Synthetic fly ash cement for building - made from fly ash from coal fired plant, has properties similar to Portland cement

摘要

Synthetic cement prod. is made by passing a mixt. of 40% fly ash from coal fired electricity generating plant or coal gasification plant and 60% blast furnace slag or coarse ash together with air into a rotary furnace and fusing the mixt. at 1400 deg.C followed by quench cooling the liq. prod. to form a glassy granulate which is finely ground to give a cement with latent hydraulic action. Prod. is made from a by-product of coal fired plant which represents an environment pollutant, and gives a cement prod. having properties similar to those of Portland cement. The cement is made using 30-35% less energy than is required for the prodn. of Portland cement, due to the unburnt carbon content of the raw material.