US2673812A - Method of producing carbonaceous molding compositions - Google Patents

Method of producing carbonaceous molding compositions Download PDF

Info

Publication number
US2673812A
US2673812A US181586A US18158650A US2673812A US 2673812 A US2673812 A US 2673812A US 181586 A US181586 A US 181586A US 18158650 A US18158650 A US 18158650A US 2673812 A US2673812 A US 2673812A
Authority
US
United States
Prior art keywords
coal
water
agent
moulding
temperature
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.)
Expired - Lifetime
Application number
US181586A
Inventor
Greaves Charles Desmond
Atkins Bernard Roy
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.)
CD Patents Ltd
Original Assignee
CD Patents Ltd
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 CD Patents Ltd filed Critical CD Patents Ltd
Application granted granted Critical
Publication of US2673812A publication Critical patent/US2673812A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • C04B35/522—Graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B33/00—Clay-wares
    • C04B33/02—Preparing or treating the raw materials individually or as batches
    • C04B33/13—Compounding ingredients
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B33/00—Clay-wares
    • C04B33/02—Preparing or treating the raw materials individually or as batches
    • C04B33/13—Compounding ingredients
    • C04B33/1305—Organic additives

Definitions

  • This invention relates to improvements in the manufacture of carbonaceous moulding compositions and more particularly, but not exclusively, to the manufacture of such composition as are suitable for extrusion moulding in which a high degree of softness or plasticity is desirable.
  • Patent 2,637,072 a method of making from coal a carbonaceous moulding composition, especially an extrusible composition, which method consists in mixing at an elevated temperature subdivided coal and a softening agent which exercises a solvent action upon the coal and consists of hydrocarbon material such .as coal tar oil, anthracene oil and the like.
  • a mixture may be moulded to the desired shape at a temperature at which the mixture will flow and the moulded shape is fired under non-oxidising conditions at a controlled rate of temperature rise.
  • Such processes may in certain cases be inconvenient because (1) the softening agent may exercise an action upon the coal, the properties of which are in consequence modified, (2) the swelling tendency may be increased, and (3) the softening agent may be unpleasant to handle or may produce fumes during the firing operation.
  • the main object of the present invention is to provide a method of producing a carbonaceous moulding composition in which no substantial modification of the original coal is produced.
  • the present invention consists in a method of producing a carbonaceous moulding composition which method comprises an intimate mixing of subdivided coal, water and a special lubricat- 2 ing agent comprising one or more carboxyl-sub stituted celluloses such for example as carboxymethyl cellulose.
  • a special lubricat- 2 ing agent comprising one or more carboxyl-sub stituted celluloses such for example as carboxymethyl cellulose.
  • carboxyl-sub stituted celluloses such for example as carboxymethyl cellulose.
  • Sodium carboxy-methyl cellulose has proved very successful.
  • This invention also includes a method of pro ducing a moulded carbon product, which method comprises the submission of the carbonaceous moulding composition above referred to to a moulding or shaping operation and they subsequent heating of the shaped article under nonoxidising conditions and at a rate of temperature rise controlled so as to prevent intumescence, to, a temperature of over 550 C.
  • the consistency of the moulding composition of the invention is governed by the quantity of water present which will not in general exceed 25-30 per cent, this percentage being dependent on the degree of subdivision of the coal. Hence during mixing care must be taken to limit loss of water by evaporation.
  • moulding composition a small proportion of a wetting agent.
  • Suitable wetting agents are soaps, s'ulphated or sulphonated hydrocarbon de-- rivatives or members of the non-ionogenic classof detergents.
  • the mount of wetting agent em-- ployed varies with the circumstances but would;
  • the amount of the special lubricating agent employed is so small that the amount of oxygen contained therein (in the cellulosic and carboxyl' groups) is not sufiicient to have a deleterious effect on the coal and the effect of such oxygen is to some extent balanced by the hydrogen present in the alkyl groups.
  • Sulphur, selenium or other substances having similar dehydrogenating properties may be added to the mixture, but care must be taken to select only such substances as are non-reactive to water, and they are preferably either finelydivided solids, or liquids which are readily miscible with water or which are dispersed in a medium containing not more than 30 per cent of water.
  • the proportion of sulphur for example may be about 2% by weight of the coal.
  • non-reactive to water is meant that the substances used shall not react to any substantial degree with water under the conditions existing during the course of the process of preparing the moulding composition.
  • Other finely-divided substances may be added which exercise the function of further reducing the swelling tendency of the coal or which confer special properties on the final product. Examples of such substances arecarbon black, finely-divided graphite and china clay.
  • coals most suitable for use in producing the composition of the invention are those having from 1 3 to 30 per cent of volatile matter calculated on the dry ash-free basis, :butpreferably coals having a volatile matter content of-between 14 and 25 percent are employed.
  • the particle size of the subdivided coal may be such that 90 per cent passes through a'100-mesh sieve but is conveniently such that the average particle size lies between 6 and 30microns.
  • the mixing of the coal, water and wettingagent may be suitably carried out at a temperature of 35 C. but higher or lower temperatures may be satisfactorily employed.
  • the mixing operation may advantageously be effected over a periodof 2 to 3 hours.
  • the moulding compositions of the invention may if desired be de-aerated,e. g. in a de-aerating mill before submitting to extrusion moulding which may-either be effected at normal room temperature or at an'elevated'temperature, for example, 50 C.
  • the moulded article After shaping or moulding the composition by extrusion or otherwise the moulded article is dried either in the air why any other convenient and well known means, care being exercised that the drying is uniform so that the article'remains' free from cracks or distortion. It is found that, whereas immediately after extrusion the rods, tubes etc. produced thereby may require considerable care in handling, after drying they are easily handled.
  • the above mixture was placed in a Z-blade type of mixer and to'this was added 268 lbs. of a jelly containing 94% of water, 5% sodium methylcarboxy cellulose and 1% of a-wetting agent soldunder the registered trade mark (LissapolN); these additives having been previously mixed to a smooth consistency.
  • Lisapol N has the formula:
  • Example II 4076 grammes-of a mixture consisting of South Wales strongly coking coal and 30% of graphite together with grammes of sodium carboxymethyl cellulose were placed in a mixer ofthe edge-runner type and to this was added a solution of 15 cos. of a wetting agent sold under the registered trade mark (Lissapol N) dissolved in 1410 grammes of water. The whole was thenwater, between 1 and 2.5 %-by weight of the coal of sodium carboxymethyl cellulose, and a dehydrogenating agent non-reactive to water selected from the group consisting of sulfur and selenium, said agent comprising about 2% by Weight of the coal.
  • a wetting agent sold under the registered trade mark (Lissapol N)
  • a method of producing a carbonaceous moulding composition which comprises the steps of intimately mixing over-a period of two to three hours sub-divided coal of average particle size between'fi and 30 microns, water, between 1% and 2.5%by weight of the coal of sodium carboxymethyl cellulose, less'than 3% by weight of the mixture of a water-soluble wetting agent, the water constituting between 25% and 30% of the weight of the mixture, and the temperature during mixing being-regulated to avoid appreciable water loss by evaporation.

Description

Patented Mar. 30, 1954 METHOD OF PRODUCING GARBONACEOUS MOLDING COMPOSITIONS Charles Desmond Greaves and Bernard Roy Atkins, London, England, assignors to C. D. 'Patents Limited, London, EnglamL-a British company No Drawing. Application August 25,1950,
' Serial No. 181,586
Claims priority, application Great Britain August 30, 1949 '2 Claims.
This invention relates to improvements in the manufacture of carbonaceous moulding compositions and more particularly, but not exclusively, to the manufacture of such composition as are suitable for extrusion moulding in which a high degree of softness or plasticity is desirable.
There have previously been proposed in United States Patent specifications Nos. 2,461,365 and 2,493,383 methods of making moulded products from finely-divided bituminous coal without a binding agent in which an intimate mixture of finely-divided coal having good agglutinating properties with a swell-inhibiting agent is moulded and subsequently fired at a controlled rate of increase in temperature to a temperature above 550 C. under non-oxidising conditions, the method being so carried out that the resulting moulded product is not swollen, has a den sity greater than that of the coal used and has no cellular structure visible to the naked eye.
The use of such methods of dry powder moulding places limitations upon the shape of the articles that can be produced.
Again there has been proposed in specification of United States Patent application Serial No. 53,992 now Patent 2,640,787 and in specification of United States Patent application Serial No. 95,890 now Patent 2,637,072 a method of making from coal a carbonaceous moulding composition, especially an extrusible composition, which method consists in mixing at an elevated temperature subdivided coal and a softening agent which exercises a solvent action upon the coal and consists of hydrocarbon material such .as coal tar oil, anthracene oil and the like. Such a mixture may be moulded to the desired shape at a temperature at which the mixture will flow and the moulded shape is fired under non-oxidising conditions at a controlled rate of temperature rise. Such processesmay in certain cases be inconvenient because (1) the softening agent may exercise an action upon the coal, the properties of which are in consequence modified, (2) the swelling tendency may be increased, and (3) the softening agent may be unpleasant to handle or may produce fumes during the firing operation.
The main object of the present invention is to provide a method of producing a carbonaceous moulding composition in which no substantial modification of the original coal is produced.
The present invention consists in a method of producing a carbonaceous moulding composition which method comprises an intimate mixing of subdivided coal, water and a special lubricat- 2 ing agent comprising one or more carboxyl-sub stituted celluloses such for example as carboxymethyl cellulose. Sodium carboxy-methyl cellulose has proved very successful.
This invention also includes a method of pro ducing a moulded carbon product, which method comprises the submission of the carbonaceous moulding composition above referred to to a moulding or shaping operation and they subsequent heating of the shaped article under nonoxidising conditions and at a rate of temperature rise controlled so as to prevent intumescence, to, a temperature of over 550 C.
The consistency of the moulding composition of the invention is governed by the quantity of water present which will not in general exceed 25-30 per cent, this percentage being dependent on the degree of subdivision of the coal. Hence during mixing care must be taken to limit loss of water by evaporation.
It may sometimes be desirable 'to add to the:
moulding composition a small proportion of a wetting agent. Suitable wetting agents are soaps, s'ulphated or sulphonated hydrocarbon de-- rivatives or members of the non-ionogenic classof detergents. The mount of wetting agent em-- ployed varies with the circumstances but would;
generally be less than three per cent by weight. of the mixture and must on no account be suificient to exercise an oxidising or other chemical action upon the coal.
The amount of the special lubricating agent employed is so small that the amount of oxygen contained therein (in the cellulosic and carboxyl' groups) is not sufiicient to have a deleterious effect on the coal and the effect of such oxygen is to some extent balanced by the hydrogen present in the alkyl groups.
Sulphur, selenium or other substances having similar dehydrogenating properties may be added to the mixture, but care must be taken to select only such substances as are non-reactive to water, and they are preferably either finelydivided solids, or liquids which are readily miscible with water or which are dispersed in a medium containing not more than 30 per cent of water. The proportion of sulphur for example may be about 2% by weight of the coal. By the term non-reactive to water is meant that the substances used shall not react to any substantial degree with water under the conditions existing during the course of the process of preparing the moulding composition. Other finely-divided substances may be added which exercise the function of further reducing the swelling tendency of the coal or which confer special properties on the final product. Examples of such substances arecarbon black, finely-divided graphite and china clay.
The coals most suitable for use in producing the composition of the invention are those having from 1 3 to 30 per cent of volatile matter calculated on the dry ash-free basis, :butpreferably coals having a volatile matter content of-between 14 and 25 percent are employed.
The particle size of the subdivided coal may be such that 90 per cent passes through a'100-mesh sieve but is conveniently such that the average particle size lies between 6 and 30microns.
The mixing of the coal, water and wettingagent may be suitably carried out at a temperature of 35 C. but higher or lower temperatures may be satisfactorily employed. The mixing operation may advantageously be effected over a periodof 2 to 3 hours.
The moulding compositions of the invention may if desired be de-aerated,e. g. in a de-aerating mill before submitting to extrusion moulding which may-either be effected at normal room temperature or at an'elevated'temperature, for example, 50 C.
After shaping or moulding the composition by extrusion or otherwise the moulded article is dried either in the air why any other convenient and well known means, care being exercised that the drying is uniform so that the article'remains' free from cracks or distortion. It is found that, whereas immediately after extrusion the rods, tubes etc. produced thereby may require considerable care in handling, after drying they are easily handled.
EwampZe I 700 1bs.of a mixtureconsisting of 70% of a South Wales strongly coking coal and 30% of graphite were ground together in a colloidal mill to a state of fine subdivision. The above mixture was placed in a Z-blade type of mixer and to'this was added 268 lbs. of a jelly containing 94% of water, 5% sodium methylcarboxy cellulose and 1% of a-wetting agent soldunder the registered trade mark (LissapolN); these additives having been previously mixed to a smooth consistency. (Lissapol N has the formula:
where R is a benzenoid ring-and n'is a whole number of -8 or more.) Mixing then took place for a period of 2 hours during which the temperature rose to 35 C. and the mixture developed a plastic consistency. The resulting mixture was then formed into a cylindrical billet by tamping in order to expel=extrapped air and the billet so produced was extruded in the form of a tube. These tubes'were then placed in an oven, main-. tained at 50 C. for 24 hours, after which they were packed in powdered coke in boxes which were then placed in an electricfurnace, the temperature of which was then raised to 850 C. at the rate of 2 C. per minute; the tubes were removed from the furnace after having been allowed to cool to approximately 200 C. under non-oxidising conditions.
Example II 4076 grammes-of a mixture consisting of South Wales strongly coking coal and 30% of graphite together with grammes of sodium carboxymethyl cellulose were placed in a mixer ofthe edge-runner type and to this was added a solution of 15 cos. of a wetting agent sold under the registered trade mark (Lissapol N) dissolved in 1410 grammes of water. The whole was thenwater, between 1 and 2.5 %-by weight of the coal of sodium carboxymethyl cellulose, and a dehydrogenating agent non-reactive to water selected from the group consisting of sulfur and selenium, said agent comprising about 2% by Weight of the coal.
2. A method of producing a carbonaceous moulding composition which comprises the steps of intimately mixing over-a period of two to three hours sub-divided coal of average particle size between'fi and 30 microns, water, between 1% and 2.5%by weight of the coal of sodium carboxymethyl cellulose, less'than 3% by weight of the mixture of a water-soluble wetting agent, the water constituting between 25% and 30% of the weight of the mixture, and the temperature during mixing being-regulated to avoid appreciable water loss by evaporation.
CHARLES DESMOND GREAVES. BERNARD ROY ATKINS.
ReferencesCited in the file of this patent UN ITED STATES PATENTS Number Name Date 2,461,365 Bennett Feb. 8, 1949 2,552,597 Smith May 15, 1951 FOREIGN PATENTS Number 7 Country Date 2,577 Great Britain 1867 329,437 Great Britain May 22, 1930 OTHER REFERENCES Hercules, CMC Hercules Pwd. Co., Wilmington, Del., 1946, p. 4.

Claims (1)

1. A METHOD OF PRODUCING A CARBONACEOUS MOULDING COMPOSITION WHICH COMPRISES THE STEPS OF INTIMATELY MIXING FINELY SUB-DIVIDED COAL, WATER, BETWEEN 1% AND 2.5% BY WEIGHT OF THE COAL OF SODIUM CARBOXYMETHYL CELLULOSE, AND A DEHYDROGENATING AGENT NON-REACTIVE TO WATER SELECTED FROM THE GROUP CONSISTING OF SULFUR AND SELENIUM, SAID AGENT COMPRISING ABOUT 2% BY WEIGHT-OF THE COAL.
US181586A 1949-08-30 1950-08-25 Method of producing carbonaceous molding compositions Expired - Lifetime US2673812A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB22547/49A GB670750A (en) 1949-08-30 1949-08-30 Improvements in or relating to the manufacture of carbonaceous moulding compositions

Publications (1)

Publication Number Publication Date
US2673812A true US2673812A (en) 1954-03-30

Family

ID=10181167

Family Applications (1)

Application Number Title Priority Date Filing Date
US181586A Expired - Lifetime US2673812A (en) 1949-08-30 1950-08-25 Method of producing carbonaceous molding compositions

Country Status (3)

Country Link
US (1) US2673812A (en)
DE (1) DE865872C (en)
GB (1) GB670750A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2822251A (en) * 1955-09-22 1958-02-04 Dow Chemical Co Charcoal briquettes and method for their manufacture
US3307927A (en) * 1959-10-13 1967-03-07 Muschenborn Walter Process for the treatment of pulverulent material
US4417899A (en) * 1981-12-17 1983-11-29 The Board Of Regents Of The University Of Oklahoma Self-bursting coal pellets and a method of making them
US20040037762A1 (en) * 2002-08-20 2004-02-26 Walker Terence B. Process and apparatus for the manufacture of carbon microballoons

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB329437A (en) * 1929-01-17 1930-05-22 James Stewart Ford Improvements in and relating to fuel briquettes
US2461365A (en) * 1944-11-02 1949-02-08 C D Patents Ltd Production of shaped and carbonized articles from coal
US2552597A (en) * 1947-07-09 1951-05-15 Donald F Othmer Process of making a molded article from lignocellulose

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE294661C (en) *
DE108579C (en) *
DE433476C (en) * 1923-07-31 1926-08-31 Maschb Anstalt Humboldt Process for the production of electrodes and sliding contacts for dynamo machines
FR948079A (en) * 1944-12-22 1949-07-21 C D Patents Ltd Improvements in the manufacture of utility articles by means of coal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB329437A (en) * 1929-01-17 1930-05-22 James Stewart Ford Improvements in and relating to fuel briquettes
US2461365A (en) * 1944-11-02 1949-02-08 C D Patents Ltd Production of shaped and carbonized articles from coal
US2552597A (en) * 1947-07-09 1951-05-15 Donald F Othmer Process of making a molded article from lignocellulose

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2822251A (en) * 1955-09-22 1958-02-04 Dow Chemical Co Charcoal briquettes and method for their manufacture
US3307927A (en) * 1959-10-13 1967-03-07 Muschenborn Walter Process for the treatment of pulverulent material
US4417899A (en) * 1981-12-17 1983-11-29 The Board Of Regents Of The University Of Oklahoma Self-bursting coal pellets and a method of making them
US20040037762A1 (en) * 2002-08-20 2004-02-26 Walker Terence B. Process and apparatus for the manufacture of carbon microballoons
US7105141B2 (en) 2002-08-20 2006-09-12 Honeywell International Inc. Process and apparatus for the manufacture of carbon microballoons
US20100143214A1 (en) * 2002-08-20 2010-06-10 Walker Terence B Apparatus for the manufacture of carbon microballoons
US7749456B2 (en) 2002-08-20 2010-07-06 Honeywell International Inc. Apparatus for the manufacture of carbon microballoons

Also Published As

Publication number Publication date
DE865872C (en) 1953-02-05
GB670750A (en) 1952-04-23

Similar Documents

Publication Publication Date Title
GB726506A (en) Modified polytetrafluoroethylene compositions and products related thereto
US3565658A (en) Carbon black dispersing agent
US4025596A (en) Method for pelletizing finely divided solids
US2673812A (en) Method of producing carbonaceous molding compositions
US4308073A (en) Pellets of graphite and carbon black and method of producing
US2647064A (en) Method of improving the cold-water solubility of a fibrous cellulose ether
GB648539A (en) Manufacture of carbonaceous moulding compositions suitable for extrusion and of moulded carbon products therefrom
US2761848A (en) Process of making shaped carbon articles
US4448914A (en) Aqueous preparation and its use in the production of ceramic compositions
US3071492A (en) Method of rendering starch hydrophobic and free flowing
US2720464A (en) Method of preparing cold-water-soluble powdered cellulose ethers
GB732097A (en) Filled polymer compositions
US2637072A (en) Manufacture of carbon molded bodies
US2466435A (en) Manufacture of molded articles from coal
ES386643A1 (en) Process for fibers containing uniform distribution of insoluble solid additives therein
US2644741A (en) Carbonaceous additive for molding sand
US2508878A (en) Process for the production of carbothermal magnesium furnace charge
US2149310A (en) Alkali cellulose
US2220385A (en) Metallurgical flux and method of producing it
US2895934A (en) Resinous compositions from coal acids and alcamines and method for making composite products thereof
US2607765A (en) Reaction of polyvinyl alcohol with boric acid
JP3495736B2 (en) Method for producing free-flowing tetrafluoroethylene polymer molding powder
KR830001985B1 (en) Preparation of Polyvinyl Chloride by Improved Suspension Polymerization
US3107153A (en) Method of fabricating carbon and graphite structures
US2048808A (en) Mold for plaster casting