镁盐和铝盐对硫酸钛溶液水解过程的影响（英文）

Influence of magnesium and aluminum salts on hydrolysis of titanyl sulfate solution

研究硫酸钛溶液中作为杂质的硫酸镁和硫酸铝对TiOSO4水解过程的影响。考察水解过程中,钛的转化率和偏钛酸粒径随硫酸钛溶液中硫酸镁和硫酸铝浓度的变化情况。采用Boltzmann生长模型拟合水解率曲线,可得到较好的拟合结果且R2>0.988。使用ICP、SEM、XRD和激光粒度仪对样品进行表征。结果表明,硫酸镁能够同时提高水解速率和最终的水解率,当硫酸钛溶液的F值(硫酸与TiO2的质量浓度比)较高时,这种趋势尤为明显(水解率由42.8%提高至83.0%),而硫酸铝对水解率的影响不明显(水解率由42.8%提高至51.9%)。通过对偏钛酸粒径的考察发现,硫酸镁和硫酸铝均能够明显地增加微晶粒径及减小偏钛酸聚集体粒径。

The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were measured as functions of the concentrations of MgSO4 and Al2（SO4）3 in the TiOSO4 solution.The Boltzmann growth model,which focuses on two main parameters,namely the concentrations of Mg2＋ and Al3＋（ρ（Mg2＋） and ρ（Al3＋）,respectively）,fits the data from the hydrolysis process well with R20.988.The samples were characterized by ICP,SEM,XRD,and laser particle size analyzer.It is found that the addition of Mg SO4 simultaneously improves the hydrolysis ratio and the hydrolysis rate,especially when F（the mass ratio of H2SO4 to TiO2） is high,hydrolysis ratio increases from 42.8% to 83.0%,whereas the addition of Al2（SO4）3 has negligible effect on the chemical kinetics of HTD precipitation during the hydrolysis process,hydrolysis ratio increases from 42.8% to 51.9%.An investigation on the particle size of HTD reveals that the addition of Mg SO4 and Al2（SO4）3 clearly increases the size of the crystallites and decreases the size of the aggregates.