Verfahren zur Herstellung von dispergierten wässrigen Suspensionen

A method of producing a dispersed aqueous suspension of an inorganic particulate material which includes the steps of (a) preparing an aqueous suspension of calcium carbonate particles having a particle size distribution such that at least 35% by weight have an esd less than 2 mu m, the solids concentration of the suspension being no more than 40% by dry weight; (b) concentrating the suspension by dewatering to increase the solids content to at least 60% by dry weight; and (c) adding a dispersing agent to the concentrated suspension to disperse the calcium carbonate particles and characterised in that the suspension produced by step (c) is pumpable and flowable, the dispersing agent comprising a water soluble copolymer of acrylic acid and maleic acid or a salt thereof having a molar ratio of acrylic acid units to maleic acid units of from 0.5:1 to 10:1 and a mass average molecular mass of from 1,000 to 100,000.