Process of manufacturing a co-ground calcium carbonate material of the GCC and PCC type with a specific steepness factor, obtained products and their uses

Abstract

An object of the present invention is to provide a process to obtain a calcium carbonate material comprising GCC and PCC, with a specific steepness factor (defined as d 30 /d 70 ×100, where d x is the equivalent spherical diameter relative to which x % by weight of the particles are finer) of at least about 30, preferably of at least about 40, and most preferably of at least about 45, in a cost efficient manner, wherein GCC and PCC are co-ground, possibly with at least another mineral material. An other object of the present invention lies in the obtained co-ground calcium carbonate material in the form of an aqueous suspension and in the form of a dry product. An other object of the present invention lies in the uses of such products in any sector making use of mineral materials, and notably in the paper, paint and plastic industries.

1 - 18 . (canceled) 
     
     
         19 . Co-ground calcium carbonate material comprising GCC and PCC, obtained by the process of co-grinding GCC and PCC to obtain co-ground calcium carbonate material having a steepness factor of at least 30, preferably of at least 40, and most preferably of at least 45. 
     
     
         20 . Co-ground calcium carbonate material comprising GCC and PCC, in the form of an aqueous suspension having a steepness factor of at least 30, preferably of at least 40, and most preferably of at least 45. 
     
     
         21 . Co-ground calcium carbonate material according to  claim 20 , comprising from 20 to 80% by dry weight of calcium carbonate material, preferably from 40 to 75% by dry weight of calcium carbonate material, and most preferably from 60 to 70% by dry weight of calcium carbonate material. 
     
     
         22 . Co-ground calcium carbonate material according to  claim 20 , wherein the PCC present accounts for 10% to 90% of the total combined PCC and GCC weight, preferably from 20% to 80% of the total combined PCC and 0CC weight, and most preferably from 30% to 70% of the total combined PCC and GCC weight. 
     
     
         23 . Co-ground calcium carbonate material according to  claim 20 , having a d 50  from about 0.2 μm to 2 μm, preferably from 0.2 μm to 0.8 μm, and most preferably from 0.25 μm to 0.45 μm. 
     
     
         24 . Co-ground calcium carbonate material according to  claim 20 , wherein the aqueous suspension contains at least one dispersing and/or grinding aid agent, such dispersing and/or grinding aid agent being present in a weight % relative to the total dry mineral material ranging from 0 to 2%, preferably from 0.2 to 1.4%, most preferably from 0.5% to 1.2%. 
     
     
         25 . Co-ground calcium carbonate material according to  claim 20 , wherein slurry water from the aqueous suspension passed through a 40 μm sieve contains less than 1000 ppm of ZrO 2  and less than 200 ppm CeO 2 . 
     
     
         26 . Co-ground calcium carbonate material according to  claim 20 , wherein slurry water from the aqueous suspension comprises a ZrO 2 /CeO 2  weight ratio of from 4 to 6.5, preferably of from 4.6 to 5.7, and most preferably of 5.3. 
     
     
         27 . Co-ground calcium carbonate material according to  claim 20 , comprising:
 a fraction of particles finer than 1 μm of greater than 80%, preferably of greater than 85%, more preferably of greater than 90%, and even more preferably of greater than 95%, and   a BET specific surface area of less than 25 m 2 /g.   
     
     
         28 . Co-ground calcium carbonate material according to  claim 27 , wherein for a fraction of particles finer than 1 μm of greater than 95%, the BET specific surface area is less than 25 m 2 /g. 
     
     
         29 . Co-ground calcium carbonate material according to  claim 27 , wherein for a fraction of particles finer than 1 μm of greater than 90%, the BET specific surface area is less than 20 m 2 /g. 
     
     
         30 . Co-ground calcium carbonate material according to  claim 27 , wherein for a fraction of particles finer than 1 μm of greater than 85%, the BET specific surface area is less than 18 m 2 /g. 
     
     
         31 . Co-ground calcium carbonate material according to  claim 27 , wherein for a fraction of particles finer than 1 μm of greater than 80%, the BET specific surface area is less than 15 m 2 /g. 
     
     
         32 . Co-ground calcium carbonate material comprising GCC and PCC, in the form of a dry product, having a steepness factor of at least 30, preferably of at least 40, and most preferably of at least 45. 
     
     
         33 . Co-ground calcium carbonate material according to  claim 32 , wherein the PCC present accounts for 10% to 90% of the total combined PCC and GCC weight, preferably from 20% to 80% of the total combined PCC and GCC weight, and most preferably from 30% to 70% of the total combined PCC and 0CC weight. 
     
     
         34 . Co-ground calcium carbonate material according to  claim 32 , comprising:
 a fraction of particles finer than 1 pm of greater than 80%, preferably of greater than 85%, more preferably of greater than 90%, and even more preferably of greater than 95%, and   a BET specific surface area of less than 25 m 2 /g.   
     
     
         35 . Co-ground calcium carbonate material according to  claim 34 , wherein for a fraction of particles finer than 1 μm of greater than 95%, the BET specific surface area is less than 25 m 2 /g. 
     
     
         36 . Co-ground calcium carbonate material according to  claim 34 , wherein for a fraction of particles finer than 1 μm of greater than 90%, the BET specific surface area is less than 20 m 2 /g. 
     
     
         37 . Co-ground calcium carbonate material according to  claim 34 , wherein for a fraction of particles finer than 1 μm of greater than 85%, the BET specific surface area is less than 18 m 2 /g. 
     
     
         38 . Co-ground calcium carbonate material according to  claim 34 , wherein for a fraction of particles finer than 1 μm of greater than 80%, the BET specific surface area is less than 15 m 2 /g. 
     
     
         39 . Co-ground calcium carbonate material according to  claim 32 , having a d 50  from about 0.2 μm to 2 μm, preferably from 0.2 μm to 0.8 μm, and most preferably from 0.25 μm to 0.45 μm. 
     
     
         40 . Co-ground calcium carbonate material according to  claim 32 , comprising a ZrO 2 /CeO 2  weight ratio of from 4 to 6.5, preferably of from 4.6 to 5.7, and most preferably of 5.3. 
     
     
         41 . Paper, paints or plastics comprising the co-ground calcium carbonate material according to  claim 19 .