矿物3CaO·3Al_(2)O_(3)·BaSO_(4)高温稳定性研究

STUDY ON THE STABILITY OF THE MINERAL 3CaO·3Al_(2)O_(3)·BaSO_(4)

矿物 3CaO·3Al2 O3·BaSO4是一种新型胶凝矿物 ,而关于其高温稳定性的研究却有多种结论 .本工作综合运用IR ,TG -DTA ,EPMA ,XRD和QXDA等多种测试方法 ,系统研究了3CaO·3Al2 O3·BaSO4的高温稳定性问题 .研究表明 ,在温度低于135 0℃的条件下 ,矿物 3CaO·3Al2 O3·BaSO4的晶相结构稳定 ;而温度高于 136 0℃时 ,3CaO·3Al2 O3·BaSO4发生分解并形成新的晶相 .3CaO·3Al2 O3·BaSO4的分解方程式可表述为 :3CaO·3Al2 O3·BaSO4→CaO·Al2 O3+ 12CaO·7Al2 O3+BaO·Al2 O3+SO2 ↑ +O2 ↑鉴于矿物BaO·Al2 O3 的形成机理与该问题紧密相关 ,本文也讨论了BaO·Al2 O3 的形成机理 .BaO·Al2 O3 的形成机理有两种 :温度低于 135 0℃时 ,BaO·Al2 O3 由原料组分发生反应而形成的 ;而温度大于 136 0℃时 ,该矿物是由 3CaO·3Al2 O3·BaSO4分解形成的 .

CaO·3Al 2O 3·BaSO 4 is a new type of cementitious mineral. The stability of 3CaO·3Al 2O 3·BaSO 4 at high temperature was studied comprehensively by means of IR, TG-DTA, EPMA, XRD and QXDA in this paper. Results state that when the temperature is not higher than 1 350 ℃, the crystal structure of 3CaO·3Al 2O 3 ·BaSO 4 is stable. However, when tempera_ ture is higher than 1 360 ℃, 3CaO·3Al 2O 3·BaSO 4 is decomposed and new minerals are formed. The chemical equation of? ?the ? decomposition may be described as follows: 3CaO?·?3Al 2O 3?·?BaSO 4? CaO·Al 2O 3+12CaO·7Al 2O 3+BaO·Al 2O 3+SO 2↑+O 2↑. The formation of the mineral BaO·Al 2O 3 is discussed due to its importance to 3CaO·3Al 2O 3·BaSO 4 stability. BaO·Al 2O 3 may form from the chemical reaction of the raw materials when temperature is lower than 1 350 ℃ or from the decomposition of 3CaO·3Al 2O 3·BaSO 4 on condition of the temperature ≥1 360 ℃ .