# US 8,465,583 B2 · Compositions comprising fine sedimentary kaolin and methods for preparing same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,583 B2 - Document ID: US8465583B2 - Status: Granted - Kind: B2 - Application number: 13/333,458 - Filed: 2011-12-21 - Published: 2012-04-19 - Granted: 2013-06-18 - Earliest claimed: 2005-05-03 - Assignees: Imerys Pigments, Inc. - Applicants: Robert J. Pruett; Paula R. Alves - Inventors: Robert J. Pruett; Paula R. Alves - Web page: https://patentgrep.com/patent/US8465583B2 ## CPC - C04B 33/04: Clay; Kaolin - C09C 1/42: Clays - C01P 2002/04: Compounds with a limited amount of crystallinty, e.g. as indicated by a crystallinity index - C01P 2004/03: obtained by SEM - C01P 2004/51: Particles with a specific particle size distribution - C01P 2004/54: Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension - C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer - C01P 2004/62: Submicrometer sized, i.e. from 0.1-1 micrometer - C01P 2006/60: Optical properties, e.g. expressed in CIELAB-values - C01P 2006/80: Compositional purity - C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS} - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract Disclosed herein are kaolin compositions, such as beneficiated fine sedimentary kaolin compositions. The beneficiated fine sedimentary kaolins may be obtained from the upper bed of the Rio Capim Kaolin deposit. The compositions may have at least one property chosen from a low iron content and low Hinckley crystallinity index, such as Fe2O3 in an amount less than about 0.8% by weight relative to the total weight of the solids content and wherein the Hinckley crystallinity index of the kaolin is less than about 0.5. Also disclosed are products obtained therefrom, such as paint and paper coating compositions. ## Claims ### Claim 1 A composition comprising a beneficiated fine sedimentary kaolin, having a particle size distribution such that at least about 97% of the kaolin has a particle size less than about 1 μm, and wherein the composition containing Fe2O3 in an amount greater than zero but less than about 0.8% by weight relative to the total weight of the solids content, wherein the kaolin exhibits a Hinckley crystallinity index of about 0.5 or less. ### Claim 2 (depends on 1) The composition according to claim 1, wherein the Fe2O3 is present in an amount greater than zero but less than about 0.6% by weight relative to the total weight of the solids content. ### Claim 3 (depends on 1) The composition according to claim 1, wherein the Fe2O3 is present in an amount greater than zero but less than about 0.4% by weight relative to the total weight of the solids content. ### Claim 4 (depends on 1) The composition according to claim 1, wherein the Hinckley crystallinity index is less than about 0.4. ### Claim 5 (depends on 1) The composition according to claim 1, wherein the Hinckley crystallinity index is less than about 0.2. ### Claim 6 (depends on 1) The composition according to claim 1, wherein the kaolin has a d50 of less than 0.5 μm. ### Claim 7 (depends on 1) The composition according to claim 1, wherein the kaolin has a d50 of less than 0.25 μm. ### Claim 8 A method of refining a kaolin, the method comprising: beneficiating fine sedimentary kaolin to form a beneficiated fine sedimentary kaolin containing sedimentary kaolin having a particle size distribution such that at least about 97% of the kaolin has a particle size less than about 1 μm, wherein the kaolin contains Fe2O3 in an amount greater than zero but less than about 0.8% by weight relative to the total weight of the solids content, wherein the kaolin exhibits a Hinckley crystallinity index of about 0.5 or less. ### Claim 9 (depends on 8) The method according to claim 8, wherein the fine sedimentary kaolin prior to the beneficiating contains TiO2 in an amount of at least 1.5% by weight relative to the total weight of the solids content, and Fe2O3 in an amount of at least about 1% by weight relative to the total weight of the solids content. ### Claim 10 (depends on 8) The method according to claim 8, wherein the fine sedimentary kaolin prior to the beneficiating is a Rio Capim fine sedimentary kaolin. ### Claim 11 (depends on 8) The method according to claim 8, wherein the beneficiating comprises at least one process chosen from dispersion, blunging, selective flocculation, ozone bleaching, classification, magnetic separation, chemical leaching, froth flotation, and dewatering of the kaolin. ### Claim 12 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin contains Fe2O3 in an amount greater than zero but less than about 0.6% by weight relative to the total weight of the solids content. ### Claim 13 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin comprises Fe2O3 in an amount greater than zero but less than about 0.4% by weight relative to the total weight of the solids content. ### Claim 14 (depends on 8) The method according to claim 8, wherein the Hinckley crystallinity index of the beneficiated fine sedimentary kaolin is less than about 0.4. ### Claim 15 (depends on 8) The method according to claim 8, wherein the Hinckley crystallinity index of the beneficiated fine sedimentary kaolin is less than about 0.2. ### Claim 16 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin has a particle size distribution such that at least about 98% of the kaolin has a particle size less than about 1 μm. ### Claim 17 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin has a particle size distribution such that at least about 99% of the kaolin has a particle size less than about 1 μm. ### Claim 18 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin has a particle size distribution such that at least about 96% of the kaolin has a particle size less than about 0.5 μm. ### Claim 19 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin has a particle size distribution such that at least about 65% of the kaolin has a particle size less than about 0.25 μm. ### Claim 20 (depends on 8) The method according to claim 8, wherein the beneficiated fine sedimentary kaolin has a GE brightness of at least about 86. ### Claim 21 (depends on 20) The method according to claim 20, wherein the GE brightness is at least about 90.