钛液水解工艺对金红石二氧化钛消色力的影响

以工业钛液为原料，采用外加晶种常压水解工艺制备了金红石型二氧化钛，研究了水解钛液的组成和操作参数对二氧化钛消色力的影响。实验结果表明：二氧化钛消色力（Tcs）和蓝相光谱值（Scx）随晶种添加量的增加先增大后减小，随判灰延时时间的增加先增大后减小，随钛液F值的增加先稍有增加后明显降低，随钛液二氧化钛质量浓度的增大而增加。在钛液F值（游离硫酸加上与钛结合的硫酸之和与二氧化钛质量浓度的比值）为1.90左右、铁钛比（铁元素与二氧化钛质量浓度的比值）＜0.5、二氧化钛质量浓度为190~200 g/L、晶种添加量（晶种中二氧化钛质量与对应批次水解浓钛液中二氧化钛质量的比值）为2.0%~2.2%、灰点为“基点+20 min”、熟化时间为0~30 min、稀释水在二沸后100 min加入的条件下进行水解，经过一次洗涤—漂白—二次洗涤—盐处理—煅烧，所得金红石型二氧化钛的消色力更好。

Influence of titanyl sulfate solution hydrolysis process on tintreducingpower of rutile titanium dioxide

Using industrial condensed titanyl sulfate solution as raw material，Rutile titanium dioxide was prepared by hydrolysis process within adding external seeds.The influences of composition of titanyl sulfate solution and operation conditions on the tintreducing power of rutile titanium dioxide were studied.The experimental results showed that the Tcs and Scx of titanium dioxide increased first and then decreased with the increase of seed addition and delay time of grey point judgment; and increased slightly and then decreased with the increase of F value，and increased with the increase of titanium dioxide concentration.The F value of titanium solution（the mass concentration ratio of free sulfuric acid+sulfuric acid combined withTi to TiO2） was about 1.90，the ratio of Fe/TiO2 （the mass concentration ratio of Fe to titanium dioixde） was less than 0.5，themass concentration of TiO2 was 190~200 g/L，the dosage of seeds（the mass ratio of titanium dioxide in crystal seed to thetitanium dioxide in related industrial condensed titanyl sulfate solution） was controlled at 2.0%~2.2%，the grey point was “base point + 20 min”，the aging time was 0~30 min，and the diluted water was added at the time of 100 min after the second boiling.Under these conditions，the rutile titanium dioxide obtained by the processes of primary washing，bleaching，secondary washing，salt treatment and calcination has better tintreducing power.