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US 12,275,853 B2Granted
Process for preparing surface-reacted calcium carbonate
AssigneeOmya International AG
InventorDaniel E. Gerard
Life of this patent
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Abstract
The present invention relates to a process for producing a surface-reacted calcium carbonate, wherein a calcium carbonate-comprising material is treated with at least one inorganic acid and carbon dioxide in an aqueous medium to form an aqueous suspension of surface-reacted calcium carbonate, wherein the at least one water-soluble, inorganic magnesium salt is added before, during and/or after the treatment step. Furthermore, the present invention relates to a surface-reacted calcium carbonate obtained from said process and its use.
Claims20
A surface-reacted calcium carbonate comprising
- a calcium carbonate-comprising material, and at least one water-insoluble calcium salt selected from tricalcium phosphate and/or apatitic calcium phosphate,
- wherein the surface-reacted calcium carbonate comprises
- (i) a specific surface area of from 20 to 200 m2/g measured using nitrogen and the BET method according to ISO 9277:2010;
- (ii) an intra-particle intruded specific pore volume in the range of from 0.1 to 2.3 cm3/g calculated from mercury porosimetry measurement, and/or an intra-particle pore size in a range of from 0.004 to 1.0 μm, determined from mercury porosity measurement, and
- (iii) whitlockite in an amount of at least 0.1 wt.-%, based on the total amount of the calcium carbonate and the at least one water-insoluble calcium salt.
2 more elements
Dependencies are inferred from the claim text.