粘土对废料制备微晶玻璃的烧结行为及组织的影响

Influence of clay on sintering behavior and structure of glass-ceramics from waste materials

以废玻璃、粉煤灰和粘土为原料,利用粉体直接烧结法制备出斜辉石-钙长石微晶玻璃,采用XRD和SEM研究粘土对微晶玻璃烧结行为和组织结构的影响。结果表明:随粘土含量增加,微晶玻璃的烧结激活能、钙长石含量以及结晶度明显增大;粘土含量≤15%时最佳烧结温度为1000℃,含量超过15%时最佳烧结温度往高温移动。1000℃烧结时含15%粘土微晶玻璃的体积密度为2.3 g/cm3,抗弯强度达到90 MPa。粘土作为固体粘接剂以及析晶晶核剂的双重作用决定了微晶玻璃的烧结行为和组织结构。

Glass-ceramics with augite and anorthite as the main crystal phases were prepared by the direct powder sintering technique using waste glass, fly ash and clay as raw materials. The effects of clay content on the sintering behavior and structure of glass-ceramics were investigated by X-ray diffraction and scanning electron microscopy. Results indicate that the sintering activation energy, the content of anorthite phase as well as the degree of crystallinity of glass-ceramics, dramatically increase with increasing clay content. As the clay content is lower than 15% , the optimal sintering temperature is 1000 ~C. However, when the clay content is higher than 15% , the optimal sintering temperature of the glass-ceramics moves to higher temperatures. The bulk density of the glass-ceramics with 15% clay sintered at 1000 ~C is 2.3 g/cm3 , of which the bending strength reaches the maximum value of 90 MPa. The dual roles of clay as a solid binder of powder compact as well as a nucleating agent of crystallization determine the sintering behavior and structure of glass-ceramics.