A fluidized-bed-type apparatus and method for treating gypsum, which activates or improves fluidity of gypsum powder to promote an effect of treatment of gypsum, such as modification or homogenization of the gypsum powder. The apparatus for treating gypsum includes a reactor vessel, a conditioned air supply port, a horizontal partition wall and a plurality of stationary vanes. The wall allows a conditioned air flow to flow upward into a reaction region. The vanes are arranged at an angular interval in a circumferential direction. A fluidized bed of calcined gypsum is provided in the vessel. The vane deflects the conditioned air flow flowing upward into the reaction region, toward a radially outward and circumferential direction of the reaction region. The calcined gypsum makes a saltational fluid motion or saltational movement in the vessel with the air flow.

A fluidized-bed-type apparatus and method for treating gypsum, which activates or improves fluidity of gypsum powder to promote an effect of treatment of gypsum, such as modification or homogenization of the gypsum powder. The apparatus for treating gypsum includes a reactor vessel, a conditioned air supply port, a horizontal partition wall and a plurality of stationary vanes. The wall allows a conditioned air flow to flow upward into a reaction region. The vanes are arranged at an angular interval in a circumferential direction. A fluidized bed of calcined gypsum is provided in the vessel. The vane deflects the conditioned air flow flowing upward into the reaction region, toward a radially outward and circumferential direction of the reaction region. The calcined gypsum makes a saltational fluid motion or saltational movement in the vessel with the air flow.

A fluidized-bed-type apparatus and method for treating gypsum, which activates or improves fluidity of gypsum powder to promote an effect of treatment of gypsum, such as modification or homogenization of the gypsum powder. The apparatus for treating gypsum includes a reactor vessel, a conditioned air supply port, a horizontal partition wall and a plurality of stationary vanes. The wall allows a conditioned air flow to flow upward into a reaction region. The vanes are arranged at an angular interval in a circumferential direction. A fluidized bed of calcined gypsum is provided in the vessel. The vane deflects the conditioned air flow flowing upward into the reaction region, toward a radially outward and circumferential direction of the reaction region. The calcined gypsum makes a saltational fluid motion or saltational movement in the vessel with the air flow.

A fluidized-bed-type apparatus and method for treating gypsum, which activates or improves fluidity of gypsum powder to promote an effect of treatment of gypsum, such as modification or homogenization of the gypsum powder. The apparatus for treating gypsum includes a reactor vessel, a conditioned air supply port, a horizontal partition wall and a plurality of stationary vanes. The wall allows a conditioned air flow to flow upward into a reaction region. The vanes are arranged at an angular interval in a circumferential direction. A fluidized bed of calcined gypsum is provided in the vessel. The vane deflects the conditioned air flow flowing upward into the reaction region, toward a radially outward and circumferential direction of the reaction region. The calcined gypsum makes a saltational fluid motion or saltational movement in the vessel with the air flow.

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 present application describes a process for the continuous production of alpha-calcium sulphate hemihydrate, the process comprising the steps of: providing particulate gypsum; providing water; mixing the particulate gypsum and the water to form a gypsum slurry; and maintaining said gypsum slurry under raised pressure and temperature to convert the particulate gypsum into alpha-calcium sulphate hemihydrate and provide an alpha-calcium sulphate hemihydrate slurry. Additionally, the particulate gypsum comprises a D10 value greater than or equal to 2 ?m, a D90 value smaller than or equal to 90 ?m and a D50 value smaller than or equal to 25 ?m. Particulate gypsum for use in the process is also provided.

The present application describes a process for the continuous production of alpha-calcium sulphate hemihydrate, the process comprising the steps of: providing particulate gypsum; providing water; mixing the particulate gypsum and the water to form a gypsum slurry; and maintaining said gypsum slurry under raised pressure and temperature to convert the particulate gypsum into alpha-calcium sulphate hemihydrate and provide an alpha-calcium sulphate hemihydrate slurry. Additionally, the particulate gypsum comprises a D10 value greater than or equal to 2 ?m, a D90 value smaller than or equal to 90 ?m and a D50 value smaller than or equal to 25 ?m. Particulate gypsum for use in the process is also provided.

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.

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.