WO2011049240A1 - Top lance for refining and method for refining molten iron using same - Google Patents
Top lance for refining and method for refining molten iron using same Download PDFInfo
- Publication number
- WO2011049240A1 WO2011049240A1 PCT/JP2010/069118 JP2010069118W WO2011049240A1 WO 2011049240 A1 WO2011049240 A1 WO 2011049240A1 JP 2010069118 W JP2010069118 W JP 2010069118W WO 2011049240 A1 WO2011049240 A1 WO 2011049240A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- gas
- refining
- oxygen
- supply path
- lance
- Prior art date
Links
Images
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
- 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
- C21C5/42—Constructional features of converters
- C21C5/46—Details or accessories
- C21C5/4606—Lances or injectors
- C21C5/4613—Refractory coated lances; Immersion lances
-
- 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
-
- 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
- C21C5/32—Blowing from above
-
- 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
- C21C5/36—Processes yielding slags of special composition
-
- 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
- C21C5/42—Constructional features of converters
- C21C5/46—Details or accessories
-
- 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/068—Decarburising
-
- 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/16—Introducing a fluid jet or current into the charge
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D3/00—Charging; Discharging; Manipulation of charge
- F27D3/18—Charging particulate material using a fluid carrier
-
- 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
- C21C5/305—Afterburning
Definitions
- the present invention relates to a top lance for refining suitable for applying oxidation refining such as dephosphorization treatment to hot metal or molten steel in a converter-type refining vessel. Furthermore, the present invention relates to a hot metal refining method using the top blowing lance.
- the oxygen-containing gas supply path and the solid oxygen source supply path such as iron oxide are separated from each other, so the oxygen-containing gas is separated from these paths.
- the solid oxygen source can be independently supplied to the hot metal or molten steel bath surface in the converter type refining vessel.
- the top blowing lance of the present invention can supply a powder other than the solid oxygen source together with the oxygen-containing gas.
- the top blowing lance of the invention can supply the oxygen-containing gas for secondary combustion to the in-furnace space of the converter-type refining vessel from the side surface of the lance separated from the lance tip.
- dephosphorizing refining agent The main component of the dephosphorizing refining agent in the hot metal preliminary dephosphorization treatment is lime.
- lime that does not flux does not contribute to the dephosphorization reaction, so to reduce the amount of lime used, promote the hatching of the added lime.
- fluorite ore containing calcium fluoride as a main component
- fluorite has been used in the dephosphorization treatment.
- solvent containing fluorine has been restricted. Therefore, means for promoting the dephosphorization reaction by lime without using fluorite have been studied, and many proposals have been made.
- Patent Document 1 proposes a hot metal preliminary dephosphorization treatment method in which a lime-based dephosphorization refining agent and an endothermic substance are added to a place where oxygen gas is supplied.
- Patent Document 2 discloses an upper blowing lance suitable for adding a lime-based dephosphorizing refining agent to a fire spot (fire spot) region formed on the hot metal surface by supplying oxygen gas.
- This top blowing lance is a quadruple in which a powder blowing nozzle for supplying a lime-based dephosphorizing refining agent is arranged at the axial center position, and a plurality of nozzles for supplying oxygen gas are arranged around it. It has a tube structure.
- Patent Document 3 a supply path for supplying a lime-based dephosphorization refining agent together with an oxygen-containing gas and an iron oxide supply path are separated, and oxygen-containing gas and lime-based dephosphorization are separated from these paths.
- An upper blowing lance for refining a five-pipe structure for supplying a refining agent and iron oxide to the hot metal bath surface and subjecting the hot metal to oxidative refining such as dephosphorization has been proposed.
- This Patent Document 3 also proposes detecting a broken hole in the iron oxide supply path by providing a buffer space around the iron oxide supply path.
- Patent Document 1 and Patent Document 2 disclose working temperatures of about 1300 ° C. to about 1350 ° C.
- the free board space other than the space occupied by static molten iron in the furnace
- the preliminary dephosphorization of hot metal is performed in a converter-type smelting vessel. Is common.
- the hot metal scattered during the dephosphorization process adheres to and solidifies on the side walls and furnace opening of the converter-type smelting vessel and deposits the metal, resulting in a reduction in the hot metal yield and the production of the metal. It was causing a decline in sex.
- This problem of metal adhesion is not limited to hot metal preliminary dephosphorization, but also to hot metal decarburization and refining in converters.
- the inner wall of the converter and the furnace port are scattered by metal splattering (referred to as “spitting”) and slag ejection (referred to as “slipping”) during blowing. Ingots accumulate, causing problems such as hindering hot metal and iron scrap charging into the furnace.
- a horizontal or downward secondary combustion nozzle is disposed on a side surface of an upper blowing lance that is spaced a predetermined distance from a distal end portion of an upper blowing lance having a main hole nozzle at the distal end portion.
- a refining method is proposed in which oxygen gas is supplied from the main hole nozzle to oxidize and refine hot metal or molten steel in the converter, and at the same time, oxygen gas is supplied from the secondary combustion nozzle to melt the metal attached to the converter.
- a gaseous oxygen source such as an oxygen-containing gas and a solid oxygen source such as iron oxide are used together as an oxygen source, and these are located at the same location or in close proximity.
- the oxidation refining method added to the mainstream has become the mainstream.
- the gaseous oxygen source is used as a carrier gas, and a flux such as a dephosphorizing refining agent is carried together with the gaseous oxygen source (see Patent Document 3).
- a refining method for adding to the addition position is also performed.
- top blowing lances are verified as a top blowing lance for carrying out such refining. None of the above top blowing lances can be employed. Moreover, even if the conventional top blowing lance is combined, it cannot be a satisfactory top blowing lance. For example, even if the secondary combustion nozzle proposed in Patent Document 4 is installed by connecting to the oxygen-containing gas supply path of the top blowing lance proposed in Patent Document 3, oxygen is supplied through the oxygen-containing gas supply path. When the flux is transported together with the contained gas, there arises a problem that the secondary combustion nozzle is blocked by the flux.
- the present invention has been made in view of such circumstances, and the object thereof is to efficiently perform hot metal or hot steel in an oxidizing refining vessel in a converter-type refining vessel, such as preliminary dephosphorization of hot metal. It is to provide an upper blowing lance for refining that can efficiently oxidize and refining ingots adhering to a converter type refining vessel. The object of the present invention is also to provide a hot metal refining method using this top blowing lance.
- the gist of the present invention for solving the above problems is as follows.
- a secondary combustion nozzle in a horizontal or obliquely downward direction on the side surface of the upper blowing lance at a position separated upward from the tip A powder different from the solid oxygen source is supplied to the inside of the blowing lance with the oxygen-containing gas for blowing through the main hole nozzle, or an oxygen-containing gas for blowing is supplied through the main hole nozzle.
- the first supply path includes a refining flux introduction section that introduces a powder (hereinafter also referred to as “refining flux”) different from the solid oxygen source, and an oxygen-containing gas that introduces an oxygen-containing gas into the path.
- refining flux introduction part may be an introduction part for introducing the refining flux together with the carrier gas, and this carrier gas is also preferably an oxygen-containing gas.
- the refining flux and the oxygen-containing gas are introduced from the same introduction portion (that is, the refining flux and the oxygen-containing gas previously mixed in the ratio when supplying the refining flux and the oxygen-containing gas through the main hole nozzle).
- the introduction of the refining flux may be stopped, and only the oxygen-containing gas may be introduced into the first supply path from the oxygen-containing gas introduction section.
- the second supply path has an oxygen-containing gas introduction unit that introduces the oxygen-containing gas into the path.
- the third supply path has a solid oxygen source introduction part that introduces a solid oxygen source into the path together with the carrier gas.
- the supply of the solid oxygen source may be stopped and only the carrier gas may be introduced into the third supply path from the introduction unit.
- the first supply path and the second supply path may share the oxygen-containing gas introduction part.
- a partition structure is provided to prevent the refining flux from entering the second supply path.
- the terminal of the second supply path is closed, and the oxygen-containing gas supplied through the second supply path is configured not to join the first supply path and the third supply path.
- the top blowing lance for refining as described in said (1) characterized by the above-mentioned.
- the end of the second supply path means a portion of the path ahead of the nozzle for secondary combustion closest to the lance tip (on the lance tip).
- It is configured to supply any one or more of reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas to the second supply path.
- a buffer space in which any one or more of air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas is present is provided around the third supply path.
- the broken hole in the third supply path is detected based on the change in the pressure or flow rate of the gas existing in the buffer space.
- the top blow lance for refining according to any one of the above.
- the first supply path, the second supply path, and the third supply path are arranged concentrically, as described in any one of (1) to (4) above Top blow lance for refining.
- the top blowing lance is supplied with a powder different from the solid oxygen source, such as a lime-based dephosphorizing refining agent, together with the oxygen-containing gas for blowing through the main hole nozzle.
- a first supply path for supplying the oxygen-containing gas for blowing through the main hole nozzle, and a second supply path for supplying the oxygen-containing gas for secondary combustion through the nozzle for secondary combustion And a third supply path for supplying the powdered solid oxygen source together with the carrier gas through the sub-hole nozzle. Therefore, even if powder is supplied from the first supply path and the third supply path, only the oxygen-containing gas is injected from the secondary combustion nozzle, and the secondary combustion nozzle is not blocked for a long period of time.
- the oxygen-containing gas for secondary combustion is stably injected over the entire area.
- adhesion of bullion to the converter-type smelting vessel is suppressed, adverse effects due to adhesion of bullion are prevented, and iron yield and productivity are improved.
- fluxes such as oxygen-containing gas, solid oxygen source, and lime-based dephosphorizing refining agent can be supplied to the same location or in the vicinity of each, enabling efficient smelting of hot metal and molten steel. Is done.
- FIG. 1 is a schematic cross-sectional view showing an example of a refining top blowing lance according to the present invention.
- FIG. 2 is a diagram showing a buffer gas supply path to the buffer space in the refining top blow lance according to the present invention.
- FIG. 3 is a schematic sectional view showing another example of the refining top blow lance according to the present invention.
- FIG. 1 is a schematic cross-sectional view showing an example of a refining top blowing lance according to the present invention.
- an upper blowing lance 1 according to the present invention includes a cylindrical lance main body 2, a lance nozzle 3 connected to the lower end of the lance main body 2 by welding, and the upper end of the lance main body 2.
- the lance body 2 is composed of six kinds of concentric steel pipes, that is, a six-fold pipe, that is, an outermost pipe 5, an outer pipe 6, an intermediate pipe 7, a partition pipe 8, an inner pipe 9, and an innermost pipe 10.
- the copper lance nozzle 3 is provided with a vertically downward sub-hole nozzle 12 at the axial center thereof, and around the sub-hole nozzle 12, a plurality of main hole nozzles whose discharge direction is a vertically oblique downward direction. 11 is installed.
- a plurality of secondary combustion nozzles 13 whose discharge direction is horizontal or obliquely downward is provided on the side surface of the lance body 2 at a position separated upward from the tip of the lance nozzle 3. It is installed at almost equal intervals in the circumferential direction. In FIG. 1, although there are two stages in the vertical direction, it may be one stage or three stages or more.
- the horizontal or obliquely downward secondary combustion nozzle 13 is provided on the side surface portion at a position separated upward from the tip of the upper blow lance 1 when the injection direction from the secondary combustion nozzle is the furnace of the refining vessel. It means selecting the position and direction (angle) on the side surface of the lance so as to face the wall.
- the distance from the tip of the lance of the secondary combustion nozzle 13 closest to the tip of the lance is 300 mm from the tip of the lance in consideration of design restrictions such as a cooling water channel in a general converter top blowing lance nozzle 3. It is preferable that they are separated from each other.
- the main hole nozzle 11 is an oxygen-containing gas that is a blowing gas, or a powder ("refining flux") such as a flux other than a solid oxygen source together with the oxygen-containing gas using the oxygen-containing gas as a carrier gas, that is,
- This is a nozzle for blowing powder such as a lime-based dephosphorizing refining agent into a refining vessel (not shown) such as a converter.
- the sub-hole nozzle 12 is a nozzle for blowing a solid oxygen source such as iron ore and mill scale into the smelting vessel together with the carrier gas.
- the secondary combustion nozzle 13 is a nozzle for blowing an oxygen-containing gas for secondary combustion into the internal space of the refining vessel. As shown in FIG.
- the main hole nozzle 11 has a so-called Laval nozzle that has a cross-section that expands toward the tip.
- the sub-hole nozzle 12 and the secondary combustion nozzle 13 have a straight shape, but the sub-hole nozzle 12 and the secondary combustion nozzle 13 may also take the shape of a Laval nozzle.
- the upper blowing lance 1 is supported by a support device (not shown) above the refining vessel so that it can be moved up and down inside the refining vessel.
- the oxygen-containing gas is a gas having oxygen gas (pure oxygen gas), oxygen-enriched air, a mixed gas of oxygen gas and rare gas, and the oxygen gas concentration is higher than that of air. is there.
- dust collection dust is dust containing FeO or Fe 2 O 3 that is recovered from exhaust gas in a blast furnace, converter, and sintering process.
- a flux such as quick lime which is a kind of lime-based dephosphorizing refining agent, blows oxygen-containing gas from the main hole nozzle 11 as a carrier gas.
- a flux such as quick lime may be blown in combination with the oxygen source.
- the flow rate ejected from the sub hole nozzle 12 and the flow rate ejected from the main hole nozzle 11 are independently controlled by independent flow meters (not shown).
- the gap between the outermost pipe 5 and the outer pipe 6 and the gap between the outer pipe 6 and the middle pipe 7 serve as cooling water flow paths for cooling the upper blowing lance 1. Cooling water supplied from a water supply pipe (not shown) provided at the lance top 4 reaches the site of the lance nozzle 3 through the gap between the outer tube 6 and the middle tube 7 and is reversed at the site of the lance nozzle 3. Then, the water is discharged from a drain pipe (not shown) provided on the lance top 4 through a gap between the outermost pipe 5 and the outer pipe 6. The water supply / drainage route may be reversed.
- the gap between the middle tube 7 and the partition tube 8 is a second supply path for supplying the oxygen-containing gas to the secondary combustion nozzle 13.
- the oxygen-containing gas introduced into the inside of the intermediate pipe 7 from the oxygen-containing gas supply pipe 14 that communicates with the intermediate pipe 7 provided at the lance top 4 passes through the second supply path and becomes the secondary combustion nozzle 13.
- the secondary combustion nozzle 13 is ejected.
- the upper end portion of the partition tube 8 does not reach the installation site of the oxygen-containing gas supply tube 14 (the introduction portion of the oxygen-containing gas).
- the oxygen-containing gas introduced from the oxygen-containing gas supply pipe 14 into the middle pipe 7 is a gap between the partition pipe 8 and the inner pipe 9 (as described later, the gap between the partition pipe 8 and the inner pipe 9 is Also flows into the first supply path), and is ejected to the main hole nozzle 11 through this gap. Also, the lower end of the partition tube 8 does not reach the lance nozzle 3 part. That is, the oxygen-containing gas that has passed through the gap between the intermediate pipe 7 and the partition pipe 8, that is, the second supply path, but has not been ejected from the secondary combustion nozzle 13 joins the first supply path, It ejects from the hole nozzle 11.
- the gap between the partition pipe 8 and the inner pipe 9 is an oxygen-containing gas for blowing or a powder different from solid oxygen together with this oxygen-containing gas (“refining flux”), for example, a lime-based dephosphorizing agent.
- the first supply path for supplying the powder such as to the main hole nozzle 11.
- the lance top 4 is provided with a powder supply pipe 15 for supplying a refining flux using oxygen-containing gas as a carrier gas (a portion where the supply pipe is installed serves as a refining flux introduction part).
- 8 and the oxygen-containing gas supply pipe 14 (the portion where the supply pipe is installed serves as the oxygen-containing gas introduction part) is provided in communication with the middle pipe 7 as described above.
- the partition pipe 8 functions as a partition structure for preventing the refining flux from being mixed into the second supply path.
- the refining flux that is, the powder different from the solid oxygen source
- all known (or foreseeable) solid substances that are added to efficiently realize refining other than the solid oxygen source can be applied.
- the lime-based dephosphorizing refining agent quick lime (CaO), limestone (CaCO 3 ), dolomite (CaCO 3 .MgCO 3 ), decarburized slag, secondary refining slag, etc.
- raw materials for slag examples thereof include silica (SiO 2 ), brick scraps containing magnesium oxide, etc., hatching accelerators (including fluorite, titanium oxide, aluminum oxide, etc.) and the like.
- at least a lime-based dephosphorizing refining agent is supplied as a refining flux.
- the inside of the innermost pipe 10 is a third supply path for supplying a solid oxygen source to the sub-hole nozzle 12 together with the carrier gas. That is, the solid oxygen source supplied to the inside of the innermost pipe 10 together with the carrier gas from a supply pipe (not shown) provided at the lance top 4 and communicating with the innermost pipe 10 is the inside of the innermost pipe 10. It passes through to the sub-hole nozzle 12 and is ejected from the sub-hole nozzle 12.
- the installation section (not shown) of the supplier is a solid oxygen source introduction section.
- a gas having an oxygen content equal to or lower than air is suitable, and in particular, any one of air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas or It is preferable to use two or more gases.
- the reason for using air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas as the carrier gas for the solid oxygen source is as follows.
- the air contains less oxygen gas than the oxygen-containing gas blown from the main hole nozzle 11, and the reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas substantially contain oxygen gas. Not in. Therefore, it is possible to prevent combustion during the transportation of a small amount of metallic iron contained in the solid oxygen source, and the innermost due to the spark generated by the contact between the solid oxygen source and the innermost tube 10 during the transportation.
- the combustion of the tube 10 can be prevented.
- the reducing gas is a hydrocarbon gas such as propane gas and CO gas
- the non-oxidizing gas is a gas having no oxidizing ability such as nitrogen gas
- the rare gas is Ar gas or He.
- An inert gas such as a gas.
- the gap between the inner tube 9 and the innermost tube 10 is sealed at the tip portion of the lance nozzle 3 to make a dead end, and is supplied from a buffer gas supply tube 16 provided on the lance top 4.
- the gas present in the buffer space is referred to as “buffer gas”.
- a buffer gas supply pipe 16 provided at the lance top 4 includes a detector 20, a remote control valve 21, a flexible hose 22, and a plurality of manual shut-off valves 23.
- a gas introduction device 19 is connected.
- the buffer gas is supplied to the buffer space via the buffer gas introducing device 19.
- a pressure gauge or a flow meter, or both a pressure gauge and a flow meter are installed.
- the remote control valve 21 may be shut off and the buffer gas may be sealed in the buffer space, or the remote control valve 21 may be opened to buffer the buffer space.
- the gas pressure may always be applied.
- FIG. 1 In the example of FIG.
- the flexible hose 22 is a margin when the upper blowing lance 1 moves up and down.
- the detector 20 is installed closer to the upper blowing lance 1 than the flexible hose 22, but it may be installed closer to the supply side than the flexible hose 22. It can be installed anywhere.
- the detector 20 needs to be arranged on the upper blowing lance 1 side than the remote control valve 21. Therefore, from the viewpoint of operational flexibility, the detector 20 is preferably disposed on the upper blowing lance 1 side than the remote control valve 21.
- the reason for using air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas as the buffer gas is the same as the reason for using these gas types as the carrier gas for the solid oxygen source.
- the buffer gas and the solid oxygen source come into contact with each other even if a hole is generated in the innermost tube 10 which is the supply path of the solid oxygen source, that is, the third supply path, due to the transport of the solid oxygen source
- this gas species is used as a buffer gas
- combustion of metallic iron in the solid oxygen source and combustion of the innermost tube 10 due to sparks generated by contact between the solid oxygen source and the innermost tube 10 can be prevented. Because it can. Therefore, any gas other than the above can be used as a buffer gas as long as the oxygen content is less than air.
- Detecting broken holes during refining of the innermost pipe 10 can be performed as follows. That is, if a hole breaks in the innermost pipe 10 during refining, the buffer space communicates with the inside of the innermost pipe 10, the pressure in the buffer space changes, or the flow rate of the buffer gas supplied to the buffer space Changes, so a hole is detected based on the change.
- the following two methods can be taken as specific detection methods.
- One method is to install a pressure gauge or both a pressure gauge and a flow meter as the detector 20, introduce a buffer gas into the buffer space, shut off the remote control valve 21, and buffer the gas into the buffer space. And the pressure in the buffer space is measured by the detector 20 during refining to detect a broken hole.
- a flow meter is installed as the detector 20, the remote control valve 21 is opened, and the pressure of the buffer gas is constantly applied to the buffer space. In this state, the flow rate is measured by the detector 20, and the hole is broken. This is a method for detecting a broken hole from a change in flow rate.
- the upper blowing lance 1 is disposed at a predetermined position above the hot metal in the converter, and oxygen gas is blown from the main hole nozzle 11 toward the hot metal bath surface as an oxygen-containing gas.
- a solid oxygen source is used as a hot metal bath by using any one or more of air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas as a carrier gas. Spray toward the surface.
- the solid oxygen source sprayed from the sub-hole nozzle 12 is supplied to or near the hot metal bath surface where the oxygen gas is supplied.
- the dephosphorization treatment requires a slag for dephosphorization and refining for absorbing the phosphorus oxide (P 2 O 5 ) produced by the dephosphorization reaction, and the lime-based dephosphorization for slag to be the slag for dephosphorization and refining.
- Add agent
- the refining agent for lime-based dephosphorization is not particularly limited as long as it contains CaO and can be dephosphorized as intended in the present case. Usually, it consists of CaO alone, or contains 50 mass% or more of CaO, and contains other components as necessary. As specific examples, quick lime (CaO), limestone (CaCO 3 ), or dolomite (CaCO 3 .MgCO 3 ) can be used. Further, as a hatching accelerator for these substances, titanium oxide, oxidation A mixture of materials containing aluminum and magnesium oxide can also be used. In addition, decarburization slag and ladle refining slag are mainly composed of CaO and have a low phosphorus content, so that they can be sufficiently used as a refining agent for lime-based dephosphorization. .
- the location where the oxygen gas collides with the hot metal bath surface (referred to as “fire point”) is heated due to the reaction between the oxygen gas and the carbon in the hot metal, and is supplied to or near the fire point.
- the resulting solid oxygen source melts rapidly and increases the FeO component in the slag. This increases the oxygen potential of the slag, that is, the slag optimum for the dephosphorization reaction is rapidly formed, and the dephosphorization treatment is possible even at a small amount of slag or at a high temperature.
- the hatching of the lime-based dephosphorization refining agent is promoted, and the dephosphorization refining slag is formed at an early stage.
- the reaction is further promoted. Therefore, it is preferable to add the lime-based dephosphorizing refining agent to the fire point or the vicinity of the fire point through the main hole nozzle 11 or the main hole nozzle 11 and the sub hole nozzle 12.
- oxygen gas for secondary combustion is supplied from the secondary combustion nozzle 13 to melt the ingot from the furnace body in parallel with the dephosphorization or prevent the adhesion of the ingot.
- the oxygen gas supply amount (Q) from the secondary combustion nozzle 13 is preferably in the range of 5 to 30% of the oxygen gas supply amount (Q O ) from the main hole nozzle 11.
- the amount of oxygen gas for secondary combustion is too small, and the calorific value of secondary combustion is insufficient, so that the adhered metal cannot be dissolved.
- 100 Q / Q 2 O exceeds 30%, the secondary combustion exothermic heat becomes excessive and the melting loss of the furnace refractory is promoted.
- V 0 the flow velocity (m / sec) of the oxygen gas jet at the outlet of the secondary combustion nozzle, de: the outlet diameter (mm) of the secondary combustion nozzle
- C 0.016 + 0. 19 / (P 0 -P e )
- P 0 Oxygen back pressure (kgf / cm 2 ) expressed in absolute pressure of the secondary combustion nozzle
- P e Atmospheric pressure (absolute pressure displayed in the converter type refining vessel) kgf / cm 2 ).
- top blowing lance and controlling the blowing conditions within an appropriate range so that this distance X does not reach the furnace wall, local melting of the metal and melting of the furnace wall refractory can be avoided.
- the heat of combustion reaction can be uniformly distributed in the furnace.
- the flow rate of the oxygen-containing gas ejected from the secondary combustion nozzle 13 depends on the ratio of the total cross-sectional area of the main hole nozzle 11 and the total cross-sectional area of the secondary combustion nozzle 13, and the secondary combustion nozzle
- the amount of ejection from 13 cannot be controlled independently. That is, the total amount of oxygen-containing gas supplied from the oxygen-containing gas supply pipe 14 and the powder supply pipe 15 is distributed according to the ratio of the total cross-sectional area of both.
- the oxygen-containing gas flow rate for secondary combustion can be controlled independently. However, in this case, it is necessary to change the internal structure of the upper blowing lance from the upper blowing lance 1 shown in FIG.
- FIG. 3 shows an example of an upper blowing lance that can control the flow rate of the oxygen-containing gas for secondary combustion independently of the oxygen-containing gas for blowing.
- the lower end of the partition pipe 8 reaches the portion of the lance nozzle 3, where the gap between the middle tube 7 and the partition tube 8 is the second supply path. Sealed. Further, in the lance top 4, the upper end of the partition pipe 8 is located above the upper end position of the middle pipe 7, and a sealing material for sealing is installed between the middle pipe 7 and the partition pipe 8, so that the second The supply path is sealed.
- the oxygen-containing gas supply pipe 18 communicates with the middle pipe 7 (the installation section of the supply pipe is an oxygen-containing gas introduction section). That is, the oxygen-containing gas supplied from the oxygen-containing gas supply pipe 18 to the inside of the middle pipe 7 passes through the gap between the middle pipe 7 and the partition pipe 8, that is, the second supply path, from the secondary combustion nozzle 13. It comes to erupt.
- an oxygen-containing gas / powder supply pipe 17 communicates with the partition pipe 8 (the installation section of the supply pipe serves as a refining flux introduction section and an oxygen-containing gas introduction section). .
- the oxygen-containing gas for blowing supplied from the oxygen-containing gas / powder supply pipe 17 to the inside of the partition pipe 8 or the refining flux using the oxygen-containing gas as the transport gas is separated from the partition pipe 8 and the inside.
- the gas is ejected from the main hole nozzle 11 through the gap with the pipe 9, that is, through the first supply path.
- the top blowing lance 1A is the same as that of the top blowing lance 1 shown in FIG. 1, and the same parts are denoted by the same reference numerals, and the description thereof is omitted. Further, the preliminary dephosphorization treatment of the hot metal using the upper blowing lance 1A may be performed in accordance with the case where the upper blowing lance 1 is used.
- the top blowing lances 1, 1 ⁇ / b> A mainly contain a powder different from a solid oxygen source, such as a lime-based dephosphorizing refining agent, together with an oxygen-containing gas for blowing.
- the first supply path and the first supply path Even if the powder is supplied from the supply path 3, only the oxygen-containing gas is injected from the secondary combustion nozzle 13, and the secondary combustion nozzle 13 is not blocked, and the secondary combustion is stable over a long period of time. Oxygen containing gas is injected. This will suppress the adhesion of bullion to the converter-type smelting vessel, and prevent harmful effects associated with adhesion of bullion.
- the hot metal discharged from the blast furnace is desiliconized in the blast furnace casting floor as necessary, and then transferred to a 300-ton converter, using the top blow lance shown in FIG. 1 for a total of four times.
- the preliminary dephosphorization treatment was carried out (Invention Examples 1 to 4).
- the number of main hole nozzles was four in a uniform arrangement on a concentric circle.
- the secondary combustion nozzles are arranged in an evenly arranged manner on the circumference, and each of the eight upper and lower nozzles is provided.
- the angle ⁇ (°) formed between the secondary combustion nozzle and the upper blowing lance is determined by the oxygen jet flow from the secondary combustion nozzle.
- the distance X (m) from the nozzle outlet of the secondary combustion nozzle 13 at a flow rate of 30 m / sec was set to satisfy the following formula (2).
- X is a distance (m) from the nozzle outlet of the secondary combustion nozzle determined from the equation (1)
- H is a horizontal distance (m) from the center of the top blowing lance to the converter furnace wall.
- the phosphorus concentration in the hot metal before the dephosphorization treatment was unified to 0.12% by mass, the phosphorus concentration in the hot metal after the dephosphorization treatment was set to 0.020% by mass or less, and the iron yield was set to 98% or more.
- the iron yield ( ⁇ ) is the hot metal discharged after dephosphorization with respect to the total mass (W 0 + W S ) of the mass (W 0 ) of the hot metal charged in the converter and the mass (W S ) of the iron scrap.
- oxygen gas is supplied from the oxygen-containing gas supply pipe 14, and quick lime powder (average particle size of 1 mm or less) is supplied from the powder supply pipe 15 as a carrier gas, and inside the innermost pipe.
- quick lime powder average particle size of 1 mm or less
- a solid oxygen source in powder form was supplied using nitrogen gas as a carrier gas.
- the first supply path is a supply path for oxygen gas and quicklime powder
- the second supply path is a supply path for oxygen gas.
- dephosphorization was performed without using a fluorine compound such as CaF 2 as a dephosphorizing refining agent.
- nitrogen gas was blown from the tuyeres at the bottom of the converter furnace at a flow rate of 0.03 to 0.30 Nm 3 / min per ton of hot metal.
- the flow rate of oxygen gas supplied from the main hole nozzle and the secondary combustion nozzle was 0.6 to 2.5 Nm 3 / min per ton of hot metal.
- the basic unit of oxygen gas was 12 Nm 3 / t excluding oxygen gas necessary for desiliconization.
- the oxygen gas flow rate (Q) from the secondary combustion nozzle relative to the oxygen gas flow rate (Q 2 O 3 ) from the main hole nozzle, that is, 100 Q / Q 2 O was 6%.
- any one of powdered iron ore average particle size 50 ⁇ m
- iron sand average particle size 100 ⁇ m
- mill scale average particle size 500 ⁇ m
- iron ore sintered ore average particle size 100 ⁇ m
- a secondary combustion nozzle of the upper blow lance shown in FIG. 1 is mechanically closed, and a dephosphorization process is performed in which oxygen gas for secondary combustion is not supplied to the furnace space (Comparative Example 1). did.
- the other dephosphorization treatment conditions of the comparative example were performed according to the examples of the present invention.
- Table 1 shows the hot metal components and operating conditions before and after the dephosphorization treatment in the inventive examples and the comparative examples.
- the amount of CaO basic unit and solid oxygen source used in Table 1 is the amount per ton of hot metal.
- the hot metal discharged from the blast furnace is desiliconized in the blast furnace casting floor as necessary, and then transferred to a 300-ton converter, using the top blow lance shown in FIG. 3 twice in total.
- the preliminary dephosphorization treatment was carried out (Invention Examples 5 to 6).
- the oxygen gas flow rate (Q) from the secondary combustion nozzle to the oxygen gas flow rate (Q O ) from the main hole nozzle is: That 100Q / Q O was 12%. Also in this case, it was confirmed that Xsin ⁇ was in a range satisfying the formula (2).
- Other dephosphorization conditions were the same as those in Example 1.
- Table 2 shows hot metal components and operating conditions before and after the dephosphorization treatment.
- the CaO basic unit and the amount of solid oxygen source used in Table 2 are amounts per ton of hot metal, and the definition of iron yield is the same as in Example 1.
- the hot metal discharged from the blast furnace is desiliconized in a blast furnace casting floor as necessary, and then transferred to a 350-ton capacity converter using the top blowing lance shown in FIGS. 1 and 3.
- Preliminary dephosphorization was performed (Invention Examples 7 to 8).
- Oxygen gas was blown from the tuyeres at the bottom of the converter furnace as a stirring gas at a flow rate of 0.3 Nm 3 / min per ton of hot metal.
- the tuyeres at the bottom of the furnace had a double tube structure, and oxygen gas was blown from the inner tube and propane gas was blown from the outer tube as a cooling gas according to the flow rate of oxygen gas.
- As a solid oxygen source 6 kg of iron ore sintered ore (average particle size 100 ⁇ m) was used per 1 ton of hot metal, and sprayed from the sub-hole nozzle of the top blowing lance.
- the condition of the oxygen jet from the secondary combustion nozzle was set in a range satisfying the formula (2).
- Other dephosphorization conditions were the same as those in Example 1.
- Table 3 shows hot metal components and operating conditions before and after the dephosphorization treatment.
- the oxygen gas flow rate (Q) from the secondary combustion nozzle to the oxygen gas flow rate (Q O ) from the main hole nozzle during the dephosphorization process, that is, 100 Q / Q O is also shown.
- the basic unit of CaO in Table 3 is the amount per 1 ton of hot metal, and the definition of the yield rate is the same as in Example 1.
- the hot metal discharged from the blast furnace is transported to a converter with a capacity of 300 tons, and the converter is decarburized and dephosphorized using the top blowing lance shown in FIG. 9)
- dephosphorization occurs in parallel by increasing the basicity of the slag in the furnace.
- oxygen gas is supplied from the oxygen-containing gas supply pipe 18, and quick lime powder (average particle size of 1 mm or less) is supplied from the oxygen-containing gas / powder supply pipe 17 using oxygen gas as a carrier gas.
- a solid oxygen source in powder form was supplied using argon gas as a carrier gas.
- the flow rate of oxygen gas supplied from the main hole nozzle was 3.2 Nm 3 / min per ton of hot metal.
- oxygen gas was supplied in the first half of the time from the start to the end of blowing and Ar gas was supplied in the second half.
- the oxygen gas flow rate (Q) from the secondary combustion nozzle with respect to the oxygen gas flow rate (Q O ) from the main hole nozzle was 5%. It was confirmed that the condition of the oxygen jet from the secondary combustion nozzle was in a range satisfying the formula (2).
- As the solid oxygen source 6 kg of iron ore sintered ore (average particle size 100 ⁇ m) was used per 1 ton of hot metal, and sprayed from the sub-hole nozzle.
- a dephosphorization process is performed in which the secondary combustion nozzle of the upper blow lance shown in FIG. 3 is mechanically closed and oxygen gas for secondary combustion is not supplied to the furnace space (Comparative Example 3). did.
- the other decarburization and dephosphorization treatment conditions of the comparative example were performed in accordance with the present invention.
- Table 4 shows the hot metal components and operating conditions before and after the dephosphorization treatment in the examples of the present invention and comparative examples.
- the amount of CaO basic unit and solid oxygen source used in Table 4 is the amount per ton of hot metal.
- the iron yield of Invention Example 9 was slightly superior to that of Comparative Example 3. That is, even under conditions of high-temperature treatment and less metal adhesion, the yield can be improved by partially using secondary combustion.
- the nozzle stably injects the oxygen-containing gas for secondary combustion over a long period of time without clogging.
- adhesion of bullion to the converter-type smelting vessel is suppressed, adverse effects due to adhesion of bullion are prevented, and iron yield and productivity are improved.
- fluxes such as oxygen-containing gas, solid oxygen source, and lime-based dephosphorizing refining agent can be supplied to the same location or in the vicinity of each, enabling efficient smelting of hot metal and molten steel. Is done.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Furnace Charging Or Discharging (AREA)
Abstract
Description
(1)転炉型精錬容器に収容された溶銑または溶鋼の酸化精錬に使用する精錬用上吹きランスであって、上吹きランスの先端部に、鉛直下向きまたは斜め下向き方向の吹錬用主孔ノズル及び固体酸素源吹き込み用副孔ノズルを有するとともに、前記先端部から上方に隔離した位置の上吹きランスの側面部に、水平または斜め下向き方向の二次燃焼用ノズルを有し、且つ、上吹きランスの内部には、固体酸素源とは異なる粉体を吹錬用の酸素含有ガスとともに前記主孔ノズルを通じて供給するか、または、吹錬用の酸素含有ガスを前記主孔ノズルを通じて供給するための第1の供給経路と、二次燃焼用の酸素含有ガスを前記二次燃焼用ノズルを通じて供給するための第2の供給経路と、粉体状の固体酸素源を搬送用ガスとともに前記副孔ノズルを通じて供給するための第3の供給経路と、を有することを特徴とする精錬用上吹きランス。
すなわち。第1の供給経路は、固体酸素源とは異なる粉体(以下「精錬用フラックス」とも記す)を当該経路に導入する精錬用フラックス導入部と、酸素含有ガスを当該経路に導入する酸素含有ガス導入部とを有する。 精錬用フラックス導入部は、精錬用フラックスを搬送ガスと共に導入する導入部であってもよく、この搬送ガスも酸素含有ガスであることが好ましい。 言うまでも無く、精錬用フラックスと酸素含有ガスとが同一の導入部から導入される(すなわち、前記精錬用フラックスと酸素含有ガスとを前記主孔ノズルを通じて供給する際の比率に予め混合したものが、該導入部から導入される)構造としてもよい。 なお、操業においては、精錬用フラックスの導入を停止し、酸素含有ガスのみを前記酸素含有ガス導入部より第1の供給経路に導入してもよい。
また、第2の供給経路は、酸素含有ガスを当該経路に導入する酸素含有ガス導入部を有する。 さらに、第3の供給経路は搬送用ガスと共に固体酸素源を当該経路に導入する固体酸素源導入部を有する。 なお、操業においては、固体酸素源の供給を停止し、搬送用ガスのみを前記導入部より第3の供給経路に導入してもよい。
ここで、第1の供給経路および第2の供給経路が酸素含有ガス導入部を共有しても良い。その場合は、前記精錬用フラックスが第2の供給経路に混入することを防ぐための仕切り構造を設けるものとする。 The gist of the present invention for solving the above problems is as follows.
(1) A refining top blow lance used for the oxidation refining of hot metal or molten steel contained in a converter type refining vessel, and a main hole for refining vertically or obliquely downward at the tip of the top blow lance A secondary combustion nozzle in a horizontal or obliquely downward direction on the side surface of the upper blowing lance at a position separated upward from the tip, A powder different from the solid oxygen source is supplied to the inside of the blowing lance with the oxygen-containing gas for blowing through the main hole nozzle, or an oxygen-containing gas for blowing is supplied through the main hole nozzle. A second supply path for supplying a secondary combustion oxygen-containing gas through the secondary combustion nozzle, and a powdery solid oxygen source together with a carrier gas. Hole nozzle Lance on for refining and having a third supply path for supplying through.
That is. The first supply path includes a refining flux introduction section that introduces a powder (hereinafter also referred to as “refining flux”) different from the solid oxygen source, and an oxygen-containing gas that introduces an oxygen-containing gas into the path. And an introduction part. The refining flux introduction part may be an introduction part for introducing the refining flux together with the carrier gas, and this carrier gas is also preferably an oxygen-containing gas. Needless to say, the refining flux and the oxygen-containing gas are introduced from the same introduction portion (that is, the refining flux and the oxygen-containing gas previously mixed in the ratio when supplying the refining flux and the oxygen-containing gas through the main hole nozzle). However, it is good also as a structure introduced from this introduction part. In operation, the introduction of the refining flux may be stopped, and only the oxygen-containing gas may be introduced into the first supply path from the oxygen-containing gas introduction section.
In addition, the second supply path has an oxygen-containing gas introduction unit that introduces the oxygen-containing gas into the path. Furthermore, the third supply path has a solid oxygen source introduction part that introduces a solid oxygen source into the path together with the carrier gas. In operation, the supply of the solid oxygen source may be stopped and only the carrier gas may be introduced into the third supply path from the introduction unit.
Here, the first supply path and the second supply path may share the oxygen-containing gas introduction part. In that case, a partition structure is provided to prevent the refining flux from entering the second supply path.
なお、第2の供給経路の末端とは、該経路の、最もランス先端部に近い二次燃焼用ノズルよりも先(ランス先端部側)の部分を意味する。
(3)前記第2の供給経路に還元性ガス、炭酸ガス、非酸化性ガス、希ガスのうちの何れか1種または2種以上のガスを供給するように構成されていることを特徴とする、上記(2)に記載の精錬用上吹きランス。
すなわち、第2の供給経路は、前記いずれか1種または2種以上のガスを当該経路に導入する導入部を有する。 言うまでも無く、これらのガスが前記酸素含有ガスと同一の導入部から導入される構造としてもよい。 (2) The terminal of the second supply path is closed, and the oxygen-containing gas supplied through the second supply path is configured not to join the first supply path and the third supply path. The top blowing lance for refining as described in said (1) characterized by the above-mentioned.
Note that the end of the second supply path means a portion of the path ahead of the nozzle for secondary combustion closest to the lance tip (on the lance tip).
(3) It is configured to supply any one or more of reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas to the second supply path. The top blowing lance for refining according to the above (2).
That is, the second supply path has an introduction part that introduces any one or more of the gases into the path. Needless to say, a structure may be adopted in which these gases are introduced from the same introduction portion as the oxygen-containing gas.
なお、前記石灰系脱燐用精錬剤の少なくとも一部を、第1の供給経路より前記溶銑に供給することが好ましい。 (6) Add the lime-based dephosphorization refining agent to the hot metal contained in the converter-type refining vessel, and hatch the added dephosphorizing refining agent to form slag. In doing so, using the top blowing lance for refining according to any one of the above (1) to (5), the oxygen gas for blowing is supplied from the first supply path to the hot metal bath surface, The solid oxygen source is supplied to the hot metal bath surface in the vicinity of the location where the oxygen gas for blowing is supplied from the supply path, and the oxygen gas for secondary combustion is converted from the second supply path. A method for refining hot metal, which comprises supplying to the furnace space of a furnace-type refining vessel and carrying out oxidation refining.
In addition, it is preferable to supply at least a part of the lime-based dephosphorizing refining agent to the hot metal from the first supply path.
そして主孔ノズル11から吹錬用酸素含有ガスとともに精錬用フラックスを吹き込む場合には、酸素含有ガス供給管14から供給される酸素含有ガスと、粉体供給管15から供給される粉体及び酸素含有ガスとが、合流して第1の供給経路を通るようになっている。この場合、仕切り管8の下端位置は二次燃焼用ノズル13の設置位置よりも下方であるので、第1の供給経路を通る粉体が二次燃焼用ノズル13に流入することはない。 すなわち、仕切り管8は、前記精錬用フラックスが第2の供給経路に混入することを防ぐための仕切り構造として機能する。
主孔ノズル11から吹錬用酸素含有ガスのみを吹き込む場合には、粉体供給管15を停止するか、粉体供給管15から酸素含有ガスのみを供給すればよい。
精錬用フラックス、すなわち固体酸素源とは異なる粉体としては、固体酸素源以外で精錬を効率的に実現するために投入される公知の(あるいは予見しうる)全ての固体物質が適用できる。 例えば、前記の石灰系脱燐用精錬剤(生石灰(CaO)や石灰石(CaCO3)、またはドロマイト(CaCO3・MgCO3)、脱炭スラグ、二次精錬スラグなど)の他、スラグの原料(例えば珪石(SiO2)、酸化マグネシウムを含むレンガ屑等)や、滓化促進剤(蛍石、酸化チタン、酸化アルミニウムなどを含むもの等)、等々が挙げられる。 なお、通常は、少なくとも石灰系脱燐用精錬剤が精錬用フラックスとして供給される。 The gap between the
When the refining flux is blown together with the oxygen-containing gas for blowing from the
When only the oxygen-containing gas for blowing is blown from the
As the refining flux, that is, the powder different from the solid oxygen source, all known (or foreseeable) solid substances that are added to efficiently realize refining other than the solid oxygen source can be applied. For example, in addition to the lime-based dephosphorizing refining agent (quick lime (CaO), limestone (CaCO 3 ), dolomite (CaCO 3 .MgCO 3 ), decarburized slag, secondary refining slag, etc.), raw materials for slag ( Examples thereof include silica (SiO 2 ), brick scraps containing magnesium oxide, etc., hatching accelerators (including fluorite, titanium oxide, aluminum oxide, etc.) and the like. In general, at least a lime-based dephosphorizing refining agent is supplied as a refining flux.
なお、吹錬の状況によっては、第2の供給経路を通じて二次燃焼用ノズル13から酸素ガスを噴出する必要がない場合がある。 この場合には、図3に示す上吹きランス1Aにおいては、二次燃焼ノズル13の閉塞を防止するために第2の供給経路から還元性ガス、炭酸ガス、非酸化性ガス、希ガスのうちの何れか1種または2種以上のガスを供給することができるように構成されている。 On the other hand, in the lance top 4, an oxygen-containing gas /
Depending on the state of blowing, it may not be necessary to eject oxygen gas from the
脱燐処理前の溶銑の燐濃度は0.12質量%に統一し、脱燐処理後の溶銑の燐濃度は0.020質量%以下、鉄歩留まりは98%以上を目標とした。 鉄歩留まり(η)は、転炉内に装入した溶銑の質量(W0)と鉄スクラップの質量(WS)との総質量(W0+WS)に対して脱燐処理後に出湯した溶銑の質量(W)を百分率で表示(η=100W/(W0+WS))した値である。 The hot metal discharged from the blast furnace is desiliconized in the blast furnace casting floor as necessary, and then transferred to a 300-ton converter, using the top blow lance shown in FIG. 1 for a total of four times. The preliminary dephosphorization treatment was carried out (Invention Examples 1 to 4). The number of main hole nozzles was four in a uniform arrangement on a concentric circle. In addition, the secondary combustion nozzles are arranged in an evenly arranged manner on the circumference, and each of the eight upper and lower nozzles is provided. The angle θ (°) formed between the secondary combustion nozzle and the upper blowing lance is determined by the oxygen jet flow from the secondary combustion nozzle. The distance X (m) from the nozzle outlet of the
The phosphorus concentration in the hot metal before the dephosphorization treatment was unified to 0.12% by mass, the phosphorus concentration in the hot metal after the dephosphorization treatment was set to 0.020% by mass or less, and the iron yield was set to 98% or more. The iron yield (η) is the hot metal discharged after dephosphorization with respect to the total mass (W 0 + W S ) of the mass (W 0 ) of the hot metal charged in the converter and the mass (W S ) of the iron scrap. The mass (W) is expressed as a percentage (η = 100 W / (W 0 + W S )).
最内管及び内管における破孔の有無は、緩衝用ガス流量変化から検知する方式で監視したが、とくに破孔は発生しなかった。 The flow rate of oxygen gas supplied from the main hole nozzle and the secondary combustion nozzle was 0.6 to 2.5 Nm 3 / min per ton of hot metal. The basic unit of oxygen gas was 12 Nm 3 / t excluding oxygen gas necessary for desiliconization. The oxygen gas flow rate (Q) from the secondary combustion nozzle relative to the oxygen gas flow rate (Q 2 O 3 ) from the main hole nozzle, that is, 100 Q /
The innermost pipe and the presence or absence of a broken hole in the inner pipe were monitored by a method of detecting from a change in the buffer gas flow rate, but no broken hole was generated.
[実施例2] As shown in Table 1, in all the inventive examples in which the solid oxygen source was supplied in the vicinity of the oxygen gas blowing surface from the top blowing lance, the phosphorus concentration in the hot metal after dephosphorization was 0.020% by mass or less. And the iron yield was 98% or more. On the other hand, in Comparative Example 1, the phosphorus concentration in the hot metal after the dephosphorization treatment was 0.020% by mass or less, but the iron yield was less than 98%. That is, the hot metal loss in the dephosphorization treatment was 1.2 to 1.7% in the present invention example compared with 2.1% in the comparative example, which was remarkably improved.
[Example 2]
[実施例3] As shown in Table 2, since the oxygen gas flow rate from the secondary combustion nozzle increased as compared with Example 1, the secondary combustion heat generation amount increased, the adhesion of the metal was further suppressed, and dephosphorization was achieved. The iron yield in the treatment was almost 99% (that is, the hot metal loss was almost 1%), and it was confirmed that the iron yield was further increased.
[Example 3]
[実施例4] As shown in Table 3, even under strong stirring conditions in which oxygen gas is blown from the bottom blowing tuyere, the increase in the secondary combustion heat generation further suppresses the adhesion of the metal, and the iron yield in the dephosphorization process is further increased. It was confirmed that
[Example 4]
脱炭脱燐処理は、酸素含有ガス供給管18から酸素ガスを供給し、酸素含有ガス・粉体供給管17から酸素ガスを搬送用ガスとして生石灰粉(平均粒径1mm以下)を供給し、最内管の内部である第3の供給経路からはアルゴンガスを搬送用ガスとして粉体の固体酸素源を供給した。 The hot metal discharged from the blast furnace is transported to a converter with a capacity of 300 tons, and the converter is decarburized and dephosphorized using the top blowing lance shown in FIG. 9) In hot metal decarburization refining, dephosphorization occurs in parallel by increasing the basicity of the slag in the furnace.
In the decarburization and dephosphorization treatment, oxygen gas is supplied from the oxygen-containing
1A 上吹きランス
2 ランス本体
3 ランスノズル
4 ランス頂部
5 最外管
6 外管
7 中管
8 仕切り管
9 内管
10 最内管
11 主孔ノズル
12 副孔ノズル
13 二次燃焼用ノズル
14 酸素含有ガス供給管
15 粉体供給管
16 緩衝用ガス供給管
17 酸素含有ガス・粉体供給管
18 酸素含有ガス供給管
19 緩衝用ガス導入装置
20 検出器
21 遠隔操作弁
22 フレキシブルホース
23 手動遮断弁 DESCRIPTION OF SYMBOLS 1
Claims (7)
- 転炉型精錬容器に収容された溶銑または溶鋼の酸化精錬に使用する精錬用上吹きランスであって、
上吹きランスの先端部に、鉛直下向きまたは斜め下向き方向の吹錬用主孔ノズル及び固体酸素源吹き込み用副孔ノズルを有し、
前記先端部から上方に隔離した位置の上吹きランスの側面部に、水平または斜め下向き方向の二次燃焼用ノズルを有し、
且つ、上吹きランスの内部には、
固体酸素源とは異なる粉体を吹錬用の酸素含有ガスとともに前記主孔ノズルを通じて供給するか、または、吹錬用の酸素含有ガスを前記主孔ノズルを通じて供給するための第1の供給経路と、
二次燃焼用の酸素含有ガスを前記二次燃焼用ノズルを通じて供給するための第2の供給経路と、
粉体状の固体酸素源を搬送用ガスとともに前記副孔ノズルを通じて供給するための第3の供給経路と、
を有する精錬用上吹きランス。 An upper blow lance for refining used for oxidation refining of hot metal or molten steel contained in a converter type refining vessel,
At the front end of the upper blowing lance, there is a main hole nozzle for blowing downward and an obliquely downward direction and a sub hole nozzle for blowing a solid oxygen source,
On the side surface portion of the upper blowing lance at a position separated upward from the tip portion, there is a nozzle for secondary combustion in a horizontal or obliquely downward direction,
And inside the top blowing lance,
A first supply path for supplying a powder different from the solid oxygen source together with the oxygen-containing gas for blowing through the main hole nozzle or supplying the oxygen-containing gas for blowing through the main hole nozzle When,
A second supply path for supplying an oxygen-containing gas for secondary combustion through the secondary combustion nozzle;
A third supply path for supplying a powdered solid oxygen source together with a carrier gas through the sub-hole nozzle;
Refining top blow lance. - 前記第2の供給経路の末端は閉ざされていて、第2の供給経路で供給される酸素含有ガスが第1の供給経路及び第3の供給経路に合流しないように構成されている、請求項1に記載の精錬用上吹きランス。 The terminal of the second supply path is closed, and the oxygen-containing gas supplied through the second supply path is configured not to join the first supply path and the third supply path. The top blowing lance for refining according to 1.
- 前記第2の供給経路に還元性ガス、炭酸ガス、非酸化性ガス、希ガスのうちの何れか1種または2種以上のガスを供給するように構成されている、請求項2に記載の精錬用上吹きランス。 3. The apparatus according to claim 2, wherein one or more of a reducing gas, a carbon dioxide gas, a non-oxidizing gas, and a rare gas are supplied to the second supply path. Top blow lance for refining.
- 前記第3の供給経路の周囲に、空気、還元性ガス、炭酸ガス、非酸化性ガス、希ガスのうちの何れか1種または2種以上のガスが存在する緩衝空間が備えられ、該緩衝空間に存在するガスの圧力または流量の変化に基づいて第3の供給経路での破孔が検知されるように構成されている、請求項1ないし請求項3の何れか1項に記載の精錬用上吹きランス。 Around the third supply path, a buffer space in which any one or two or more gases of air, reducing gas, carbon dioxide gas, non-oxidizing gas, and rare gas are present is provided. The refining according to any one of claims 1 to 3, wherein a hole in the third supply path is detected based on a change in pressure or flow rate of gas existing in the space. Top blowing lance.
- 前記第1の供給経路、前記第2の供給経路および前記第3の供給経路が同心円上に配置されていることを特徴とする、請求項1ないし請求項3の何れか1項に記載の精錬用上吹きランス。 The refining according to any one of claims 1 to 3, wherein the first supply path, the second supply path, and the third supply path are arranged concentrically. Top blowing lance.
- 前記第1の供給経路、前記第2の供給経路および前記第3の供給経路が同心円上に配置されている、請求項4に記載の精錬用上吹きランス。 The upper blow lance for refining according to claim 4, wherein the first supply path, the second supply path, and the third supply path are arranged concentrically.
- 石灰系脱燐用精錬剤を転炉型精錬容器に収容された溶銑に添加し、添加した前記脱燐用精錬剤を滓化させてスラグとなし、溶銑に対して酸化精錬を実施するにあたり、
請求項1ないし請求項6の何れか1項に記載の精錬用上吹きランスを用い、第1の供給経路から吹錬用の酸素ガスを溶銑浴面に供給すると同時に、第3の供給経路から固体酸素源を吹錬用の酸素ガスが供給されている場所の近傍の溶銑浴面に搬送用ガスとともに供給し、更に、第2の供給経路から二次燃焼用酸素ガスを転炉型精錬容器の炉内空間に供給して酸化精錬を行う、溶銑の精錬方法。 When adding the lime-based dephosphorizing refining agent to the hot metal contained in the converter-type refining vessel, the added dephosphorizing refining agent is hatched to form slag, and when carrying out oxidation refining on the hot metal,
Using the upper blowing lance for refining according to any one of claims 1 to 6, the oxygen gas for blowing is supplied from the first supply path to the hot metal bath surface, and at the same time from the third supply path. A solid oxygen source is supplied together with the transfer gas to the hot metal bath surface near the place where the oxygen gas for blowing is supplied, and further, the secondary combustion oxygen gas is supplied from the second supply path to the converter type refining vessel. A hot metal refining method in which oxidation refining is performed by supplying it to the furnace space.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR112012009231-6A BR112012009231B1 (en) | 2009-10-22 | 2010-10-21 | HOT METAL REFINING METHOD USING TOP BOOM |
KR1020127010192A KR101346726B1 (en) | 2009-10-22 | 2010-10-21 | Method for refining molten iron |
CN201080047492.XA CN102575306B (en) | 2009-10-22 | 2010-10-21 | Top lance for refining and method for refining molten iron using same |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2009243268 | 2009-10-22 | ||
JP2009-243268 | 2009-10-22 | ||
JP2010233357A JP5644355B2 (en) | 2009-10-22 | 2010-10-18 | Hot metal refining method |
JP2010-233357 | 2010-10-18 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011049240A1 true WO2011049240A1 (en) | 2011-04-28 |
Family
ID=43900460
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2010/069118 WO2011049240A1 (en) | 2009-10-22 | 2010-10-21 | Top lance for refining and method for refining molten iron using same |
Country Status (6)
Country | Link |
---|---|
JP (1) | JP5644355B2 (en) |
KR (1) | KR101346726B1 (en) |
CN (1) | CN102575306B (en) |
BR (1) | BR112012009231B1 (en) |
TW (1) | TWI448555B (en) |
WO (1) | WO2011049240A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021229422A1 (en) * | 2020-05-11 | 2021-11-18 | Arcelormittal | Stirring method of liquid metal and associated device |
CN114369728A (en) * | 2021-12-07 | 2022-04-19 | 广西金川有色金属有限公司 | Top-blown oxidation-reduction method for refining furnace |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101529843B1 (en) * | 2011-12-20 | 2015-06-17 | 제이에프이 스틸 가부시키가이샤 | Converter steelmaking method |
JP5915568B2 (en) * | 2012-03-01 | 2016-05-11 | Jfeスチール株式会社 | Method of refining hot metal in converter type refining furnace |
US9732393B2 (en) * | 2012-07-10 | 2017-08-15 | Lumar Metals Ltda. | Blowing spear for fabrication of metals and maintenance of loading and blowing operational conditions |
JP2017002331A (en) * | 2015-06-04 | 2017-01-05 | 株式会社神戸製鋼所 | Method for supplying solid oxygen source in dephosphorization treatment of molten iron |
CN106086289B (en) * | 2016-08-01 | 2018-05-29 | 朱荣 | A kind of method for making steel and device of the smelting stainless steel mother liquid that dusted using top blow oxygen lance |
KR101798844B1 (en) * | 2016-09-02 | 2017-11-17 | 주식회사 포스코 | Lance and the converter operation method using the same |
JP6702369B2 (en) * | 2017-09-15 | 2020-06-03 | Jfeスチール株式会社 | Dephosphorization treatment method |
US11293069B2 (en) | 2017-12-22 | 2022-04-05 | Jfe Steel Corporation | Method for oxygen-blowing refining of molten iron and top-blowing lance |
KR102556136B1 (en) | 2019-04-05 | 2023-07-14 | 제이에프이 스틸 가부시키가이샤 | Refining vessel of hot melt |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008208407A (en) * | 2007-02-26 | 2008-09-11 | Jfe Steel Kk | Top-blowing lance for refining and method for detecting broken hole on top-blowing lance for refining |
JP2009174029A (en) * | 2008-01-28 | 2009-08-06 | Jfe Steel Corp | Method for operating converter |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5866712A (en) * | 1981-10-16 | 1983-04-21 | Nippon Zeon Co Ltd | Corrosion preventing method for incidental equipment of fluidized bed incinerator |
US7600489B2 (en) * | 2004-03-04 | 2009-10-13 | H2Gen Innovations, Inc. | Heat exchanger having plural tubular arrays |
-
2010
- 2010-10-18 JP JP2010233357A patent/JP5644355B2/en active Active
- 2010-10-21 KR KR1020127010192A patent/KR101346726B1/en active IP Right Grant
- 2010-10-21 CN CN201080047492.XA patent/CN102575306B/en active Active
- 2010-10-21 WO PCT/JP2010/069118 patent/WO2011049240A1/en active Application Filing
- 2010-10-21 BR BR112012009231-6A patent/BR112012009231B1/en active IP Right Grant
- 2010-10-22 TW TW099136117A patent/TWI448555B/en not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008208407A (en) * | 2007-02-26 | 2008-09-11 | Jfe Steel Kk | Top-blowing lance for refining and method for detecting broken hole on top-blowing lance for refining |
JP2009174029A (en) * | 2008-01-28 | 2009-08-06 | Jfe Steel Corp | Method for operating converter |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021229422A1 (en) * | 2020-05-11 | 2021-11-18 | Arcelormittal | Stirring method of liquid metal and associated device |
WO2021229263A1 (en) * | 2020-05-11 | 2021-11-18 | Arcelormittal | Stirring method of liquid metal and associated device |
CN114369728A (en) * | 2021-12-07 | 2022-04-19 | 广西金川有色金属有限公司 | Top-blown oxidation-reduction method for refining furnace |
CN114369728B (en) * | 2021-12-07 | 2023-09-01 | 广西金川有色金属有限公司 | Top-blown oxidation-reduction method for refining furnace |
Also Published As
Publication number | Publication date |
---|---|
KR101346726B1 (en) | 2014-01-02 |
TW201130989A (en) | 2011-09-16 |
BR112012009231B1 (en) | 2021-06-01 |
CN102575306A (en) | 2012-07-11 |
BR112012009231A2 (en) | 2016-08-23 |
CN102575306B (en) | 2014-10-01 |
TWI448555B (en) | 2014-08-11 |
KR20120064710A (en) | 2012-06-19 |
JP5644355B2 (en) | 2014-12-24 |
JP2011106028A (en) | 2011-06-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5644355B2 (en) | Hot metal refining method | |
US9580764B2 (en) | Top-blowing lance and method for refining molten iron using the same | |
US6558614B1 (en) | Method for producing a metal melt and corresponding multifunction lance | |
US9493854B2 (en) | Converter steelmaking method | |
JP6036172B2 (en) | Method of refining hot metal in converter | |
KR101018535B1 (en) | Refining ferroalloys | |
JP4715384B2 (en) | Method for dephosphorizing hot metal and top blowing lance for dephosphorization | |
JP5834980B2 (en) | Manufacturing method of molten steel | |
JP2006348331A (en) | Top-blowing lance for refining molten metal, and blowing method for molten metal | |
JPH1180825A (en) | Top-blown lance for converter refining and converter refining method by using this | |
JP5471151B2 (en) | Converter steelmaking method | |
JP2013209703A (en) | Refining method of molten iron | |
WO2007055404A1 (en) | Method of hot metal dephosphorization treatment | |
JP2019002045A (en) | Top blown lance for refining and method for refining molten iron | |
JP5915568B2 (en) | Method of refining hot metal in converter type refining furnace | |
JP6051561B2 (en) | Manufacturing method of molten steel | |
JP2005089839A (en) | Method for refining molten steel | |
JP5928095B2 (en) | Method for refining molten iron | |
ZA200108634B (en) | Method of decarburisation and dephosphorisation of a molten metal. | |
JP6327298B2 (en) | Hot metal refining method | |
JPS61227119A (en) | Manufacture of steel in converter using cold material containing iron as principal starting material | |
JP2013209737A (en) | Method for producing molten steel | |
JPH03111507A (en) | Method and apparatus for producing molten ferrous alloy |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201080047492.X Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10825087 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12012500625 Country of ref document: PH |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2898/CHENP/2012 Country of ref document: IN |
|
ENP | Entry into the national phase |
Ref document number: 20127010192 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 10825087 Country of ref document: EP Kind code of ref document: A1 |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112012009231 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112012009231 Country of ref document: BR Kind code of ref document: A2 Effective date: 20120419 |