硅灰石与盐酸快速反应规律及应用研究

The regularity of rapid reaction between wollastonite and hydrochloric acid and its application

反应体系pH≤ 1.5时 ,硅灰石与盐酸快速反应。反应后体系中Si、Ca、Fe、Mg等元素在固液两相中化学状态及分布不同。当pH值为 0 .3～ 0 .6时 ,液相中SiO2 (硅溶胶 )比例最大 ,Ca主要存在于液相中 ,但固相中总有少量Ca存在。快速反应固相比表面积较大 ,若反应前添加PEG ,反应后中和到 pH =4 ,可制备高比表面积多孔SiO2 ,其比表面积 >4 30m2 / g ,孔径 1～ 2nm。该产物在合成以二氧化硅为基质的纳米复合材料及用作催化剂载体等方面有较好的应用前景。

Wollastonite and hydrochloric acid react quickly when the pH value is not higher than 1.5. This paper studies the chemical conditions and distribution of such elements as Si, Ca, Fe and Mg in solid phase and liquid phase after reaction. When the pH value is 0.3～0.6, the ratio of silica in liquid phase (silica sol) is the highest. Ca is mainly in liquid phase, with always a little in solid phase. The specific surface area of solid phase is large in rapid reaction. If PEG is added to the system before reaction and the PH value is adjusted to 4 after reaction, porous silica with specific surface area larger than 430 m 2/g and pore size of 1～2 nm can be prepared. The product can be used in the preparation of nano_composite based on silica and catalyst holder.