不同硬化方法形成的水玻璃胶粒的微观形态变化及其原因探讨

The Formation Changes of Silicate Particles Morphology Cured by Different Methods and Its Reasons

采用有机酯硬化、加热硬化钠水玻璃砂的强度均比CO2硬化的成倍提高。通过实验和分析可知:水玻璃砂CO2硬化法比有机酯硬化法、加热硬化法强度低的主要原因是CO2硬化法的凝胶胶粒粗大。酯硬化法之所以可获得细小的水玻璃凝胶胶粒是由于醋酸和聚硅酸表面硅羟基以氢键键合,即通过氢键使醋酸束缚在高聚硅酸盐粒子上阻抑胶粒长大。加热硬化时胶粒细小是靠外加的能量,使水玻璃水溶液减少,浓度增大,这样,既增加硅酸分子间碰撞机会,有利形成更多的胶粒,也使胶粒中包含的水溶液变少,因而胶粒细小。CO2硬化时,硅酸的硅羟基与硅羟基间的结合可以自由进行,缺乏制约,而且,胶粒中包含的水溶液较多,因而胶粒粗大。所以,提高CO2水玻璃砂粘结强度的关键在于抑制硬化过程中胶粒的过于长大。

The intensity of silicate-bonded sand either cured by organic ester or hardened by heating is improved several times than that of the CO2 cured.The experiments and analysis show that：the main reason of the fact that the intensity of the latter is lower than that of both the organic ester cured and the heating hardened lies in thick gel particles of the CO2 cured one.Small sodium silicate gel particles gained by ester is due to acetic acid and poly hydroxy acid to hydrogen-bonded silicon surface bonding,viz, bound by hydrogen bonds in the high-acetate silicate particles stop the plastic tablets growing.Small particles gained while heating sclerosis depend on the energy,causing the reduction of sodium silicate solution,the increase of concentration,which will increase opportunities of collision among the acid molecules,enabling the formation of more particles,making the particles contain less solution,hence small particles formed.CO2 sclerosis, hydroxy acid silicon and silicon can be a free combination of inter-hydroxy, lacking constraints.In addition,the particles contains much solution so particles become big.Therefore, stopping the hardening process of particles from growing is the key of increasing CO2 sodium silicate sand bond strength.