Production and properties of alinite cements from steel plant wastes

Abstract

A class of cements based on a new cementitious phase alinite has been produced by clinkering at 1150°C, the steel plant wastes such as fly ash, limestone fines, mill scale, magnesite dust and with calcium chloride as a sintering aid. An important empirical correlation between the alinite cement strength and a parameter called 'lime index' has been established for the purpose of raw mix design. The optimum CaCl₂ addition to the raw mix is found to be 7-8% by weight. Alinite clinkers which are very friable can be produced at 1150°C. Their strength properties are comparable to or even superior to portland cement. In addition to the substantial energy savings, these cements have also been found to be relatively insensitive to various impurities in the raw mix. This low temperature clinkering route thus appears to be a promising method of converting industrial wastes into hydraulic setting cements.