Process with calcium sulfite hemihydrate in a powdery byproduct from dry flue gas desulfurization for the production of fly ash cement

摘要

A byproduct recovered in a dry flue gas desulfurization method for the production of fly ash cement. The flue gas, which results from the combustion of fossil fuel and which also carries along all or a part of the fly ash which results during the combustion, is treated in an absorber with a calcium-containing suspension (absorbing substance) in such a way that the solid materials leave the absorber as dry end product and are added entirely or partially to one or more dust removing apparatuses and are filtered off. The byproduct has a composition of 1 to 99% by weight, preferably 20 to 95% by weight, of fly ash, and 1 to 99% by weight, preferably 5 to 80% by weight, of the sum of the desulfurization products, preferably comprising calcium sulfate dihydrate and/or calcium sulfate hemihydrate and/or calcium sulfate and/or calcium sulfite hemihydrate.