硅酸聚合过程中粘度变化的研究

在制备聚硅酸盐类混凝剂的过程中,聚硅酸的粘度是影响聚硅酸盐类混凝剂混凝效能的重要因素。以水玻璃为原料,硫酸、盐酸为酸化剂,采用酸性条件下制备聚硅酸的方法,研究pH值、二氧化硅浓度、温度、不同酸化剂等因素对硅酸聚合过程中粘度变化的影响,结果表明：粘度达到0.006 Pa.S前变化缓慢,粘度达到0.009 Pa.S后变化迅速,0.020 Pa.S以后在极短的时间内粘度急剧增大而胶凝;通过混凝搅拌实验确定制备聚硅酸铝混凝剂时聚硅酸粘度的最佳值,以此最佳值作为控制聚硅酸最佳聚合程度的指标。

Study on the Viscosity Changes in Polymerization Process of Polymerized Sihcic Acid

The viscosity of polymerized silicic acid was an important factor that impacted the coagulation property of polisilicate coagulants. Polymerized silicic acid were synthesized under an acidic condition with water glass and different acidities;the influences of pH value, temperature, SiO2 concentration and different acidifiers on the viscosity of polymerized silicic acid were systematically investigated. The results showed that the viscosity of polymerized silicic acid changed slowly under 0. 006 Pa · S and rapidly above 0. 009 Pa ·S, while the viscosity would rise sharply above 0. 020 Pa· S until the gelling would occur. The optimal viscosity value of polymerized silicic acid for preparingpolysilicate aluminum was confirmed by coagulation jar test as the key indicator of polymerization degree.