氧化铝熟料溶出过程二次反应的热力学讨论

Thermodynamic analysis of secondary reactions in the clinker leaching process

对氧化铝熟料溶出过程涉及的二次反应进行了热力学计算和讨论。对原硅酸钙在铝酸钠溶液中的稳定性、硅酸钙与铝酸钠溶液的反应、水化石榴石与NaOH和Na2CO3作用和原硅酸钙水化反应分别进行了热力学分析。结果表明,原硅酸钙、硅酸钙在NaOH、Na2CO3和NaAl(OH)4这3种溶液成分中的稳定性是不同的;温度升高,NaOH、Na2CO3溶液分解水化石榴石的趋势变大,饱和系数较大的水化石榴石稳定性好于饱和系数较小的,水化石榴石在NaOH中的稳定性强于在Na2CO3溶液中的;低温下原硅酸钙最有可能水化成2CaO.SiO2.1.17H2O和4CaO.3SiO2.1.5H2O。

Thermodynamic computations and discussion of some reactions involved in the clinker leaching process are described. The stability of 2CaO· SiO2 in sodium aluminate liquor, the reactions between calcium Silicate and sodium aluminate liquors, the reactions between hydrogarnet and NaOH and Na2CO3, and the hydration of 2CaO·SiO2 have all been analyzed in thermodynamic terms. The results indicate that the stability subsequences of 2CaO·SiO2 and calcium silicate in the three alkaline solutions are dissimilar. The decomposition tendency of hydrogarnet in NaOH and Na2CO3 solutions increases with elevation of temperature. The stability of hydrogarnet with large saturation coefficient is higher than that with smaller saturation coefficient. Hydrogarnet is more stable in NaOH solution than in Na2CO3 solution. At low temperatures, hydration of calcium orthosilicate to afford 2CaO·SiO2·1.17H2O and 4CaO·3SiO2·1.5H2O is thermodynamically most favorable.