US3619171A - Method and a mixture for the preparation of an iron melt with a low sulphur content - Google Patents

Method and a mixture for the preparation of an iron melt with a low sulphur content Download PDF

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Publication number
US3619171A
US3619171A US780555A US3619171DA US3619171A US 3619171 A US3619171 A US 3619171A US 780555 A US780555 A US 780555A US 3619171D A US3619171D A US 3619171DA US 3619171 A US3619171 A US 3619171A
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US
United States
Prior art keywords
mixture
melt
nacl
composition
mixture according
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
US780555A
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English (en)
Inventor
Hermanus Bakkerus
Bernardus J J Van Der Holst
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.)
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Original Assignee
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
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Priority claimed from NL6716522A external-priority patent/NL6716522A/xx
Application filed by Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO filed Critical Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/02—Dephosphorising or desulfurising

Definitions

  • the invention relates to a method and a mixture for the preparation of an iron melt with a low sulfur content.
  • a mixture is introduced into the melt, the mixture consisting of Na,CO and at least one calcium compound, such as CaC and possibly CaO, to which, according to the invention, a quantity (by weight) of NaCl (at least oneiron ores, and fuels used for smelting these in a furnace, have a 5 third and at most three times the quantity of Na CO is high sulfur content, and attempts have been made to reduce added.
  • Preferably equal amounts of NaCl and Na,CO are the sulfur content by adding substances while charging the furadded, but the amount of neither substance is more than that nace. Some of such added substances produce side effects on of the calcium compound(s).
  • This desulfurization is not very effective or takes a very sive extra devices, the quantity of the mixture being relatively l ti because th l temperature i f i l small and not giving rise to attack or dangerous gas genera- Na,CO;, is also used as a desulfurizing agent, but it is very tion- While the slag moreover. is y to removeaggl'essive and attacks ningi Preferably, not more than 20 kg.
  • the f yj mixture can also be added to the melt with Me, and a large Percentage of z a in the mixture results in the aid of conventional devices, such as in a ladle with a lance, a y Severe altack the lining- 3 an agitator, or a dipper or in a vibrating ladle.
  • Desulfurization According to another method, in addition to about 17 kg. of calcium compounds, such as CaO and CaF 2 to 7 kg. of Na CO per ton of melt is added to a bath. This bath is then agitated for a number of minutes with the aid of a lowfrequency electric current.
  • the desulfurizing agent used for cast iron which has a higher temperature than pig iron, is mainly CaC,. It is expensive and does not work quickly. Its use, moreover, may adversely increase the carbon content of the melt.
  • blocks of CaC are melted on the melt bath in a ladle by means of an electric arc, and NaCl is used as a flux in the slag.
  • a mixture of CaC and NaCl may be introduced in the form of a briquette into the ladle by means of a dipper.
  • the quantities used generally do not exceed 25 kg. per ton of melt, whereas the reaction time is fairly long.
  • the object of the present invention is a method whereby an inexpensive desulfurizing mixture with a very short reaction time so that it can be introduced into the melt without any adverse effects, for instance by adding it on or in the stream of melt.
  • Table A shows that CaC, alone has hardly any effect in this short time. Addition of N a CO considerably increases the desulfurization percentage but the slag becomes more difficult to work, while the aggressiveness of the Na,CO continues to exist and the lining is attached.
  • Tests were next made to ascertain how effective a mixture in accordance with the invention is with low sulfur contents, and what quantity is advisable.
  • Desulfurization with the mixtures is effected in a short time Tests were carried out m which the sulfur content was determined after 1 minute. after 3 minutes and after 8 minutes. The mixture was not introduced In the stream of melt but was added to a small amount of melton the bottom of the ladle.
  • the preferred mixture results in greater desulfurization at a lower temperature than at a higher temperature
  • a number of tests were carried out with pig iron, which has a much lower temperature.
  • the mixture was introduced into a ladle holding 25 tons, the bottom of which was covered with pig iron, and the ladle was filled with pig iron in two to three minutes.
  • the quantity of the mixture was very small but gas generation was great.
  • the slag was crumbly to firm, but easy to remove. With continuous addition to the stream gas generation is much slighter.
  • a mixture for desulfurizing a sulfur-containing iron melt outside a furnace consisting essentially of (a) Na CO (b) NaCl and (c) a material, each component of which is a desul furizing calcium compound; the weight of NaCl being at least one-third and at most three times the weight of Na CO and the material comprising at least one-third of the mixture.
  • a mixture according to claim 1 wherein the material comprises a calcium compound selected from the group consisting of CaC and CaO.
  • a mixture according to claim 3 containing equal amounts of NaCl and Na CO 5.
  • a mixture according to claim 3 less than one-fourth of which consists of Na CO 7.
  • a method according to claim 10 wherein the sum of the amounts of NaCl and Na CO in the mixture is not more than one-third of the quantity of the calcium compound content thereof.
  • a mixture according to claim 1 wherein the material consists essentially of at least one member selected from the group consisting ofCaC, and CaO.
  • a method according to claim 16 which comprises introducing the mixture into a stream of said melt before the melt enters a ladle.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Compounds Of Iron (AREA)
US780555A 1967-12-05 1968-12-02 Method and a mixture for the preparation of an iron melt with a low sulphur content Expired - Lifetime US3619171A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL6716522A NL6716522A (de) 1967-12-05 1967-12-05
DE19681807332 DE1807332A1 (de) 1967-12-05 1968-11-06 Verfahren und Zugabematerial zur Herstellung einer Eisenschmelze mit niedrigem Schwefelgehalt

Publications (1)

Publication Number Publication Date
US3619171A true US3619171A (en) 1971-11-09

Family

ID=25756371

Family Applications (1)

Application Number Title Priority Date Filing Date
US780555A Expired - Lifetime US3619171A (en) 1967-12-05 1968-12-02 Method and a mixture for the preparation of an iron melt with a low sulphur content

Country Status (8)

Country Link
US (1) US3619171A (de)
AT (1) AT306766B (de)
BE (1) BE724879A (de)
CH (1) CH501730A (de)
ES (1) ES361266A1 (de)
FR (1) FR1594112A (de)
GB (1) GB1219300A (de)
SE (1) SE346565B (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3716352A (en) * 1969-10-24 1973-02-13 Kawasaki Steel Co Sintered desulfurizer for off-furnace use
US3932170A (en) * 1974-08-19 1976-01-13 The United States Of America As Represented By The Secretary Of The Interior Use of scavenger in recovery of metal values
US4042377A (en) * 1973-12-14 1977-08-16 Battelle Memorial Institute Method of and composition for the desulfurization of steel

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2755180A (en) * 1952-03-15 1956-07-17 Jr Carl George De Laval Reverberatory furnace practice
US2834668A (en) * 1954-05-10 1958-05-13 Union Carbide Corp Mixture for treating cast iron
GB812410A (en) * 1954-08-27 1959-04-22 Knorr Bremse Gmbh Process for reducing the sulphur content in iron and for economising in coke in cupola furnaces
US3051564A (en) * 1959-08-12 1962-08-28 Carborundum Co Composition for metallurgical use and process of using the same
US3158465A (en) * 1961-09-07 1964-11-24 Kerchner Marshall & Company Metallurgical material and process for treating iron therewith
US3258328A (en) * 1962-08-23 1966-06-28 Fuji Iron & Steel Co Ltd Method and apparatus for treating steel

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2755180A (en) * 1952-03-15 1956-07-17 Jr Carl George De Laval Reverberatory furnace practice
US2834668A (en) * 1954-05-10 1958-05-13 Union Carbide Corp Mixture for treating cast iron
GB812410A (en) * 1954-08-27 1959-04-22 Knorr Bremse Gmbh Process for reducing the sulphur content in iron and for economising in coke in cupola furnaces
US3051564A (en) * 1959-08-12 1962-08-28 Carborundum Co Composition for metallurgical use and process of using the same
US3158465A (en) * 1961-09-07 1964-11-24 Kerchner Marshall & Company Metallurgical material and process for treating iron therewith
US3258328A (en) * 1962-08-23 1966-06-28 Fuji Iron & Steel Co Ltd Method and apparatus for treating steel

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3716352A (en) * 1969-10-24 1973-02-13 Kawasaki Steel Co Sintered desulfurizer for off-furnace use
US4042377A (en) * 1973-12-14 1977-08-16 Battelle Memorial Institute Method of and composition for the desulfurization of steel
US3932170A (en) * 1974-08-19 1976-01-13 The United States Of America As Represented By The Secretary Of The Interior Use of scavenger in recovery of metal values

Also Published As

Publication number Publication date
AT306766B (de) 1973-04-25
CH501730A (de) 1971-01-15
BE724879A (de) 1969-06-04
GB1219300A (en) 1971-01-13
SE346565B (de) 1972-07-10
ES361266A1 (es) 1970-11-01
FR1594112A (de) 1970-06-01

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