通过对工业水玻璃进行pH调节、降低Na⁺浓度、运用不同酸化剂、添加硼和引入铝、铁金属离子等,研究了延缓聚硅酸胶凝时间、提高其稳定性的问题。实验结果表明,pH对聚硅酸稳定性有很大影响，降低Na⁺浓度可提高其在中性区域的稳定性,乙酸、硼、铝离子、铁离子的加入有利于聚硅酸的稳定，同时还得出了各影响因素的适用条件，为聚硅酸金属盐复合絮凝剂的研究及实际应用提供了一定的理论依据。

To prolong the gel time of polysilicic acid， the effect of various factors， including the pH value， the concentration of sodium ion in the industry water glass，kinds of acidifier，boron added，aluminium and iron ions introduced is observed respectively. The experimental results show that the stability of polysilicic acid is effected greatly by the pH value，and by reducing the concentration of sodium ion in pH value near neutral area and introducing acetic acid，B，Al and Fe，the stability of polysilicic acid can be enhanced.The applicable conditions about the effect factors are educed. The study of increasing the stability has been combined with the polymerization mechanism of polysilicic acid. The results can provide some theoretical basis for the studies and applications of inorganic compound flocculants.