高钛渣富氧碱转化过程中物相转化与杂质脱除

Phase conversion and removal of impurities during oxygen-rich alkali conversion of high titanium slag

为了实现低碱浓度下高钛渣的高效碱转化和除杂,提出在氢氧化钾溶液中富氧碱转化的新途径。研究富氧碱转化过程中各元素赋存状态转化规律以及转化条件对钛转化率及硅铝杂质去除率的影响规律。结果表明:氢氧化钾溶液将高钛渣中钛氧化物转化为晶须状钛酸钾,硅和铝元素溶解进入溶液;当氢氧化钾浓度为6 mol/L,转化温度为260℃,初始氧分压为2 MPa,液固比为35 mL/g,转化时间为4 h,高钛渣粒度为48−74μm时,高钛渣中钛氧化物的转化率为97.0%,硅铝去除率分别为90.2%和76.2%。富氧碱转化产物经酸解转化可得到TiO^(2)品位为99.1%的金红石。

In order to achieve high-efficiency alkali conversion and impurity removal of high titanium slag under the condition of low alkali concentration,a new way of oxygen-rich alkali conversion in KOH solution was proposed.The conversion law of element occurrence state and the influence of the conversion conditions on the titanium conversion rate and removal rate of silicon and aluminum were studied.The results showed that the KOH solution converted the titanium oxide in high titanium slag into whisker-like potassium titanate.Silicon and aluminum elements were dissolved into the solution.Under the following conditions,KOH concentration of 6 mol/L,conversion temperature of 260℃,initial oxygen partial pressure of 2 MPa,liquid−solid ratio of 35 mL/g,conversion time of 4 h,and high titanium slag particle size of 48−74μm,the conversion rate of titanium was 97.0%,and the removal rates of silicon and aluminum were 90.2%and 76.2%,respectively.Oxygen-rich alkali conversion product was converted to rutile with a TiO_(2) grade of 99.1%by acid hydrolysis conversion.