烧结法制备金矿尾砂CaO-Al_2O_3-SiO_2微晶玻璃及其性能研究

Preparation and Properties of CaO-Al_2O_3-SiO_2 Glass-Ceramics from Gold Tailings by Sintering

以汉阴金矿尾砂、方解石为主要原料,硼砂、ZnO、Sb2O3、Na2SiF6等为辅助原料,采用烧结法制备CaO-Al2O3-SiO2系微晶玻璃。通过差热分析、X射线衍射及扫描电子显微镜对所制备微晶玻璃样品的热性能、物相组成及微观结构进行表征,并分析不同烧结温度和保温时间对所得样品性能的影响。结果表明:在950℃,保温3h的条件下,所得微晶玻璃样品的性能较好,主晶相为透辉石(CaMgSi2O3)和钙长石(CaAl2Si2O8),其热膨胀系数、抗折强度及密度分别为65.4×10-7/℃,166MPa,2.623 8g/cm3。

CaO-A12 03-SiO2 glass-ceramics were prepared with gold tailings from Hanyin and calcite as main raw materials, and borax, ZnO, Sbz 03, Naz SiF6 as auxiliary materials by a sintering method. The thermal properties, phases and microstructures of the glass-ceramics samples were characterized by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, respectively. The effects of the sintering temperature and time on the properties of the as-prepared samples were investigated. The results show that the optimal properties of the glass-ceramic are achieved by sintering at 950 ℃ for 3 h, and the main crystalline phases of the glass-ceramic are diopside （CaMgSi2 03 ） and Anorthite （CaA12 Si2O8 ）. The thermal expan- sion coefficient, bending strength and bulk density of the glass-ceramic are 65.4× 10-7/℃, 166 MPa and 2. 623 8 g/cm3 , re- spectively.