常压石灰法处理烧结法赤泥脱碱及其机理研究

摘要

采用石灰( CaO)作为脱碱剂处理烧结法赤泥,研究了反应温度、反应时间、脱碱剂添加量、液固比等因素对赤泥中钾、钠溶出率等碱脱除效果的影响,分析了石灰处理赤泥的脱碱机理.结果表明:温度升高、反应时间延长、石灰掺量增加以及液固比增大均能提高赤泥的脱碱效果,其中尤以反应时间和石灰掺量的影响效果更显著.添加石灰处理烧结法赤泥的脱碱机理是部分方钠石( NasAl6Si6O24CO3)中的2个Na+1个Ca2+置换出,生成了更难溶的钙霞石[ Na6CaAl6Si6(CO3)O24·2H2O].%Dealkalization of sintering process red mud was made by lime (CaO) as de-alkali agent. Reaction temperature, reaction time, addition dosage of de-alkali agent, and liquid-solid ratio on the alkali removal effects, such as dissolution rates of potassium and sodium in the red mud were studied and dealkalization mechanism of lime process was analyzed. Results showed that the rise of temperature,the elongation of reaction time, the augment of lime dosage,and the increase of liquid-solid ratio were all able to improve the dealkalization effect of red mud,especially,the reaction time and lime dosage.Dealkalization mechanism of sintering process red mud by adding CaO was that two Na* were replaced by one Ca2*in the part of sodalite(Na8Al3Si6O24CO3)to produce a more insoluble calcium nep