Abstract:

Panzhihua Iron and Steel Co. releases 3 million tons of blast furnace slag containing 20% to 25% TiO₂ annually, resulting in a large amount of blast furnace slag occupying land, causing dust pollution and posing a threat. To solve the utilization problem of titanium containing blast furnace slag, this article adopted the “selective precipitation technology”, which involved adding insulation measures after the blast furnace slag was discharged to slowly cool the slag. The titanium component was enriched in the perovskite phase, and the grains grow. Further beneficiation and separation can obtain a concentrate of 35% to 50% TiO₂. In the paper, experimental study was conducted on sulfuric acid acidolysis of the perovskite concentrate. The research showed that the optimal conditions for acid acidolysis of the concentrate were: the mass ratio of ore to acid was 1 to 1.21, the reaction temperature was 180℃, the concentration of H₂SO₄ was 90%, the concentrate size was less than 76μm, and the reaction time was 4h. An acidolysis rate of 94.62% can be achieved under the optimal conditions. The acidolysis kinetics experiment indicated that in the initial stage (x=0—0.3), chemical reaction kinetics were the principal characteristic. In the intermediate stage (x=0.5—0.7), a mixture of chemical reactions and internal diffusion controlled the rate. In the later stage (x>0.7), the internal diffusion dominanted the rate.

Key words: titanium bearing blast furnace slag, selective precipitation technology, perovskite Ti-bearing concentrate, sulfuric acidolysis

摘要：

攀钢每年排放含TiO₂（20%～25%）的高炉渣300万吨，大量的高炉渣占用土地、引起灰尘污染，形成危害。为解决攀钢含钛高炉渣的利用问题，本文采用“选择性析出”技术，即在高炉排出高炉渣后加入保温措施使炉渣缓慢冷却，将钛组分富集到钙钛矿相中，晶粒长大，进一步选矿分离，可得到含TiO₂ 35%～50%的精矿。进一步对得到的以钙钛矿为主的含钛精矿进行了硫酸酸解的实验研究。研究表明酸解精矿的最优条件是使用小于76μm的精矿、90%的H₂SO₄，精矿和硫酸质量比为1∶1.21，180℃温度反应4h，在该条件下钛元素酸解率达到94.62%。酸解动力学实验表明，在精矿酸解反应初始阶段（x=0～0.3），化学反应动力学为主要特征；中间阶段（x=0.5～0.7）为化学反应和内扩散混合控速；酸解反应进入后期（x>0.7）为内扩散控速步骤。

关键词: 含钛高炉渣, 选择性析出技术, 钙钛矿相含钛精矿, 硫酸酸解