# US 2023/0053620 A1 · Particle size control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0053620 A1 - Document ID: US20230053620A1 - Status: Published application - Kind: A1 - Application number: 17/759,255 - Filed: 2021-02-03 - Published: 2023-02-23 - Earliest claimed: 2020-02-06 - Assignees: Coatex - Applicants: Coatex - Inventors: Benoit MAGNY; Celine METHIVIER; Jacques MONGOIN - Web page: https://patentgrep.com/patent/US20230053620A1 ## CPC - C09C 3/041: {Grinding} - C01B 25/01: Treating phosphate ores or other raw phosphate materials to obtain phosphorus or phosphorus compounds - C08F 20/06: Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof - C08F 120/06: Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof - C09K 23/52: Natural or synthetic resins or their salts - C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer - 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} - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract The invention relates to a method for grinding phosphate rock in the presence of a particular anionic polymer having a molecular weight of between 1000 and 90000 g/mol, which makes it possible to control the extent (S) of the volume distribution of the particle size of obtained phosphate mineral particles. The invention also relates to a method for improving the production yield of a phosphate rock grinding method. ## Claims ### Claim 1 A method for preparing an aqueous suspension of phosphate mineral particles, comprising: grinding a of at least one phosphate material in the presence of water and an anionic polymer (P) with a molecular mass by weight (MW) between 1,000 and 90,000 g/mol, wherein the anionic polymer (P) is obtained by polymerisation reaction of at least one acid selected from the group consisting of acrylic acid, methacrylic acid and salts thereof, wherein a span (S) of a volume distribution of particle sizes [(d0.9−d0.1)/d0.5] measured by laser diffraction is less than 4.1. ### Claim 2 (depends on 1) The method according to claim 1, wherein the span (S) is less than 4.0. ### Claim 3 (depends on 1) The method according to claim 1 further comprising separating a fraction of particles of the phosphate material whose size d0.1 is less than 4 μm. ### Claim 4 (depends on 3) The method according to claim 3, wherein the separation is carried out in a liquid-cyclone, centrifuge or a combination thereof. ### Claim 5 (depends on 3) The method according to claim 3, wherein a concentration by weight of the phosphate mineral particles of the aqueous suspension during the grinding is greater than 10%. ### Claim 6 (depends on 5) The method according to claim 5, wherein the particles of the phosphate material have a size d0.9 before the grinding that is greater than 800 μm. ### Claim 7 (depends on 6) The method according to claim 6, wherein the particles of the phosphate material have a size d0.5 after the grinding that is less than 300 μm. ### Claim 8 (depends on 1) The method according to claim 1, wherein a grinding time is less than 5 hrs and 30 min. ### Claim 9 (depends on 1) The method according to claim 1, wherein a grinding time is reduced by at least 10% relative to a grinding time in an absence of the anionic polymer (P). ### Claim 10 (depends on 1) The method according to claim 1, wherein the anionic polymer (P) is partially or completely neutralised. ### Claim 11 (depends on 1) The method according to claim 1, wherein the anionic polymer (P) is obtained by a polymerisation reaction with at least one acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid and salts thereof or at least one ester of an acid chosen among acrylic acid and methacrylic acid. ### Claim 12 (depends on 1) The method according to claim 1, wherein the anionic polymer (P) has a molecular mass by weight (MW) between 2,000 and 90,000 g/mol. ### Claim 13 (depends on 1) The method according to claim 1, wherein an amount by weight (dry/dry) of the anionic polymer (P) is between 0.07 and 2% relative to an amount of the phosphate material. ### Claim 14 An aqueous suspension of mineral particles of a phosphate material, comprising: at least one anionic polymer (P) with a molecular mass by weight (MW) between 1,000 and 90,000 g/mol, wherein the anionic polymer (P) is obtained by polymerisation reaction of at least one acid selected from the group consisting of acrylic acid, methacrylic acid and salts thereof, wherein a span (S) of a volume distribution of particle sizes [(d0.9−d0.1)/d0.5] measured by laser diffraction is less than 4.1. ### Claim 15 (depends on 1) A suspension obtained by the method of claim 1. ### Claim at position 16 -19. (canceled) ### Claim 20 (depends on 11) The method according to claim 11, wherein the anionic polymer (P) is partially or completely neutralised by at least one derivative selected from the group consisting of lithium, sodium, calcium, magnesium and mixtures thereof.