摘要:
NaOH熔盐法用钛渣制备TiO2是一种制备二氧化钛的新方法,水解制备偏钛酸是新工艺中重要的环节之一。试验考察了钛液的浓度、F值及水解时间等影响偏钛酸粒度及转化率的因素。结果表明,钛液水解率在开始的30 min左右均较低,50 min以后迅速提高,100 min以后水解率随时间变化趋于平缓。温度越高,F值越低,钛液浓度越低,水解反应进行得越快,且最终转化率较高。水解产物偏钛酸粒度开始随水解反应时间增加而增大,3 h后偏钛酸的粒度随时间增加略有波动,偏钛酸的粒径随钛液浓度及F值增大而减小,随钛液稳定度提高而减小。试验确定的偏钛酸制备工艺条件如下:TiO2浓度200 g/L左右,F值1.8~1.9,微沸状态下水解,水解时间4 h。
关键词:
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TiO2 /
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熔盐法 /
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偏钛酸 /
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水解 /
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钛渣
Abstract:
Preparation of TiO2 with titanium slag by molten-salt method is a new way to produce TiO2 in which the preparation of metatitanic acid by hydrolysis is an important step due to its huge influence on the quality and yield of the finished products.This paper has identified the factors including concentration of titanium solution,F value and hydrolysis time that influence the grain size and conversion ratio of the metatitanic acid.The results show that the hydrolysis ratio of the titanium solution under different temperatures remains relatively low during the initial 30 min,and after 50 min it rises quickly while after 100 min,the variation of the hydrolysis ratio with time becomes milder.With the increase of temperature,the F value becomes lower,and with the decrease of the concentration of titanium solution,hydrolysis reaction proceeds faster and a higher ultimate conversion ratio can be obtained as a result.At the beginning,the grain size of the metatitanic acid resulting from hydrolysis increases with the time of the hydrolysis reaction.Three hours later,the grain size of the metatitanic acid exhibits a little fluctuation with time.The grain diameter of the metatitanic acid decreases with the increase of the concentration of titanium solution and F value and increases with better stability of the titanium solution.During preparation of metatitanic acid in the new TiO2 pigment production process,the TiO2 concentration and F value should be controlled at about 200 g/L and 1.8 ~ 1.9 respectively,and hydrolysis process should be carried out for 4 hours under the condition of slight boiling.