Hydration of high-calcium quicklime with methanol-water mixtures

In this study, hydration of quicklime was accomplished with different methanol-water mixtures. The greater the percentage of methanol, the more intense was the suppression of the hydration conditions. The reactivity was not greatly affected by the presence of methanol up to 20%, while for hydration mixtures with 30 to 60% methanol a great reduction of reactivity was observed. In all cases of hydration the complete conversion of CaO into Ca(OH)(2) was established by the XRD method. From the SEM study it was ascertained that in a percentage Of up to 20% methanol, a normal hydration was observed, expressed by aggregates of hydrated lime grains, whereas the hydration in mixtures of 30-60% methanol, progressively leads to the formation of tabular crystals, the size of which increases with the methanol percentage. What is more important is that the maximum hydration temperature decreases up to 12.5degreesC for hydration mixtures up to 20% methanol without the quality of the produced hydrated lime being affected. (C) 2002 Elsevier Science Ltd. All rights reserved.