以钢渣为原料的SiO2-CaO-Al2O3系陶瓷烧结机理

摘要

The SiO2-CaO-Al2O3 system ceramic was prepared using the steel slag mainly composed of CaO and SiO2. Thermodynamic calculation, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were introduced to analyze the sintering reaction and sintering mechanism. The results indicate that anorthite is the main crystal phase in the slag-clay-feldspar-quartz system. Sintering of ceramic based on steel slag is controlled by mass transfer reaction at initial step, and then liquid phase is formed, which promotes reaction, crystal growth and further densification. A large amount of calcium hydroxide in steel slag forms after wet milling. Calcium oxide transformed from calcium hydroxide during sintering process has a strong reactivity and promote the reaction among ingredients of ceramic.%以主要化学成分为CaO和SiO2的钢渣为原料，制备SiO2-CaO-Al2O3系钢渣陶瓷，采用差分扫描量热仪(DSC)、X 线衍射仪(XRD)、扫描电子显微镜(SEM)与热力学计算研究钢渣陶瓷烧结过程及反应机理。研究结果表明：在以钢渣−黏土−长石−石英为主要原料的SiO2-CaO-Al2O3体系中，钢渣陶瓷晶相以钙长石相为主；钢渣陶瓷烧结初期以扩散传质反应为主，之后形成高温液相，促进反应进行和晶体长大，并完成坯体致密化；经过湿磨的钢渣中存在大量的氢氧化钙等矿相，这些矿相在钢渣陶瓷烧结过程中能够分解产生具有很强反应活性的氧化钙，因而促进了原料间的反应和陶瓷致密化过程。