Gypsum (calcium sulphate) is a material that calcines at a relatively low temperature to produce the required hemihydrates product. The proportions and forms of di-hydrate and anhydrate in the plaster products are very sensitive to calcining conditions, particularly temperature.
Our Fluidised bed Calciner design provides very limited temperature gradients across the bed of material being processed with the result that the calcining conditions can be more readily controlled to provide the required plaster product specification. The essence of the design is that it provides a pronounced velocity gradient across the lower region of the fluidised bed with the effect of keeping the whole bed of material in suspension. Under these circumstances there is no opportunity for material to settle out or partially de-fluidise and thus be subjected to over – temperature conditions. Our fluidised bed calcining concept differs significantly from other calcining process (kettle and Rotary kiln) which produces only low strength plasters. The calciner at our plant is designed to produce consistently high quality/grade plasters avoiding under burn and over burn of gypsum. GFRG panels are manufatured in moulding process from high grade gypsum plaster and glass fibre rovings to a size of 12 metres by 3 metres by 124 millimetres thick. The hollow sections have 250 milli metres. Panels are loaded on to collapsable frames called stillages ready for transport to the building site. The production and quality of panels and wall plaster are monitored using sophisticatied control systems.