以油泥为主要原料的SiO2-Al2O3-CaO系陶瓷制备及机理

Preparation and Mechanism of SiO2-Al2O3-CaO System Ceramics Using Oily Sludge as Main Raw Material

针对油泥含有机物并具有高硅、高铝组成的特点,提出以油泥为主要原料制备SiO2-Al2O3-CaO系陶瓷的方法,利用陶瓷高温烧结过程,将油泥中有机物分解以实现无害化,并将其中的SiO2和Al2O3等无机组分转化为陶瓷。制备了油泥、粉煤灰和大理石锯泥掺入量(质量分数)分别为50%、30%和20%的全固废陶瓷,分析了陶瓷在高温烧结过程的析晶和致密化规律。结果表明:所制备全固废陶瓷组分属于SiO2-Al2O3-CaO体系,其主晶相为钙长石和辉石;油泥中有机物的分解温度为300~730℃,有机物在陶瓷烧结过程中能够完全反应,该反应温度区间低于陶瓷最佳烧结温度1120~1160℃,对后续陶瓷高温致密化过程无显著影响;当烧结温度为1120℃时,油泥陶瓷力学性能较佳,其抗折强度为80.80 MPa,吸水率为0.21%,优于陶瓷砖国家标准的要求。

For containing organic components and high-silica/high-alumina composition,oily sludge as main raw material was prepared into SiO2-Al2O3-CaO system ceramics,with decomposition of its organic components for harmlessness,and conversion of its high-silica/high-alumina inorganic components into ceramics during its high temperature sintering process.Ceramics were prepared from solid wastes,including oily sludge,fly ash and marble saw mud with proportions(mass fraction)of 50%,30%and 20%.Its crystallization and densification process during sintering process were further analyzed.The results show that main crystalline phases of the ceramics,which belong to the composition of SiO2-Al2O3-CaO system,are anorthite and pyroxene.The organic components decompose and volatilize in the range of 300-730℃,which is much lower than the sintering temperature from 1120℃to 1160℃,and the volatilization process shows insignificant effects on the subsequent sintering and densification process.The ceramic sintered at 1120℃has optimum physical properties with flexural strength of 80.80 MPa and water absorption of 0.21%,which are much better than the national standard.