EP0020275A1 - Process for improving the recovery of clean coal from flotation circuits - Google Patents

Process for improving the recovery of clean coal from flotation circuits Download PDF

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Publication number
EP0020275A1
EP0020275A1 EP80400775A EP80400775A EP0020275A1 EP 0020275 A1 EP0020275 A1 EP 0020275A1 EP 80400775 A EP80400775 A EP 80400775A EP 80400775 A EP80400775 A EP 80400775A EP 0020275 A1 EP0020275 A1 EP 0020275A1
Authority
EP
European Patent Office
Prior art keywords
coal
flotation
improving
recovery
clean coal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP80400775A
Other languages
German (de)
French (fr)
Inventor
Glen F. Snow
Hugh L. Bell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Calgon Corp
Original Assignee
Calgon Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Calgon Corp filed Critical Calgon Corp
Publication of EP0020275A1 publication Critical patent/EP0020275A1/en
Withdrawn legal-status Critical Current

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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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/001—Flotation agents
    • B03D1/004—Organic compounds
    • B03D1/016—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L9/00—Treating solid fuels to improve their combustion
    • 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D2203/00—Specified materials treated by the flotation agents; specified applications
    • B03D2203/02—Ores
    • B03D2203/04—Non-sulfide ores
    • B03D2203/08—Coal ores, fly ash or soot

Definitions

  • Flotation processes have been used for some time in the coal industry to recover coal fines from previously discarded aqueous streams generated by processing raw coal.
  • the flotation feed consists of fine coal and clay which results from prior coarse separation steps such as baths, jigs, dewatering screens, sieve bends and cyclones.
  • the feed is normally 28 x 0 mesh and contains 4 to 12 percent solids.
  • the flotation circuit consists of four to eight cells in a single bank with the number of banks proportional to the total tonnage to be processed.
  • the concentrate produced in the flotation cells goes to a vacuum filter where it is concentrated to approximately 75 to 80 percent solids.
  • the tailings from the flotation process are discharged to a waste pond or a refuse vacuum filter.
  • the very fine clay that is in the circuit often becomes entrapped in and/or adsorbed on the coal being floated and increases the amount of ash in the final product.
  • the polymer may be added to the feed to the flotation circuit or to the individual cells by conventional feeding means and it is believed that it functions by flocculating the fine coal fraction.
  • the polymer may be used in dosages of between 0.025 and 1 pound per ton, preferably at least 0.05 pounds per ton, based on the weight of the dry flotation feed.
  • Suitable polymers which may be used in accordance with the teachings of this invention are water soluble, partially hydrolyzed polyacrylamides having a degree of hydrolysis of from 1 percent to 50 percent and a molecular weight of at least 50,000, and preferably at least 1,000,000.

Abstract

Adding an effective amount of a water soluble, partially hydrolyzed polyacrylamide to the coal being processed to decrease the amount of the clay being floated and removed from the cells with the fine coal.

Description

    Background of the Invention
  • Flotation processes have been used for some time in the coal industry to recover coal fines from previously discarded aqueous streams generated by processing raw coal. Generally, the flotation feed consists of fine coal and clay which results from prior coarse separation steps such as baths, jigs, dewatering screens, sieve bends and cyclones. The feed is normally 28 x 0 mesh and contains 4 to 12 percent solids.
  • The flotation circuit consists of four to eight cells in a single bank with the number of banks proportional to the total tonnage to be processed. The concentrate produced in the flotation cells goes to a vacuum filter where it is concentrated to approximately 75 to 80 percent solids. The tailings from the flotation process are discharged to a waste pond or a refuse vacuum filter. During the flotation process, the very fine clay that is in the circuit often becomes entrapped in and/or adsorbed on the coal being floated and increases the amount of ash in the final product.
  • Accordingly, it is an object of this invention to improve the operation of the coal flotation circuit by improving the overall yield of coal.
  • It is another object of this invention to improve the operation of the coal flotation circuit by improving the overall yield of coal.
  • It is another object of this invention to improve the operation of the coal flotation circuit by decreasing the ash content of the coal.
  • These and other objects of this invention are accomplished by the addition of the partially hydrolyzed polyacrylamides to coal flotation circuits.
    • Detailed Description of the Invention
  • The polymer may be added to the feed to the flotation circuit or to the individual cells by conventional feeding means and it is believed that it functions by flocculating the fine coal fraction. The polymer may be used in dosages of between 0.025 and 1 pound per ton, preferably at least 0.05 pounds per ton, based on the weight of the dry flotation feed.
  • Suitable polymers which may be used in accordance with the teachings of this invention are water soluble, partially hydrolyzed polyacrylamides having a degree of hydrolysis of from 1 percent to 50 percent and a molecular weight of at least 50,000, and preferably at least 1,000,000.
  • The following examples will illustrate this invention.
    • Example 1
  • A series of flotation tests were conducted. The objectives of the tests were to reduce the ash in the clean coal, increase the percent recovery of the coal and reduce the amount of fuel oil being used in the flotation circuit. The results of these tests are set forth in Table I.
    Figure imgb0001
    Figure imgb0002
    • Example 2
  • A similar series of flotation tests were conducted and the results of these tests are set forth in Table II.
    Figure imgb0003
    Figure imgb0004

Claims (1)

1. A process for improving the recovery of clean coal from flotation circuits which comprises adding an effective amount of a water soluble, partially hydrolyzed polyacrylamide to the coal being processed to decrease the amount of the clay being floated and removed from the cells with the fine coal.
EP80400775A 1979-06-01 1980-05-30 Process for improving the recovery of clean coal from flotation circuits Withdrawn EP0020275A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US4473679A 1979-06-01 1979-06-01
US44736 1979-06-01

Publications (1)

Publication Number Publication Date
EP0020275A1 true EP0020275A1 (en) 1980-12-10

Family

ID=21934041

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80400775A Withdrawn EP0020275A1 (en) 1979-06-01 1980-05-30 Process for improving the recovery of clean coal from flotation circuits

Country Status (2)

Country Link
EP (1) EP0020275A1 (en)
AU (1) AU5856080A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2502028A1 (en) * 1981-03-23 1982-09-24 American Cyanamid Co METHOD FOR DECREASING THE FLOATABILITY OF SYLVINITE MINERALS IN A FLOTATION SYSTEM USING AS DEPRESSING A LOW MOLECULAR MASS COPOLYMER
FR2525494A1 (en) * 1982-04-26 1983-10-28 American Cyanamid Co SYLVITY CONCENTRATION PROCESS IN A SYLVINITE ORE FLOTATION SYSTEM
US4533465A (en) * 1982-04-26 1985-08-06 American Cyanamid Company Low molecular weight copolymers as depressants in sylvinite ore flotation
EP0246105A2 (en) * 1986-05-14 1987-11-19 Fospur Limited Recovering coal fines
US4830740A (en) * 1988-04-19 1989-05-16 The Dow Chemical Company Pyrite depressants useful in the separation of pyrite from coal
US4857221A (en) * 1986-05-14 1989-08-15 Fospur Limited Recovering coal fines
US4859318A (en) * 1987-10-16 1989-08-22 Fospur Limited Recovering coal fines
US4956077A (en) * 1987-11-17 1990-09-11 Fospur Limited Froth flotation of mineral fines
US5402894A (en) * 1993-10-18 1995-04-04 Chemical Dewatering Technology, Inc. Coal conditioning process

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3717574A (en) * 1971-09-21 1973-02-20 American Cyanamid Co Flocculation of coal slimes
SU362568A1 (en) * 1970-05-12 1973-09-17 FSH | LCHPN 1 "Ofei ^ R! And ITj ^ M.Posypayko, A.I. Olfert, A.M. Yakovenko, V.X. Kontorovich, and Cherepovets Order of Lenin Iron and Steel Works
US4141691A (en) * 1977-12-12 1979-02-27 Calgon Corporation Use of water soluble polymers in coal flotation circuits
BE873001A (en) * 1977-12-23 1979-06-22 American Cyanamid Co COAL RECOVERY PROCESS BY FLOTATION

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU362568A1 (en) * 1970-05-12 1973-09-17 FSH | LCHPN 1 "Ofei ^ R! And ITj ^ M.Posypayko, A.I. Olfert, A.M. Yakovenko, V.X. Kontorovich, and Cherepovets Order of Lenin Iron and Steel Works
US3717574A (en) * 1971-09-21 1973-02-20 American Cyanamid Co Flocculation of coal slimes
US4141691A (en) * 1977-12-12 1979-02-27 Calgon Corporation Use of water soluble polymers in coal flotation circuits
EP0002633A1 (en) * 1977-12-12 1979-06-27 Calgon Corporation Use of water soluble polymers in coal flotation circuits and process for its preparation
BE873001A (en) * 1977-12-23 1979-06-22 American Cyanamid Co COAL RECOVERY PROCESS BY FLOTATION
GB2010702A (en) * 1977-12-23 1979-07-04 American Cyanamid Co Froth flotation of coal
DE2853410A1 (en) * 1977-12-23 1979-07-05 American Cyanamid Co PROCESS FOR COAL PROCESSING BY FLOTATION
FR2412350A1 (en) * 1977-12-23 1979-07-20 American Cyanamid Co COAL RECOVERY PROCESS BY FLOTATION

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, Vol. 74, Nr. 26, 1971, page 142, Abstract 144265r. Columbus, Ohio, USA KAL'CHENKO, D.A. et al. "Improvement in the water slurry scheme of a coal concentrating mill". & Koks Khim. 1971 (4), 11-12. * Whole Abstract * *
CHEMICAL ABSTRACTS, Vol. 83, Nr. 18, 1975, page 178, Abstract 150081e. Columbus, Ohio. USA BIMBEREKOV, A. "Mechanism of the reaction between 47% hydrolysed polyacrylamide and coal flotation residues". & Vopr. Obogashch. Polezn. Iskop. Sib. 1974, 71-80. * Whole Abstract * *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2502028A1 (en) * 1981-03-23 1982-09-24 American Cyanamid Co METHOD FOR DECREASING THE FLOATABILITY OF SYLVINITE MINERALS IN A FLOTATION SYSTEM USING AS DEPRESSING A LOW MOLECULAR MASS COPOLYMER
FR2525494A1 (en) * 1982-04-26 1983-10-28 American Cyanamid Co SYLVITY CONCENTRATION PROCESS IN A SYLVINITE ORE FLOTATION SYSTEM
US4533465A (en) * 1982-04-26 1985-08-06 American Cyanamid Company Low molecular weight copolymers as depressants in sylvinite ore flotation
US4857221A (en) * 1986-05-14 1989-08-15 Fospur Limited Recovering coal fines
EP0246105A3 (en) * 1986-05-14 1989-04-05 Fospur Limited Recovering coal fines
EP0246105A2 (en) * 1986-05-14 1987-11-19 Fospur Limited Recovering coal fines
US4859318A (en) * 1987-10-16 1989-08-22 Fospur Limited Recovering coal fines
US4956077A (en) * 1987-11-17 1990-09-11 Fospur Limited Froth flotation of mineral fines
US5051199A (en) * 1987-11-17 1991-09-24 Fospur Limited Froth flotation of mineral fines
US4830740A (en) * 1988-04-19 1989-05-16 The Dow Chemical Company Pyrite depressants useful in the separation of pyrite from coal
EP0338778A2 (en) * 1988-04-19 1989-10-25 The Dow Chemical Company Pyrite depressants useful in the separation of pyrite from coal
WO1989010200A1 (en) * 1988-04-19 1989-11-02 The Dow Chemical Company Pyrite depressants useful in the separation of pyrite from coal
EP0338778A3 (en) * 1988-04-19 1991-01-16 The Dow Chemical Company Pyrite depressants useful in the separation of pyrite from coal
US5402894A (en) * 1993-10-18 1995-04-04 Chemical Dewatering Technology, Inc. Coal conditioning process

Also Published As

Publication number Publication date
AU5856080A (en) 1980-12-04

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Inventor name: BELL, HUGH L.

Inventor name: SNOW, GLEN F.