SiO-2包覆超细CaCO-3的结构和机理分析

合成了表面包覆SiO2的超细CaCO3。通过XPS，XRD对包覆表面层结构的分析，证实了SiO2以无定形包覆于CaCO3表面，并在其表面形成了Si-O-Ca键。对SiO2包覆超细CaCO3的机理分析结果可知：Na2SiO3的加入量是影响包覆效率的重要因素，由于硅酸易自聚，控制SiO2与CaCO3的重量比约为4％－5％时为包覆的最佳点；CaCO3晶粒度大小影响分散性能，进而影响包覆效率，分散性能好的包覆效率较高。

Mechanism and structure analysis of SiO-2-coated CaCO-3 superfine particles.

The superfine particles of CaCO\-3 coated by SiO\-2 has been studied. By XPS and XRD analysis, it has been confirmed that the SiO\-2 layer is present as amorphous phase, and is formed via Si-O-Ca bond on the surface. Further studies show that the amount of Na\-2SiO\-3 added into the system plays an important role in the coating efficiency. The optimistic ratio of the SiO\-2 to CaCO\-3 has been found to be 4%-5% for the self\|polymerization of H\-2SiO\-3. It has been concluded that the better condition of CaCO\-3 dispersion is influenced by grain size, which may contribute to the better coating efficiency.