CN112553409B - Vanadium-titanium-containing molten iron slag conglomeration agent and preparation method thereof - Google Patents
Vanadium-titanium-containing molten iron slag conglomeration agent and preparation method thereof Download PDFInfo
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- CN112553409B CN112553409B CN202011451225.0A CN202011451225A CN112553409B CN 112553409 B CN112553409 B CN 112553409B CN 202011451225 A CN202011451225 A CN 202011451225A CN 112553409 B CN112553409 B CN 112553409B
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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
- 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
- C21C7/064—Dephosphorising; Desulfurising
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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Abstract
The invention discloses a vanadium-titanium-containing molten iron slag conglomeration agent, which is characterized by comprising the following raw materials in parts by weight: 20-40 parts of calcium oxide, 20-40 parts of aluminum oxide, 10-30 parts of porous silicon dioxide and 10-20 parts of fiber gypsum particles. The porous silica is spherical particles, the average particle size is 1-2mm, and the average size of the fibrous gypsum particles is 3-5mm. The use method of the slag conglomeration agent comprises the following steps: after desulfurization pretreatment of the vanadium-titanium-containing molten iron, adding a slag conglomeration agent before slagging off, adding the slag conglomeration agent for the second time when the amount of the desulfurized slag is 20-30% of the original mass, and slagging off again. The slag conglomeration agent has good spreadability, can gather the thin slag to form a slag block with larger volume, and brings convenience for slag skimming.
Description
Technical Field
The invention belongs to the technical field of steel smelting, and particularly relates to a vanadium-titanium molten iron slag conglomeration agent which can effectively reduce the desulphurization slagging iron loss of vanadium-titanium-containing molten iron and simultaneously reduce the sulfur return amount of the desulfurized vanadium-titanium-containing molten iron.
Background
The vanadium-titanium-containing molten iron is usually obtained by blast furnace smelting, and in the tapping process of the blast furnace, part of blast furnace slag enters the molten iron tank along with the vanadium-titanium-containing molten iron, so that the vanadium-titanium-containing molten iron generally has a large amount of blast furnace slag. The blast furnace slag carried by the vanadium-titanium-containing molten iron is the vanadium-titanium-containing blast furnace slag which has higher melting point and poorer fluidity and has more iron in the slag. The desulfurized slag after desulfurization of the molten iron containing vanadium and titanium is relatively dilute in state, and the condition that the slag is not divided is relatively serious, so that the resulfurization amount of the molten iron containing vanadium and titanium needs to be controlled after desulfurization.
The main reason for resulfurizing desulfurized molten iron containing vanadium and titanium is that the desulfurized slag has poor slag state and is not easy to completely remove, and the sulfur in the residual desulfurized slag is melted back into the desulfurized molten iron containing vanadium and titanium to cause resulfurization.
With the continuous development of steel smelting technology, the requirements of downstream products on the quality of steel are higher and higher, so that the steel is required to have lower content of sulfur. In the traditional technology, KR is generally adopted for desulfurization pretreatment, so that the sulfur content in molten iron can reach below 0.001wt%, and the molten iron subjected to desulfurization pretreatment is poured into a converter for smelting, so that the sulfur content in the molten steel obtained by smelting in the converter is reduced, and the quality of steel is improved. Currently, the technical problems encountered by those skilled in the art are: when molten iron after desulfurization pretreatment is poured into a converter for smelting, the sulfur content in the molten steel is basically over 0.005wt% due to resulfurization of the desulfurization slag, and the quality of steel is seriously affected.
In conclusion, the important way for improving the quality of the molten steel is to reduce the resulfurization of the desulfurized slag as much as possible and reduce the iron loss in the slag skimming process. The slag conglomeration agent is widely used for the slag removing process of the molten iron pretreatment at present, can simplify the slag removing operation and improve the smelting production efficiency. The ideal slag conglomeration agent has the following characteristics: 1, the spreadability is good, and the iron ladle can be uniformly spread and covered on the surface of molten iron after being added; 2, the slagging speed is high, the thin slag can be rapidly gathered into large blocks, and the massive slag blocks enable the slag skimming operation to be easy and rapid, and the slag removal rate is high; 3, improving the alkalinity of the slag system on the surface of the molten iron and preventing the resulfurization of the desulfurized slag; 4, converting the slag system on the surface of the molten iron into a slag system with a low melting point, and separating a large amount of iron from the slag system to dissolve the iron into the molten iron, thereby primarily reducing the iron content in the slag.
Patent document 201310632828.4 discloses a method for reducing the iron loss of desulfurization and slagging-off of vanadium-titanium-containing molten iron, which comprises adding 1.25-1.75kg/t of molten iron desulfurization slag modifier into the vanadium-titanium-containing molten iron in two times. The desulfurization slag modifier comprises 30-40% of CaO and SiO 2 30-40％、Al 2 O 3 8-16％、Na 2 CO 3 4-9％、CaF 2 4-8%, S0.01-0.08%, and P0.01-0.08%. The desulfurization slag modifier can improve the alkalinity of a slag system on the surface of vanadium-titanium-containing molten iron before desulfurization, and simultaneously, the slag system is converted into a slag system with a lower melting point.
Patent document 201510852379.3 discloses a slag modifier for semisteel desulfurization and slagging-off, which is spherical particles prepared from the following raw materials in proportion: 20-40% of C and 2-10% of SiO 2 2-20% of Al 2 O 3 30-40% of MgO. The slag modifier can effectively reduce the sulfur return amount after semisteel desulfurization, and simultaneously reduce the iron loss in the slag skimming process after semisteel desulfurization.
Patent document 201410543374.8 discloses a method for controlling the amount of sulfur returned in converter smelting, which comprises the steps of performing molten iron pretreatment desulfurization by using KR, wherein the content of S in the molten iron after KR desulfurization is 0.0002-0.0010wt%, performing slag skimming with the removal rate of the desulfurized slag of 95-99%, adding 1-3kg/t of lime of the molten iron into the molten iron after the slag skimming, pouring the molten iron into a converter for smelting, and the content of S in the molten iron after the converter smelting is 0.0016-0.0030wt%.
Although the slag conglomeration agent or the slag modifier disclosed by the prior art can achieve the purposes of reducing the resulfurization of the desulfurized slag and reducing the iron loss of the slag, the components of the slag conglomeration agent or the slag modifier are relatively complex, and the characteristics of no good spreadability of the slag modifier and no disclosure on whether the slag conglomeration can be carried out on the thin slag to form a slag block with a large volume or not are carried out in the technical scheme. Based on the background, the invention provides the vanadium-titanium-containing molten iron slag conglomeration agent which has the characteristics of good spreadability and good slag conglomeration, and brings convenience to slag skimming operation.
Disclosure of Invention
The invention aims to provide a slag conglomeration agent for molten iron containing vanadium and titanium, and the invention also aims to provide a preparation method of the slag conglomeration agent for molten iron containing vanadium and titanium.
The purpose of the invention is realized by the following technical scheme.
In a first aspect, the invention provides a vanadium-titanium-containing molten iron slag conglomeration agent, which is characterized by comprising the following raw materials in parts by weight: 20-40 parts of calcium oxide, 20-40 parts of aluminum oxide, 10-30 parts of porous silicon dioxide and 10-20 parts of fiber gypsum particles.
Preferably, the porous silica is spherical particles having an average particle diameter of 1 to 2mm.
Preferably, the fibrous gypsum particles have an average size of 3 to 5mm.
Preferably, the slag conglomeration agent is prepared from the following raw materials: 30-40 parts of calcium oxide, 30-40 parts of aluminum oxide, 20-30 parts of porous silicon dioxide and 10 parts of fiber gypsum particles.
In the most preferred embodiment of the invention, the slag conglomeration agent is prepared from the following raw materials: 40 parts of calcium oxide, 30 parts of aluminum oxide, 30 parts of porous silicon dioxide and 10 parts of fiber gypsum particles.
Preferably, the average particle size of the slag conglomeration agent particles is 2-4mm, the particles with the particle size of less than 1mm are not more than 10 percent of the total weight, and the particles with the particle size of more than 5mm are not more than 10 percent of the total weight.
In a second aspect, the invention provides a preparation method of a vanadium-titanium-containing molten iron slag conglomeration agent, which comprises the following steps: and uniformly mixing the calcium oxide, the alumina, the porous silicon dioxide and the fiber gypsum particles according to the mass part, and drying until the water content is less than 2% to obtain the slag conglomeration agent.
In a third aspect, the invention provides a use method of a vanadium-titanium-containing molten iron slag conglomeration agent, which is characterized in that after desulfurization pretreatment of the vanadium-titanium-containing molten iron, the slag conglomeration agent is added before slag skimming, slag skimming is carried out, and when the slag skimming reaches that the amount of the desulfurized slag is 20-30% of the original mass, the slag conglomeration agent is added for the second time, and slag skimming is carried out again.
Preferably, the dosage of the slag conglomeration agent added for the first time is 0.4-0.8 kg/ton of molten iron, and the dosage of the slag conglomeration agent added for the second time is 0.2-0.5 kg/ton of molten iron.
The calcium oxide in the slag conglomeration agent can carry out calcification treatment on the desulfurized slag, improve the alkalinity of the desulfurized slag, separate the desulfurized slag from the molten iron interface, prevent more iron from being taken away in the slag skimming process, and effectively reduce the iron loss. The aluminum oxide is matched with the porous silicon dioxide, so that the desulfurization slag is converted into a silicate slag system with a higher melting point, and a better slag-iron separation effect is achieved. In addition, the porous silicon dioxide also has a good adsorption function, and can adsorb and gather the thin slag on the surface of the molten iron into a slag block with a larger volume. On one hand, the fibrous gypsum particles are matched with calcium oxide to calcify desulfurized slag, and the density of the fibrous gypsum particles is smaller while the slag-iron separation range is increased, so that the fibrous gypsum particles are favorable for further increasing the volume of slag blocks in the process of gathering rare slag, the slag is more thoroughly removed, and the slag removal rate is improved.
The slag conglomeration agent provided by the invention has the following advantages: 1, the components are simple, the preparation is simple, and the raw materials can be prepared in situ in a smelting workshop; 2, the main raw material porous silicon dioxide in the slag conglomeration agent has a good adsorption function, and can conglomerate the rare slag which is difficult to conglomerate into slag blocks with larger volume, thereby being beneficial to slag raking; 3, the fiber gypsum particles have smaller density, so that the volume of slag blocks can be further increased in the process of rare slag aggregation, and convenience is brought to slag skimming; 4, the slag conglomeration agent provided by the invention can effectively reduce the resulfurization amount of desulfurized vanadium-titanium-containing molten iron, and relieve the phenomena of molten iron loss, high slagging iron loss and resource waste caused by the fact that most of molten iron and desulfurized slag are removed at the later stage of slagging.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Preparation of vanadium-titanium-containing molten iron slag conglomeration agent
Example 1
Uniformly mixing 20 parts of calcium oxide, 20 parts of aluminum oxide, 10 parts of porous silicon dioxide and 10 parts of fiber gypsum particles, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Example 2
And uniformly mixing 30 parts of calcium oxide, 30 parts of aluminum oxide, 20 parts of porous silicon dioxide and 10 parts of fiber gypsum particles, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Example 3
Uniformly mixing 40 parts of calcium oxide, 30 parts of aluminum oxide, 30 parts of porous silicon dioxide and 10 parts of fiber gypsum particles, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Comparative example 1
And uniformly mixing 40 parts of calcium oxide, 30 parts of alumina and 30 parts of porous silicon dioxide, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Comparative example 2
And uniformly mixing 40 parts of calcium oxide, 30 parts of aluminum oxide and 10 parts of fiber gypsum particles, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Comparative example 3
Uniformly mixing 40 parts of calcium oxide, 30 parts of aluminum oxide, 30 parts of common silicon dioxide and 10 parts of fiber gypsum particles, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
Application of slag conglomeration agent for vanadium-titanium-containing molten iron
The purpose of the test is as follows: the slag conglomeration agent prepared in the examples 1 to 3 and the comparative examples 1 to 3 is tested for the effect of slagging off the molten iron containing vanadium and titanium.
The test method comprises the following steps:
s1: performing desulfurization pretreatment on the vanadium-titanium-containing molten iron of the enterprise by using KR, and detecting the sulfur content in the molten iron after the desulfurization pretreatment is finished;
s2: adding a slag conglomeration agent into the molten iron, wherein the adding amount of the slag conglomeration agent is 0.6 kg/ton of the molten iron, starting to carry out slag raking by using a slag raking machine, adding the slag conglomeration agent again when the slag raking is carried out until about 30% of the residual slag amount is left, wherein the adding amount of the slag conglomeration agent is 0.3 kg/ton of the molten iron, continuing to carry out slag raking, detecting the sulfur content in the molten iron after the slag raking is finished, and calculating the slag raking rate of the desulfurized slag and the iron loss caused by slag raking.
And (3) test results:
TABLE 1 slag conglomeration agent for molten iron containing vanadium and titanium
The slag conglomeration agent prepared in the embodiments 1-3 of the invention simultaneously contains calcium oxide, aluminum oxide, porous silicon dioxide and fibrous gypsum particles, and the difference is only the content difference. Compared with examples 1-3, comparative example 1 is a slag conglomeration agent without fibrous gypsum particles, comparative example 2 is a slag conglomeration agent without porous silica, and comparative example 3 is a slag conglomeration agent with porous silica replaced by common silica.
In the test, the sulfur content of the molten iron containing vanadium and titanium after desulfurization pretreatment is basically maintained between 0.0008 and 0.0010 percent, after the slag removal is finished by adding the slag conglomeration agent, the sulfur content of the molten iron in example 3 is the lowest, namely 0.0015 percent, and the resulfurization of the desulfurized slag is the lowest, which indicates that the component proportion of the slag conglomeration agent in example 3 is the optimal choice. When the slag conglomeration agent does not contain porous silica (comparative example 2) or fibrous gypsum particles (comparative example 1), the desulfurization slag resulfurization is obviously increased compared with that of example 3. The porous silicon dioxide and the fibrous gypsum particles have the function of separating slag iron, and particularly, the silicon dioxide can calcify the surface of the desulfurized slag and reduce the resulfurization of the desulfurized slag.
Compared with the effect data of the slagging rate of the desulfurized slag, the slag conglomeration agent group which does not contain the porous silicon dioxide (comparative example 2) or replaces the porous silicon dioxide with the common silicon dioxide (comparative example 3) can be found, the desulfurized slagging rate of the desulfurized slag conglomeration agent group is the lowest, and the porous silicon dioxide is important for improving the slagging rate. The porous silicon dioxide has good adsorption performance, can adsorb the thin slag on the surface of the molten iron to form a slag block with larger volume, and is beneficial to slag removal of the slag remover. The slagging rate of the desulfurized slag and the slagging iron loss are almost the same, when the desulfurized slag block has larger volume and the slagging is carried out more smoothly, the molten iron taken away in the slagging process is less naturally, and the iron loss is correspondingly reduced.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (1)
1. The using method of the slag conglomeration agent for the molten iron containing vanadium and titanium is characterized in that the slag conglomeration agent is added before slag skimming after desulfurization pretreatment of the molten iron containing vanadium and titanium, slag skimming is carried out, and when the slag skimming reaches that the amount of the desulfurized slag is 20-30% of the original mass, the slag conglomeration agent is added for the second time, and slag skimming is carried out again; the dosage of the slag conglomeration agent is 0.4-0.8 kg/ton of molten iron for the first time, and the dosage of the slag conglomeration agent is 0.2-0.5 kg/ton of molten iron for the second time;
the vanadium-titanium-containing molten iron slag conglomeration agent comprises the following raw materials in parts by weight: 40 parts of calcium oxide, 30 parts of aluminum oxide, 30 parts of porous silicon dioxide and 10 parts of fiber gypsum particles; the average particle size of the slag conglomeration agent particles is 2-4mm, the particles with the particle size smaller than 1mm are not more than 10 percent of the total weight, and the particles with the particle size larger than 5mm are not more than 10 percent of the total weight;
the slag conglomeration agent for molten iron containing vanadium and titanium is prepared by the following method: uniformly mixing the calcium oxide, the alumina, the porous silicon dioxide and the fiber gypsum particles according to the mass part, and drying until the water content is 1.3-1.5% to obtain the slag conglomeration agent.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103627850A (en) * | 2013-11-27 | 2014-03-12 | 攀钢集团研究院有限公司 | Desulphurization slag modifier for molten iron containing vanadium and titanium, preparation method of desulphurization slag modifier and desulphurization slag modifying method |
| CN110666113A (en) * | 2019-10-24 | 2020-01-10 | 安徽信息工程学院 | Slag remover for cast iron smelting and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103205521A (en) * | 2013-04-11 | 2013-07-17 | 内蒙古包钢钢联股份有限公司 | Application method of slag conglomeration agent for desulphurization pre-treatment of molten iron |
| CN103642963B (en) * | 2013-11-27 | 2015-04-15 | 攀钢集团研究院有限公司 | Method for lowering sulfur return amount of desulfurized vanadium-titanium-containing molten iron |
| CN103627838B (en) * | 2013-11-27 | 2015-10-14 | 攀钢集团研究院有限公司 | A kind of method reducing hot metal containing V-Ti desulphurization and slag skimming iron loss |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103627850A (en) * | 2013-11-27 | 2014-03-12 | 攀钢集团研究院有限公司 | Desulphurization slag modifier for molten iron containing vanadium and titanium, preparation method of desulphurization slag modifier and desulphurization slag modifying method |
| CN110666113A (en) * | 2019-10-24 | 2020-01-10 | 安徽信息工程学院 | Slag remover for cast iron smelting and preparation method thereof |
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