| 摘要 |
PURPOSE:To evaporate easily the water contents by adding a material obtained by adding, if necessary, Ca sulfate, alumina, etc. to calcined and activated alunite in the presence of cement to form ettringite in the treatment of high- water content wastes. CONSTITUTION:In treating high-water content wastes, a material obtained by adding, if necessary, Ca sulfate, alumina, etc. to alunite which is calcined and activated is added to the wastes in the presence of cement not necessarily to cure the wastes but to form efficiently ettringite, or a low-sulfuric acid type ettringite double salt contg. 14-16 molecules of water of crystallization and Ca sulfate are added to form ettringite. The water content is thus separated into the upper layer to the utmost and removed as much as possible, or the wastes are swollen and made easily dryable. The easily dryable condensate is dried naturally or by heating to obtain massive, granular, or powdery cake in a short time. The shape of the obtained cake can be freely regulated, and the reutilization of the cake is also possible.
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