5 ℃ /min, and then naturally cooled to room temperature. Due to increasing the total oxygen, FeO transformed into Fe_2O_3, which increases the viscosity of molten slag and restrains the growth of perovikite. In addition, the particles of TiC and TiN decrease or vanish because of oxidation of slag, thus the number of nuclei of perovikite decreases, resulting in reduction of the precipitation temperature.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第2期141-144,共4页
Acta Metallurgica Sinica
基金
中国科学院金属研究所快速凝固非平衡合金国家重点实验室资助
关键词
高炉渣
钙钛矿
析出
氧化
结晶
钛
furnace slag, perovskite phase, precipitation, oxide
