CN104955965B - The preprocess method of molten iron - Google Patents

The preprocess method of molten iron Download PDF

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Publication number
CN104955965B
CN104955965B CN201480005778.XA CN201480005778A CN104955965B CN 104955965 B CN104955965 B CN 104955965B CN 201480005778 A CN201480005778 A CN 201480005778A CN 104955965 B CN104955965 B CN 104955965B
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clinker
desiliconization
molten iron
stove
height
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CN104955965A (en
Inventor
小笠原泰志
内田佑
内田佑一
三木佑司
伊藤友彦
手塚浩
手塚浩一
田中高太郎
根岸秀光
川畑涼
山本和人
奥山悟郎
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JFE Engineering Corp
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NKK Corp
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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
    • C21C5/35—Blowing from above and through the bath
    • 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
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/04—Removing impurities other than carbon, phosphorus or sulfur
    • 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

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (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)

Abstract

The present invention relates to a kind of preprocess method of molten iron, it using a converter type refining furnace when continuously carrying out accompanying the desiliconization processing of the molten iron of deslagging process of centre and dephosphorization treatment, the clinker of sufficient amount is promptly expelled to outside stove in deslagging process, sufficiently dephosphorization treatment can be carried out in terms of the cost and in terms of quality.The preprocess method of the present invention includes：Desiliconization treatment process, desiliconization processing is carried out from molten iron (5) supplying gaseous oxygen source of the top-blown spray gun (2) into converter type refining furnace (1) to molten iron；Deslagging process, at least a portion of the clinker generated in desiliconization treatment process is discharged from converter type refining furnace；Dephosphorization treatment process, after deslagging process, CaO systems fluxing agent is added into converter type refining furnace, by top-blown spray gun supplying gaseous oxygen source, dephosphorization treatment is carried out to the molten iron of residual, wherein, the clinker in stove is highly measured in desiliconization processing, in the clinker height determined relative in the state of the ratio of the height of melting chamber is given range in stove defined in distance of the molten iron bath face untill fire door in stove, terminate desiliconization processing.

Description

The preprocess method of molten iron
Technical field
The present invention relates to the desiliconization processing that molten iron is continuously carried out using a converter type refining furnace and the iron of dephosphorization treatment The preprocess method of water, and accompany between desiliconization processing and dephosphorization treatment the deslagging process of centre.
Background technology
In recent years, continued to develop, and developed following using the exploitation of the preconditioning technique of the molten iron of converter type refining furnace Preprocess method.That is, following method of refining is developed：Molten iron in converter type refining furnace is carried out after desiliconization processing, Make converter type refining furnace tilt and by stove clinker (by desiliconization handle generation clinker be referred to as " desiliconization clinker ") at least one Part is discharged, then, and CaO systems fluxing agent is put into stove, and the method for refining (is referred to as by the molten iron progress dephosphorization treatment to residual " 2 method for discharging residue ") (referring for example to patent document 1).
2 method for discharging residue and existing preprocess method in converter type refining furnace, i.e. refine start when input CaO systems help Flux and in converter type refining furnace molten iron carry out desiliconization, dephosphorization treatment preprocess method compare, with advantages below. That is, have the following advantages that：(1), can be by so the processing of the high molten iron of silicone content can be carried out because discharging desiliconization clinker in midway Silicon in molten iron is effectively utilized as thermal source；(2) by discharging desiliconization clinker in midway, when can cut down dephosphorization treatment thereafter The usage amount of CaO systems fluxing agent.
How in 2 method for discharging residue, in the deslagging process after desiliconization processing, mesh will be promptly used as in a short time The desiliconization clinker of target specified rate is discharged out of stove, as operational key point.The row of desiliconization clinker in deslagging process In the case that output is few, it is impossible to obtain above-mentioned effect, and it is identical with the preprocess method of above-mentioned existing converter type refining furnace.
In addition, also developed following method of refining：After dephosphorization treatment terminates, by the molten iron after dephosphorization treatment from stove Tap a blast furnace, but the clinker (being referred to as the clinker generated in dephosphorization treatment " dephosphorization clinker ") generated in dephosphorization treatment is residued in stove It is interior, and into the converter type refining furnace for remain dephosphorization clinker load following core molten iron, to the molten iron in the order described above Pre-processed (for example, referring to patent document 1 and patent document 2).The method of refining also has the following advantages that.That is, have Advantages below：(3) by the way that the dephosphorization generated in dephosphorization treatment clinker is residued in stove, CaO systems during desiliconization processing can be cut down Ferrous components in fluxing agent, the sensible heat for effectively utilizing dephosphorization clinker and recovery dephosphorization clinker；(4) by recycling dephosphorization clinker And the silicon in molten iron is effectively utilized as thermal source and the thermal efficiency can be improved, the mixing ratio of cold iron source is improved；(5) alkali is suppressed Spend ((quality %CaO)/(quality %SiO2)) it is of a relatively high and need carry out Ageing Treatment dephosphorization clinker generation, can will take off Even if phosphorus clinker is converted into omitting the desiliconization clinker that Ageing Treatment also results in good volume stability.
But, make in the method that dephosphorization clinker is remained, if the discharge rate of the clinker after desiliconization processing is insufficient, from upper The phosphorus of the dephosphorization clinker remained in one furnace charge can be residued in largely in stove, and the phosphorus for making molten iron is difficult in dephosphorization treatment next time Concentration is reduced to target level, accordingly, it would be desirable to substantially ensure that the discharge rate of clinker in the deslagging process after desiliconization processing.The opposing party Face, if extending the activity duration for deslagging in order to ensure the discharge rate of clinker, can implement adding for such pretreatment Material number is restricted, if moreover, making the angle of inclination of body of heater excessively increase to increase the velocity of discharge of clinker, with stove The discharge increase for the molten iron that slag flows out together, so that the problem of yield rate reduction that there is iron is such.Therefore, in order to not cause These problems in the deslagging process after desiliconization is handled, it is necessary to efficiently carry out the discharge of clinker.
In addition, including comprising desiliconization clinker or dephosphorization clinker, steel stove slag processed contains substantial amounts of ferriferous oxide, therefore, with day Right stone sand material or blast-furnace slag etc. are compared, and have the tendency of density high.Therefore, steel stove slag processed not be used to worry steel stove slag meeting processed Encourage in civil engineering applications as the unstability of gravity.Moreover, the volume of the per unit mass of steel stove slag processed with it is natural Stone sand material etc. is compared to smaller, therefore, and transportation expenses increase also turns into it as shortcoming during civil engineering material, therefore, In order to which steel stove slag processed, as the material for being readily used for the wide civil engineering applications of scope, is expected to reduce the volume ratio of steel stove slag processed Weight.
Therefore, the discharge of the desiliconization clinker in deslagging process after the present inventor etc. is handled desiliconization is studied. Its result understands that, if the foaming of the desiliconization clinker in desiliconization processing is few, the mobility of desiliconization clinker is low, it is difficult in the stipulated time The desiliconization clinker of interior discharge sufficient amount.Therefore following opinion has been obtained：In order to rapid in deslagging process and make the de- of sufficient amount Silicon clinker flows out out of stove, it is necessary to desiliconization clinker is stably bubbled in silicon blow.Here, the foaming of clinker refers to melting The clinker of state contains bubble, the phenomenon of apparent upper volume expansion.
That is, following opinion has been obtained：Detect the clinker material position in desiliconization processing, and control the foaming of desiliconization clinker to attaching most importance to Will.But, the excess of desiliconization clinker rises to steep oneself-meeting causes the clinker of bumping to flow out, it is necessary to carry out suppressing the outflow in deslagging process Processing, the time of deslagging process can be extended on the contrary, it has further been found that moderately control foaming be important.These find not It is described in patent document 1 and patent document 2.
At present, as the method for the slag bloating in detection converter type refining furnace, proposed in patent document 3 such as lower section Method：While certain vibration number, vibration (forced vibration) of amplitude is assigned to secondary spray gun, while the vibration of secondary spray gun is determined, While secondary spray gun is inserted into stove, the foam height of clinker in stove is detected according to the attenuation of the forced vibration assigned. However, this method is that the technology being immersed in premised on the state of the clinker of foaming is buried by the front end of secondary spray gun, foaming less, secondary spray gun Front end do not bury the clinker for being immersed in foaming in the case of, it is impossible to detect foam height.In addition, the attenuation of forced vibration can basis Composition, the temperature of the clinker of generation and change, therefore, it is difficult to accurately detect foam height.
In addition, proposing using microwave to determine the side of the clinker height in refining in patent document 4 and patent document 5 Method.However, these technologies are the foaming detection techniques of the Decarburising and refining of the molten iron in converter, at the desiliconization pre-processed due to molten iron Desiliconization clinker in reason and the converter slag in the Decarburising and refining of converter are big in terms of the temperature, basicity, iron oxide concentration of clinker Differ, so electrical conductivity differs widely, therefore, the reflection characteristic of microwave is different from Decarburising and refining in desiliconization processing, it is impossible to Real achievement in Decarburising and refining is directly applied in desiliconization processing.
For example, although principle is simultaneously indefinite, but the mixed recharge based on send wave and back wave has been recorded in patent document 4 Frequency change detects clinker material position and detects the technology of clinker material position according to the reflectivity of microwave.However, for conductance For the small desiliconization clinker of rate, the reflectivity of microwave is very small and major part is passed through, therefore there is also bathe the anti-of face from molten iron Ejected wave and the flutter echo of face and slag surface is bathed in molten iron, therefore the method for patent document 4 can not detect clinker material Position.
In addition, for patent document 5, will send in the antenna insertion stove of reception, the clinker exposed to high temperature, In the refining furnace of the drop of molten iron, used even in the short time, these drops can also adhere to and freeze solidly on antenna, therefore, it is difficult to It is interior during refining to be continuously measured.
Prior art literature
Patent document
Patent document 1：Japanese Unexamined Patent Publication 11-323420 publications
Patent document 2：Japanese Unexamined Patent Publication 2001-271113 publications
Patent document 3：Japanese Unexamined Patent Publication 5-255726 publications
Patent document 4：Japanese Unexamined Patent Application 59-41409 publications
Patent document 5：Japanese Unexamined Patent Publication 3-281717 publications
The content of the invention
The invention problem to be solved
The present invention is to carry out in view of the foregoing, and its object is to provide a kind of preprocess method of molten iron, the party Method continuously carries out accompanying desiliconization processing and the dephosphorization treatment of the molten iron of the deslagging process of centre using a converter type refining furnace, Wherein it is possible to suppress the outflow of the clinker of bumping in the deslagging process after desiliconization is handled, and the specified rate of target will be used as Desiliconization clinker is promptly expelled to outside stove in a short time, in the dephosphorization treatment of subsequent processing, can be carried out in terms of cost And sufficient dephosphorization treatment for quality aspect.Additionally, it is provided a kind of obtain the body for being suitable for various civil engineering materials The preprocess method of the molten iron of the relatively small clinker of product proportion.
The method solved the problems, such as
Main points of the invention for solving above-mentioned problem are as follows.
[1] a kind of preprocess method of molten iron, this method includes：
Desiliconization treatment process, is carried out from molten iron supply gas oxygen source of the top-blown spray gun into converter type refining furnace to molten iron Desiliconization is handled；
Deslagging process, by least a portion of the clinker generated in the desiliconization treatment process from the converter type refining furnace Discharge；And
Dephosphorization treatment process, after the deslagging process, CaO systems fluxing agent is added into the converter type refining furnace, by institute Top-blown spray gun supply gas oxygen source is stated, dephosphorization treatment is carried out to the molten iron of residual, wherein,
The desiliconization processing in, the clinker in stove is highly measured, determined clinker height relative to from Molten iron in stove bathes the ratio of face height of melting chamber in the stove untill fire door in the state of given range, to terminate at desiliconization Reason.
[2] preprocess method of the molten iron described in above-mentioned [1], wherein, the given range of the ratio is 0.5~0.9 Scope.
[3] preprocess method of the molten iron described in above-mentioned [1] or [2], wherein, the measure knot based on the clinker height Really, it is high to the spray gun of the supply flow rate selected from the gas oxygen source from top-blown spray gun, top-blown spray gun in desiliconization processing In degree, the supply flow rate of stirring gas from bottom blowing nozzle, the clinker composition in stove, the input amount of the calm material of foaming At least one kind of to be adjusted, the clinker in being handled by the adjustment desiliconization in stove is highly controlled.
[4] preprocess method of the molten iron described in above-mentioned [3], wherein, the clinker in handling desiliconization in stove is highly carried out Control so that clinker height is relative to the model that the ratio of the height of melting chamber in stove is 0.5~0.9 described in the desiliconization processing In enclosing.
[5] preprocess method of the molten iron any one of above-mentioned [1]~[4], wherein, at simulation random signalses Radar mode microwave ranger is managed, below frequency 10GHz microwave is sent to the converter type refining furnace and reflection is received Ripple, the distance away from object is obtained according to the round trip propagation time of back wave, and reflection more than intensity is given in certain received In the signal of ripple, the distance away from object corresponding with the signal of back wave is more than the distance away from fire door and closest to away from stove The signal determining of the back wave of the distance of mouth is the signal of the back wave from slag surface, obtains the distance away from slag surface, The clinker height is determined based on the distance away from slag surface tried to achieve again.
[6] preprocess method of the molten iron described in above-mentioned [5], wherein, in the letter of the back wave received by the rangefinder In number, the distance away from object corresponding with the signal of back wave is not just changed when desiliconization is handled and continued The signal of the back wave of presence is removed as noise, then judges the signal of the back wave from slag surface.
[7] preprocess method of the molten iron any one of above-mentioned [1]~[4], wherein, at simulation random signalses Radar mode microwave ranger is managed, below frequency 10GHz microwave is sent to the converter type refining furnace and received comes from Back wave in stove, the distance away from object is obtained according to the round trip propagation time of back wave, from be present in from fire door to In the signal of the back wave of object in the range of molten iron bath face, by it is corresponding with the signal of back wave away from object away from The signal for the back wave for just not changing and persistently existing when from being handled since desiliconization is removed as noise, then will be with iron The signal determining that the signal of the corresponding back wave in water-bath face removes back reflection intensity highest back wave is from slag surface Back wave signal, obtain the distance away from slag surface, then described to determine based on the distance away from slag surface tried to achieve Clinker height.
[8] preprocess method of the molten iron any one of above-mentioned [1]~[7], wherein, in the converter type refining furnace In previous furnace charge molten iron dephosphorization treatment process terminate after, the molten iron after dephosphorization treatment is come out of the stove, does not make dephosphorization treatment institute In the stove of generation clinker discharge and in the state of residuing in the converter type refining furnace in, the loading into the converter type refining furnace New molten iron, the desiliconization treatment process is implemented to the molten iron, and at the end of the desiliconization is handled, the basicity for making clinker in stove is More than 0.8 and less than 1.5, the silicone content that the temperature for making molten iron is more than 1280 DEG C and less than 1380 DEG C, make molten iron is 0.10 matter Below % is measured, in the deslagging process, more than the 30 mass % of the clinker generated in desiliconization treatment process are expelled to outside stove, Then, the dephosphorization treatment process is implemented to the molten iron in stove, after the dephosphorization treatment process terminates, by the iron after dephosphorization treatment Water is come out of the stove, in the stove for being generated dephosphorization treatment clinker discharge and in the state of residuing in the converter type refining furnace, Load new molten iron into the converter type refining furnace, the molten iron is pre-processed.
[9] preprocess method of the molten iron any one of above-mentioned [1]~[8], wherein, the dephosphorization after deslagging process The clinker height in stove, the spray to supply flow rate, top-blown spray gun selected from the gas oxygen source from top-blown spray gun are determined in processing At least one kind of in rifle height, the supply flow rate of stirring gas from bottom blowing nozzle is adjusted, and is controlled by the adjustment Clinker in stove processed does not spray from fire door.
The effect of invention
According to the present invention, continuously carrying out accompanying the molten iron of middle deslagging process using a converter type refining furnace In the pretreatment of the molten iron of desiliconization processing and dephosphorization treatment, at the end of desiliconization is handled, in the height phase of the desiliconization clinker of foaming Ratio for the height of melting chamber in stove is handled to terminate desiliconization in the state of given range, therefore, deslagging work behind In sequence, the bumping of desiliconization clinker is not only inhibited to flow out, and can realize will be rapid as the desiliconization clinker of the specified rate of target Ground is expelled to outside stove in a short time.Successfully carried out thereby, it is possible to postpone deslagging process, and in subsequent processing In dephosphorization treatment, the phosphorus concentration of molten iron can be reduced to by low concentration with the usage amount of less CaO systems fluxing agent.
Brief description of the drawings
[Fig. 1] is the schematic section of used converter type refining furnace when implementing the preprocess method of the molten iron of the present invention Figure.
[Fig. 2] is the schematic diagram for the preprocess method that the molten iron of the present invention is shown according to the order of process.
[Fig. 3] is the figure of one of the signal for the back wave for being shown with the acquirement of micro-wave oven slag level-sensing device.
[Fig. 4] is by obtaining the clinker in the stove in desiliconization processing by the measurement result that micro-wave oven slag level-sensing device is obtained The figure of the change of height.
[Fig. 5] is the figure for showing the clinker height at the end of desiliconization processing and the relation between the middle deslagging time.
[Fig. 6] is in molten iron after the clinker height and dephosphorization treatment for showing at the end of desiliconization processing terminate between phosphorus concentration Relation figure.
[Fig. 7] is the figure for showing the influence for sending oxygen speed to carry out clinker altitudinal belt from top-blown spray gun.
[Fig. 8] is the figure for showing the influence that the spray gun height of top-blown spray gun is come to clinker altitudinal belt.
[Fig. 9] is the figure for showing the influence that Bottom Blowing Gas Flow Rate comes to clinker altitudinal belt.
[Figure 10] be in the desiliconization processing for show example 1,2 of the present invention and comparative example 1,2 clinker height relative to molten in stove Change the figure of the change of the ratio of room height.
[Figure 11] is to show that clinker height is high relative to the melting chamber in stove in example 3 of the present invention, the dephosphorization treatment of comparative example 2 The figure of the change of the ratio of degree.
Symbol description
1 converter type refining furnace
2 top-blown spray guns
3 bottom blowing nozzles
4 tapping holes
5 molten iron
6 desiliconization clinkers
7 cold iron sources
8 oxygen
9 bottom blown gas
10 charging pots
11 flues
12 coaming plates
13 opening portions
14 opening portions
15 micro-wave oven slag level-sensing devices
16 waveguides
17 transmission antennas
18 reception antennas
Embodiment
Hereinafter, the present invention is specifically described referring to the drawings.Fig. 1 is when implementing the preprocess method of the molten iron of the present invention The constructed profile of used converter type refining furnace, Fig. 2 is the preprocess method that the molten iron of the present invention is shown by process sequence Process schematic diagram.In addition, Fig. 1 is the figure for the desiliconization treatment process for showing Fig. 2-(B).
In the preprocess method of the molten iron of the present invention, refined using the converter type that can carry out top blast bottom blowing shown in Fig. 1 Stove 1.Top blast is carried out as follows：Using the top-blown spray gun 2 that can be lifted in the inside of converter type refining furnace 1, from the front end of top-blown spray gun 2 The oxygen-containing gas as gaseous state oxygen source is supplied to molten iron 5.As oxygen-containing gas, oxygen, oxygen-enriched air, air, oxygen can be used With the mixed gas of non-active gas.Fig. 1 is illustrated that the example for using oxygen 8 as oxygen-containing gas.Here, oxygen 8 is work Industry pure oxygen.Bottom blowing is carried out using the bottom blowing nozzle 3 of the bottom of converter type refining furnace 1 is arranged on., can be with as bottom blown gas 9 It is oxygenous gas, or may also be only the non-active gas such as argon gas or nitrogen.In addition, bottom blown gas is except with passing through It is blown into molten iron and strengthens the stirring of molten iron 5 and promote beyond the function of melting of cold iron source, can also be had and be sprayed by bottom blowing Conveying is blown into the function in molten iron by mouth 3 with gas together with slag former.In addition, Fig. 1 detailed description is carried out below Narration.
In the present invention, the converter type refining furnace 1 of more than 2 is used in the refining of molten iron 5, by least 1 converter therein Type refining furnace 1 is used for the molten iron pretreatment of the present invention, and remaining at least 1 is used to implement after molten iron pretreatment of the invention Molten iron 5 Decarburising and refining.That is, pre-processed in molten iron pretreatment with converter type refining furnace 1, then, pre- place will be implemented Molten iron 5 after reason is transferred to Decarburising and refining with carrying out carbonization treatment in converter type refining furnace 1.
For the preprocess method of the molten iron 5 of the present invention, such as shown in Fig. 2-(A), being previously charged into, iron filings etc. are cold In the converter type refining furnace 1 of source of iron 7, (the molten iron dress of molten iron 5 that desiliconization processing and dephosphorization treatment is not carried out is loaded using the pot 10 that feeds Enter process).
Then, the molten iron 5 into the converter type refining furnace supplies the gaseous state oxygen source as oxygen source or supplying gaseous oxygen source And the solid oxygen source such as iron oxide, implement desiliconization processing (desiliconization treatment process) shown in such as Fig. 2-(B).Contained silicon in molten iron 5 Reacted (Si+2O → SiO with the oxygen in oxygen source2) and carry out desiliconization processing.The oxidation of the silicon produced using the desilication reaction Heat rises molten iron temperature, so as to promote the melting of the cold iron source 7 in molten iron.
In the present invention, desiliconization processing and dephosphorization treatment are implemented using a converter type refining furnace 1, is implementing desiliconization processing When, the dephosphorization clinker that the dephosphorization treatment of a upper furnace charge is generated adheres to and residued on the furnace wall of converter type refining furnace 1.Therefore, In desiliconization processing, in basicity ((quality %CaO)/(quality %SiO not to desiliconization clinker 62)) (following, also only table sometimes Be shown as " basicity ") be controlled in the case of, there is a possibility that occur so-called " returning phosphorus ", " the returning phosphorus " is the de- of residual Contained phosphorous oxides (P in phosphorus clinker2O5) decompose and the phosphorus concentration of molten iron 5 is increased.In order to cut down during desiliconization processing CaO systems fluxing agent usage amount and intentionally make in the case that dephosphorization clinker residued in stove, have that to return phosphorus caused by phosphorus dense The bigger possibility of rising of degree.That is, in order to prevent it is such return phosphorus, be preferably the desiliconization clinker 6 generated in handling desiliconization Basicity be adjusted.
Under common desiliconization treatment conditions, molten iron temperature is that the FeO concentration in 1300 DEG C or so, and desiliconization clinker is 10 Mass % of quality %~20 or so, if in view of these, the basicity of the desiliconization clinker 6 after being handled by making desiliconization for 0.8 with On suppress to return phosphorus reaction.
Basicity ((quality %CaO)/(quality %SiO of desiliconization clinker 62)) can be calculated according to following formula (1).
Basicity=[(stove in residual CaO amounts (kg/ molten iron-t))+(desiliconization handle in addition CaO amounts (kg/ molten iron- T))]/[(residual Si O in stove2Measure (kg/ molten iron-t))+(the generation SiO in desiliconization processing2Measure (kg/ molten iron-t))] ... (1)
It should be noted that remaining residual Si O in CaO amounts and stove in stove2The dephosphorization for the upper furnace charge for measuring to remain in stove Contained CaO amounts and SiO in clinker2Amount, the generation SiO in desiliconization processing2Amount can be by the Si in desiliconization before and after the processing molten iron The change of concentration and calculate.
As the oxygen source handled for desiliconization, the oxygen 8 from top-blown spray gun 2 can be used only, alternatively, it is also possible to by oxygen The solid oxygen source such as 8 and iron oxide (not shown) is applied in combination.Target alkali is generated in being handled for the desiliconization carried out in a short time The desiliconization clinker 6 of degree, is effective using the iron oxide of the function with the scorification for promoting CaO systems fluxing agent.However, from conduct An object of the present invention makes from the viewpoint of a large amount of cold iron sources 7 melt, a large amount of using during heating and oxygen that the when of decomposition absorbs heat It is undesirable to change iron, it is therefore preferable that the usage amount for making iron oxide is necessary Min..Further, since using converter type Refining furnace 1 can increase oxygen feed speed as refining vessel, even if carrying out desiliconization processing using only oxygen 8, The scorification of CaO systems fluxing agent can be sufficiently promoted and the desiliconization clinker 6 of target basicity is generated.
After the desiliconization treatment process, such as shown in Fig. 2-(C), make converter type refining furnace 3 to being provided with the side of tapping hole 4 Opposite inclination tiltedly so that produced during desiliconization is handled contain a large amount of SiO2Stove of the desiliconization clinker 6 through converter type refining furnace 1 Mouthful and be expelled in slag pot (end diagram) of the configuration on lower track (deslagging process).Make converter type refining furnace 1 in molten iron 5 It will not be tilted in the range of fire door outflow, desiliconization clinker 6 be discharged by the overflow from fire door, from the fire door of inclined body of heater The height that lower end is risen untill slag surface is higher, can more be effectively discharged out, but can not be completely exhausted out desiliconization clinker 6, takes off A part for silicon clinker 6 can be still residued in stove.The deslagging process of desiliconization clinker 6 is entered between desiliconization processing and dephosphorization treatment OK, therefore, also referred to as " middle deslagging ".
After deslagging process, CaO system's fluxing agents and oxygen source are supplied to the molten iron 5 residued in converter type refining furnace, is such as schemed Shown in 2- (D), dephosphorization treatment (dephosphorization treatment process) is carried out to molten iron 5.In dephosphorization treatment process, the basicity of the clinker in stove It is adjusted to 1.3~3.5 scope.In the same manner as desiliconization processing, the oxygen source used in the dephosphorization treatment process from top blast to spray The oxygen 8 of rifle 2 is main body, but it is also possible to partly using iron oxide.But, an object of the present invention is to melt substantial amounts of cold Source of iron 7, as described above, it is preferred to which the iron oxide absorbed heat when avoiding will heat up as far as possible and when decomposing is used as oxygen source.
As the CaO systems fluxing agent used in dephosphorization treatment, quick lime or calcium carbonate etc. can be used.But it is not limited to this A bit, can also be by the CaO containing more than 40 mass % and the change containing other compositions such as fluorine, aluminum oxide, iron oxide as needed Compound is used as CaO systems fluxing agent during dephosphorization treatment., can will be granular and block as the adding method of the CaO systems fluxing agent Fluxing agent puts into the fluxing agent of powdery via the grade of top-blown spray gun 2 from the hopper input on stove.
It is oxidized in the presence of oxygen of the phosphorus in the oxygen source supplied in molten iron and forms phosphorous oxides (P2O5), the phosphorus Oxide is with 3CaOP2O5The form of compound of stable form enter and generated by the scorification of CaO systems fluxing agent In clinker as dephosphorization refining agent function, the dephosphorisation reaction of molten iron 5 is carried out.After dephosphorization treatment, generation contains phosphorus oxidation The dephosphorization clinker of thing.
Dephosphorisation reaction carries out and phosphorus concentration in molten iron is reduced to after set-point, terminates dephosphorization treatment.Then, as Fig. 2- (E) shown in, converter type refining furnace 1 is tilted to the side for being provided with tapping hole 4, by the molten iron 5 in converter type refining furnace through going out Iron mouthful 4 taps a blast furnace into molten iron holding container (end diagram) (process of tapping a blast furnace).
This taps a blast furnace after process, dephosphorization clinker in stove can not be discharged and load into converter type refining furnace 1 cold iron source 7 and Molten iron 5, starts the desiliconization treatment process of following core, after the dephosphorization clinker in discharge stove, loads cold iron source 7 and molten iron 5, start the desiliconization treatment process of following core.In the whole amount or majority of the dephosphorization clinker for making to generate in stove Residue in stove and in the case of starting the desiliconization processing of following core, the heat that the dephosphorization clinker of a upper furnace charge can be had And ferrous components are reclaimed in the desiliconization processing of following core, and can be by the CaO compositions in the dephosphorization clinker of a upper furnace charge The CaO sources in the desiliconization processing of following core are acted effectively as, the use of CaO systems fluxing agent during so as to cut down desiliconization processing Amount.
In the present invention, when so implementing desiliconization processing and dephosphorization treatment to molten iron 5, in order to be given in deslagging process The desiliconization clinker 6 of the quantitative above promptly flows out to outside stove, the height of desiliconization clinker 6 is determined in desiliconization processing, at desiliconization Desiliconization clinker 6 is bubbled in reason so that the clinker that is determined at the time of desiliconization processing terminates height (from static in stove when iron Distance of the water-bath face untill the upper end of desiliconization clinker 6) it is target zone.In addition, the present inventor etc. confirms：If at desiliconization The foaming for managing the desiliconization clinker 6 of finish time is few, then the mobility of desiliconization clinker 6 is low, thus is difficult to discharge within preset time The desiliconization clinker 6 of sufficient amount.Therefore, in order to which the desiliconization clinker 6 for promptly making sufficient amount in deslagging process flows out out of stove, need Desiliconization clinker 6 is set to bubble in the way of the scope for reaching given clinker height at the end of being handled in desiliconization.Here, clinker Foaming refer to molten slag comprising bubble and apparent upper volume expansion phenomenon.
Therefore, the converter type refining furnace 1 used in the present invention needs to have the function of determining the clinker height in stove.
Shown in Fig. 1 the present invention used in converter type refining furnace 1 in, converter type refining furnace 1 fire door it is upper Side is provided for reclaiming the coaming plate 12 of the waste gas produced in stove, is provided with the top of coaming plate 12 for waste gas to be directed into collection The flue 11 of dirt machine.Opening portion 13 and opening portion 14, the pass through openings portion 13 of top-blown spray gun 2 are provided with coaming plate 12 and is inserted into In stove, in addition, pass through openings portion 14 is provided with 2 waveguides 16, and simulation random signalses processing radar mode is installed in Microwave ranger 15 (be only denoted as below " micro-wave oven slag level-sensing device 15 ") on.In the front end of 2 waveguides 16, transmission antenna 17 and Reception antenna 18 is separately positioned on the position directly below of opening portion 14.That is, consist of：Determined by micro-wave oven slag level-sensing device 15 The height of desiliconization clinker 6 in stove.
It is 10 because the desiliconization clinker 6 of foaming is minimum for the reflectivity of microwave-4Hereinafter, therefore, at one of the present invention Radar is used in embodiment, the radar is clever using measure is improved as the signal obtained by simulation random signalses modulated microwave Sensitivity.As simulation random signalses, for example, it can be used and appropriate logic circuit combined by 800MHz or so high frequency clock signal And the frequency with 6MHz or so produced repeats the simulation random signalses of same waveform.Above-mentioned situation is defeated by clock signal Enter 27Secondary (128 times) and circulate one wheel logic circuit produce simulation random signalses situation example.
As the carrier wave of used microwave, the microwave for the use of such as frequency being about 10GHz, and it is random to be multiplied by simulation Signal and the transmission antenna 17 of the opening portion 14 of the configured coaming plate 12 on stove of microwave modulated are into converter type refining furnace 1 Radiate in portion.
Here, the skyborne wavelength of frequency 10GHz electromagnetic wave is about 3.0cm, the ripple in the case where frequency is less than 10GHz A length of more than 3.0cm, the particle more than the dust in converter type refining furnace or cigarette shape thing will be grown, therefore, be not easily susceptible to dust etc. Influence, and because wavelength is short, therefore be conducive to the miniaturization of antenna.In addition, transmission antenna 17 and reception antenna 18 for example make With box horn, the back wave beyond slag surface is reduced as much as possible by significantly reducing directive property.Microwave When frequency is low, the influence of dust etc. is not easily susceptible to, therefore, as the microwave used in the present invention, the higher limit of frequency is set to 10GHz, i.e. be preferably shorter than 10GHz frequency, more preferably below 8GHz.If however, the underfrequency of microwave, in the presence of Between and the resolution ratio of distance the problem of reduce, and need the maximization of antenna, in terms of preventing dust to be attached to antenna also not Ideal, therefore, the frequency of microwave are preferably set to more than 2GHz.
Reflected from the electromagnetic wave that transmission antenna 17 is radiated into converter type refining furnace in slag surface, and via reception day Line 18 and be converted to electric signal.Micro-wave oven slag level-sensing device 15 supplies the time of input signal to receiver certainly from transmission antenna The time delay of 17 emitting electromagnetic ripples electromagnetic wave propagation time, electromagnetic wave propagation time refers to that electromagnetic wave will be up to turning The distance untill clinker material position in type of furnace refining furnace makes a round trip, the time untill reception antenna 18 is reached.The propagation Time can be carried out by the phase difference for the simulation random signalses for being compared the carrier wave for being modulated to microwave with send wave in received wave Determine.
At this time it is also possible to according to the time correlation function for the simulation random signalses composition for being modulated to received wave and send wave Directly the propagation time is obtained, but carried out by using the simulation random signalses that clock frequency is altered slightly and produces at signal Reason, can significantly expand the time shaft of time correlation function and carry out the measure of high resolution.
For example, the frequency weight with about 6MHz that the clock signal for the high frequency by 800MHz is produced using logic circuit The simulation random signalses of complex phase same waveform, are utilizing as frequency shift the clock signal (such as 800.004MHz) obtained by 4kHz In the case of the simulation random signalses produced using identical logic circuit, if both simulation random signalses are multiplied, When both phases are inconsistent, multiplied result is only radio-frequency component more than clock frequency degree, but when both phases one During cause, flip-flop or low-frequency component can be produced in the multiplied result of the simulation random signalses of 2 same waveforms.Therefore, if entering One step is removed the frequency signal component higher than the repetition rate degree of simulation random signalses by low pass filter, then is detected The phase of the 2 simulation random signalses consistent time within 4kHz cycle.Because：Because in both simulation random signalses 4kHz is differed only by as the clock frequency of benchmark, so phase difference changes bit by bit, phase only has 1 within 4kHz cycle It is secondary consistent.
So, the phase difference in the cycle of the repetition rate of about 6MHz simulation random signalses, i.e. time delay are changed For the time difference in 4kHz cycle, time shaft is extended to about 1500 times, can detect that the simulation of received wave and send wave with The phase difference of machine signal.
The back wave from various paths and object, the back wave from each object are included in the back wave received In include the simulation random signalses composition corresponding with the phase delay of reflected intensity and time-of-flight measurement.For above-mentioned reflection Ripple, carries out signal transacting using the simulation random signalses for changing above-mentioned clock signal frequency, has been carried out in the same manner as at signal The signal of the send wave of reason is compared, and the propagation time is extended to about 1500 times, detect with the back wave from each object thing into Propagation time and the intensity corresponding signal divided.
To the signal detected as described above, the propagation time will be scaled from the time delay of send wave, to the propagation time It is multiplied by the spread speed (3 × 10 of microwave8M/s) and divided by 2, thus can calculate until the object corresponding with the signal detected Distance untill thing.
Fig. 3 is that the dephosphorization clinker generated in the dephosphorization treatment for make a furnace charge is residued in stove and by the molten iron 5 of the furnace charge When carrying out desiliconization processing after loading in stove, one of the signal of the back wave obtained using above-mentioned micro-wave oven slag level-sensing device 15. The relation of the intensity as distance of the object of the occurring source of back wave away from antenna and its back wave is shown in Fig. 3.Fig. 3's Transverse axis uses following value, the value be the send wave for the signal for measuring self-inspection time delay be scaled from transmission antenna 17 and It is worth obtained from distance of the reception antenna 18 untill object.In the case where carrying out signal transacting as described above, The detection signal of the back wave such as Fig. 3 is obtained in 4kHz cycle, therefore, processing can be further averaged and improve letter Number/noise ratio, and continuously measure the change of clinker material position.
The detection signal for the back wave that there is peak value in multiple positions is shown in Fig. 3, is less than certain fixed value on intensity Peak (signal of back wave), be by from body of heater refractory body or adhere to furnace wall feed metal or top-blown spray gun 2 it is multiple The peak of back wave caused by reflection.Moreover, in the peak position of intensity more than with certain fixed value, by the distance away from antenna The peak of the back wave away from slag surface is set to more than the distance away from fire door and closest to the peak of the distance away from fire door.
Specifically, in the detection signal of back wave as Fig. 3, by more than the 100 times intensity with background level Peak in be more than the distance away from fire door and closest to the distance away from fire door peak be set to foaming desiliconization clinker 6 surface it is relative The peak answered.It should be noted that in figure 3, the distance from antenna to the position equivalent to fire door is about 9m, the distance away from antenna The wide and big peak of scope for 19m or so corresponds to molten iron and bathes face.
In addition, producing the peak that position (distance away from antenna) does not just change and persistently existed when desiliconization is handled Can determine whether to be not corresponding with the back wave from slag surface, therefore, if using such peak as after noise remove, as above State and judge the peak corresponding with slag surface like that, then can carry out the higher measurement of reliability.
In addition, following method is also effective, the high measurement of reliability can be carried out, methods described is：Will be from desiliconization After position continues the peak that exists with not changing as noise remove when processing starts, it will correspond to and face is bathed from fire door to molten iron Scope position peak in bathe the corresponding back wave in face with molten iron peak remove, intensity highest peak is judged to come from stove The back wave on slag surface, and calculate the distance away from slag surface.
Subtracted by the slag surface judged using these methods relative to the height of reference plane (position of antenna) by the stove Input molten iron and height of the molten iron bath face relative to reference plane (position of antenna) of iron filings amount sum presumption in material, by it The absolute value of difference is set to clinker height.It is illustrated that and is obtained by the measurement result obtained using micro-wave oven slag level-sensing device 15 in Fig. 4 The example of the change of clinker height in desiliconization processing in stove.For the appropriateness of the clinker height obtained, by with foaming Desiliconization clinker 6 compareed and be confirmed that from the time of the ejection (splash of clinker) of fire door.
In addition, the present inventor etc. desiliconization is handled at the end of clinker height and relation between the middle deslagging time, with And the clinker height and dephosphorization treatment at the end of desiliconization processing terminate after molten iron in relation between phosphorus concentration studied. Fig. 5 is illustrated that the result of study of the relation between the clinker height at the end of desiliconization processing and middle deslagging time, in addition, figure 6 be illustrated that the clinker height at the end of desiliconization processing and dephosphorization treatment terminate after molten iron in relation between phosphorus concentration grind Study carefully result.Fig. 5 and Fig. 6 transverse axis is by clinker height relative to (also referred to as " void tower portion ", molten iron bath when static of melting chamber in stove Space between face and fire door) the ratio of height (molten iron bath the distance between face and fire door) under inactive state represent.
If clinker height relative to the height of melting chamber in stove ratio more than 0.9, the foaming of desiliconization clinker 6 is excessively Acutely temporarily stove is erect to make the counter-measure that desiliconization clinker 6 is calm, it is necessary to take in deslagging, causes the middle deslagging time Extension.On the other hand, it is less than in clinker height relative to the ratio of the height of melting chamber in stove in the case of 0.5, middle deslagging When desiliconization clinker 6 discharge it is poor, in the dephosphorization treatment of subsequent processing, desiliconization clinker 6 can remain superfluously, so clinker Basicity reduction, the phosphorus concentration increase in the molten iron after dephosphorization treatment.
That is, desiliconization clinker 6 clinker height relative to the height of melting chamber in stove ratio for more than 0.5 and 0.9 with Under given range, be preferably more than 0.7 and less than 0.9 given range in the state of, terminate desiliconization processing, thus, at it In deslagging process afterwards, the desiliconization clinker 6 of sufficient amount is promptly expelled to outside stove by realization, has been thereby confirmed that in subsequent processing The phosphorus concentration of molten iron can be reduced to by low concentration with the usage amount of few CaO systems fluxing agent in dephosphorization treatment.Need explanation Be, it is believed that the higher limit and lower limit of scope given herein above according to its different optimum value of stove Internal periphery and fire door shape not yet Together, therefore, it more desirable to the data of Fig. 5 and Fig. 6 according to calculated by the embodiment of each refining furnace, it is appropriate within the above range to adjust Whole above-mentioned higher limit and lower limit.
In addition, top blast condition and Bottom Blowing Gas Flow Rate that the present inventor etc. enters to exercise the top-blown spray gun 2 in desiliconization processing become The experiment of change, is studied for the influence that these operation factors are brought to the change of clinker height.Fig. 7, which is illustrated that, to be come from The research knot for sending influence that the change of oxygen speed (oxygen supply flow rate) causes to the pace of change of clinker height of top-blown spray gun 2 Really, Fig. 8 is illustrated that the research knot for the influence that the change of the spray gun height of top-blown spray gun 2 comes to clinker height change speed band Really, Fig. 9 is illustrated that the result of study for the influence that the change of Bottom Blowing Gas Flow Rate is brought to the pace of change of clinker height.Understand Improve clinker when sending oxygen speed from top-blown spray gun 2 and highly increase (Fig. 7), clinker when increasing the spray gun height of top-blown spray gun 2 Highly increase (Fig. 8), in addition, clinker height (Fig. 9) can be reduced by increasing the stirring gas flow from bottom blowing nozzle 3. Here, the spray gun of top-blown spray gun 2 highly refers to the distance untill the molten iron bath face of inactive state from the lower end of top-blown spray gun 2.
In addition, the influence that clinker composition comes to clinker altitudinal belt is also big, have that basicity is lower, iron oxide concentration is higher or The bigger tendency of the more high then clinker height of alumina concentration, therefore, in order to adjust clinker composition, the measure knot based on clinker height The input that fruit carries out slag former is also effective.And then, when entering to exercise the adjustment that clinker highly reduces, use the cooling of solid The calm material of the foaming such as agent, gas generant is also effective.
That is, in the present invention, it is preferred to which the height to the desiliconization clinker 6 in stove in desiliconization processing is measured, and root According to the measurement result, to the supply flow rate selected from the gaseous state oxygen source from top-blown spray gun 2, the spray gun height of top-blown spray gun 2, come from In the supply flow rate of the stirring gas of bottom blowing nozzle 3, the composition of the clinker in stove, the input amount of the calm material of foaming at least 1 kind is adjusted, and controls by the adjustment height of desiliconization clinker 6 in stove in given scope.Thus, can be easily Realize that the height of the clinker at the end of desiliconization is handled is adjusted to scope given herein above relative to the ratio of melting chamber height.
The measure of clinker height in stove is not limited to carry out according to above-mentioned in desiliconization processing, dephosphorization treatment. In dephosphorization treatment, by being controlled such that dephosphorization clinker will not spray (splash) from fire door, the CaO systems that can suppress addition help The ejection loss amount of flux, so as to carry out effective dephosphorization treatment.That is, clinker height is melted relative in stove in dephosphorization treatment The ratio for changing the height of room is adjusted to be less than 1.0.It is also preferred that using the micro-wave oven slag charge position of described above in dephosphorization treatment 15 are counted to determine clinker height.
In addition, in the present invention, it is preferred to the ash-retention efficiency (ash-retention efficiency (quality %)=(row of the desiliconization clinker 6 in deslagging process Slag discharging quality) × 100/ [(the clinker quality generated in desiliconization treatment process)+(the residual clinker quality of a upper furnace charge)]) really Protect as more than 30 mass %.Because, dephosphorisation reaction is carried out in dephosphorization treatment process behind to be needed dephosphorization clinker Basicity is adjusted to 1.3~3.5, if ash-retention efficiency is less than 30 mass %, the CaO systems fluxing agent that should be added in dephosphorization treatment process Amount increases.In addition, if the desiliconization slag amount of residual is excessive, the slag amount in dephosphorization treatment increases, it is impossible to suppress dephosphorization treatment In slag bloating, also there is clinker to spray and cause the possibility of operating barrier from the fire door of converter type refining furnace 1.
In addition, the ash-retention efficiency in order to increase desiliconization clinker 6, preferably makes the basicity of desiliconization clinker 6 at the end of desiliconization is handled For more than 0.5 and less than 1.5, and the temperature of molten iron temperature or desiliconization clinker 6 is set to be more than 1280 DEG C.In desiliconization clinker 6 Basicity is less than in the case of 0.5, and viscosity rises and the mobility of clinker is reduced, and is easily caused the velocity of discharge, the reduction of ash-retention efficiency, In the case where basicity is more than 1.5, slag fluidity is reduced because producing solid phase clinker.Even if in addition, slag temperature is less than 1280 DEG C, similarly produce the reduction of slag fluidity as caused by the increase of solid phase clinker and liquid phase clinker in itself Viscosity rises, therefore, and the mobility of desiliconization clinker 6 reduces and is easily caused the velocity of discharge of clinker, the reduction of ash-retention efficiency.
The present inventor etc. are studied for civil engineering as described below with the various characteristics of clinker product, the soil Wood engineering is manufactured as follows with clinker product：The desiliconization clinker 6 being expelled in above-mentioned deslagging process in slag pot is set to be put from slag pot Go out into manufacture field and solidify it, be then ground into particle diameter 30mm or so following.In addition, based on the result of study, it is right It can obtain and be suitable for various civil engineerings and carried out with the preprocess method of the molten iron of the relatively small clinker of the bulk specific gravity of material Further research.
The mass per volume of given granularity and the dephosphorization clinker under compaction state is 2.0~2.3kg/L or so, than natural 1.6~1.8kg/L of earth rock material is big.Therefore, dephosphorization clinker is suitable for big to quality the stability height of wave such as expecting Material applications, conversely, it is difficult to suitable for worry can encourage the instable civil engineering applications of gravity, further, since body Product also haves the shortcomings that transportation expenses increase than great.
Therefore, in order to strongly reduce the yield of the great dephosphorization clinker of volume ratio, dephosphorization clinker is converted into low volume The desiliconization clinker 6 of proportion, it is preferred to use the preprocess method for repeating following order and carrying out：In the dephosphorization treatment work of a upper furnace charge After sequence, make after the molten iron in stove taps a blast furnace, the dephosphorization clinker in stove not being discharged and makes the dephosphorization clinker of a furnace charge remain in stove In the state of load new molten iron, implement desiliconization treatment process to the molten iron, after desiliconization processing, by deslagging process by desiliconization A part for clinker 6 is discharged from refining furnace, then implements dephosphorization treatment process to residuing in the molten iron in stove.Now, preferably At the end of desiliconization is handled, the basicity for making desiliconization clinker 6 is more than 0.8 and less than 1.5, makes molten iron temperature or desiliconization clinker 6 Temperature is more than 1280 DEG C and less than 1380 DEG C, and it is below 0.10 mass % to make silicone content in molten iron, and is arranged in deslagging process Go out more than 30 mass % of desiliconization clinker 6.
By making the basicity of desiliconization clinker 6 be more than 0.8 and less than 1.5, the temperature that makes molten iron temperature or desiliconization clinker 6 be Less than more than 1280 DEG C 1380 DEG C, return phosphorus of the dephosphorization clinker from a upper furnace charge to molten iron can be prevented, and effectively carry out deslagging The discharge of desiliconization clinker 6 in process.Here, at the end of desiliconization is handled, because the temperature of desiliconization clinker 6 is close to molten iron temperature, Therefore any one in the temperature of molten iron temperature or desiliconization clinker 6 can be regard as index.Can be by the way that thermocouple be impregnated in into iron Water determines molten iron temperature, but it is also possible to use the various chills such as the temperature and composition, iron filings of the molten iron according to desiliconization before processing The usage amount and oxygen of the various heating exothermic mixtures such as usage amount, the ferrosilicon of the various auxiliary materials such as usage amount, the quick lime in source are supplied Thermal balance is calculated to operating conditions such as amounts and the molten iron temperature that calculates replaces said determination value.
In addition, being below 0.10 mass % by making silicone content in the molten iron after desiliconization processing, even if iron oxide in clinker Concentration relative reduction, the CO gases as caused by decarburizing reaction, which are produced, in desiliconization processing becomes active, and therefore, can also promote desiliconization stove The foaming of slag 6, it is favourable to improve clinker height at the end of being handled for desiliconization.Moreover, in this case, desiliconization in deslagging process The foaming of clinker 6, which is captivated so that, makes clinker highly be maintained at higher, therefore, in terms of the expulsion efficiency of desiliconization clinker 6 is improved It is also advantageous.
The ash-retention efficiency of desiliconization clinker 6 is preferably set more than 30 mass % in deslagging process.Thus, the de- of a furnace charge will not be made Phosphorus clinker is excessively accumulated in stove, will not also cause the excessive reduction of the basicity of slag in dephosphorization treatment process, can be at dephosphorization Suppress the usage amount of the Dephosphorising agents such as quick lime in science and engineering sequence to reduce phosphorus concentration in molten iron.
The condition at the end of desiliconization processing is met as described above, and determines the clinker at the end of desiliconization is handled in stove highly, And be adjusted so that the clinker height determined is entered relative to the ratio that the height of melting chamber in stove is that 0.5~0.9 grade gives Row deslagging process, thus, with high ash-retention efficiency can be discharged desiliconization clinker 6 from converter type refining furnace 1 within the relatively short time. Make so to be expelled to the desiliconization clinker 6 of slag pot further from slag pot be released to manufacture field in and solidify it, then powder In the clinker product for being broken into the civil engineering manufactured below particle diameter 30mm or so, containing relatively more small bubble in particle, Therefore, mass per volume is reduced to below 1.2kg/L or so.As a result, being suitable for expecting low-gravity purposes, and may be used also Obtain the effect of the trucking expenses of reduction unit in charge of construction volume.
For the small clinker product of stably manufacturer's volume mass, expect to make desiliconization handle at the end of desiliconization clinker 6 basicity is more than 0.8 and less than 1.25, and slag temperature is less than 1360 DEG C and carrys out increased viscosity；Make stove at the end of desiliconization processing Phosphoric acid (P in slag2O5) content is that more than 2 mass % reduce surface tension；When being released from slag pot to manufacture field, use Inclined place, or move clinker while releasing, the clinker of releasing is disperseed on a large scale, so as to improve desiliconization The cooling velocity of clinker 6；Etc..In addition, low relative to the height of melting chamber in stove with clinker height at the end of desiliconization is handled Ratio in 0.5 is carried out in the furnace charge group of deslagging process, and the average ash-retention efficiency of desiliconization clinker 6 is less than 30 mass %, and average Mass per volume increases to 1.3kg/L or so.
It is as described above, according to the present invention, continuously carrying out accompanying the deslagging of centre using a converter type refining furnace 1 In the desiliconization processing of the molten iron 5 of process and the pretreatment of the molten iron of dephosphorization treatment, when desiliconization is handled, in the desiliconization clinker of foaming 6 height is handled relative to the height of melting chamber in stove to terminate desiliconization in the state of the ratio of given range, therefore, behind Deslagging process in, can be achieved promptly the desiliconization clinker 6 of sufficient amount is expelled to outside stove.
It should be noted that the present invention is not limited to the scope of described above, various changes can be carried out.For example, on state In bright, clinker height is determined using micro-wave oven slag level-sensing device 15, but it is also possible to according to the survey of the short transverse Temperature Distribution in stove The clinker face of fixed, the measured value installed in top-blown spray gun or the vibrometer of body of heater, the measured value of the volume produced by body of heater etc. Detection information come determine clinker height.
Embodiment
Using the converter type refining furnace of 330 tons of capacity shown in Fig. 1, the molten iron pretreatment (present invention of the present invention is implemented The molten iron of example 1~3) and the existing method highly controlled by micro-wave oven slag charge position-finding clinker height but without clinker is pre- Handle (comparative example 1, comparative example 2), and respectively it is each carried out 20 times charging.At the end of pretreatment in molten iron phosphorus concentration desired value It is set to 0.030 mass %.
In example 1 of the present invention, the clinker height in oxygen blowing is determined in desiliconization processing using micro-wave oven slag level-sensing device, and it is right Oxygen speed, spray gun height, at least one kind of in stirring gas flow is sent to be adjusted from top-blown spray gun, what adjustment was measured Clinker height and desiliconization oxygen efficiency is assumed into 50% and to obtain having supplied relative to the ratio of the height of melting chamber in stove The desiliconization processing end time point of oxygen amount required for the desiliconization obtained is 0.5~0.9, carries out middle deslagging, is then blown by oxygen Refine and proceed dephosphorization treatment.
In example 2 of the present invention, the clinker height in oxygen blowing is determined in desiliconization processing using micro-wave oven slag level-sensing device, and it is right Oxygen speed, spray gun height, at least one kind of in stirring gas flow is sent to be adjusted from top-blown spray gun, although wanting will The clinker height measured is adjusted to be assumed to desiliconization oxygen efficiency having supplied relative to the ratio of the height of the melting chamber in stove 50% and time point of the oxygen amount required for the desiliconization that obtains is more than 0.5, but after the time, clinker height is relative to stove The ratio of the height of interior melting chamber is less than 0.5, therefore extension oxygen duration of blast, is reached in clinker height relative to the height of melting chamber Time point to 0.5 terminates desiliconization processing and carries out middle deslagging, is then blown by oxygen and proceeds dephosphorization treatment.
In example 3 of the present invention, carried out in desiliconization processing with carrying out intermediate row slag after the identical of example 1 of the present invention control, then, The clinker height in oxygen blowing is determined using micro-wave oven slag level-sensing device in dephosphorization treatment, when clinker height melts relative in stove When the ratio for changing the height of room is more than 0.8, to sending oxygen speed, spray gun height, stirring gas flow from top-blown spray gun In it is at least one kind of be adjusted, and adjust clinker height and taken off relative to the ratio of the height of melting chamber in stove less than 1.0 Phosphorus processing.
In comparative example 1 and comparative example 2, required for having supplied in the desiliconization that desiliconization oxygen efficiency is assumed to 50% and obtained Oxygen amount time point terminate desiliconization processing, carry out in the middle of deslagging, then by oxygen blowing proceed dephosphorization treatment.Here, Molten iron temperature is more than 1300 DEG C in comparative example 1, and molten iron temperature is less than 1300 DEG C in comparative example 2.Comparative example is divided into comparative example 1 The reasons why with comparative example 2, is, in the case where molten iron temperature is up to more than 1300 DEG C, and the scorification of clinker is promoted, and clinker is high Spend to high position passage, in contrast, in the case where molten iron temperature is less than 1300 DEG C, clinker height is elapsed to low level.
Base condition is used as in example 1~3 of the present invention and comparative example 1,2 using following conditions：Oxygen speed is sent when desiliconization is handled Spend for 30000Nm3/ hr, spray gun are highly that 2.5m, Bottom Blowing Gas Flow Rate are 1200Nm3/hr.In addition, being used as base using following conditions Floating screed part：Oxygen speed is sent to be 25000Nm during dephosphorization treatment3/ hr, spray gun are highly that 2.1m, Bottom Blowing Gas Flow Rate are 1200Nm3/ hr.As bottom blown gas, nitrogen has been used in desiliconization processing and dephosphorization treatment.
Table 1 shows the result of the test of the respective typical example of example 1~3 of the present invention and comparative example 1,2.In addition, shown in Figure 10 It is example 1,2 of the present invention and comparative example 1,2 respective typical examples height of the clinker height relative to melting chamber in stove in desiliconization processing The change of the ratio of degree.In addition, Figure 11 is illustrated that example 3 of the present invention, the respective typical example clinker in dephosphorization treatment of comparative example 2 Passage of the height relative to the ratio of the height of melting chamber in stove.Table 1, Figure 10, Tu11Zhong, respective typical example is by example of the present invention 1~3 and comparative example 1,2 represent.
For the example of the present invention 1 shown in table 1, because molten iron temperature is high, the scorification speed that desiliconization handles initial stage is high, institute Highly elapse high with clinker.Therefore, Bottom Blowing Gas Flow Rate is made to increase to 2400Nm after 2 minutes since being handled desiliconization3/hr。 Thus, the increase of clinker height is suppressed, required in the desiliconization that desiliconization oxygen efficiency is assumed to 50% in supply and obtained The time point of oxygen amount, clinker height is 0.8 relative to the ratio of the height of melting chamber in stove.
In contrast, using with example 1 of the present invention with the comparative example 1 shown in the table 1 of the molten iron of equitemperature, because not carrying out The control of clinker height, therefore the clinker height of desiliconization processing end time point is relative to the ratio of the height of melting chamber in stove 1.0, the outflow of clinker acutely, temporary transient inclined stove is erected again, reduced using sedative after clinker height during middle deslagging Deslagging in the middle of carrying out again.Thus, middle deslagging time lengthening.
For the example of the present invention 2 shown in table 1, molten iron temperature is low, and the scorification speed that desiliconization handles initial stage is low, therefore, Clinker highly elapses low.Therefore, desiliconization processing makes to send oxygen speed to increase to from top-blown spray gun after starting 2 minutes 50000Nm3/ hr, and spray gun height also increase to 3.5m and carried out oxygen blowing.But desiliconization oxygen efficiency is assumed to having supplied 50% and the time point of the oxygen amount required for the desiliconization that obtains, clinker height is less than relative to the ratio of the height of melting chamber in stove 0.5.Therefore, the desiliconization processing blown using oxygen is proceeded, in ratio of the clinker height relative to the height of melting chamber in stove Terminate desiliconization processing for 0.5 time point, then carry out middle deslagging.Thus, the ash-retention efficiency in deslagging process is up to 70%.
In contrast, using with example 2 of the present invention with the comparative example 2 shown in the table 1 of the molten iron of equitemperature, because not carrying out The control of clinker height, thus the oxygen amount required for having supplied the desiliconization that desiliconization oxygen efficiency is assumed to 50% and obtains when Between point, clinker height relative to melting chamber in stove height be less than 0.5.Middle deslagging has been carried out in this condition, as a result deslagging Rate is reduced, the basicity reduction of dephosphorization treatment thereafter, causes dephosphorization bad.
For the example of the present invention 3 shown in table 1, clinker height is controlled when desiliconization is handled, and in dephosphorization treatment Implement makes to send oxygen speed to be ± 5000Nm relative to a reference value3/ hr scope, spray gun are highly ± 0.5m scope, bottom blowing Gas flow is ± 1200Nm3Appoint one kind or two or more adjustment in/hr scope so that clinker height melts relative in stove The ratio for changing the height of room is less than 1.0.This prevents the splash in dephosphorization treatment, it can prevent the CaO systems loaded in stove from helping Sprayed outside the stove of flux, as a result, the phosphorus concentration at the end of dephosphorization treatment in molten iron can be reduced.In contrast, in comparative example 2 In, the phosphorus concentration in dephosphorization treatment at the end of generation splash (clinker ejection), dephosphorization treatment in molten iron can not reach desired value.

Claims (8)

1. a kind of preprocess method of molten iron, this method includes：
Desiliconization treatment process, desiliconization is carried out from molten iron supply gas oxygen source of the top-blown spray gun into converter type refining furnace to molten iron Processing；
Deslagging process, at least a portion of the clinker generated in the desiliconization treatment process is arranged from the converter type refining furnace Go out；And
Dephosphorization treatment process, after the deslagging process, CaO systems fluxing agent is added into the converter type refining furnace, by the top Rifle supply gas oxygen source is blowed and sprayed, dephosphorization treatment is carried out to the molten iron of residual, wherein,
Radar mode microwave ranger is handled using simulation random signalses, below frequency 10GHz microwave is sent to described turn In type of furnace refining furnace and receive the back wave in stove, according to the round trip propagation time of back wave obtain away from object away from From, be present in away from from fire door to the distance of the object molten iron bath face in the range of back wave signal in, will with it is anti- The reflection that the corresponding distance away from object of signal of ejected wave does not just change and persistently existed when desiliconization is handled The signal of ripple is removed as noise, and it is strong that the signal of the back wave corresponding with the distance that face is bathed away from molten iron then is removed into back reflection The signal determining for spending highest back wave is the signal of the back wave from slag surface, obtains the distance away from slag surface, then Based on the distance away from slag surface tried to achieve, in desiliconization processing, the clinker in stove is highly measured, surveyed Fixed clinker height relative to from the molten iron bath face in stove in the stove untill fire door the ratio of the height of melting chamber be given model In the state of enclosing, terminate desiliconization processing.
2. the preprocess method of molten iron according to claim 1, wherein, the given range of the ratio is 0.5~0.9 Scope.
3. the preprocess method of molten iron according to claim 1, wherein, based on the measurement result of the clinker height, In the desiliconization processing, to the supply flow rate selected from the gas oxygen source from top-blown spray gun, the spray gun height of top-blown spray gun, come from It is clinker composition in the supply flow rate of the stirring gas of bottom blowing nozzle, stove, at least one kind of in the input amount of the calm material of foaming It is adjusted, the clinker in being handled by the adjustment desiliconization in stove is highly controlled.
4. the preprocess method of molten iron according to claim 2, wherein, based on the measurement result of the clinker height, In the desiliconization processing, to the supply flow rate selected from the gas oxygen source from top-blown spray gun, the spray gun height of top-blown spray gun, come from It is clinker composition in the supply flow rate of the stirring gas of bottom blowing nozzle, stove, at least one kind of in the input amount of the calm material of foaming It is adjusted, the clinker in being handled by the adjustment desiliconization in stove is highly controlled.
5. the preprocess method of molten iron according to claim 3, wherein, the clinker in handling desiliconization in stove is highly carried out Control so that clinker height is relative to the model that the ratio of the height of melting chamber in stove is 0.5~0.9 described in the desiliconization processing In enclosing.
6. the preprocess method of molten iron according to claim 4, wherein, the clinker in handling desiliconization in stove is highly carried out Control so that clinker height is relative to the model that the ratio of the height of melting chamber in stove is 0.5~0.9 described in the desiliconization processing In enclosing.
7. according to the preprocess method of molten iron according to any one of claims 1 to 6, wherein, in the converter type refining furnace In previous furnace charge molten iron dephosphorization treatment process terminate after, the molten iron after dephosphorization treatment is come out of the stove, does not make dephosphorization treatment institute In the stove of generation clinker discharge and in the state of residuing in the converter type refining furnace in, the loading into the converter type refining furnace New molten iron, the desiliconization treatment process is implemented to the molten iron, and at the end of the desiliconization is handled, the basicity for making clinker in stove is More than 0.8 and less than 1.5, the silicone content that the temperature for making molten iron is more than 1280 DEG C and less than 1380 DEG C, make molten iron is 0.10 matter Below % is measured, in the deslagging process, more than the 30 mass % of the clinker generated in desiliconization treatment process are expelled to outside stove, Then, the dephosphorization treatment process is implemented to the molten iron in stove, after the dephosphorization treatment process terminates, by the iron after dephosphorization treatment Water is come out of the stove, in the stove for being generated dephosphorization treatment clinker discharge and in the state of residuing in the converter type refining furnace, Load new molten iron into the converter type refining furnace, the molten iron is pre-processed.
8. according to the preprocess method of molten iron according to any one of claims 1 to 6, wherein, the dephosphorization after deslagging process The clinker height in stove, the spray to supply flow rate, top-blown spray gun selected from the gas oxygen source from top-blown spray gun are determined in processing At least one kind of in rifle height, the supply flow rate of stirring gas from bottom blowing nozzle is adjusted, and is controlled by the adjustment Clinker in stove processed does not spray from fire door.
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