Utilization of lime-sinter process residue for the manufacture of a low-alumina portland cement

The lime-sinter process for recovery of alumina from coal conversion solid wastes produces a residue that is largely dicalcium silicate (C/sub 2/S) and that contains only 3 to 5% Al/sub 2/O/sub 3/. Use of this residue will eliminate the need for its disposal and will make the lime-sinter process more attractive financially. The unique composition of the residue makes it an attractive raw material for the manufacture of ASTM Type V (sulfate resistant) portland cement. There is a substantial demand for this type of cement in the western states. The feasibility of thus using the residue is examined and a cost analysis for a combined alumina-portland cement plant capable of using the fly ash from a 1000 MWe coal-fired power station is presented. 12 references, 1 figure, 6 tables.