外加剂对可水合氧化铝水化行为的影响

Effect of admixtures on hydration behavior of hydratable alumina

分别以柠檬酸、乳酸铝和硫酸铝为外加剂,配制可水合氧化铝料浆,并进行水化热测试和水化处理。对终止水化后的试样进行干燥处理,测试其质量变化率,分析其物相组成和显微结构,研究不同外加剂对可水合氧化铝水化行为的影响。结果表明:无外加剂的料浆水化75 h时水化累积放热量为85 J·g-1,水化24 h时水化质量增加率达11%,水化产物以薄片状拜耳石为主。引入外加剂的料浆水化累积放热量明显降低,水化质量增加率明显减小,水化产物以凝胶状勃姆石为主。乳酸铝对水合氧化铝水化行为和水化产物的影响更为明显。

Hydratable alumina slurries were prepared with citric acid,aluminum lactate and aluminum sulfate as admixtures,respectively.The hydration heat test and the hydration treatment were carried out.After the hydration process of the slurries was terminated,the products were dried and their mass change rates were measured.The phase composition and microstructure of the hydration products were analyzed.The effect of different admixtures on the hydration behavior of the hydratable alumina was investigated.The results show that the cumulative heat of the hydratable alumina slurry without admixture hydrated for 75 h is 85 J·g-1,the mass gain after 24 h hydration is 11%and the main phase of the hydration products is flaky bayerite;while,the cumulative heat of the hydratable alumina slurry with admixtures and the mass gain are lower and the main phase of the hydration products is boehmite;and the effect of aluminum lactate on the hydration behavior and the hydration products of hydratable alumina is more obvious.