Abstract: A two-step extracting and separating process of air-cooled Ti-bearing blast furnace slag was proposed and investigated. The slag was firstly leached with HCl, leading to a preliminary separation of titanium and silicon with other dissolvable impurities. The resulting solid residue was then subjected to high temperature treatment for further separation of titanium and silicon species. The results showed that the leaching produced a preliminarily enriched residue with 33% TiO2 and 36% SiO2, in which the titania mainly came from the H2TiO3 formed during the hydrolysis and un-reacted CaTiO3. During the heat treatment, TiO2 in the H2TiO3 was carbothermally reduced to Ti3O5 and crystallized out, and the Ti3O5 content and mean size were about 85% and 20 mm, respectively. The grain size could be further increased to 36 mm upon the addition of a small amount of anatase TiO2. Therefore, it is possible to separate the Ti3O5-rich phase from the silicon-rich phase by gravity separation method. A theoretical recovery rate of Ti was calculated as 39%.

Key words: Ti-bearing blast furnace slag, hydrochloric acid leaching, high temperature heat treatment

摘要： 对自然冷却含钛高炉渣中钛的提取与分离进行了研究，提出了钛的两段富集路线，即先用盐酸浸出含钛高炉渣，初步分离钛、硅与其他可溶性杂质；所得酸浸渣再作高温热处理结晶分离硅与钛. 研究结果表明，盐酸浸出可获得含TiO2约33%, SiO2约36%的一次浸渣，TiO2主要来自钛液水解生成的偏钛酸(H2TiO3)与原渣中未反应的钙钛矿(CaTiO3). 热处理过程中偏钛酸中的TiO2被还原为Ti3O5并从熔体中结晶析出，Ti3O5含量约85%，平均粒径为20 mm. 添加少量锐钛型TiO2可使Ti3O5的晶体尺寸增大，平均粒径达36 mm，因此可以通过重选的方法分离Ti3O5相与富含硅物相. 计算出钛的理论收率约为39%.

关键词: 含钛高炉渣, 盐酸浸出, 高温热处理