铝硼硅酸盐硼挥发抑制的初步研究

Preliminary Study on Boron Volatilization of Alumino-borosilicate Glass

通过热分析手段研究氧化镧对铝硼硅酸盐玻璃熔制过程中硼挥发量的影响。TG测试结果表明,随着玻璃配合料中氧化镧质量分数的增加,硼挥发量逐渐降低。当La2O3与B2O3摩尔比超过0.2时,这种趋势变化不明显。同时通过XRD分析出了不同热处理机制下,氧化镧和硼酸的混合物的产物在650,℃时,除了La2O3和H3BO3之外,还有新相LaBO3生成;800,℃时,产物为La(BO2)3。与碱土金属硼酸盐相比,La(BO2)3和LaBO3具有更低的饱和蒸汽压,这是硼的挥发量降低的根本原因。

The boron volatilization of alumino-borosilicate glass batch with different La2O3 content was investigated by differential thermal analyzer. TG results showed that boron volatilization decreased as the La2O3 content increased. When molar ratio of La2O3/B2O3 was more than 0.20,the trend became slower. The product of lanthanum oxide and boric acid mixture with different heat treatment were examined by X-ray diffraction （XRD）. When the lanthanum oxide and boric acid mixture was kept at 650,℃ for 4h,new phase LaBO3 emerged in addition to boric acid and lanthanide oxide. When the temperature was up to 800,℃,La（BO2）3 appeared. Compared with alkaline earth metal borate,La（BO2）3 and LaBO3 have lower saturation vapor pressure,which reduces the boron volatilization.