CN108300836B - Composite deoxidizer - Google Patents
Composite deoxidizer Download PDFInfo
- Publication number
- CN108300836B CN108300836B CN201810161576.4A CN201810161576A CN108300836B CN 108300836 B CN108300836 B CN 108300836B CN 201810161576 A CN201810161576 A CN 201810161576A CN 108300836 B CN108300836 B CN 108300836B
- Authority
- CN
- China
- Prior art keywords
- carbonate
- magnesium
- deoxidizer
- oxide
- deoxidation
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention provides a novel deoxidizer for steelmaking of a converter and a refining furnace, wherein the composite deoxidizer comprises carbonate, alkaline oxide, expanded graphite and a magnesium treating agent, and the magnesium treating agent is passivated magnesium particles. The composite deoxidizer can form a plurality of small slag drops in the smelting process of a converter tapping station and an LF refining furnace station, quickly reacts with oxides generated by deoxidation to form compounds to form a slag washing process, and simultaneously, the carbonate and the expanded graphite release air bubbles when being heated, and can adhere impurities to float upwards, thereby achieving the purposes of purifying molten steel and improving quality.
Description
Technical Field
The invention relates to the field of converter steelmaking, in particular to molten steel deoxidation and inclusion removal.
Background
The non-metallic inclusions in the steel are mainly compounds formed by metal elements such as iron, manganese, chromium, aluminum, titanium and the like and oxygen, sulfur, nitrogen and the like. Wherein the oxide is mainly a deoxidation product, including a primary deoxidation product which cannot float upwards and a deoxidation product formed by a deoxidation reaction (secondary oxidation) in the molten steel solidification process; or due to slag, refractories, etc. mixed into the steel. The existence of the non-metallic inclusion destroys the continuity of a steel matrix, causes the nonuniformity of a steel structure, and has certain influence on various properties of the steel, such as the reduction of the strength, the toughness and the like of the steel. The non-metallic inclusions are mainly sulfides (MnS, FeS, etc.), oxides (FeO, MnO, CaO, Al)2O3Etc.), silicates and nitrides (TiN, AlN), etc.
Chinese patent application CN105950826A discloses a deoxidizer of refining slag of a ladle refining furnace and a use method thereof, wherein the deoxidizer of the refining slag comprises the following components: CaCO3：10～30％，Al2O3: 30-60%, Al: 10-35%, and others: less than or equal to 5 percent, which are all mass percent. The refining slag deoxidizer is added in the slagging process of the ladle refining furnace, so that the refining slag has higher capabilities of desulfurizing and adsorbing impurities, and the TFe + MnO after slagging is less than 1%.
The Chinese patent application CN102344992A discloses a compound deoxidizer used in steel making, which comprises the following chemical components in percentage by mass: more than or equal to 14 percent of Si, more than or equal to 14 percent of Ca, more than or equal to 25 percent of Al, less than or equal to 0.06 percent of P, less than or equal to 0.08 percent of S, less than or equal to 0.10 percent of As and less than or equal to 0.01 percent of Pb. The use method of the compound deoxidizer comprises the following steps: in the tapping process, when tapping is started, the composite deoxidizer is added into molten steel, the adding method mainly comprises hand casting, and the adding amount is added according to the following standard requirements: when the carbon of the converter steel is more than 0.06 percent, the adding amount of the compound deoxidizer is 1.8-2.0kg/t steel; when the carbon content of the converter steel is between 0.04 and 0.06 percent, the high addition amount of the compound deoxidizer is 2.0 to 2.2kg/t steel; when the carbon of the converter steel is less than 0.04%, the adding amount of the compound deoxidizer is 2.2-2.4kg/t steel.
The aforesaid patent applications, however, relate to technical solutions that involve various technical problems that have been pointed out above and that need to be overcome.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a novel compound deoxidizer and a corresponding method for preparing the compound deoxidizer.
The invention firstly provides a novel composite deoxidizer which comprises carbonate, alkaline oxide, expanded graphite and a magnesium treating agent, wherein the carbonate is calcium carbonate, the alkaline oxide is calcium oxide, and the magnesium treating agent is passivated magnesium particles.
As a better choice of the composite deoxidizer, the mass ratio of the carbonate, the alkaline oxide, the expanded graphite and the magnesium treating agent is 20-30: 20-30: 35-45: 4-8. The composite deoxidizer can also contain other impurities which do not influence smelting, for example, the composite deoxidizer contains 7 percent of impurities which do not influence smelting.
As a better choice of the composite deoxidizer, the carbonate is magnesium carbonate or calcium carbonate. When the carbonate is generally heated below 1500 ℃, the carbonate can be broken and decomposed to release fine CO2The bubbles and the similar adherent inclusions float upward.
As a better choice of the composite deoxidizer, the content of the carbonate in the novel composite deoxidizer is 20 to 30 weight percent. The carbonate may be provided in the following manner: the carbonate is first ground and then granulated. The carbonate obtained in the above manner is thermally expanded into individual onesThe small particles participate in the reaction, all the reactions are the dissociation of large particle substances according to the metallurgy transmission theory, then the particles can participate in the reaction from macromolecules to small molecules, atoms or atomic groups, the carbonate in the composite deoxidizer provided by the invention can rapidly expand and dissociate to participate in the reaction, and the carbonate can form a plurality of small slag drops after being heated, can rapidly react with oxides generated by deoxidation to form a compound, and achieves the purpose of slag washing. When the carbonate is generally heated below 1500 ℃, the carbonate can be broken and decomposed to release fine CO2The bubbles and the similar adherent inclusions float upward.
As a better choice of the composite deoxidizer, the basic oxide is magnesium oxide, magnesium carbonate, calcium oxide or calcium carbonate.
As a better choice of the composite deoxidizer, the expanded volume ratio of the expanded graphite is 150-200 mL/g. The carbon in the composite deoxidizer is graphite with larger expansion volume ratio, the graphite is crushed to 500 meshes, and the graphite is synthesized with carbonate and the like by adopting a mechanochemical reaction principle, and the existing form of the graphite is a form of lamellar graphite fine particles. The carbon deoxidation has the advantages that the deoxidation amount is large (the carbon deoxidation amount of 1kg is larger than the deoxidation amount of aluminum of 1 kg), the product after the deoxidation is micro CO bubbles which can escape from the middle of molten steel and does not pollute the molten steel, and meanwhile, when the CO bubbles escape from the middle of the molten steel, impurities adhered to the middle of the molten steel can float upwards to remove the impurities. The novel composite deoxidizer is characterized by rapid decomposition after being heated, dispersion after decomposition into a plurality of small particles for diffusion, rapid participation in the deoxidation of molten steel, and compared with industrial calcium carbide, the deoxidation speed and the influence on the recarburization of the molten steel are superior to that of the industrial calcium carbide.
As a better choice of the composite deoxidizer, the alkaline oxide is calcium oxide, the expansion volume ratio of the expanded graphite is 150-200mL/g, and the magnesium treating agent is passivated magnesium particles; the mass ratio of the carbonate to the alkaline oxide to the expanded graphite to the magnesium treating agent is 23: 23: 41: 6, and the others are 7% impurities.
In the invention, the novel composite deoxidizer is added with passivated magnesium particles and can be mixed with molten steelThe alumina reacts to form smaller particle magnesium aluminate spinel with CO adhesion2Floating on the bubbles or the argon bubbles. Even if the inclusions can not float upwards, the inclusions are remained in the middle of molten steel, and the harmfulness of the inclusions is much smaller than that of alumina inclusions.
The mechanism of deoxidation using the composite deoxidizer of the invention is as follows:
the bubbles in the molten steel are small in size, so that the collision probability of the bubbles and the inclusions can be increased, and the removal efficiency of the inclusions is improved; the existence of fine slag droplets has a slag washing effect. The expanded graphite added in the product can react with free oxygen or a pumice body (ferric oxide) in the middle of molten steel after being heated to form CO bubbles, so that the CO bubbles can deoxidize and form small bubbles adhered with inclusions, and the purification of the molten steel is facilitated. By introducing carbonate into the molten steel, the carbonate can generate tiny CO in the molten steel after being heated and decomposed2The bubbles and the small bubbles not only can make the components and the temperature of the molten steel uniform, but also can directly remove the inclusions through the capturing and adsorbing actions of the bubbles.
The invention can realize the smelting process at the converter tapping station and the LF refining furnace station, can form a plurality of small slag drops, quickly react with oxides generated by deoxidation to form compounds to form a slag washing process, and simultaneously, the carbonate and the expanded graphite release air bubbles when being heated, can adhere impurities to float upwards, thereby achieving the purposes of purifying molten steel and improving quality.
Detailed Description
The following are examples of the present invention, which are intended to be illustrative of the invention only and not limiting.
The following embodiments provide a novel composite deoxidizer including a carbonate, a basic oxide, expanded graphite, and a magnesium treating agent, the carbonate being calcium carbonate, the basic oxide being calcium oxide, the magnesium treating agent being passivated magnesium particles; the mass ratio of the carbonate to the alkaline oxide to the expanded graphite to the magnesium treating agent is 20-30: 20-30: 35-45: 4-8. The composite deoxidizer can also contain other impurities which do not influence smelting, for example, other 7 percent of impurities in the composite deoxidizer.
The carbonate may be magnesium carbonate, and the corresponding basic oxide may be magnesium oxide, magnesium carbonate, or calcium hydrochloride, but the use of a magnesium-containing material can achieve the same effect as a corresponding calcium-containing material, but significantly increases the cost of the enterprise, and therefore the following examples will be described only with the carbonate as calcium carbonate and the basic oxide as calcium oxide.
In the raw materials used in the following examples, the mass ratio of the carbonate, the basic oxide, the expanded graphite, and the magnesium treatment agent was 23: 23: 41: 6, and the others are 7% impurities. Of course, the mass ratio of the carbonate, the basic oxide, the expanded graphite and the magnesium treating agent can also be 20-30: 20-30: 35-45: 4-8, and can obtain better technical effect on the premise of providing purer raw materials.
The process of deoxidation by the deoxidizer of the invention is as follows:
(1) when tapping of the converter is started, the molten steel in the steel ladle reaches about 10t, a novel compound deoxidizer is added, and steel core aluminum, alloy, slag auxiliary materials, lime and the like are added.
(2) The addition is completed before the molten steel is poured out to four fifths of the tapping amount. If the steel tapping hole of the converter is bigger than normal, the adding speed can be increased, and the adding is stopped after the molten steel is completely discharged;
(3) the use amount suggests that: the carbon content W [ C ] at the converter tapping terminal point is less than 0.10 percent, and 2kg of steel is added per ton; w < C > 0.10%, the amount of steel used per ton is 1.5 kg;
(4) the operation method of adding the product into the bottom of the ladle at one time and then tapping is forbidden, so that the safety accident caused by violent boiling of molten steel is prevented.
(5) The deoxidation in the LF refining process is mainly diffusion deoxidation and composition adjustment. In the process, the novel composite deoxidizer is used, so that the alkalinity of the slag can be rapidly improved, the foaming of the slag is facilitated, the atmosphere in the furnace is maintained, and meanwhile, the magnesium content in the middle of the deoxidizer is beneficial to rapidly increasing the alkalinity and viscosity of the slag, and the deoxidizer is beneficial to smelting operation and protection of a steel ladle slag line.
The using method in the LF refining process is the same as that of calcium carbide, and the calcium carbide can be replaced and used in an equivalent manner.
The novel composite deoxidizer is adopted for deoxidation, and has the following advantages:
⑴ tapping molten steel to 10t, adding the molten steel, heating and disintegrating into N fine particles, wherein the expanded graphite carbon participates in the carbon deoxidation reaction to produce dispersed CO/CO2The bubbles float upwards. The carbonate in the middle of the sphere forms N small slag drops which become the best deoxidation substance for slag washing molten steel;
⑵ because the deoxidation speed of aluminum is much higher than that of carbon, after steel core aluminum is added, the deoxidation reaction produces fine dispersed Al2O3Particles, will adhere to CO/CO generated by deoxidation2The surface of the bubble floats upwards, which is beneficial to dispersed Al2O3Removing;
⑶ small slag drops formed by carbonate in the middle of the sphere, Al generated by deoxidation with aluminium2O3The particles react to form calcium aluminate with low melting point, which is beneficial to floating removal;
⑷ it has been proved by the present study that the desulfurization reaction of molten steel, the product CaS of the desulfurization reaction, is reacted with 12 CaO.7 Al2O3Form the compound 11 CaO.7 Al2O3CaS, then floating upward, and according to the principle of chemical reaction equilibrium movement, using the novel oxygen composite deoxidizer is beneficial to the desulfurization reaction;
⑸ compared with calcium carbide, the product has unique advantages in storage and use, no safety risk, and superior deoxidation effect to that of calcium carbide;
⑹ the cost of steel-making ton steel can be reduced by using the product in the middle of the steel-making process;
⑺ the product can reduce the operation difficulty of argon blowing and calcium treatment wire feeding process for removing inclusions in the steel-making process and improve the quality of molten steel.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (4)
1. A composite deoxidizer is characterized in that: the composite deoxidizer comprises carbonate, alkaline oxide, expanded graphite and a magnesium treating agent, wherein the magnesium treating agent is passivated magnesium particles;
the mass ratio of the carbonate to the alkaline oxide to the expanded graphite to the magnesium treating agent is 20-30: 20-30: 35-45: 4-8;
the expansion volume ratio of the expanded graphite is 150-200 mL/g.
2. The composite deoxidizer of claim 1, wherein the carbonate is magnesium carbonate or calcium carbonate.
3. The composite deoxidizer of claim 1, wherein the basic oxide is magnesium oxide or calcium oxide.
4. The composite deoxidizer of claim 1, wherein the basic oxide is calcium oxide, and the mass ratio of the carbonate, the basic oxide, the expanded graphite and the magnesium treating agent is 23: 23: 41: 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810161576.4A CN108300836B (en) | 2018-02-27 | 2018-02-27 | Composite deoxidizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810161576.4A CN108300836B (en) | 2018-02-27 | 2018-02-27 | Composite deoxidizer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108300836A CN108300836A (en) | 2018-07-20 |
| CN108300836B true CN108300836B (en) | 2020-01-17 |
Family
ID=62848956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810161576.4A Active CN108300836B (en) | 2018-02-27 | 2018-02-27 | Composite deoxidizer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108300836B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110331255B (en) * | 2019-08-09 | 2020-11-20 | 王强 | Precipitation deoxidation method of low-carbon aluminum killed steel |
| CN111850238B (en) * | 2020-07-23 | 2021-11-02 | 芜湖县天海耐火炉料有限公司 | Deoxidizer for smelting metal waste residues and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU404866A1 (en) * | 1972-05-18 | 1973-10-22 | ||
| JPS5212656B2 (en) * | 1972-03-13 | 1977-04-08 |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100535133C (en) * | 2006-12-30 | 2009-09-02 | 李继宗 | Steel making lime additive and its production process |
| CN102827999B (en) * | 2011-06-14 | 2014-09-03 | 鞍钢股份有限公司 | Magnesium deoxidation composite powder for molten steel deoxidation and preparation method thereof |
| CN105177223B (en) * | 2015-08-25 | 2017-06-30 | 新疆中合大正商贸有限公司 | The technique that a kind of magnesium calcium carbon ball is used for LF steel-making |
| CN105296707A (en) * | 2015-11-30 | 2016-02-03 | 新疆中合大正商贸有限公司 | Process of calcium carbonate carbon balls for converter or electric furnace steel tapping deoxidation |
-
2018
- 2018-02-27 CN CN201810161576.4A patent/CN108300836B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5212656B2 (en) * | 1972-03-13 | 1977-04-08 | ||
| SU404866A1 (en) * | 1972-05-18 | 1973-10-22 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108300836A (en) | 2018-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102586543B (en) | Steel ladle slag reducing agent with high calcium oxide content, and preparation method thereof | |
| CN102199684A (en) | Production method of ultralow-oxygen titanium-containing ferrite stainless steel | |
| CN101935740B (en) | White slag refining agent for LF (Ladle Furnace) refining furnace and preparation method thereof | |
| CN108300836B (en) | Composite deoxidizer | |
| WO2013134889A1 (en) | Process for producing low-cost clean steel | |
| CN103103312B (en) | The sulfur method of semisteel desulfurizing agent and this sweetening agent of use | |
| CN108359910B (en) | Method for manufacturing low-carbon low-silicon aluminum killed steel composite purifying agent alloy | |
| TWI664294B (en) | Dephosphorization method of molten iron | |
| CN106119462A (en) | A kind of Al base ladle top slag modifier and the method improving its utilization rate | |
| JP2012087002A (en) | Steelmaking slag and manufacturing method of the same | |
| JP5341849B2 (en) | Manufacturing method of recycled slag | |
| CN111020115A (en) | Method for refining molten steel outside furnace by using liquid blast furnace slag | |
| JP6658049B2 (en) | Hot metal desiliconization method | |
| KR100226901B1 (en) | Desulphurization agent of molten metal | |
| US3954446A (en) | Method of producing high duty cast iron | |
| KR100557004B1 (en) | The additive made of Al-dross for desulfurizing | |
| CN115418441B (en) | Efficient denitrification agent and denitrification method for converter tapping process | |
| KR100328016B1 (en) | Composition for simultaneous desiliconization and desulfurization of hot metal | |
| CN113151638B (en) | Composite molten steel purifying agent and preparation method thereof | |
| CN103320575A (en) | Molten-steel desulphurization dephosphorization treatment agent and preparation method | |
| RU2181382C2 (en) | Method of desulfurization of liquid cast iron | |
| JP7338663B2 (en) | Method for producing chromium-containing molten iron | |
| KR101863916B1 (en) | Composition of Steelmaking Flux for Desulfurization and Deoxidation Using By-proudut of Magnesium Smelting Process and Waste By-product of Aluminum Smelting Process | |
| CN117925949A (en) | High-efficiency slag melting agent for steelmaking and preparation method thereof | |
| KR100436652B1 (en) | Flux having Low Melting Point for controlling Slag Foaming and having Dephosophorizing ability in BOF Refining |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |