US3652262A - Refining of pig iron - Google Patents

Refining of pig iron Download PDF

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Publication number
US3652262A
US3652262A US661401A US3652262DA US3652262A US 3652262 A US3652262 A US 3652262A US 661401 A US661401 A US 661401A US 3652262D A US3652262D A US 3652262DA US 3652262 A US3652262 A US 3652262A
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United States
Prior art keywords
converter
hood
decarbonization
intensity
pig iron
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Expired - Lifetime
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US661401A
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English (en)
Inventor
Etienne Marie Denis
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Centre de Recherches Metallurgiques CRM ASBL
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Centre de Recherches Metallurgiques CRM ASBL
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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
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/30—Regulating or controlling the blowing

Definitions

  • the present invention relates to a method for controlling the refining operation of pig iron carried out in a converter.
  • the oxidizing gas injected into the liquid metal in the converter has the effect of oxidizing the undesirable elements contained in the said metal, i.e., phosphorus, silicon, manganese, and sulphur, as well as the greater part of the carbon.
  • the first four elements mentioned are found in oxidized form in the slag, whereas the carbon, which burns to form CO and then possibly to form CO escapes from the converter based on the extent to which the decarbonization of the pig iron progresses.
  • the rate of flow of CO and CO escaping from the converter can constitute a means for measuring the state of progress of the phenomenon of decarbonization, since during decarbonization the carbon contained in the CO and in the CO comes practically exclusively from the metal in the converter.
  • a number of methods have already been proposed for measuring the progress of the decarbonization of the pig iron by means of measuring the rates of flow of gas issuing from the converter.
  • a number of these methods are based on measuring the amount of heat supplied by the practically complete combustion of the CO into CO in the interior of a suction hood for the gases issuing from the converter.
  • the said processes have in general the disadvantage that the indications they supply are not very accurate and are frequently delayed.
  • the present invention aims at producing a method by which it is possible easily to observe the evolution of the phenomenon of decarbonization of the pig iron, while avoiding the disadvantages mentioned above.
  • the method of the invention in which pig iron in a converter is subjected to a top refining operation, has the essential feature that the gases issuing from the converter are drawn through a hood arranged above the converter, the reduced pressure creating vacuum effect proportional to the rate of flow of the gases issuing from the converter, in such a way that during the refining operation the surrounding air cannot be drawn into the hood with the said gases.
  • the intensity of the radiation of the flame is measured in the course of its passage between the spout of the converter and the hood, which makes it possible to deduce the rate of decarbonization of the pig iron.
  • the measurement takes place continuously, for instance by means of a cell which is sensitive to infra-red radiations and which is connected to a recording member.
  • the operator supervising the graph as it develops, produced by the recording member, is accordingly given almost instantaneous information on the state of progress of the decarbonization, and can take opportunely any measure or countermeasure which may be judged to be useful or necessary.
  • FIG. 1 schematically shows the entire system used, from the converter to the recording instruments
  • FIG. 2 shows the course of the two recorded curves, i.e., the speed of decarbonization of the metal bath and the intensity of the flame arising from the combustion of CO in the hood as a function of time.
  • FIG. 1 shows an elevation of a basic oxygen furnace (converter) containing the melt subjected to the refining operation at the top by means of an oxygen jet 2. Also shown is the catchment hood 3 for the fumes leaving the converter 1.
  • a basic oxygen furnace converter
  • FIG. 1 shows an elevation of a basic oxygen furnace (converter) containing the melt subjected to the refining operation at the top by means of an oxygen jet 2. Also shown is the catchment hood 3 for the fumes leaving the converter 1.
  • the flame which follows the gases leaving the converter 1 and passing through the hood 3 consists of a central spear (4), which is substantially conical and contains chiefly CO, and unburned CO which has not been mixed with air.
  • This spear (4) is capped by a brighter gas envelope (5) or zone which is the area of combustion of CO by the air.
  • the gases leaving the converter 1 are sucked into the hood and the intensity of the radiation emitted by the zone (5) where the combustion of CO by the oxygen of the air takes place is measured.
  • the cell 6 viewing the zone 5 of the flame is placed at such a point in the hood 3 that its line of sight 7 meets the zone (5) at a greater distance and the spear (4) at a lesser distance, preference being given to a line of sight whose axis 7 is close to the point of the spear (4) without touching it, as shown in FIG. 1.
  • the viewing cell 6 is connected to a recording instrument 9 by means of an appropriate circuit 8, comprising means of amplification, adaptation and thermal compensation of the transmitted signals.
  • the recording instrument 9 yields the graph II shown in FIG. 2, this graph representating as a function of time (on abscissa) the measurement of the intensity of the flame (on ordinate, conventional units) due to the combustion of CO in the hood.
  • the hood 3 is also provided with a gas pickup 10 connected to an analyzer 11 adapted to indicate the concentrations of CO and CO in the combustion (burned) gases.
  • Another gas pickup 12 measures the gas output by means of an output meter 13.
  • the data collected by the analyzer 1 l and the output meter 13 are then fed into an analogue computer 14, whose output signal is passed on to a recorder 15 which yields the curve of the rate of decarbonization of the metal bath contained in the converter 1.
  • This curve of the rate of decarbonization is the curve 1 shown in FIG. 2, where the ordinate is kilogrammes of carbon per minute and the abscissa is in minutes.
  • the curve traced by the recorder 9 is a graph derived from measurements, it is obtained almost instantaneously and by means of relatively simple apparatus.
  • the curve yielded by the recorder 15 is a graph arising from calculations the results of which are not known till after a certain interval by means of such apparatus as, for instance, an analogue computer. In general the curve supplied by the recorder 15 cannot be obtained till after a minute to a minute and a half after that supplied by the recorder 9.
  • the curve I shows on the ordinate, in kilogrammes of carbon per minute, the speed of decarbonization of the metal bath calculated as a function of time plotted on the abscissa the two graphs are striking and the importance of replacing the calculated curve (I) by the measured curve (ll) will be readily appreciated.
  • the curve l shows the speed of decarbonization during the first refining stage of a phosphorous melt by means of oxygen blown over its top.
  • a method as claimed in claim 2 inwhich the air inside the hood, including the external air drawn in, is sufficient to burn to CO essentially all the CO in said gases issuing from the spout of the converter.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
US661401A 1966-08-23 1967-08-17 Refining of pig iron Expired - Lifetime US3652262A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU51811A LU51811A1 (fr) 1966-08-23 1966-08-23
LU51810A LU51810A1 (fr) 1966-08-23 1966-08-23

Publications (1)

Publication Number Publication Date
US3652262A true US3652262A (en) 1972-03-28

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US661401A Expired - Lifetime US3652262A (en) 1966-08-23 1967-08-17 Refining of pig iron

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US (1) US3652262A (fr)
FR (1) FR1535067A (fr)
GB (1) GB1176809A (fr)
LU (2) LU51810A1 (fr)
NL (1) NL6711618A (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3871871A (en) * 1967-12-11 1975-03-18 Centre Nat Rech Metall Monitoring and control of pig iron refining
US5603746A (en) * 1995-10-31 1997-02-18 Bethlehem Steel Corporation Method and apparatus to determine and control the carbon content of steel in a BOF vessel
US5984998A (en) * 1997-11-14 1999-11-16 American Iron And Steel Institute Method and apparatus for off-gas composition sensing
US20130276582A1 (en) * 2012-01-19 2013-10-24 Centro De Investigación En Química Aplicada Physical process for the recovery of iron from magnetic cementitious spherical particles generated from metallurgical byproducts
CN115125354A (zh) * 2022-06-16 2022-09-30 首钢集团有限公司 一种转炉高效利用二氧化碳的方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2207309A (en) * 1939-03-22 1940-07-09 Jones & Laughlin Steel Corp Controlling bessemer converters
US2354400A (en) * 1942-06-22 1944-07-25 Us Steel Corp Of Delaware Bessemer converter blow control method
US2803987A (en) * 1953-05-04 1957-08-27 Siderurgie Fse Inst Rech Device for measuring the variations of opacity of the flame of a thomas converter and automatically determining the end of the operation
US2807537A (en) * 1954-11-01 1957-09-24 Bethlehem Steel Corp Method of controlling the partial blowing of bessemer steel
US3222045A (en) * 1961-01-10 1965-12-07 Huettenwerk Oberhausen Ag Method and apparatus for waste heat economy in rotary converter plants

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2207309A (en) * 1939-03-22 1940-07-09 Jones & Laughlin Steel Corp Controlling bessemer converters
US2354400A (en) * 1942-06-22 1944-07-25 Us Steel Corp Of Delaware Bessemer converter blow control method
US2803987A (en) * 1953-05-04 1957-08-27 Siderurgie Fse Inst Rech Device for measuring the variations of opacity of the flame of a thomas converter and automatically determining the end of the operation
US2807537A (en) * 1954-11-01 1957-09-24 Bethlehem Steel Corp Method of controlling the partial blowing of bessemer steel
US3222045A (en) * 1961-01-10 1965-12-07 Huettenwerk Oberhausen Ag Method and apparatus for waste heat economy in rotary converter plants

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3871871A (en) * 1967-12-11 1975-03-18 Centre Nat Rech Metall Monitoring and control of pig iron refining
US5603746A (en) * 1995-10-31 1997-02-18 Bethlehem Steel Corporation Method and apparatus to determine and control the carbon content of steel in a BOF vessel
WO1997016571A1 (fr) * 1995-10-31 1997-05-09 Bethlehem Steel Corporation Procede et dispositif de determination et de modulation de la teneur en carbone d'un acier dans un convertisseur a soufflage d'oxygene au-dessus du bain
EP1046720A1 (fr) * 1995-10-31 2000-10-25 Bethlehem Steel Corporation Dispositif de détermination et de modulation de la teneur en carbone d'un acier dans un convertisseur a soufflage d'oxygène
CN1068633C (zh) * 1995-10-31 2001-07-18 伯利恒钢铁公司 测定和控制bof转炉中的钢的碳含量的方法和设备
USRE37922E1 (en) 1995-10-31 2002-12-10 Bethlehem Steel Corporation Method and apparatus to determine and control the carbon content of steel in a BOF vessel
US5984998A (en) * 1997-11-14 1999-11-16 American Iron And Steel Institute Method and apparatus for off-gas composition sensing
US20130276582A1 (en) * 2012-01-19 2013-10-24 Centro De Investigación En Química Aplicada Physical process for the recovery of iron from magnetic cementitious spherical particles generated from metallurgical byproducts
CN115125354A (zh) * 2022-06-16 2022-09-30 首钢集团有限公司 一种转炉高效利用二氧化碳的方法
CN115125354B (zh) * 2022-06-16 2024-02-06 首钢集团有限公司 一种转炉高效利用二氧化碳的方法

Also Published As

Publication number Publication date
GB1176809A (en) 1970-01-07
FR1535067A (fr) 1968-08-02
DE1583227B1 (de) 1971-12-09
NL6711618A (fr) 1968-02-26
LU51811A1 (fr) 1968-03-25
LU51810A1 (fr) 1968-03-25

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