关键词: 碳酸钡;分解;差热热重分析

Abstract: The decomposition temperature of pure BaCO 3is higher than that of ordinary carbonate,and its decomposition process is more complex.The decomposition of BaCO 3in borosilicate glass is particularly complex and it can affect the quality of the molten glass and the optimization of the melting process.The purpose of this paper was exploring the decomposition rule of BaCO 3in the smelting process of borosilicate glass studying a formula(BaO-CaO-Al2O3-B2O3-SiO2)for the sealing glass of intermediate temperature solid oxide fuel cell(IT-SOFC).Three kinds of powder were designed to explore the rules, they were respectively A powder which was original formula, B powder which was just a BaCO 3, SiO2and Al2O3 mixture based on the original recipe,C powder which was pure BaCO 3.The properties of three powders were analyzed and characterized using differential thermal analysis /thermogravimetric(DTA/TG), and X-ray diffraction technology(XRD)was used to analyze the crystal of glass powder prepared by A powder.The results show that the BaCO 3decomposition began to happen at 1010 ℃ after two steps of crystallization.However, in the melting process of A powder, one part of BaCO3is decomposed via reacting with SiO2and Al2O3at low temperature; another part of BaCO 3is self-broken down with the temperature rising.In the end,the crystal phase of BaAl 2Si2O8is precipitated out in A glass at 1176.5℃.

Key words: barium carbonate;decomposition;differential thermal analysis/thermogravimetric