硫酸法钛白废酸浓缩工艺研究

Study on concentration process of titanium white waste acid by sulfuric acid method

为了提升废酸浓缩效率,以现场废酸为原料,在实验室采用真空旋转蒸发仪模拟现场废酸真空蒸发浓缩,开展废酸浓缩工艺单因素试验及正交试验,然后以实验室研究结果为依据,在现场开展了废酸浓缩工艺优化工业试验。结果表明,在相同的硫酸浓度条件下,废酸相对纯硫酸密度大,且随着硫酸浓度的增加,两者密度差逐渐减少;随着废酸浓缩时间、浓缩温度及浓缩真空度的增加,废酸浓缩浓度均逐渐增加,影响废酸浓缩浓度的关键影响因素为浓缩时间、浓缩真空度、浓缩时间×浓缩真空度、浓缩温度,重要度排序为浓缩时间>浓缩真空度>浓缩真空度×浓缩时间>浓缩温度。工业试验结果表明,当废酸浓缩时间、浓缩温度及浓缩真空度分别由2.06 h、108℃及30 kPa提升至2.68 h、112℃及45 kPa时,一级浓缩酸浓度均值由29.5%提升至38.5%。研究结果为硫酸法钛白生产企业提升废酸浓缩效率提供了重要的数据及理论支撑。

In order to improve the efficiency of waste acid concentration,the single factor test and orthogonal test of waste acid concentration process were carried out in the laboratory by using vacuum rotary evaporator to simulate the vacuum evaporation concentration of waste acid.Then,based on the results of laboratory research,the industrial test of waste acid concentration process optimization was carried out in the field.The results show that the density of waste acid is larger than that of pure sulfuric acid under the same sulfuric acid concentration,and the density difference between them decreases with the increase of sulfuric acid concentration.With the increase of concentration time,temperature and vacuum degree of waste acid,the concentration of waste acid increases gradually.The key influencing factors affecting the concentration of waste acid are concentration time,concentration vacuum degree,concentration time×concentration vacuum degree and concentration temperature.The order of importance is concentration time>concentration vacuum degree>concentration vacuum degree×concentration time>concentration temperature.The industrial test results show that when the concentration time,concentration temperature and concentration vacuum degree of waste acid increase from 2.06 h,108°C and 30 kPa to 2.68 h,112°C and 45 kPa,respectively,the average concentration of primary concentrated acid increases from 29.5%to 38.5%.The research results provide important data and theoretical support for improving the concentration efficiency of waste acid in titanium dioxide production enterprises by sulfuric acid method.