Embodiments of a system and a method for manufacturing calcined gypsum can include an in-line calcination control device having an x-ray analyzer. The x-ray analyzer is adapted to analyze at least one of the calcined gypsum being discharged from the calciner and the calcined gypsum being fed into a mixer of a gypsum boardline. The x-ray analyzer is configured to determine the proportion of different calcium sulphate phases found therein which can be used to control at last one of the calciner and the boardline.

Embodiments of a system and a method for manufacturing calcined gypsum can include an in-line calcination control device having an x-ray analyzer. The x-ray analyzer is adapted to analyze at least one of the calcined gypsum being discharged from the calciner and the calcined gypsum being fed into a mixer of a gypsum boardline. The x-ray analyzer is configured to determine the proportion of different calcium sulphate phases found therein which can be used to control at last one of the calciner and the boardline.

A new integrated method to capture polluted CO.sub.2 using CaO produced from phosphogypsum calcination using sulfur as non-CO.sub.2 fuel where (1) both pollutants of phosphogypsum and CO.sub.2 are transformed into environmentally neutral or useful products such as limestone or clinker and sulfuric acid; (2) low-CO.sub.2 CaO produced from calcination of phosphogypsum with sulfur as fuel can be used to produce low-CO.sub.2 clinker that replaces the use of high-CO.sub.2 limestone as raw material; (3) the use of sulfur as fuel to calcine phosphogypsum allows the production of low-cost sulfuric acid.

A new integrated method to capture polluted CO.sub.2 using CaO produced from phosphogypsum calcination using sulfur as non-CO.sub.2 fuel where (1) both pollutants of phosphogypsum and CO.sub.2 are transformed into environmentally neutral or useful products such as limestone or clinker and sulfuric acid; (2) low-CO.sub.2 CaO produced from calcination of phosphogypsum with sulfur as fuel can be used to produce low-CO.sub.2 clinker that replaces the use of high-CO.sub.2 limestone as raw material; (3) the use of sulfur as fuel to calcine phosphogypsum allows the production of low-cost sulfuric acid.

A system for conditioning stucco particulate material includes a vessel having separation chamber in communication with a holding chamber having a holding volume therein. The conditioning system includes the holding volume sufficient to condition the stucco particulate material therein and/or a control system configured to delay discharge of the stucco particulate material from the holding chamber. The system for conditioning stucco particulate material is configured to increase residence time of the stucco particulate material in the holding chamber to promote calcining conditioning therein.

A method for heat treatment of a grain-shaped feed material uses a calcination device in order to remove carbonate or water of crystallization from the feed material. In order to continuously check the quality of the heat treatment process, the bulk density of the heat-treated material is measured continuously, wherein upon detection of a deviation of the determined bulk density from the at least one desired bulk density at least one heat treatment parameter of the heat treatment is adapted automatically or manually.

A method for heat treatment of a grain-shaped feed material using a calcination device to remove carbonate or water of crystallization from the feed material are provided. To continuously check the quality of the heat treatment process, the bulk density of the heat-treated material is measured continuously, wherein upon detection of a deviation of the determined bulk density from the at least one desired bulk density at least one heat treatment parameter of the heat treatment is adapted automatically or manually.

A calcining kettle includes an outer kettle shell, an inner kettle shell, an interior heat exchanger assembly defining at least one tortuous path inside a volume defined by the inner kettle shell, and an agitator within the inner kettle shell. The inner kettle shell is disposed within the outer kettle shell such that the inner kettle shell and the outer kettle shell together at least partially define a jacket adjacent the inner kettle shell. The inner kettle shell and the interior heat exchanger assembly at least partially define a processing volume. The agitator is configured to rotate at least one paddle to cause movement of a feedstock material within the processing volume. A heating device may be structured and adapted to circulate a heat transfer fluid in the at least one tortuous path and the jacket. Calcining methods are also disclosed.

A calcined gypsum treatment apparatus has an agitating type of cooler provided with a cooling region for cooling the calcined gypsum, and a moisture supplying device for incorporating moisture into the calcined gypsum. The moisture supplying device includes a humid gas-feeding port which introduces humid gas including moisture or steam, directly into the cooling region. The calcined gypsum is introduced through a calcined gypsum introduction port into the cooling region, and the moisture is incorporated into the calcined gypsum to modify the calcined gypsum. The humid gas-feeding port is positioned in vicinity to the calcined gypsum introduction port so as to allow the spouted or delivered flow of the humid gas to be brought into contact with the calcined gypsum immediately after introduced into the cooling region.

The invention pertains to a process for modifying gypsum, wherein a continuous feed of raw gypsum is provided; the water content of the raw gypsum is determined in the continuous feed by near infrared spectroscopy (NIR) measurement; the raw gypsum is calcined in a calcination unit at a fire rate to remove water from the raw gypsum and to obtain a continuous feed of calcined gypsum having a water content within a selected range; a water content of the calcined gypsum is determined by near infrared spectroscopy, and the fire rate is adjusted based on the water content of the raw gypsum and of the calcined gypsum. Further, the invention pertains to an apparatus for performing said process.