CN109825665A - A method of reducing converter terminal molten steel carbon oxygen product - Google Patents
A method of reducing converter terminal molten steel carbon oxygen product Download PDFInfo
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- CN109825665A CN109825665A CN201910296906.5A CN201910296906A CN109825665A CN 109825665 A CN109825665 A CN 109825665A CN 201910296906 A CN201910296906 A CN 201910296906A CN 109825665 A CN109825665 A CN 109825665A
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Abstract
The invention belongs to metallurgical technology fields, and in particular to a method of reduce converter terminal molten steel carbon oxygen product.Technical problem to be solved by the invention is to provide the methods for reducing converter terminal molten steel carbon oxygen product, reduce carbon oxygen product before reaching blow off to the adjustment of oxygen supply intensity by top blast oxygen blast process first；The secondary reduction carbon oxygen product of residue adjustment is carried out by the way that carbonaceous reducing material, top gun nitrogen flushing and bottom blowing stirring is added after top blast blow off oxygen again.The method of the present invention can reduce converter terminal molten steel carbon oxygen product, to achieve the purpose that drop this upgrading.
Description
Technical field
The invention belongs to metallurgical technology fields, and in particular to a method of reduce converter terminal molten steel carbon oxygen product.
Background technique
It must require control converter terminal carbon content of molten steel according to steel grade when converter smelting, in production low-carbon and ultralow
Converter terminal carbon content of molten steel is generally required when carbon steel lower than 0.05%, in order to the processing of rear process.However, endpoint molten steel carbon
After content is relatively low, molten steel oxygen activity is higher, so that deoxidation is at high cost, lining wear is fast, and foreign substance in molten steel is higher.Therefore, exist
How reducing molten steel oxygen activity when low-carbon section and then reducing carbon oxygen product becomes the research and development focus for dropping this upgrading.
Carbon oxygen product (m) reacts the carbon that ([C]+[O]=CO ↑) relationship obtains i.e. at certain temperature and pressure, according to C-O
With relational expression m=ω [C] × ω [O]=K/Pco of oxygen.When converter smelting, when temperature (K) is constant and carbon monoxide pressure of tension (PCO)
One timing, endpoint molten steel carbon oxygen concentration product m is a constant.And when converter smelting, the height direct relation of endpoint molten steel oxygen activity
To deoxygenated alloy cost and Molten Steel Cleanliness, molten steel oxygen activity is higher, and deoxygenated alloy consumption is big, and deoxidation is at high cost, takes off simultaneously
The field trash that oxygen generates is more, and Cleanliness of Molten Steel is poor.Therefore, reduction endpoint molten steel carbon oxygen product drops the important of this upgrading as converter and arranges
It applies.
In the prior art about the patent literature report of control converter terminal molten steel carbon oxygen product.CN109182640A
" a method of reduce converter smelting endpoint carbon oxygen product " disclose a kind of method of reduction converter smelting endpoint carbon oxygen product, the party
Method is bessemerizing the middle and later periods, and 1.1~1.2kg of waste magnesia carbon bricks ton steel and (the magnesia carbon brick addition of fluorite catalyst are added into furnace
The 20% of amount), achieve the purpose that reduce converter smelting endpoint carbon oxygen product, but the invention needs the addition fluorite in furnace fluxing, firefly
The addition meeting Eroded furnace lining of stone, converter current smelting do not use fluorite substantially.A kind of CN104004877A " reduction converter
The method of aim carbon oxygen product " it discloses through the adjustment of top blast and bottom blowing gas parameter and realizes the control to carbon oxygen product, it smelts
The flow of bottom blowing early period nitrogen or argon gas is 40~60m3/ h, the flow for smelting mid-term argon bottom-blowing is 40~60m3/ h, after smelting
The flow of phase argon bottom-blowing is 70~90m3/ h, the flow of tapping process argon bottom-blowing are 40~60m3/ h, top blast oxygen oxygen rifle rifle
Position is 1.4~1.8m, and oxygen flow is 25000~35000m3/ h can control using this method endpoint molten steel carbon oxygen product
0.00275~0.0028, which, which only passes through top blast and the optimization of bottom blowing parameter, can not reach good carbon oxygen product control effect
Fruit, the effect for reducing carbon oxygen product to the lower molten steel of carbon content are more unobvious.
Summary of the invention
It must require control converter terminal carbon content of molten steel according to steel grade when converter smelting, in production low-carbon and ultralow
Converter terminal carbon content of molten steel is generally required when carbon steel lower than 0.05%, in order to the processing of rear process, the present invention for low-carbon,
The requirement of Ultra-low carbon steel grade terminal point control provides a kind of side for reducing molten steel carbon oxygen product of carbon content of molten steel at 0.03~0.04%
Method.Under the premise of this method can guarantee that meeting carbon content needs, the carbon oxygen product of molten steel is reduced.
The method that the present invention reduces converter terminal molten steel carbon oxygen product, comprising the following steps:
A, it blows after converter iron making, 3~4m of top blow oxygen lance oxygen supply intensity3/(min·tSteel), oxygen lance position 1.3~
1.8m, 0.03~0.08m of bottom blowing gas intensity3/(min·tSteel)；When top blow oxygen lance oxygen blast progress is 90~95%, control top
2~2.5m of oxygen-blowing gun oxygen supply intensity3/(min·tSteel) and 1.2~1.5 times of oxygen rifle height to rifle position before continue blowing to steel
Water carbon content is 0.05% hereinafter, then finishing blowing；
B, carbonaceous reducing material is added, controls top blow oxygen lance nitrogen blowing and bottom blowing gas, it is 1.0~1.2m of top blast rifle position, strong
Spend 1.5~2.0m3/(min·tSteel), 0.01~0.03m of bottom blowing gas intensity3/(min·tSteel)；Continue bottom blowing after top blast to supply
Gas is extremely tapped.
Specifically, the carbonaceous reducing material is smokeless in the method and step a of above-mentioned reduction converter terminal molten steel carbon oxygen product
Coal or coke.
Preferably, in the method and step a of above-mentioned reduction converter terminal molten steel carbon oxygen product, the granularity of the carbonaceous reducing material
For 10~20mm.
Preferably, in the method and step a of above-mentioned reduction converter terminal molten steel carbon oxygen product, the addition of the carbonaceous reducing material
Amount is 0.8~1.5kg/tSteel。
Specifically, the gas of the bottom blowing gas is argon in the method and step a of above-mentioned reduction converter terminal molten steel carbon oxygen product
Gas or nitrogen.
Specifically, the gas of the bottom blowing gas is argon in the method and step b of above-mentioned reduction converter terminal molten steel carbon oxygen product
Gas or nitrogen.
Preferably, in the method and step b of above-mentioned reduction converter terminal molten steel carbon oxygen product, the time of the top blast is 0.5~
1min。
Preferably, in the method and step b of above-mentioned reduction converter terminal molten steel carbon oxygen product, the time for continuing bottom blowing is 1
~2min.
The method of the present invention pass through first top blast oxygen blast process the adjustment of oxygen supply intensity is reached reduce before blow off carbon oxygen product (after
Phase reduces air supply intensity, reduces to molten steel and passes oxygen)；Again by the way that carbonaceous reducing material is added as slag adjusting agent after top blast blow off oxygen
Top gun nitrogen flushing and bottom blowing stirring is cooperated to carry out residue adjustment to secondary reduction carbon oxygen product.The method of the present invention can significantly reduce terminal steel
Water carbon oxygen product reduces deoxygenated alloy consumption, reduces foreign substance in molten steel quantity, improves steel quality.
Specific embodiment
The present invention requires final carbon content of molten steel to need the needs 0.03~0.04% according to certain steel grades, to provide
A kind of method reducing endpoint molten steel carbon oxygen product.The method of the present invention is first by adjusting parameters such as top blast oxygen blast by smelting endpoint
When the control of molten steel carbon mass fraction is to below 0.05%, then again by the way that reducing material is added, changes top blast for gas medium, ginseng
Several and bottom blowing parameter etc. carries out residue adjustment, and the mesh for reducing endpoint molten steel carbon oxygen product is finally reached while guaranteeing that carbon content needs
's.
The method of the present invention specifically includes the following steps:
Blowing: blowing after converter iron making, and top blow oxygen lance oxygen supply intensity is 3~4m3/(min·tSteel), oxygen lance position is
1.3~1.8m, bottom blowing are 0.03~0.08m for argon gas or nitrogen intensity3/(min·tSteel), it is 90 in top blow oxygen lance oxygen blast progress
When~95%, reduction top blow oxygen lance oxygen supply intensity is 2~2.5m3/(min·tSteel), and oxygen rifle height is improved to blowing rifle position
1.2~1.5 times, until then oxygen blast terminates when carbon content is below 0.05% in molten steel；
Residue adjustment: after oxygen blast, residue adjustment is carried out to terminal clinker, carbonaceous reducing material, carbonaceous is added when residue adjustment into furnace
The additive amount of reducing material is that steel per ton adds 0.8~1.5kg, and carbonaceous reducing material granularity is 10~20mm, controls top blowing oxygen
Rifle nitrogen flushing 0.5~1min of gas agitating, 1.0~1.2m of rifle position, air supply intensity is 1.5~2.0m3/(min·tSteel), when top blast simultaneously
Bottom blowing is stirred for argon gas or nitrogen, 0.01~0.03m of intensity3/(min·tSteel)；After top blast continue bottom blowing stirring 1~
Then 2min taps.
In the method for the present invention, the residue adjustment passes through FeO in addition carbonaceous reducing material and steel slag and reacts C+ (FeO)
=[Fe]+CO ↑, so that FeO in slag is reduced, and the oxygen after FeO is reduced in slag in molten steel is transmitted to clinker, [O]+[Fe]=
(FeO), to reduce the oxygen in molten steel, and at this time since molten steel carbon is lower, carbon content is hardly reduced, and then reduces molten steel
Carbon oxygen product, oxygen rifle nitrogen flushing and bottom blowing stirring are for the dynamic conditions between enhancing steel-slag, mass transfer reaction between promotion steel slag
Quickly carry out.
In the method for the present invention, the purpose that carbonaceous reducing material is added is to carry out residue adjustment, and top blast and bottom blowing purpose are for
It is stirred to realize abundant residue adjustment.Consider residue adjustment cost, generallys use carbon containing carbonaceous reducing material.
Embodiment 1
The 120t converter of certain factory uses semi-steel making, normally blows after converter iron making, and top blow oxygen lance oxygen supply intensity is 3m3/
(min·tSteel), bottom blowing gas intensity 0.03m3/(min·tSteel), blowing oxygen lance position be 1.3m, top blow oxygen lance oxygen blast into
When degree is 90%, reduction top blow oxygen lance oxygen supply intensity is 2m3/(min·tSteel), and oxygen rifle height is improved to 1.95m, until oxygen blast
Terminate.It is 0.05% that endpoint molten steel carbon content is measured at the end of oxygen blast, and molten steel oxygen activity is 650 × 10-6, carbon oxygen product is
0.00325；After oxygen blast, residue adjustment is carried out to terminal clinker, anthracite (carbon content 92%) ton steel is added when residue adjustment into furnace
0.8kg, granularity 10-20mm, top blow oxygen lance nitrogen blowing is stirred 0.5min after residue adjustment, and top blast nitrogen air supply intensity is
1.5m3/(min·tSteel), argon bottom-blowing, intensity 0.01m3/(min·tSteel), top gun uses normal bottom blowing gas after stirring 0.8min
It taps after intensity stirring 1min.
It is 0.04% that carbon content of molten steel is measured before tapping, and molten steel oxygen activity is 450 × 10-6, carbon oxygen product is 0.0018.
Embodiment 2
The 120t converter of certain factory uses semi-steel making, normally blows after converter iron making, and top blow oxygen lance oxygen supply intensity is 3.5m3/
(min·tSteel), bottom blowing gas intensity 0.05m3/(min·tSteel), blowing oxygen lance position be 1.5m, top blow oxygen lance oxygen blast into
When degree is 92%, reduction top blow oxygen lance oxygen supply intensity is 2.3m3/(min·tSteel), and oxygen lance position is improved to 1.8m, until blowing
Oxygen terminates.It is 0.04% that endpoint molten steel carbon content is measured at the end of oxygen blast, and molten steel oxygen activity is 800 × 10-6, carbon oxygen product is
0.0032；After oxygen blast, residue adjustment is carried out to terminal clinker, anthracite (carbon content 92%) ton steel is added when residue adjustment into furnace
1kg, granularity 10-20mm, top blow oxygen lance nitrogen blowing is stirred 0.8min after residue adjustment, and top blast nitrogen air supply intensity is 1.8m3/
(min·tSteel), argon bottom-blowing, intensity 0.02m3/(min·tSteel), top gun uses normal bottom blowing gas intensity after stirring 0.6min
It taps after stirring 1.5min.It is 0.033% that carbon content of molten steel is measured before tapping, and molten steel oxygen activity is 600 × 10-6, carbon oxygen product is
0.00198。
Embodiment 3
The 120t converter of certain factory uses semi-steel making, normally blows after converter iron making, and top blow oxygen lance oxygen supply intensity is 4m3/
(min·tSteel), bottom blowing gas intensity 0.08m3/(min·tSteel), blowing oxygen lance position be 1.8m, top blow oxygen lance oxygen blast into
When degree is 95%, reduction top blow oxygen lance oxygen supply intensity is 2.5m3/(min·tSteel), and oxygen lance position is improved to 2.34m, until blowing
Oxygen terminates.It is 0.032% that endpoint molten steel carbon content is measured at the end of oxygen blast, and molten steel oxygen activity is 1100 × 10-6, carbon oxygen product is
0.00352；After oxygen blast, residue adjustment is carried out to terminal clinker, anthracite (carbon content 93%) ton steel is added when residue adjustment into furnace
1.5kg, granularity 10-20mm, top blow oxygen lance nitrogen blowing is stirred 1min after residue adjustment, and top blast nitrogen air supply intensity is 2.0m3/
(min·tSteel), argon bottom-blowing, intensity 0.03m3/(min·tSteel) stirred using normal bottom blowing gas intensity after top gun stirring 0.9min
It taps after mixing 2min.It is 0.030% that carbon content of molten steel is measured before tapping, and molten steel oxygen activity is 690 × 10-6, carbon oxygen product is
0.00207。
Claims (8)
1. the method for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: the following steps are included:
A, it blows after converter iron making, 3~4m of top blow oxygen lance oxygen supply intensity3/(min·tSteel), 1.3~1.8m of oxygen lance position, bottom
Blow 0.03~0.08m of air supply intensity3/(min·tSteel)；When top blow oxygen lance oxygen blast progress is 90~95%, top blow oxygen lance is controlled
2~2.5m of oxygen supply intensity3/(min·tSteel) and 1.2~1.5 times of oxygen rifle height to rifle position before continue blowing to molten steel carbon and contain
Amount is 0.05% hereinafter, then finishing blowing；
B, carbonaceous reducing material is added, controls top blow oxygen lance nitrogen blowing and bottom blowing gas, 1.0~1.2m of top blast rifle position, intensity 1.5
~2.0m3/(min·tSteel), 0.01~0.03m of bottom blowing gas intensity3/(min·tSteel)；Continue bottom blowing gas extremely after top blast
Tapping.
2. the method according to claim 1 for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: described in step a
Carbonaceous reducing material is anthracite or coke.
3. the method according to claim 1 or 2 for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: in step a,
The granularity of the carbonaceous reducing material is 10~20mm.
4. described in any item methods for reducing converter terminal molten steel carbon oxygen product according to claim 1~3, it is characterised in that: step
In rapid a, the additive amount of the carbonaceous reducing material is 0.8~1.5kg/tSteel。
5. the method according to any one of claims 1 to 4 for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: step
In rapid a, the gas of the bottom blowing gas is argon gas or nitrogen.
6. described in any item methods for reducing converter terminal molten steel carbon oxygen product according to claim 1~5, it is characterised in that: step
In rapid b, the gas of the bottom blowing gas is argon gas or nitrogen.
7. the method according to claim 1 for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: described in step b
The time of top blast is 0.5~1min.
8. the method according to claim 1 for reducing converter terminal molten steel carbon oxygen product, it is characterised in that: described in step b
The time for continuing bottom blowing is 1~2min.
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| CN112626312A (en) * | 2020-12-14 | 2021-04-09 | 山东钢铁集团日照有限公司 | Low-carbon aluminum killed steel Al for reducing RH single process2O3Method of inclusion |
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