Abstract: A granular fibre-free microporous thermal insulation material, having a thermal conductivity less than 0.05 W/mK and a shrinkage of not more than 10%, which is free flowing and consists of granules of an intimate mixture of: 30-95% dry weight microporous insulating material; 5-70% dry weight infrared opacifier material; 0-50% particulate insulating filler material; and 0-5% binder material.

Abstract: A process for improving the brightness of an alkaline earth metal carbonate utilizing formamidine sulfinic acid or sodium dithionite as a reductive bleaching agent is disclosed. Where the alkaline earth metal carbonate is calcium carbonate, addition of the reductive bleaching agent to an aqueous slurry of the calcium carbonate takes place prior to, during, or after formation of the carbonate, which is chosen from at least one of a precipitated calcium carbonate and a ground calcium carbonate.

Abstract: A method of producing a rheologically stable concentrated aqueous suspension of a particulate alkaline earth metal carbonate which method comprises the following steps: (a) preparing a dilute aqueous suspension of the carbonate having a solids content of not more than 40% by weight; (b) dewatering the dilute aqueous suspension to form a carbonate suspension having a solids content in the range of from 45% to 65% by weight; (c) optionally mixing with the dewatered suspension formed in step (b) a dispersing agent for the carbonate to form a fluid suspension; (d) further dewatering the fluid suspension formed in step (b) by thermal evaporation under reduced pressure to raise the solids content of the suspension by a further differential amount of at least 5% by weight; and (e) after at least some of the dewatering in step (c) treating the suspension by a mechanical working process in which at least 1 kW.hr per tonne of carbonate on a dry weight basis is dissipated to refluidise the suspension.