铁尾矿-CRT玻璃协同制备CMAS微晶玻璃的研究

Preparation of CMAS Glass-ceramics by the Combination of Ferrous Tailing and CRT Glass

以废弃的承德铁尾矿和CRT显像管废玻璃为主要原料,采用烧结法制备Ca O-Mg O-Al2O3-SiO_2微晶玻璃,并利用DSC、XRD和EPMA等测试手段对样品的晶相种类、微观结构以及各项理化性能进行表征。结果表明:CRT玻璃的合适引入量为20%。直接采用CRT玻璃和铁尾矿进行烧结,微晶玻璃主晶相为石英,无法制备具有预期晶相的试样;将铁尾矿高温熔化后进行水淬,可以有效提高烧结反应活性,有利于制备CMAS微晶玻璃;铁尾矿中额外添加11.6wt%Ca O,6.2wt%Mg O和2.7wt%Al2O3后再熔化水淬,与CRT玻璃复合在900℃保温2 h进行烧结后样品的主晶相为透辉石,此时微晶玻璃结晶度最高,样品体积密度为2.54 g/cm3,气孔率0.8%,维氏硬度为6.9 GPa。

Iron mine tailings from Chengde and waste glass from dismantled cathode ray tubes （CRT） had been employed for the production of CaO-MgO-Al2O3-SiO2 glass-ceramics by sintering process. The crystallization and properties of samples were investigated by means of differential scanning calorimetry （DSC）, X-Ray diffraction （XRD） and electron probe micro-analyzer （EPMA）. Results showed that the proper introduction of CRT glass was 20wt%. Quartz as major crystalline phase was precipitated in CMAS glass-ceramics prepared by iron tailing and CRT glass, which was not the prospective crystal phase. The reactivity of sintering was enhanced after the melted iron tailing was quenched into cold water. Furthermore, the iron tailing exhibited the highest activity when several oxides, such as 11.6wt% CaO, 6.2wt% MgO and 2.7wt% Al2O3 were added before quenched. CMAS glass-ceramics with the best properties were produced by sintering of optimized quenched iron tailing and CRT glass at 900℃ for two hours, the samples showed the highest crystallinity of diopside and excellent properties, bulk density of 2.54 g/cm^3, porosity of 0.8% and Vickers hardness of 6.9 GPa.