熔盐高效分解含钛高炉渣制备纳米二氧化钛

Preparation of nano TiO_2 from Ti-bearing blast furnace slag by molten salt method

采用熔盐法对含钛高炉渣进行高效分解并提取含钛组分,利用含钛滤液为原料制备了纳米二氧化钛粉体。对熔盐分解含钛高炉渣进行了热力学分析,并研究了碱渣比、熔盐反应温度及熔盐反应时间对钛组分浸出率的影响和p H及水解温度对二氧化钛产品纯度的影响。实验结果表明高炉钛渣在氢氧化钠熔盐中反应生成钛酸钠在热力学上是可行的。确定了最佳的碱渣比为3：1,最佳熔盐反应温度为500℃,最佳反应时间为3 h,在此条件下钛元素的浸出率为99.8%。得出较佳的水解p H范围为0.1-0.2,最佳水解温度为100℃。实验中制备的纳米二氧化钛粒子球形度好,粒度大小均匀且分散性好,颗粒直径为100 nm左右。

A novel process was proposed for preparing titanium dioxide by decomposition of titanium-bearing blast furnace slag（TBBFS） in molten Na OH-Na F system. Thermodynamic analysis was conducted on the molten salt decomposition of TBBFS. The effects of mass ratio of alkali and slag, reaction time and reaction temperature on titanium extraction and the effects of p H and hydrolysis temperature on purity of titanium dioxide were discussed. The reaction of sodium titanate from TBBFS with sodium hydroxide was feasible thermodynamically. When optimum mass ratio of alkali and slag was 3：1, reaction temperature was 500℃, and reaction time was 3 h, titanium extraction was 99.8%. Optimum p H and hydrolysis temperature were 0.1—0.2 and 100℃ respectively. Analysis results indicated good sphericity and dispersibility of TiO2 particles with diameter about 100 nm.