Effect of calcium/aluminium ratio on crystal structure and A12O3 leaching property of 12CaO7Al2O3

Abstract

12CaO7Al2O3 (C12A7) with different calcium/aluminum ratio (C/A) were synthesized by sol-gel method and high-temperature sintering method in the paper. The phase composition of sinters was analyzed by XRD and the lattice constant was calculated by celref software. Finally, the alumina leaching experiments on sinters obtained from different synthesis methods were carried out. The results show the C/A of sinter with single phase C12A7 is 1.7 and the range of the best alumina leaching rate is between 1.6 and 1.8 when sol-gel method is used. On the other hand, the C/A is 1.6 and the range is between 1.4 and 1.6 when high-temperature sintering method is used. And the alumina leaching rate is direct proportion to the content of C12A7 and is inversely to the lattice constant under a certain conditions. Compared to sol-gel method, high-temperature sintering process can reduce the optimal C/A of C 12A7. Copyright © 2014 by The Minerals, Metals & Materials Society.