关键词: 含钛高炉渣, 盐酸浸出, 高温热处理

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