Study on Continuous Hydrolysis in a Microchannel Reactor for the Production of Titanium Dioxide by a Sulfuric Acid Process

The development of a continuous hydrolysis process of titanium sulfate is an innovation to the traditional production process of titanium dioxide by the sulfuric acid process. In the experiment, a microchannel reactor was designed, and the hydrolysis rate of titanium sulfate, the particle size, and particle size distribution of metatitanic acid agglomerates were used as indicators to investigate the effect of operating conditions on the continuous hydrolysis of titanium sulfate. The results have shown that as the amount of dilution water increased, the hydrolysis rate of titanium sulfate decreased, and the particle size of primary aggregates of metatitanic acid increased from 39 to 54 nm. As the alkali mass concentration of dilution water increased, the hydrolysis rate of titanyl sulfate increased, and the particle size of primary aggregates of metastatic acid first decreased and then increased, and the particle size range was 40-48 nm. As the flow rate increased, the hydrolysis rate of titanyl sulfate increased, and the particle size of primary aggregates of metatitanic acid dropped from 59 to 43 nm. Compared with the batch hydrolysis operation, the continuous process has stronger anti-disturbance ability, significantly shorter operation time of the reaction section, and narrower particle size distribution of the product metatitanic acid.