# US 10,307,766 B1 · Systems and methods for separating soft burned and hard burned calcium oxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,307,766 B1 - Document ID: US10307766B1 - Status: Granted - Kind: B1 - Application number: 15/144,258 - Filed: 2016-05-02 - Granted: 2019-06-04 - Earliest claimed: 2015-05-01 - Assignees: Mississippi Lime Company - Applicants: Mississippi Lime Company - Inventors: Mark DeGenova; Randy J. Griffard; David Venhaus - Web page: https://patentgrep.com/patent/US10307766B1 ## CPC - B02C 23/38: in apparatus having multiple crushing or disintegrating zones - B07B 7/00: Selective separation of solid materials carried by, or dispersed in, gas currents (sieves or filters for separating dispersed particles from gases or vapours B01D) - B07B 13/04: according to size - C04B 2/10: Preheating, burning calcining or cooling (decarbonation during burning of cement raw materials C04B7/43; {obtaining CaO or MgO otherwise than by thermal decomposition of the corresponding carbonates C01F11/02, C01F5/02}) - B02C 23/14: with more than one separator - Y02P 40/40: Production or processing of lime, e.g. limestone regeneration of lime in pulp and sugar mills - B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02}) - B07B: SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL (wet separating processes, sorting by processes using fluent material in the same way as liquid B03; combinations of dry separating apparatus with wet separating apparatus B03B; using liquids B03B, B03D; sorting by magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high voltage electric fields B03C; centrifuges or vortex apparatus for carrying out physical processes B04; hand sorting, postal sorting, sorting by switching or other devices actuated in response to detection or measurement of some feature of articles or samples of material B07C) - 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 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Systems and methods to effectively sort calcined lime (quicklime) particles to produce products with more consistent size and burn time characteristics after the quicklime particles have been created and without the use of specialized additives. Specifically, such systems and methods sort the quicklime particles below a selected size into a softer burned and harder burned fraction based on their size. The fractions are burned in the kiln together and as a singular product, but can be classified from each other after calcining. ## Claims ### Claim 1 A method for separating soft-burned quicklime from hard-burned quicklime, the method comprising: grinding a limestone feedstock including limestone and impurities to a first size; calcining said limestone in said limestone feedstock to produce a quicklime; milling said quicklime into a quicklime particulate, said quicklime particulate having between 80% and 90% of its particles smaller than 100 mesh; separating said quicklime particles which are smaller than 100 mesh from a remainder which is larger than 100 mesh, said quicklime particles which are smaller than 100 mesh having a size distribution with two peaks in a bimodal distribution; and running said quicklime particles which are smaller than 100 mesh through a classifier to separate said quicklime particles which are smaller than 100 mesh into a soft burned and a hard burned fraction separated by a dividing point, said soft burned fraction being particles smaller than said dividing point and said hard burned fraction being particles larger than said dividing point; wherein said dividing point is between said two peaks in said bimodal distribution. ### Claim 2 (depends on 1) The method of claim 1 wherein said dividing point is defined by a specific particle size. ### Claim 3 (depends on 2) The method of claim 2 wherein said dividing point is selected to be between 4 and 7 microns. ### Claim 4 (depends on 1) The method of claim 1 wherein said dividing point is defined as a size under which a percentage of particles in said remainder is below. ### Claim 5 (depends on 4) The method of claim 4 wherein said percentage is 20%. ### Claim 6 (depends on 1) The method of claim 1 wherein said soft burned fraction has an R180 of greater than 40 degrees. ### Claim 7 (depends on 6) The method of claim 6 wherein said hard burned fraction has an R180 of less than 30 degrees. ### Claim 8 (depends on 1) The method of claim 1 further comprising: grinding said remainder to a size which is smaller than 100 mesh; and classifying said ground remainder as a very hard burned fraction. ### Claim 9 (depends on 1) The method of claim 1 further comprising: selecting a second dividing point; and removing from said soft burned fraction a medium burned fraction, said medium burned fraction being particles larger than said second dividing point. ### Claim 10 (depends on 9) The method of claim 9 wherein said soft burned fraction has an R180 of greater than 40 degrees, said medium burned fraction has an R180 between 30 and 40 degrees, and said hard burned fraction has an R180 of less than 30 degrees. ### Claim 11 (depends on 1) The method of claim 1 further comprising: selecting a second dividing point; and removing from said hard burned fraction a medium burned fraction, said medium burned fraction being particles smaller than said second dividing point. ### Claim 12 (depends on 11) The method of claim 11 wherein said soft burned fraction has an R180 of greater than 40 degrees, said medium burned fraction has an R180 between 30 and 40 degrees, and said hard burned fraction has an R180 of less than 30 degrees.