US3876421A - Process for desulfurization of molten pig iron - Google Patents

Process for desulfurization of molten pig iron Download PDF

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Publication number
US3876421A
US3876421A US412766A US41276673A US3876421A US 3876421 A US3876421 A US 3876421A US 412766 A US412766 A US 412766A US 41276673 A US41276673 A US 41276673A US 3876421 A US3876421 A US 3876421A
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United States
Prior art keywords
pig iron
molten pig
gas
desulfurization
carrier gas
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Expired - Lifetime
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US412766A
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English (en)
Inventor
Yozo Takemura
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Nippon Steel Corp
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Nippon Steel Corp
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Publication date
Priority claimed from JP11163672A external-priority patent/JPS4970813A/ja
Priority claimed from JP2186673A external-priority patent/JPS5243170B2/ja
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Application granted granted Critical
Publication of US3876421A publication Critical patent/US3876421A/en
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    • 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

  • PATENTEUAFR 819 73 sum 2 or g AONEIIOIi-El NOLLVZIHFH'IDSHU PROCESS FOR DESULFURIZATION OF MOLTEN PIG IRON
  • the present invention relates to a process for desulfurization of molten pig iron.
  • the desulfurization shows a reaction efficiency of to percent when it is added through a carrier gas and of to percent when it is mechanically agitated for desulfurization, for example, by an impeller.
  • the reaction efficiency is particularly low with carrier gas.
  • the present invention provides an excellent method to improve the efficiency when a carrier gas is used and is characterized by (l) a process for desulfurization of molten pig iron in which calcium carbide having a particle size of of about 10 mm or less is mixed with a gas generating substance and added to the molten pig iron through a carrier gas; (2) a process for desulfurization of molten pig iron, in which carbide is mixed with a gas generating substance and added to the molten pig iron through a carrier gas, having a reducing gas therein; (3) a process for desulfurization of molten pig iron, in which a granulated desulfurizing agent, made of carbide mixed with a gas generating substance is added to the molten pig iron; (4) a process for desulfurization of molten pig iron, in which petroleum substances are added to the molten pig iron to promote the desulfurization; and (5) a desulfurizing agent for molten pig iron composed of calcium carb
  • FIG. l is a diagram, showing the relation of the size of the desulfurizing agent (carbide) to the desulfurization effect;
  • FIG. 2 is a diagram, showing the relation of the size of the sulfurizing agent and the ratio of mixing in the carrier gas (including the gas generating substance) to the desulfurization efficiency;
  • FIG. 3 is a diagram showing the relation between the ratio of the desulfurizing agent, mixed with the carrier gas (foaming gas) and the desulfurization efficiency.
  • carbide having a particle size of 0.5 to 1.1 mm shows the increase of the desulfurization efficiency, but it is not possible to improve the desulfurization efficiency when sizes different from those shown in the drawing are used.
  • particle sizes of about 1.1 mm or above the surface of the desulfurizingagent becomes small and the area to be contacted with molten pig iron becomes small, so that it is natural that the desulfurization efficiency is decreased.
  • the desulfurizing agent When the desulfurizing agent is blown (added) into the molten pig iron through a carrier gas, it is desirable to introduce the agent in the bottom part of the vessel in order to increase the efficiency by elongation of the contact time with the molten pig iron.
  • the time depends upon the capacity of the vessel, but it generally takes about 1.0 sec. for the foam of carrier gas to be floated from the point at which it is blown in to the surface of the molten pig iron. It is necessary that the desulfurizing agent, blown in through the carrier gas, is sufficiently contacted with the molten pig iron during this time.
  • particle size range which enables the the movement of the agent toward the periphery of the foam by its own weight is 0.5 to 1.1 mm. If the size is about 0.5 mm or below, the agent floats in the foam and comes to the surface of the molten pig iron without contacting the molten pig iron. Consequently, the desulfurization efficiency can be significantly increased if the floating foam is broken and the desulfurizing agent in the foam is fully contacted with the molten pig iron.
  • the desulfurizing agent is mixed with a foam breaking substance.
  • a reducing agent for example, petroleum substances, such as heavy oil, tar or the like, cokes, Al powders or polyester, are mixed in a C0 gas generating substance, such as, limestone or MgCO to convert CO to CO (a reducing gas).
  • the quantity to be added in the desulfurizing agent is 7 to 20 percent.
  • a mixing ratio with the carrier gas as explained below is used. The mixture of the desulfurizing agent and the gas generating substance can sufficiently break the foam in the molten pig iron when the mixing ratio with the carrier gas, i.e.:
  • the desulfurization efficiency can be increased as shown in FIG. 2, when the mixing ratio with the carrier gas is about percent or above.
  • the desulfurization can be efficiently performed by adding the desulfurizing agent through the carrier gas. Such excellent desulfurization effects can be brought about easily and simply.
  • a reducing gas such as, H CH C l-L, or CQHB is contained in the carrier gas and the carbide, mixed with the beforementioned gas generating substance is carried in the molten pig iron, CO generated in the molten pig iron is reduced in the reaction of CO reducing gas CO.
  • the carbide can be prevented from the surface oxidization of CO gas.
  • the surface of carbide, dispersed in the molten pig iron by the breaking of the foam, can be contacted with the molten pig iron in the active condition, so that the desulfurization reaction may be significantly improved.
  • the reaction of CO reduction CO is instantaneously carried out as compared with the case of a solid substance, such as C, used as the reducing agent. Therefore, carbide is almost not oxidized and the desulfurization effect can be largely improved.
  • the present inventors have found that when calcium carbide, a desulfurizing agent, is granulated after mixing with a gas generating substance and added to the molten pig iron, gas is generated by the heat of the molten pig iron to pulverize or explode the desulfurizing agent in the molten pig iron, whereby the area of the desulfurizing agent, contacted with the molten pig iron is increased, so that the desulfurization efficiency can be improved.
  • the present inventors have learned that when carbide is added through the carrier gas, the carbide, blown in the molten pig iron, is confined in the bubble of the carrier gas and often comes to the surface of the molten pig iron without taking part in the desulfurization reaction, so that the yield ofthe desulfurizing agent is sometimes decreased.
  • any such substance in the form of a gas, liquid and solids will do.
  • Gases such as, propane, butane liquids, such as, heavy oil, tar, kerosene, naphtha, solids, and such as, polyethylene, and vinyl chloride may be used.
  • the carbide is covered with the cracked gas (H to interrupt the reaction of N 0 and carbide, so that the change of CaC C210 and CaCN does not occur. Further, when it is added in the molten pig iron through the carrier gas, the foam is broken by the cracked gas (H of the petroleum substance and the carbide, contained in the foam, is contacted with the molten pig iron to react, whereby the desulfurization effect can be improved.
  • the quantity of petroleum substance to be added may be so determined as to be 0.04 to 1.0 percent, computed on the basis of the quantity ,of H gas to be generated Quantity of H generated from the petroleum substance Kg Quantity of carbide Kg whereby the desulfurization efficiency can be advantageously increased.
  • Quantitv of CO gas generated from the gas generating substance/min.
  • the molten pig iron of [200C was filled in a ladle and blown in umder the surface of molten pig iron.
  • the molten pig iron of l250C was filled in a ladle (250 t) and added with the above mentioned desulfurizing agent as the molten pig iron being agitated by an impeller at 80 r.p.m. Note 2:
  • the desulfurizing agent was added at the almost uniform rate of addition for 10 minutes. In all cases. the molten pig iron was agitated by an impeller for l6 minutes l 5 after the beginning of the addition.
  • the molten pig iron of I200C was filled in a ladle (250 t) and the desulfurizing agent was blown in under the surface of the molten pig iron.
  • N was used for the carrier gas (foaaming gas).
  • the addition with carrier gas shown in the column desulfurization method. means that a desulfurizing agent (calcium carbide) was carried with N2 gas. the carrier gas. to be added into the molten pig iron.
  • the agitation shows that the molten pig iron is mechanically agitated by an impeller and added with a desulfurizing agent to further the contact with the molten pig iron.
  • the petroleum substances and the desulturizing agent were added.
  • the petroleum substance in the example 23 was pulverized an average of 0.1 mm and mixed with carbide to be added.
  • the molten pig iron was dusull'urilctl at 11201..
  • a process for desulfurizing molten pig iron com- 25 3.
  • the process of claim 2 wherein the ratio of amount prising introducing a mixture of calcium carbide and a of carbon dioxide generated to carrier gas is from 10 to solid material selected from the group consisting of 50 percent polyethylene, vinyl chloride, and polyester, in a carrier 4.
  • a process according to l i 1, i whi h the partig to the molten P g irOncle size of the calcium carbide is from 0.5 to 1.1 mm.
  • a substance which 5 A process according to claim 1, in which H CH generates carbon dioxide selected from the group con- C l-l or C l-l is contained in the carrier gas.

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  • 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)
US412766A 1972-11-09 1973-11-05 Process for desulfurization of molten pig iron Expired - Lifetime US3876421A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP11163672A JPS4970813A (it) 1972-11-09 1972-11-09
JP2186673A JPS5243170B2 (it) 1973-02-23 1973-02-23

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US3876421A true US3876421A (en) 1975-04-08

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US (1) US3876421A (it)
BR (1) BR7308802D0 (it)
DE (1) DE2355736B2 (it)
IT (1) IT1001677B (it)
NL (1) NL7315376A (it)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992195A (en) * 1974-04-20 1976-11-16 Thyssen Niederrhein Ag Hutten- Und Walzwerke Process for the production of steel with increased ductility
US4067730A (en) * 1974-04-20 1978-01-10 Thyssen Niederrhein Ag Hutten-Und Walzwerke Process for the production of steel with increased ductility
US4089677A (en) * 1976-05-28 1978-05-16 British Steel Corporation Metal refining method and apparatus
US4169724A (en) * 1977-02-26 1979-10-02 Skw Trostberg Aktiengesellschaft Desulfurization of iron melts
US4198229A (en) * 1976-06-28 1980-04-15 Nippon Steel Corporation Method of dephosphorization of metal or alloy
US4242126A (en) * 1979-07-11 1980-12-30 Skw Trostberg Aktiengesellschaft Process for the treatment of iron melts and for increasing the scrap portion in the converter
US4315773A (en) * 1979-11-27 1982-02-16 Skw Trostberg Aktiengesellschaft Desulfurization mixture and process for desulfurizing pig iron
US4409028A (en) * 1979-10-24 1983-10-11 Moore William H Process for producing cast iron
USRE31676E (en) 1982-09-29 1984-09-18 Thyssen Aktiengesellschaft vorm August Thyssen-Hutte AG Method and apparatus for dispensing a fluidizable solid from a pressure vessel
US4539042A (en) * 1983-02-23 1985-09-03 Mannesmann Ag Preventing an increase of the nitrogen content in molten steel
US5358550A (en) * 1992-10-26 1994-10-25 Rossborough Manufacturing Company Desulfurization agent
US5772727A (en) * 1993-12-21 1998-06-30 Stahlwerke Bremen Gmbh Process for the production of metal from metal ores
US5873924A (en) * 1997-04-07 1999-02-23 Reactive Metals & Alloys Corporation Desulfurizing mix and method for desulfurizing molten iron
EP1067202A2 (en) * 1999-07-05 2001-01-10 Kawasaki Steel Corporation Method of desulfurizing molten iron alloy
US6352570B1 (en) 2000-04-10 2002-03-05 Rossborough Manufacturing Co., Lp Magnesium desulfurization agent
US6395058B2 (en) 2000-04-10 2002-05-28 Rossborough Manufacturing Co. L.P. Method of alloying ferrous material with magnesium injection agent
US20040074339A1 (en) * 2002-10-18 2004-04-22 Rossborough Manufacturing Company, A Delaware Corporation Process for magnesium granules
US20040083851A1 (en) * 2002-10-30 2004-05-06 Rossborough Manufacturing Company, A Delaware Corporation Reclaimed magnesium desulfurization agent
US20070221012A1 (en) * 2006-03-27 2007-09-27 Magnesium Technologies Corporation Scrap bale for steel making process
US20080196548A1 (en) * 2007-02-16 2008-08-21 Magnesium Technologies Corporation Desulfurization puck
US9187792B2 (en) 2011-01-15 2015-11-17 Alamamet GmbH Agent for treating molten metals, method for the production and use thereof

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2432550A1 (fr) * 1978-08-04 1980-02-29 Sueddeutsche Kalkstickstoff Procede pour la fabrication d'un melange de desulfuration pulverulent facilement fluidifiable
DE2934193A1 (de) * 1979-08-23 1981-03-26 Denki Kagaku Kogyo K.K., Tokio/Tokyo Mittel zur entschwefelung von geschmolzenem eisen.
FR2473061A1 (fr) * 1980-01-07 1981-07-10 Sueddeutsche Kalkstickstoff Procede pour reduire le degagement de poussieres et de flammes lors de la manipulation des scories apres desulfuration de la fonte, et melange de desulfuration approprie
CA1240842A (en) * 1984-05-16 1988-08-23 Heinrich Rellermeyer Method, process and composition for desulfurizing pig-iron melts
DE102011008691A1 (de) * 2011-01-15 2012-07-19 Mechthilde Döring-Freißmuth Mittel zur Behandlung von Metallschmelzen, Verfahren zur Herstellung und Verwendung desselben

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2577764A (en) * 1949-11-04 1951-12-11 Air Reduction Desulfurization of ferrous metals
US2863755A (en) * 1957-04-22 1958-12-09 Union Carbide Corp Oil-treated calcium carbide for desulfurization of iron
US2870004A (en) * 1955-02-07 1959-01-20 Air Reduction Method of producing nodular cast iron
US2979393A (en) * 1958-10-02 1961-04-11 Jr Russell Pearce Heuer Process of desulfurizing pig iron
US3158913A (en) * 1961-07-17 1964-12-01 American Metallurg Products Co Method of treating steel
US3350196A (en) * 1964-07-20 1967-10-31 Bot Brassert Oxygen Technik A Basic steelmaking
US3473917A (en) * 1966-08-25 1969-10-21 Bot Brassert Oxygen Technik Ag Basic steelmaking process
US3556773A (en) * 1966-09-26 1971-01-19 Steel Co Of Wales Ltd Refining of metals
US3622302A (en) * 1968-02-15 1971-11-23 Kobe Steel Ltd Method for removing arsenic from metals or alloys
US3704230A (en) * 1970-02-17 1972-11-28 Carborundum Co Exothermic compositions
US3768999A (en) * 1968-10-23 1973-10-30 Nippon Kokan Kk Coated wire feeding technique for making addition of components to molten metals

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2577764A (en) * 1949-11-04 1951-12-11 Air Reduction Desulfurization of ferrous metals
US2870004A (en) * 1955-02-07 1959-01-20 Air Reduction Method of producing nodular cast iron
US2863755A (en) * 1957-04-22 1958-12-09 Union Carbide Corp Oil-treated calcium carbide for desulfurization of iron
US2979393A (en) * 1958-10-02 1961-04-11 Jr Russell Pearce Heuer Process of desulfurizing pig iron
US3158913A (en) * 1961-07-17 1964-12-01 American Metallurg Products Co Method of treating steel
US3350196A (en) * 1964-07-20 1967-10-31 Bot Brassert Oxygen Technik A Basic steelmaking
US3473917A (en) * 1966-08-25 1969-10-21 Bot Brassert Oxygen Technik Ag Basic steelmaking process
US3556773A (en) * 1966-09-26 1971-01-19 Steel Co Of Wales Ltd Refining of metals
US3622302A (en) * 1968-02-15 1971-11-23 Kobe Steel Ltd Method for removing arsenic from metals or alloys
US3768999A (en) * 1968-10-23 1973-10-30 Nippon Kokan Kk Coated wire feeding technique for making addition of components to molten metals
US3704230A (en) * 1970-02-17 1972-11-28 Carborundum Co Exothermic compositions

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4067730A (en) * 1974-04-20 1978-01-10 Thyssen Niederrhein Ag Hutten-Und Walzwerke Process for the production of steel with increased ductility
US3992195A (en) * 1974-04-20 1976-11-16 Thyssen Niederrhein Ag Hutten- Und Walzwerke Process for the production of steel with increased ductility
US4089677A (en) * 1976-05-28 1978-05-16 British Steel Corporation Metal refining method and apparatus
US4198229A (en) * 1976-06-28 1980-04-15 Nippon Steel Corporation Method of dephosphorization of metal or alloy
US4169724A (en) * 1977-02-26 1979-10-02 Skw Trostberg Aktiengesellschaft Desulfurization of iron melts
US4242126A (en) * 1979-07-11 1980-12-30 Skw Trostberg Aktiengesellschaft Process for the treatment of iron melts and for increasing the scrap portion in the converter
US4409028A (en) * 1979-10-24 1983-10-11 Moore William H Process for producing cast iron
US4315773A (en) * 1979-11-27 1982-02-16 Skw Trostberg Aktiengesellschaft Desulfurization mixture and process for desulfurizing pig iron
USRE31676E (en) 1982-09-29 1984-09-18 Thyssen Aktiengesellschaft vorm August Thyssen-Hutte AG Method and apparatus for dispensing a fluidizable solid from a pressure vessel
US4539042A (en) * 1983-02-23 1985-09-03 Mannesmann Ag Preventing an increase of the nitrogen content in molten steel
US5358550A (en) * 1992-10-26 1994-10-25 Rossborough Manufacturing Company Desulfurization agent
US5368631A (en) * 1992-10-26 1994-11-29 Rossborough Manufacturing Company Desulfurization agent
US5772727A (en) * 1993-12-21 1998-06-30 Stahlwerke Bremen Gmbh Process for the production of metal from metal ores
US5972072A (en) * 1997-04-07 1999-10-26 Reactive Metals & Alloys Corporation Desulfurizing mix
US5873924A (en) * 1997-04-07 1999-02-23 Reactive Metals & Alloys Corporation Desulfurizing mix and method for desulfurizing molten iron
KR100600237B1 (ko) * 1999-07-05 2006-07-13 제이에프이 스틸 가부시키가이샤 용융철합금의 탈황방법
EP1067202A2 (en) * 1999-07-05 2001-01-10 Kawasaki Steel Corporation Method of desulfurizing molten iron alloy
EP1067202A3 (en) * 1999-07-05 2001-06-13 Kawasaki Steel Corporation Method of desulfurizing molten iron alloy
US6328784B1 (en) 1999-07-05 2001-12-11 Kawasaki Corporation Method of desulfurizing molten iron alloy
US6352570B1 (en) 2000-04-10 2002-03-05 Rossborough Manufacturing Co., Lp Magnesium desulfurization agent
US6395058B2 (en) 2000-04-10 2002-05-28 Rossborough Manufacturing Co. L.P. Method of alloying ferrous material with magnesium injection agent
US6383249B2 (en) 2000-04-10 2002-05-07 Rossborough Manufacturing Co. Lp Magnesium desulfurization agent
US20040074339A1 (en) * 2002-10-18 2004-04-22 Rossborough Manufacturing Company, A Delaware Corporation Process for magnesium granules
US6770115B2 (en) 2002-10-18 2004-08-03 Remacor, Inc. Process for magnesium granules
US20040083851A1 (en) * 2002-10-30 2004-05-06 Rossborough Manufacturing Company, A Delaware Corporation Reclaimed magnesium desulfurization agent
US6989040B2 (en) 2002-10-30 2006-01-24 Gerald Zebrowski Reclaimed magnesium desulfurization agent
US20060021467A1 (en) * 2002-10-30 2006-02-02 Magnesium Technologies, Inc. Reclaimed magnesium desulfurization agent
US20070221012A1 (en) * 2006-03-27 2007-09-27 Magnesium Technologies Corporation Scrap bale for steel making process
US7731778B2 (en) 2006-03-27 2010-06-08 Magnesium Technologies Corporation Scrap bale for steel making process
US20080196548A1 (en) * 2007-02-16 2008-08-21 Magnesium Technologies Corporation Desulfurization puck
US9187792B2 (en) 2011-01-15 2015-11-17 Alamamet GmbH Agent for treating molten metals, method for the production and use thereof

Also Published As

Publication number Publication date
IT1001677B (it) 1976-04-30
DE2355736B2 (de) 1977-10-27
NL7315376A (it) 1974-05-13
DE2355736A1 (de) 1974-05-22
BR7308802D0 (pt) 1974-08-15

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