Process to disperse and/or grind and/or concentrate calcium carbonate in aqueous media using an aqueous solution containing zirconium compounds
The present invention is directed to a process for manufacturing a calcium carbonate product including the steps of (i) contacting calcium carbonate with of one or more zirconium compounds in an aqueous suspension and/or of an aqueous emulsion and/or of an aqueous solution to obtain a calcium carbonate-containing slurry, and (ii) dispersing the calcium carbonate-containing slurry to obtain a calcium carbonate product.
1. A process for manufacturing an aqueous dispersion or aqueous suspension of calcium carbonate comprising the steps of (i) contacting calcium carbonate with a dispersing aid agent in water to obtain a calcium carbonate-containing slurry, wherein the dispersing aid agent comprises a zirconium compound selected from the group consisting of ammonium zirconium carbonate, potassium zirconium carbonate, and mixtures thereof, and (ii) dispersing the calcium carbonate-containing slurry so that the dispersing aid agent is dispersed throughout the calcium carbonate-containing slurry to obtain an aqueous dispersion or aqueous suspension of calcium carbonate, wherein the aqueous suspension or aqueous dispersion of calcium carbonate so obtained consists of calcium carbonate, water, the zirconium compound and optionally one or more polyacrylates as a grinding agent or a dispersing agent or as both a grinding agent and a dispersing agent.
2. The process according to claim 1 , wherein the dispersing aid agent is ammonium zirconium carbonate.
3. The process according to claim 1 , wherein the dispersing aid agent is potassium zirconium carbonate.
4. The process according to claim 1 , wherein the dispersing aid agent is supplied in a form of an aqueous solution or an aqueous suspension or an aqueous emulsion, containing from 0.01% to 10% by dry weight of the zirconium compound.
5. The process according to claim 1 , wherein the dispersing aid agent is supplied in a form of an aqueous solution or an aqueous suspension or an aqueous emulsion, containing from 0.03% to 5% by dry weight of the zirconium compound.
6. The process according to claim 1 , wherein the dispersing aid agent is supplied in a dry form.
7. The process according to claim 1 , wherein in step (i), calcium carbonate in a dry form or in a form of an aqueous dispersion or an aqueous suspension or an aqueous filtercake, is added to an aqueous suspension or an aqueous emulsion or an aqueous solution containing the dispersing aid agent to obtain the calcium carbonate-containing slurry.
8. The process according to claim 1 , wherein in step (i), the zirconium compound in a dry form or in a form of an aqueous suspension or an aqueous emulsion or an aqueous solution, is added to an aqueous dispersion or an aqueous suspension or an aqueous filtercake of calcium carbonate in water to obtain the calcium carbonate-containing slurry.
9. The process according to claim 1 , wherein in step (i), calcium carbonate in a form of a pigment cake is added to an aqueous suspension or an aqueous emulsion containing the zirconium compound to obtain the calcium carbonate-containing slurry.
10. The process according to claim 9 , wherein the pigment cake is a filter-cake or a centrifuge cake or a cake obtained by a process of electro-concentration.
11. The process according to claim 9 , wherein the cake has a moisture content above 20% by dry weight of mineral matter.
12. The process according to claim 1 , wherein in step (i), the zirconium compound in a dry form or in a form of an aqueous suspension or an aqueous emulsion, is mixed with a pigment cake in water to obtain the calcium carbonate-containing slurry.
13. The process according to claim 12 , wherein the pigment cake is a filter-cake or a centrifuge cake or a cake obtained by a process of electro-concentration.
14. The process according to claim 12 , wherein the cake has a moisture content above 20% by dry weight of mineral matter.
15. The process according to claim 1 , wherein the calcium carbonate slurry comprises one or more polyacrylates.
16. The process according to claim 1 , wherein the calcium carbonate slurry does not include any dispersing aid agent other than the zirconium compound.
17. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate obtained in step (ii) is concentrated.
18. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate obtained in step (ii) is dried.
19. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate contains more than 45% by weight of calcium carbonate.
20. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate contains more than 65% by weight of calcium carbonate.
21. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate contains more than 75% by weight of calcium carbonate.
22. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate consists essentially of (i) calcium carbonate, (ii) ammonium zirconium carbonate, potassium zirconium carbonate, or mixtures thereof, and (iii) water.
23. The process according to claim 1 , wherein the aqueous dispersion or aqueous suspension of calcium carbonate consists essentially of (i) calcium carbonate, (ii) ammonium zirconium carbonate, potassium zirconium carbonate, or mixtures thereof, (iii) water, and (iv) one or more polyacrylates.
24. The process according to claim 18 , wherein the dried calcium carbonate consists of (i) calcium carbonate, and (ii) ammonium zirconium carbonate, potassium zirconium carbonate, or mixtures thereof.
25. The process according to claim 18 , wherein the dried calcium carbonate consists of (i) calcium carbonate, (ii) ammonium zirconium carbonate, potassium zirconium carbonate, or mixtures thereof, and (iii) one or more polyacrylates.