Mineral material powder with high dispersion ability and use of said mineral material powder

A process for preparing a ground mineral material in the absence of a dispersing agent consisting of the steps of:

• a) wet grinding mineral material in at least one grinding step in an aqueous suspension or slurry in the absence of a dispersing agent until the mineral material has a weight median particle diameter d50 from 1.1 μm to 1.5 μm, wherein the mineral material is selected from the group consisting of marble, chalk, dolomite, calcite, limestone, magnesium hydroxide, talc, gypsum, titanium oxide, and any mixture thereof;
• b) up-concentrating or dewatering the aqueous suspension or slurry of step a) in the absence of a dispersing agent to achieve a solids content of between 50% and 70%;
• c) drying the aqueous suspension or slurry of step a) or b) to achieve a solid content of 99.8%, wherein no dispersing agent is present in the mineral material so obtained;
• and
• d) optionally surface treating the mineral material obtained in step c) with at least one aliphatic carboxylic acid;
• and
• e) optionally de-agglomerating the mineral material after step d), wherein the calcium carbonate after grinding in step a) and before optional treatment in step d) has a BET/N2 specific area of from 3 m2/g to 13 m2/g, wherein the mineral material obtained in step c) has a top cut d98 of 1.8 μm-5.9 μm.