CN110616286A - Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace - Google Patents
Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace Download PDFInfo
- Publication number
- CN110616286A CN110616286A CN201911054569.5A CN201911054569A CN110616286A CN 110616286 A CN110616286 A CN 110616286A CN 201911054569 A CN201911054569 A CN 201911054569A CN 110616286 A CN110616286 A CN 110616286A
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- molten iron
- iron
- blast furnace
- increasing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
Abstract
The invention provides a method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron, which relates to the technical field of blast furnace ironmaking and comprises the following steps: 1) taking a certain amount of nitrogen increasing agent, uniformly mixing, and then making a core-spun yarn on a core-spun machine by using a thin steel plate; 2) adding the nitrogen increasing agent core-spun yarn into molten iron of a tapping branch iron runner in front of a blast furnace in a yarn feeding mode by using a yarn feeding machine; 3) the molten iron flows along the branch iron runner and falls into the open type molten iron tank to carry out nitrogen increasing reaction; 4) and after the nitrogen increasing is finished, removing the nitrogen increasing slag by using a slag raking machine. The nitrogen increasing agent is added in a simple mode, is flexible, uniform and accurate in quantity adjustment, does not change the existing blast furnace production mode and flow, provides dynamic conditions by means of molten iron flowing and falling after the nitrogen increasing agent is added, enables the nitrogen increasing agent and the molten iron to be fully mixed, enables the reaction to be fully carried out, and is high in yield and strong in adaptability to industrial production.
Description
Technical Field
The invention relates to the technical field of blast furnace ironmaking, in particular to a method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron furnace.
Background
The high-purity pig iron is the pig iron which is specially used for producing high-quality castings and has low contents of elements such as Ti, Mn, S, P and the like and few contents of specific trace elements.
At present, the smelting method of high-purity pig iron mainly comprises an oxidation method and a concentrate method. The refining method is mostly adopted in China. However, with the continuous decrease of high-quality raw materials, the phenomenon of 'impurity' in the production of high-purity pig iron by a concentrate method is more prominent, and the standard exceeding of Ti element is the most typical. With the increasing shortage of low Ti concentrate, the quality of high-purity pig iron is reduced due to the excessive Ti content.
Ti is a relatively active element, and is easy to form Ti (N, C) solid solution compound with C and N in the molten iron to precipitate, thereby reducing the content of [ Ti ] in the molten iron. From the thermodynamic analysis, the carbon content of pig iron is close to saturation, and then the formation of Ti (N, C) solid solution in the molten iron is influenced by the combination of [ Ti ], [ N ] and temperature. When the content of Ti and the temperature of molten iron are fixed, the higher the content of N in the molten iron is, the more TiN is precipitated. At the interface of slag and iron in the blast furnace hearth, because of the covering of the slag layer, the molten iron does not directly contact with furnace gas, nitrogen in the furnace gas can only be dissolved in slag and then reaches the interface of the slag and iron through the slag layer, and the resistance of the mass transfer process is very large, so that the low content of the molten iron [ N ] becomes a restrictive link of TiN precipitation under the internal process conditions of the existing blast furnace.
Therefore, without changing the existing production mode and flow of high-purity pig iron, it is necessary to develop a method for increasing nitrogen in the molten iron before the blast furnace smelting of high-purity pig iron, so as to increase nitrogen in the molten iron outside the furnace, promote the [ Ti ] and [ N ] in the molten iron to be fully combined to precipitate more TiN and remove the TiN, and achieve the purpose of reducing the content of the [ Ti ] in the molten iron.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides a method for increasing nitrogen in molten iron before a blast furnace smelting high-purity pig iron furnace, which is used for fully combining [ Ti ] and [ N ] in the molten iron to precipitate more TiN and remove the TiN by increasing the [ N ] content in the molten iron so as to achieve the purpose of reducing the [ Ti ] content in the molten iron.
(II) technical scheme
In order to achieve the purpose, the invention is realized by the following technical scheme:
a method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron furnace comprises the following steps:
1) taking a certain amount of nitrogen increasing agent, uniformly mixing, and then making a core-spun yarn on a core-spun machine by using a thin steel plate;
2) adding the nitrogen increasing agent core-spun yarn into molten iron of a tapping branch iron runner in front of a blast furnace in a yarn feeding mode by using a yarn feeding machine;
3) the molten iron flows along the branch iron runner and falls into the open type molten iron tank to carry out nitrogen increasing reaction;
4) and after the nitrogen increasing is finished, removing the nitrogen increasing slag by using a slag raking machine.
Furthermore, the chemical components and contents of the nitrogen increasing agent are as follows: 30% -40%, Si: 60 to 70 percent.
Further, the nitrogen increasing agent is powder with the density of 2.5-3.5 g/cm3。
Furthermore, the maximum particle size of the solid material of the nitrogen increasing agent is less than or equal to 2.0mm, and the particle size of less than 200 meshes accounts for 60-90%.
Further, the mass ratio of the nitrogen increasing agent to the molten iron is 0.5-1.0: 2000.
further, the wire feeding speed of the wire feeding machine is 0.05-0.15 m/s, the mixing speed of the nitrogen increasing agent is 0.02-0.15 kg/s, the mixing amount is 0.3-1.0 kg/t, and the wire feeding process is accompanied with the tapping process of the blast furnace.
Further, in the step 1), the thickness of the thin steel plate for preparing the core-spun yarn is 0.8-1.2 mm, the width is 35-70 mm, the length is 40-80 m, and the diameter of the prepared core-spun yarn is 10-20 mm.
Further, the temperature of the molten iron in the step 2) is 1450-1530 ℃, and the temperature of the molten iron is reduced by 50-80 ℃ during the period of adding the nitrogen increasing agent into the slag removing period.
Further, the tapping iron supporting groove in the front of the blast furnace is positioned behind the slag-iron separation skimmer and in front of the swing spout.
(III) advantageous effects
The invention provides a method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron, which has the following beneficial effects:
1. the nitrogen increasing agent is added in a branch iron runner of a blast furnace front iron tapping, the nitrogen increasing agent belongs to a non-sealed container, a wire feeding machine is adopted to uniformly convey the nitrogen increasing agent, the nitrogen increasing agent is added and then dynamic conditions are provided by the flowing and falling of molten iron, the reaction is fully carried out, no stirring, blowing and other equipment is needed, the temperature drop, the component and other changes of the molten iron after the reaction have no influence on the subsequent procedures, and the operation is simple.
2. The nitrogen increasing agent has small consumption, no special requirement on slag components, good adaptability, small slag raking amount, and the molten iron components and the temperature drop meet the requirements of the subsequent procedures.
3. The method has the advantages of simple adding mode and operation of the nitrogen increasing agent, uniform and accurate adding quantity, flexible adjustment, no change of the existing blast furnace production mode and flow, and the nitrogen increasing agent provides dynamic conditions by the flowing and falling of molten iron after being added, so that the nitrogen increasing agent and the molten iron are fully mixed, the reaction is fully carried out, the yield of the nitrogen increasing agent is high, and the industrial production adaptability is strong.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
in this example, the molten iron is 142m3High purity pig iron conventional molten iron produced by blast furnace, N in molten iron]The content is 0.0040-0.0050%; the method for adding the nitrogen increasing agent into the molten iron in front of the blast furnace comprises the following steps:
after tapping the blast furnace, a first iron sample was taken from the open ladle and tested for composition before adding the nitrogen increasing agent.
Preparing nitrogen increasing agent according to 0.5kg/t molten iron, wherein the chemical composition and content of the nitrogen increasing agent are that N is 37.5 percent, Si is 62.5 percent, and the density is 3.0g/cm3The maximum grain size is less than or equal to 1.5mm, and the grain size of less than 200 meshes accounts for 70 percent. A core-spun core with the diameter of 15.0mm is prepared by adopting a steel plate with the thickness of 1mm, the width of 54mm and the length of 60m on a core-spun machineA wire.
And (3) coiling the prepared core-spun yarn on a fixed disc of a yarn feeding machine, feeding the core-spun yarn into molten iron in a tapping branch iron runner in front of a blast furnace at a uniform speed of 0.08m/s, enabling the molten iron to flow along the branch iron runner and fall into an open molten iron tank for nitrogen increasing reaction, conveying the molten iron in one tank of the open molten iron tank to a desulfurization station for about 60t after 12 minutes of yarn feeding, skimming, taking a second iron sample, and detecting components.
The blast furnace branch iron runner is positioned behind the slag-iron separation skimmer and in front of the swing spout.
As a result of the detection, the content of [ N ] in the molten iron before nitrogen addition was 0.0042%, the content of [ N ] in the molten iron after nitrogen addition was 0.0078%, and the content of [ N ] was increased by 85.7%.
Example 2:
in this embodiment, the molten iron is 410m3High purity pig iron conventional molten iron produced by blast furnace, N in molten iron]The content is 0.0040-0.0050%; the method for adding the nitrogen increasing agent into the molten iron in front of the blast furnace comprises the following steps:
after tapping the blast furnace, a first iron sample was taken from the open ladle and tested for composition before adding the nitrogen increasing agent.
Preparing nitrogen increasing agent according to 0.8kg/t molten iron, wherein the chemical components and content of the nitrogen increasing agent are 39.0 percent of N, 61.0 percent of Si and 2.8g/cm of density3The maximum grain size is less than or equal to 1.5mm, and the grain size of less than 200 meshes accounts for 60 percent. A core-spun yarn with the diameter of 19.1mm is prepared by adopting a steel plate with the thickness of 0.8mm, the width of 65mm and the length of 80m on a core-spun machine.
And (3) coiling the prepared core-spun yarn on a fixed disc of a yarn feeding machine, feeding the core-spun yarn into molten iron in a tapping branch iron runner in front of a blast furnace at a uniform speed of 0.06m/s, enabling the molten iron to flow along the branch iron runner and fall into an open molten iron tank for nitrogen increasing reaction, conveying the molten iron in one tank of the open molten iron tank to a desulfurization station for about 80t after feeding the yarn for 22 minutes, skimming, taking a second iron sample, and detecting components.
The blast furnace branch iron runner is positioned behind the slag-iron separation skimmer and in front of the swing spout.
As a result of the detection, the content of [ N ] in the molten iron before nitrogen addition was 0.0046%, the content of [ N ] in the molten iron after nitrogen addition was 0.0083%, and the content of [ N ] was increased by 80.4%.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron furnace is characterized by comprising the following steps:
1) taking a certain amount of nitrogen increasing agent, uniformly mixing, and then making a core-spun yarn on a core-spun machine by using a thin steel plate;
2) adding the nitrogen increasing agent core-spun yarn into molten iron of a tapping branch iron runner in front of a blast furnace in a yarn feeding mode by using a yarn feeding machine;
3) the molten iron flows along the branch iron runner and falls into the open type molten iron tank to carry out nitrogen increasing reaction;
4) and after the nitrogen increasing is finished, removing the nitrogen increasing slag by using a slag raking machine.
2. The method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the nitrogen increasing agent comprises the following chemical components in percentage by weight: 30% -40%, Si: 60 to 70 percent.
3. The method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the nitrogen increasing agent is powder and has a density of 2.5-3.5 g/cm3。
4. The method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the maximum particle size of solid materials of the nitrogen increasing agent is less than or equal to 2.0mm, and the particle size of the solid materials of the nitrogen increasing agent is less than 200 meshes and accounts for 60-90%.
5. The method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the mass ratio of the nitrogen increasing agent to the molten iron is 0.5-1.0: 2000.
6. the method for increasing nitrogen content in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the wire feeding speed of the wire feeding machine is 0.05-0.15 m/s, the adding speed of the nitrogen increasing agent is 0.02-0.15 kg/s, the adding amount is 0.3-1.0 kg/t, and the wire feeding process is accompanied with the blast furnace tapping process.
7. The method for increasing nitrogen in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein in the step 1), the thickness of a thin steel plate for preparing the core-spun yarn is 0.8 mm-1.2 mm, the width is 35 mm-70 mm, the length is 40 m-80 m, and the diameter of the prepared core-spun yarn is 10 mm-20 mm.
8. The method for increasing nitrogen content in molten iron in front of a blast furnace smelting high-purity pig iron according to claim 1, wherein the temperature of the molten iron in the step 2) is 1450-1530 ℃, and the temperature of the molten iron is reduced by 50-80 ℃ during the period of adding the nitrogen increasing agent into the slag removing period.
9. The method for increasing nitrogen in stokehole molten iron of high-purity pig iron produced by blast furnace smelting according to claim 1, wherein the stokehole tapping runner is located after the slag-iron separation skimmer and before the oscillating nozzle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911054569.5A CN110616286A (en) | 2019-10-31 | 2019-10-31 | Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911054569.5A CN110616286A (en) | 2019-10-31 | 2019-10-31 | Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110616286A true CN110616286A (en) | 2019-12-27 |
Family
ID=68927187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911054569.5A Pending CN110616286A (en) | 2019-10-31 | 2019-10-31 | Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110616286A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111334626A (en) * | 2020-03-17 | 2020-06-26 | 安徽工业大学 | Method for promoting TiN phase precipitation in high-purity molten iron outside blast furnace |
| CN111809142A (en) * | 2020-07-21 | 2020-10-23 | 安徽工业大学 | Method for promoting generation and clustering of TiN in high-purity pig iron |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000204405A (en) * | 1999-01-13 | 2000-07-25 | Kawasaki Steel Corp | Operation of blast furnace |
| CN102876960A (en) * | 2012-09-15 | 2013-01-16 | 内蒙古包钢钢联股份有限公司 | Method for increasing nitrogen content in YQ450NQR1 steels |
| CN108329042A (en) * | 2018-05-11 | 2018-07-27 | 鞍钢股份有限公司 | A kind of high nitrogen type titaniferous environmental-protection furnace stemming |
| CN110229943A (en) * | 2019-07-15 | 2019-09-13 | 安徽工业大学 | The Adding Way of removing titanium in molten iron agent before a kind of State of Blast Furnace |
| CN110283952A (en) * | 2019-08-05 | 2019-09-27 | 安徽工业大学 | A kind of blast furnace process high-purity pig iron molten iron nitrogen promoter and increasing method for nitrogen |
-
2019
- 2019-10-31 CN CN201911054569.5A patent/CN110616286A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000204405A (en) * | 1999-01-13 | 2000-07-25 | Kawasaki Steel Corp | Operation of blast furnace |
| CN102876960A (en) * | 2012-09-15 | 2013-01-16 | 内蒙古包钢钢联股份有限公司 | Method for increasing nitrogen content in YQ450NQR1 steels |
| CN108329042A (en) * | 2018-05-11 | 2018-07-27 | 鞍钢股份有限公司 | A kind of high nitrogen type titaniferous environmental-protection furnace stemming |
| CN110229943A (en) * | 2019-07-15 | 2019-09-13 | 安徽工业大学 | The Adding Way of removing titanium in molten iron agent before a kind of State of Blast Furnace |
| CN110283952A (en) * | 2019-08-05 | 2019-09-27 | 安徽工业大学 | A kind of blast furnace process high-purity pig iron molten iron nitrogen promoter and increasing method for nitrogen |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111334626A (en) * | 2020-03-17 | 2020-06-26 | 安徽工业大学 | Method for promoting TiN phase precipitation in high-purity molten iron outside blast furnace |
| CN111809142A (en) * | 2020-07-21 | 2020-10-23 | 安徽工业大学 | Method for promoting generation and clustering of TiN in high-purity pig iron |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110295261B (en) | Smelting method of high-manganese steel-making molten iron | |
| CN110616286A (en) | Method for increasing nitrogen in molten iron in front of blast furnace smelting high-purity pig iron furnace | |
| CN112267004A (en) | Smelting method of low-cost clean steel | |
| CN111057944A (en) | Nickel-saving austenitic stainless steel and method for producing nickel-saving austenitic stainless steel by using laterite nickel ore | |
| CN110512044A (en) | A kind of smelting process of high-purity pig iron | |
| CN105695664A (en) | Low-cost converter steelmaking deoxidization process | |
| CN102827997A (en) | Calcium carbide ferro-aluminium alloy used for smelting steel, and preparation method thereof | |
| CN103060523A (en) | Smelting method for non-magnetic stainless steel | |
| CN108193123B (en) | Corrosion-resistant steel bar and preparation method thereof | |
| CN110229943A (en) | The Adding Way of removing titanium in molten iron agent before a kind of State of Blast Furnace | |
| CN101413044B (en) | Alloy addition method for improving yield of ferromolybdenum | |
| EP2039788A1 (en) | Dephosphorization method in the process of smelting ni-cr pig iron from a nickel oxide ore | |
| CN110643760B (en) | Ultrahigh Al2O3Blast furnace smelting method of furnace slag | |
| CN109576441B (en) | RH refining method for controlling wettability of inclusions in low-carbon aluminum killed steel | |
| CN110453137B (en) | Smelting method of low-silicon low-aluminum steam turbine rotor steel | |
| CN111235349A (en) | Method for producing silicon-vanadium alloy by smelting vanadium-rich slag and silicon-vanadium alloy | |
| CN102010930B (en) | Method for smelting mirror plastic mould steel | |
| CN104946850B (en) | A kind of converter tapping uses low Al alumina balls wash heat method | |
| CN101550465A (en) | Manganese-based fluxing agent for converter steelmaking and preparation method thereof | |
| CN102876851B (en) | Method for improving calcium yield of RH vacuum furnace | |
| CN111334626A (en) | Method for promoting TiN phase precipitation in high-purity molten iron outside blast furnace | |
| CN108715972A (en) | A kind of low-phosphorous silicon iron product and its smelting process | |
| CN114908217A (en) | Low-cost structural steel smelting process | |
| CN104593543A (en) | Steelmaking method | |
| LU500726B1 (en) | Method for promoting precipitation of tin phase in high-quality molten iron outside blast furnace |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20191227 |
|
| RJ01 | Rejection of invention patent application after publication |