由液相SO_4^(2-)浓度的变化解译钙矾石的热稳定性

Thermal Stability of Ettringite Expounded by the Changes of Sulfate Concentrations in Solution

通过液相合成钙矾石纯晶体,采用连续加热和分次加热2种试验手段来监测与钙矾石相互平衡的液相中SO2-4的浓度最低,4的浓度变化.结果表明:在40～50℃时液相中SO2-说明此温度下钙矾石最为稳定;在70～75℃开始增大,说明钙矾石自此温度开始出现热分解;在90℃时钙矾石在1h内时的分解量为13 7%左右.

After the synthesis of pure ettringites, several samples containing synthetic ettringite and calcium hydroxide solution are prepared. The samples then are heated at different temperatures individually or in sequence. All the experiments show that the concentrations of sulfate in solution become the lowest at 40 ℃ to 50 ℃,which indicates that the most suitable temperature for ettringite formation is within 40～50 ℃. The experiments also show that the sulfate concentrations begin to increase at about 70～75 ℃, suggesting that ettringite starts to decompose at that temperature. The experiments indicate that the amount of the decomposition of ettringites is 13.72% at 90 ℃ after being heated for one hour.