Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
  • B03B9/00—General arrangement of separating plant, e.g. flow sheets
  • B03B9/005—General arrangement of separating plant, e.g. flow sheets specially adapted for coal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
  • B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
  • B03B5/28—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation
  • B03B5/30—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation using heavy liquids or suspensions
  • B03B5/44—Application of particular media therefor
  • B03B5/447—Application of particular media therefor recovery of heavy media

Definitions

• This invention concerns the separation of coal from gangue.
• the present process removes a considerable amount of the heavy media, usually a halogenated hydrocarbon, and permits its recycle.
• the improvement comprises: treating each solids portion with hot water, at the temperature of from the heavy medium water azeotroping point to the boiling point of water, for a time sufficient to remove a substantial portion of the heavy media or until the water comes off at its boiling point, and thereafter separating the solids from the water.
• a halogenated hydrocarbon-- the bromo, chloro, fluoro and mixed halogen hydrocarbons, particularly tetrachloro­ethylene (perchloroethylene), trichloroethylene, 1,1,1­-trichloroethane (methylchloroform), or methylene chloride (dichloromethane)-- is slurried with a crushed [preferivelyably 1/16 to 1 ⁇ 2 inch (0.16 to 1.27 cm)] run of the mine (R.O.M.) coal for a short period of time, usually from 15 to 10 minutes, at temperatures of from -10°C to 90°C. The slurry is allowed to settle under substan­tially quiescent or mild agitation conditions.
• each body of particles is independently treated with hot (preferably 90° to 100°C) water for a time sufficient to azeotrope off the separating liquid, i.e., the chlorinated solvent. This time is usually from several seconds to one hour, depending on the nature and the size of the particles.
• hot preferably 90° to 100°C
• Such treat ­ment reduces the retained liquid to between 100 to 19,000 parts by weight of liquid per million parts by weight of coal.
• Many coals can be freed of solvent to less than 400 parts by weight of liquid per million parts by weight of coal usually in 1 ⁇ 2 to 5 minutes contact. This is equivalent to less than 0.8 pound (0.36 kg) of liquid per ton of coal. Mild agitation may accompany the hot water treatment.
• the original coal had ash 11.7% sulfur 4.5% water 6.3%
• Ayrshire coal (R.O.M. from Amax, Indiana) was processed by a sink float method in one of the follow­ing solvents then freed of residual solvent by the hot water treatment of Example 1. Comparison is also reported using the convection oven drying technique. The following table lists the results of the hot water heavy media removal technique: Thus it is seen that the hot water treatment is equiva­lent to treatment with steam or hot air but equivalency can be achieved in shorter periods of time. The more important advantage is the ability to recover greater than 99 percent of the chlorinated solvent with the hot water treatment.
• Rocky Mountain Energy Prospect Point Mine labeled Leucite Hills, Wyoming, greater than 8 mesh coal from ground and screened R.O.M. coal, was sub­jected to heavy media separation using perchloro­ethylene as the heavy media.
• the specific gravity of each screen aliquot of coal was measured, the float/­sink from each screening filtered, and the cakes sub­jected to the hot water treatment of the present invention. The results obtained when the specific gravity varied are set forth below.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Extraction Or Liquid Replacement (AREA)

Priority Applications (2)

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Publications (1)

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Cited By (1)

Citations (7)

• 1986
  • 1986-02-14 EP EP86301033A patent/EP0234068A1/de not_active Ceased

Patent Citations (7)

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