A method of conditioning stucco comprises the steps of supplying a quantity of stucco particles to a reaction vessel, the stucco particles comprising calcium sulphate hemihydrate and/or calcium sulphate anhydrite, as well as calcium sulphate dihydrate; and conditioning the stucco particles at a temperature of at least 100? C. and a humidity of at least 70%. During the step of conditioning the stucco particles, the bulk density of the stucco particles within the reaction vessel is at least 1 g/cm.sup.3.

Composition for building materials comprises of fly ash from flue gas desulfurization. The fly ash (CaSO.sub.4 anhydrite), obtained from circulating fluidized bed flue gas desulfurization, is mixed with binder reactants at a ratio of 9:1. It's mainly used for non-structural cement mortar, bricks for paving walkways, brick wall decors, fire-resistant walls for interior partitions, plasterboards and so on. The binder reactants compose of 70% CaSO.sub.4.H.sub.2O, 10% Na.sub.2SO.sub.4, 10% CaO, 5% NaOH, 05% cement and 05% starch. When the binder reactants are mixed with fly ash and water (30% to 40% of the above total weight), the hydration process of CaSO.sub.4 anhydrite is accelerated.

Composition for building materials comprises of fly ash from flue gas desulfurization. The fly ash (CaSO.sub.4 anhydrite), obtained from circulating fluidized bed flue gas desulfurization, is mixed with binder reactants at a ratio of 9:1. It's mainly used for non-structural cement mortar, bricks for paving walkways, brick wall decors, fire-resistant walls for interior partitions, plasterboards and so on. The binder reactants compose of 70% CaSO.sub.4.H.sub.2O, 10% Na.sub.2SO.sub.4, 10% CaO, 5% NaOH, 05% cement and 05% starch. When the binder reactants are mixed with fly ash and water (30% to 40% of the above total weight), the hydration process of CaSO.sub.4 anhydrite is accelerated.

The invention concerns an ettringitic and stratlingitic binder composition comprising: A) Crystaline calcium aluminate Cement (CAC), B) Ground Granulated Blast Furnace Slag (GGBS), and C) Sulfate source selected from the group consisting of Anhydrite calcium sulfate (AC$) and/or alkali sulfate (A$).

The invention concerns an ettringitic and stratlingitic binder composition comprising: A) Crystaline calcium aluminate Cement (CAC), B) Ground Granulated Blast Furnace Slag (GGBS), and C) Sulfate source selected from the group consisting of Anhydrite calcium sulfate (AC$) and/or alkali sulfate (A$).