# US 12,214,363 B2 · Method for separating fine particles in soil using cationic magnetic nanoparticles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,363 B2 - Document ID: US12214363B2 - Status: Granted - Kind: B2 - Application number: 17/277,630 - Filed: 2019-09-18 - Published: 2021-11-11 - Granted: 2025-02-04 - Earliest claimed: 2018-09-18 - Assignees: Korea Atomic Energy Research Institute - Applicants: Korea Atomic Energy Research Institute - Inventors: Il Gook Kim; Chan Woo Park; Hee Man Yang; Kune Woo Lee; In Ho Yoon; Bum Kyoung Seo - Web page: https://patentgrep.com/patent/US12214363B2 ## CPC - B03C 1/30: Combinations with other devices, not otherwise provided for - B03C 1/0332: {using permanent magnets} - B03C 1/288: {disposed at the outer circumference of a recipient} - B03C 7/02: Separators - B09C 1/00: Reclamation of contaminated soil - C08J 3/12: Powdering or granulating - C08J 3/20: Compounding polymers with additives, e.g. colouring - C08K 3/22: of metals - C08K 9/10: Encapsulated ingredients - C08L 79/02: Polyamines - G21F 9/00: Treating radioactively contaminated material; Decontamination arrangements therefor - H01F 1/0054: {Coated nanoparticles, e.g. nanoparticles coated with organic surfactant} - H01F 1/342: {Oxides (H01F1/36 and H01F1/38 take precedence)} - B03C 2201/18: Magnetic separation whereby the particles are suspended in a liquid - B03C 2201/20: Magnetic separation of bulk or dry particles in mixtures - B82Y 25/00: Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C08G 73/0206: {Polyalkylene(poly)amines} - C08K 2201/011: Nanostructured additives - B03C: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS (separating isotopes B01D59/00; combinations of magnetic or electrostatic separation with separation of solids by other means B03B, B07B) - B09C: RECLAMATION OF CONTAMINATED SOIL (gatherers for removing stone or the like from the soil A01B43/00; sterilising soil by steam A01G11/00; removing undesirable matter, e.g. rubbish, from the land E01H15/00) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - G21F: PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR (radiation protection by pharmaceutical means A61K8/00, A61Q17/04; in cosmonautic vehicles B64G1/54; combined with a reactor G21C11/00; combined with X-ray tubes H01J35/16; combined with X-ray apparatus H05G1/02) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract A method of separating fine particles (clay, silt, etc.) that have adsorbed contaminants such as heavy metals or radioactive nuclides in soil using cationic magnetic nanoparticles. According to the method, contaminants such as heavy metals or radioactive nuclides selectively or irreversibly adsorbed to fine particles (clay, silt, etc.) in soil may be economically and efficiently separated. Therefore, the method may be effectively used to restore soil in residential areas that are contaminated with radioactive nuclides in serious accidents such as the Fukushima Daiichi nuclear disaster as well as facility sites contaminated with heavy metals or radioactive nuclides. ## Claims ### Claim 1 A method of separating fine particles in soil, comprising: preparing a cationic magnetic nanoparticle composite by mixing magnetic nanoparticles and a cationic material (Step a); mixing the composite with a contaminated soil so that the composite is bonded with fine particles containing clay or silt by electrostatic attraction (Step b); and performing magnetic separation or sequentially performing sieving and magnetic separation (Step c). ### Claim 2 (depends on 1) The method of claim 1, wherein the magnetic nanoparticles are prepared by coprecipitation method. ### Claim 3 (depends on 1) The method of claim 1, wherein the magnetic nanoparticles are iron oxide nanoparticles. ### Claim 4 (depends on 1) The method of claim 1, wherein the cationic material comprises one or more selected from the group consisting of polyethyleneimine, poly(diallyldimethylammoniumchloride) and (3-aminopropyl)triethoxysilane. ### Claim 5 (depends on 1) The method of claim 1, wherein the cationic material and the magnetic nanoparticles are mixed in a ratio of cationic material/magnetic nanoparticle (w/w) of 0.01 to 1. ### Claim 6 (depends on 1) The method of claim 1, wherein the contaminated soil contains one or more selected from the group consisting of a heavy metal and a radioactive nuclide. ### Claim 7 (depends on 1) The method of claim 1, wherein in Step c, the sieving and the magnetic separation are sequentially performed by a separator divided into a first cell in which agitation is performed and a second cell having a magnetic part based on a sieve, and particles passing through the sieve in the contaminated soil that underwent Step b, fed into the first cell, are separated by a magnetic force. ### Claim 8 (depends on 1) The method of claim 1, further comprising: in Step c, after the sequential performance of sieving and magnetic separation (first separation), additionally performing sieving and magnetic separation (second separation), wherein a mesh size of the sieve used in the second separation is smaller than that used in the first separation. ### Claim 9 (depends on 1) The method of claim 1, further comprising: after Step c, treating magnetic particles separated by a magnetic force as waste.