二次中和法制备沉淀水合二氧化硅比表面控制

采用二次中和法制备了沉淀水合二氧化硅，并通过单因素实验对产品的比表面控制影响因素进行了研究，得出较优的影响因素组合为反应温度为40 ℃，酸质量浓度为70 g/L，碱质量浓度为110 g/L，两段加酸量比例（酸液前期配合量占总配合量的比例）为70%，反应时间在60～120 min，搅拌速率在40～300 r/min。同时结合生产经验，发现影响因素的组合影响产品比表面积的规律，从而通过准确控制沉淀水合二氧化硅比表面积达到控制产品质量的目标。

Specific surface control for precipitated hydrated silica prepared by secondary-neutralization

Precipitated hydrated silica was prepared by secondary-neutralization method，and the influential factors of the product′s specific surface control were studied by single-factor experiments.Suitable factor combination was obtained：reaction temperature was 40 ℃，acid mass concentration was 70 g/L， alkali mass concentration was 110 g/L，acid adding ratio of the two stages（the proportion of the former acid dosage to the total acid dosage） was 70%，reaction time was at 60~120 min， and stirring rate was at 40~300 r/min.According to the production experiences，the law of the combinations of influential factors impacting the product′s specific surface was found，and the purpose of controlling the product′s quality through the accurate control of the specific surface of precipitated hydrated silica has been realized.