盐酸直接浸出高钛型高炉渣

摘要

基于TiO2不易溶于盐酸，采用盐酸在不同条件下直接浸出高钛型高炉渣，分析了不同的原料粒度、加热温度、酸渣比、盐酸浓度和反应时间对酸浸渣中TiO2含量及物相组成的影响，并使用正交试验方法找出最佳反应条件及影响因素的顺序．研究结果表明：在原料粒度120～180μm，加热温度95℃，酸渣比1．5：1，盐酸浓度8mol／L，反应时间4h条件下，Mg、Fe、Al等元素酸解充分，获得TiO2含量超过45％的酸浸渣，经表征分析浸出渣中钛主要以钙钛矿（CaTiO3）和偏钛酸（H2TiO3）结构形式出现．由于钙钛矿反应活性差和透辉石酸解生成硅酸胶体覆盖在炉渣表面，4h以后TiO2含量没有明显变化，分析高钛型高炉渣中各物相的浸出速率由快到慢依次为：尖晶石、透辉石、钙钛矿．%Based on the reactive differences of titan and other elements to hydrochloric acid, the Ti-bearing blast-furnace slag was leached directly with hydrochloric acid in different conditions. The effect of the particle size, heating tempera- ture, the ratio of acid and slag, hydrochloric acid concentration and reactive time on the mass fraction of acid leaching slag were analyzed. Moreover, Orthogonal Test Method was used to identify the optimal reaction conditions and the order of influencing factor. The experimental results show that Mg, Fe, Al were acid-splitting entirely, and the acid leaching residue can be obtained with over 45 % TiO2 at the conditions that the particle size is of 120 - 180 μm, heating temperature is of 95℃ ,the ratio of acid and slag is of 1.5：1 ,hydrochloric acid concentration is of 8 mol/L and reactive time is of 4 h, the titania mainly consists in unreacted CaTiO3 and H2TiO3 by representational analysis. After four hours, the percentage of TiO2 showed no significant changes due to lower reactivity of the perovskite and the coverage of silicie acid from the aeidolysis of diopside. The dissolution rate of differently phase compositions in slag descended in the following order of spinel diopside and perovskite.