CN113122678B - Smelting method for increasing vanadium and making steel by using vanadium slag - Google Patents

Abstract

The invention discloses a smelting method for increasing vanadium and making steel by using vanadium slag, which comprises the following steps: converter tapping deoxidation, LF furnace heating, vanadium slag and alloy adding alloying, vanadium slag recovery, LF refining furnace treatment and continuous casting. The vanadium increasing and steel making can recycle vanadium slag to a greater extent, the vanadium slag in each furnace can utilize 500-1500kg, and the vanadium yield reaches 65-80%; in the vanadium-increasing steelmaking process, the erosion influence of vanadium slag on a furnace lining is small, and the ladle age is the same as that of a ladle using ferrovanadium to increase vanadium; in addition, compared with the traditional method, the cost of vanadium increasing and steel making by using the method is reduced by 10-30 yuan per ton of steel, and the method is worthy of popularization and application.

Description

Smelting method for increasing vanadium and making steel by using vanadium slag

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to a smelting method for increasing vanadium and making steel by using vanadium slag.

Background

Vanadium is called monosodium glutamate in modern industry and is an important national strategic material, and the vanadium serving as an alloy additive can obviously improve the strength, toughness, ductility, plasticity and the like of steel. Carbides, nitrides and the like formed by vanadium in steel have the functions of refining grains, eliminating inclusions and enhancing ductility.

In the steelmaking process, the vanadium content in the steel is usually increased by adding ferrovanadium alloy, and the steelmaking method has the advantages of high vanadium yield, stable yield, simple and easy operation, but relatively high cost. Another method is to increase the content of vanadium element in steel by adding vanadium element extracted from vanadium slag. The vanadium slag is a product after smelting the vanadium-containing molten iron, and because the vanadium content in the vanadium slag is high and the vanadium slag has high utilization value, researchers can extract vanadium elements in the vanadium slag and add the vanadium elements into the steelmaking process.

The two vanadium-increasing steelmaking processes have high cost, so scientific researchers try to add vanadium slag to steel instead of ferrovanadium, but because the content of oxides in the vanadium slag is high, the temperature drop is large after the vanadium slag is added to the steel, the yield of vanadium is difficult to guarantee, and meanwhile, the vanadium slag has large influence on steel ladle refractory materials, so that the vanadium slag cannot be added to the steel instead of ferrovanadium in a stable process.

Aiming at the problems, the invention aims to provide a smelting process for vanadium increasing and steelmaking by using vanadium slag, which has low cost and stable process.

Disclosure of Invention

In view of the above problems, a first object of the present invention is to provide a vanadium slag for vanadium-enriched steel making, and a second object of the present invention is to provide a smelting method for vanadium-enriched steel making by using the vanadium slag.

The first purpose of the invention is realized by that the vanadium slag for vanadium increasing and steel making comprises the following components in percentage by mass: 12.00 to 20.00 percent of vanadium oxide, 5.00 to 9.00 percent of titanium oxide, 4.00 to 8.00 percent of calcium oxide, 15.00 to 20.00 percent of silicon oxide, 5.00 to 10.00 percent of manganese oxide, 1.50 to 4.00 percent of magnesium oxide, 1.00 to 3.00 percent of aluminum oxide, 0.005 to 0.01 percent of sulfur, 0.01 to 0.20 percent of phosphorus, 25.79 to 48.485 percent of iron oxide and the balance of inevitable impurities.

The second purpose of the invention is realized by the following steps: the method comprises the following steps of converter tapping deoxidation, LF furnace temperature rise, vanadium slag and alloy addition alloying, vanadium slag recovery, LF refining furnace treatment and continuous casting, and specifically comprises the following steps:

1) and (3) converter tapping deoxidation: after tapping of the molten iron converter, adding a deoxidizing agent into a ladle for deoxidizing;

2) heating an LF furnace: hoisting the molten steel to an LF refining furnace, and adding a slagging agent for slagging; heating to melt slag, heating the molten steel to more than 1650 ℃, and analyzing the components of the molten steel;

3) adding vanadium slag: adding the vanadium slag of claim 1 and other alloys required to be added according to the steel grade requirement, and switching on the bottom to blow argon for stirring to ensure that the vanadium slag is fully contacted with the molten steel;

4) and (3) recovering vanadium slag: hoisting the molten steel to a slag skimming station, and performing slag skimming treatment;

5) and (3) LF refining furnace treatment: hoisting the molten steel to an LF refining furnace, and adding 0.5-2.5kg of lime and 0-2kg of fluorite into each ton of steel; measuring temperature, sampling, analyzing molten steel components, confirming that vanadium and other alloy elements meet the component control requirement of steel, and finely adjusting the components according to the content of the alloy elements; adjusting the temperature to 50-70 ℃ above the liquidus temperature of the corresponding steel grade, and carrying out soft blowing stirring treatment to finish the molten steel treatment;

6) continuous casting: and (5) continuously casting the molten steel obtained in the step (5) to obtain the target vanadium-containing steel.

The vanadium slag has oxidability, and the vanadium slag is added into high-temperature molten steel to bring temperature drop and erode a furnace lining. And after the temperature is increased to more than 1650 ℃ after deoxidation, vanadium slag is added, so that the vanadium slag can be melted rapidly, and the yield of vanadium is ensured.

Compared with the prior art, the method of the invention has the following advantages:

1) the vanadium increasing and steel making can recycle vanadium slag to a greater extent, the vanadium slag in each furnace can utilize 500-1500kg, and the vanadium yield reaches 65-80%.

2) In the vanadium-increasing steelmaking process, the erosion influence of vanadium slag on a furnace lining is small, and the ladle age is the same as that of a ladle using ferrovanadium to increase vanadium; in addition, compared with the vanadium increasing method adopting ferrovanadium, the cost of vanadium increasing and steel making by using the method is reduced by 10-30 yuan/ton of steel, and the method is worthy of popularization and application.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to be limiting in any way, and any modifications or alterations based on the teachings of the present invention are intended to fall within the scope of the present invention.

The invention relates to vanadium slag for vanadium increasing and steelmaking, which comprises the following components in percentage by mass: 12.00 to 20.00 percent of vanadium oxide, 5.00 to 9.00 percent of titanium oxide, 4.00 to 8.00 percent of calcium oxide, 15.00 to 20.00 percent of silicon oxide, 5.00 to 10.00 percent of manganese oxide, 1.50 to 4.00 percent of magnesium oxide, 1.00 to 3.00 percent of aluminum oxide, 0.005 to 0.01 percent of sulfur, 0.01 to 0.20 percent of phosphorus, 25.79 to 48.485 percent of iron oxide and the balance of inevitable impurities.

The invention relates to a smelting method for increasing vanadium and making steel by using vanadium slag, which comprises the following steps: the method comprises the following steps of converter tapping deoxidation, LF furnace temperature rise, vanadium slag and alloy addition alloying, vanadium slag recovery, LF refining furnace treatment and continuous casting, and specifically comprises the following steps:

1) and (3) converter tapping deoxidation: after tapping of the molten iron converter, adding a deoxidizer into a ladle for deoxidation treatment;

2) heating an LF furnace: hoisting and transporting the molten steel to an LF refining furnace, and adding a slagging agent for slagging; heating to melt slag, heating the molten steel to more than 1650 ℃, and analyzing the components of the molten steel;

3) adding vanadium slag: adding the vanadium slag of claim 1 and other alloys required to be added according to the steel grade requirement, and switching on the bottom to blow argon for stirring to ensure that the vanadium slag is fully contacted with the molten steel;

4) and (3) recovering vanadium slag: hoisting the molten steel to a slag skimming station, and performing slag skimming treatment;

5) and (3) LF refining furnace treatment: hoisting the molten steel to an LF refining furnace, and adding 0.5-2.5kg of lime and 0-2kg of fluorite into each ton of steel; measuring temperature, sampling, analyzing molten steel components, confirming that vanadium and other alloy elements meet the component control requirements of steel, and finely adjusting the components according to the content of the alloy elements; adjusting the temperature to 50-70 ℃ above the liquidus temperature of the corresponding steel grade, and carrying out soft blowing stirring treatment to finish the molten steel treatment;

6) continuous casting: and (5) continuously casting the molten steel obtained in the step (5) to obtain the target vanadium-containing steel.

In the step 1, the deoxidizer is one or a combination of more of ferrosilicon, silicomanganese, high-carbon ferromanganese, aluminum or carbon.

In the step 2, the slagging agent is lime and fluorite, wherein 2.5-5.5kg of lime and 0.5-2.5kg of fluorite are added into each ton of steel, and the specific amount is determined according to the steel type.

In the step 3, the bottom blowing pressure is more than 0.3MPa, and the stirring time is 4-8 min.

In the step 4, the thickness of the slag left after slag skimming is controlled to be less than 100mm so as to reduce the corrosion to the steel ladle.

Example 1

After blowing to the end point by a 120t converter and tapping of the components, 390kg of ferrosilicon (FeSi 75), 2315kg of silicomanganese (Mn 68Si 18) and 322kg of high-carbon ferromanganese (FeMn78C8.0) are added into a ladle. Hoisting the ladle to an LF furnace, adding 452kg of lime and 147kg of fluorite, and heating to 1660 ℃. Sampling, the composition results are: c: 0.21%, Si: 0.45%, Mn: 1.35%, P: 0.03%, S: 0.018%, V: 0.004%; stirring by bottom blowing with nitrogen under the pressure of 0.35MPa, and adding 463kg of vanadium slag, wherein the vanadium slag comprises 14.3% of vanadium oxide, 7.5% of titanium oxide, 5.9% of calcium oxide, 18.6% of silicon oxide, 7.5% of manganese oxide, 2.1% of magnesium oxide and 1.2% of aluminum oxide; after bottom blowing for 5min, the temperature was measured at 1575 ℃. And hoisting to a slag skimming station for skimming, wherein the thickness of the slag is controlled to be less than 100 mm. Then the furnace is hoisted back to the LF furnace, and the temperature is measured to 1540 ℃. Adding 150kg of lime, bottom blowing and stirring, after molten steel is uniform, sampling, wherein the composition result is as follows: c: 0.23%, Si: 0.41%, Mn: 1.33%, P: 0.03%, S: 0.018%, V: 0.025 percent. According to the composition results, 80kg of ferrosilicon (FeSi 75), 50kg of silicomanganese (Mn 68Si 18) and 15kg of ferrovanadium (FeV 80A) are supplemented. Raising the temperature again, sampling, and obtaining the following components: c: 0.23%, Si: 0.47%, Mn: 1.36%, P: 0.03%, S: 0.018%, V: 0.027 percent. The temperature of the molten steel is 1560 ℃, the molten steel is treated, and the covering agent is added to prepare continuous casting.

Example 2

After 120t converter tapping, 378kg of ferrosilicon (FeSi 75), 2320kg of silicomanganese (Mn 68Si 18) and 327kg of high-carbon ferromanganese (FeMn78C8.0) are added into a ladle. Hoisting the steel ladle to an LF furnace, adding 460kg of lime and 152kg of fluorite, and heating to 1658 ℃. Sampling, the composition results are: c: 0.22%, Si: 0.44%, Mn: 1.36%, P: 0.025%, S: 0.02%, V: 0.002%. Stirring by bottom blowing with nitrogen under the pressure of 0.35MPa, and adding 459kg of vanadium slag, wherein the vanadium slag comprises 14.5% of vanadium oxide, 7.6% of titanium oxide, 5.6% of calcium oxide, 18.3% of silicon oxide, 7.2% of manganese oxide, 2.2% of magnesium oxide and 1.1% of aluminum oxide; after bottom blowing for 5min, the temperature was measured at 1571 ℃. And hoisting to a slag skimming station for skimming, wherein the thickness of the slag is controlled to be less than 100 mm. And (5) hoisting and conveying the mixture back to the LF furnace, and measuring the temperature at 1538 ℃. Adding 152kg of lime, blowing at the bottom and stirring, after the molten steel is uniform, sampling, wherein the composition result is as follows: c: 0.23%, Si: 0.40%, Mn: 1.34%, P: 0.025%, S: 0.019%, V: 0.026% of the total weight of the powder. According to the composition results, 81kg of ferrosilicon (FeSi 75), 52kg of silicomanganese (Mn 68Si 18) and 17kg of ferrovanadium (FeV 80A) were added. Raising the temperature again, sampling, and obtaining the following components: c: 0.23%, Si: 0.45%, Mn: 1.36%, P: 0.025%, S: 0.019%, V: 0.028 percent. The temperature of the molten steel is 1562 ℃, the molten steel is treated, and the covering agent is added to prepare continuous casting.

Example 3

After 120t converter tapping, 473kg of aluminum particles (Al), 678kg of carbon powder (C) and 1028kg of high-carbon ferromanganese (FeMn78C8.0) are added into a ladle. Hoisting the ladle to an LF furnace, adding 496kg of lime, 155kg of fluorite and 98kg of aluminum particles (Al), and heating to 1665 ℃. Sampling, the composition results are: c: 0.33%, Si: 0.18%, Mn: 0.65%, P: 0.015%, S: 0.002%, V: 0.002%, Cr: 0.04%, Ni: 0.01%, Cu: 0.01 percent. Stirring by bottom blowing with nitrogen under the pressure of 0.33MPa, and adding 895kg of vanadium slag, wherein the vanadium slag comprises 15.1% of vanadium oxide, 7.3% of titanium oxide, 5.7% of calcium oxide, 18.4% of silicon oxide, 7.2% of manganese oxide, 2.2% of magnesium oxide and 1.2% of aluminum oxide; after bottom blowing for 5min, the temperature was measured at 1535 ℃. The temperature is increased to 1588 ℃. And hoisting to a slag skimming station for skimming, wherein the thickness of the slag is controlled to be less than 100 mm. And (5) hoisting and conveying the mixture back to the LF furnace, and measuring the temperature of 1555 ℃. 123kg of lime are added, and 175m of aluminum wire (diameter 12 mm) is fed. After heating up, the following alloys were added: ferrochrome (FeCr 55) 335kg, nickel plate (Ni) 241kg, copper plate (Cu) 179kg, carbon powder (C) 100kg, bottom blowing stirring, after molten steel is uniform, sampling, and the composition results are: c: 0.47%, Si: 0.27%, Mn: 0.63%, P: 0.015%, S: 0.001%, V: 0.045%, Cr: 0.18%, Ni: 0.21%, Cu: 0.16 percent. According to the composition results, 63kg of ferrovanadium (FeV 80) was added. Raising the temperature again, sampling, and obtaining the following components: c: 0.48%, Si: 0.28%, Mn: 0.63%, P: 0.015%, S: 0.001%, V: 0.081%, Cr: 0.18%, Ni: 0.21%, Cu: 0.16 percent. The temperature of the molten steel is 1542 ℃, the molten steel is treated, and a covering agent is added to prepare continuous casting.

Example 4

After 120t converter tapping, 466kg of aluminum particles (Al), 688kg of carbon powder (C) and 1033kg of high-carbon ferromanganese (FeMn78C8.0) are added into a ladle. Hoisting the ladle to an LF furnace, adding 513kg of lime, 160kg of fluorite and 103kg of aluminum particles (Al), and heating to 1663 ℃. Sampling, the composition results are: c: 0.32%, Si: 0.19%, Mn: 0.65%, P: 0.016%, S: 0.002%, V: 0.002%, Cr: 0.03%, Ni: 0.01%, Cu: 0.01 percent. Stirring by bottom blowing with nitrogen under the pressure of 0.33MPa, and adding 892kg of vanadium slag containing vanadium oxide 14.7%, titanium oxide 7.1%, calcium oxide 5.7%, silicon oxide 18.1%, manganese oxide 7.3%, magnesium oxide 2.1% and aluminum oxide 1.1%; after bottom blowing for 5min, the temperature was measured at 1537 ℃. The temperature is increased to 1582 ℃. And hoisting to a slag skimming station for skimming, wherein the thickness of the slag is controlled to be less than 100 mm. And (5) hoisting and conveying the steel back to the LF furnace, and measuring the temperature of 1553 ℃. 135kg of lime is added, and 168m of aluminum wire (diameter 12 mm) is fed. After the temperature is raised, the following alloys are added: 332kg of ferrochrome (FeCr 55), 242kg of nickel plate (Ni), 181kg of copper plate (Cu) and 100kg of carbon powder (C), bottom blowing and stirring, after molten steel is uniform, sampling, and obtaining the composition result: c: 0.46%, Si: 0.28%, Mn: 0.64%, P: 0.016%, S: 0.001%, V: 0.047%, Cr: 0.17%, Ni: 0.22%, Cu: 0.16 percent. According to the composition results, 61kg of ferrovanadium (FeV 80) was added. Raising the temperature again, sampling, and obtaining the following components: c: 0.47%, Si: 0.28%, Mn: 0.64%, P: 0.016%, S: 0.001%, V: 0.080%, Cr: 0.17%, Ni: 0.22%, Cu: 0.16 percent. The temperature of the molten steel is 1539 ℃, after the molten steel treatment is finished, a covering piece is added to prepare continuous casting.

What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.

Claims (2)

1. A smelting method for vanadium increasing and steel making by using vanadium slag is characterized in that the vanadium slag for vanadium increasing and steel making comprises the following components in percentage by mass: 12.00-20.00% of vanadium oxide, 5.00-9.00% of titanium oxide, 4.00-8.00% of calcium oxide, 15.00-20.00% of silicon oxide, 5.00-10.00% of manganese oxide, 1.50-4.00% of magnesium oxide, 1.00-3.00% of aluminum oxide, 0.005-0.01% of sulfur, 0.01-0.20% of phosphorus, 25.79-48.485% of iron oxide and the balance of inevitable impurities; the smelting method comprises the following specific steps:

1) and (3) converter tapping deoxidation: after tapping of the molten iron converter, adding a deoxidizing agent into a ladle for deoxidizing;

2) heating an LF furnace: hoisting and transporting the molten steel to an LF refining furnace, and adding a slagging agent for slagging; the slag former is lime and fluorite, wherein 2.5-5.5kg of lime and 0.5-2.5kg of fluorite are added into each ton of steel, and the specific amount is determined according to the steel type; heating to melt slag, heating the molten steel to more than 1650 ℃, and analyzing the components of the molten steel;

3) adding vanadium slag: adding the vanadium slag and other alloys required to be added according to the steel type requirement, and switching on bottom argon blowing for stirring, wherein the bottom blowing pressure is more than 0.3MPa, and the stirring time is 4-8min, so as to ensure that the vanadium slag is fully contacted with the molten steel;

4) and (3) recovering vanadium slag: hoisting the molten steel to a slag skimming station, and performing slag skimming treatment, wherein the thickness of remained slag is controlled to be less than 100mm so as to reduce the corrosion to a steel ladle;

5) and (3) LF refining furnace treatment: hoisting and conveying the molten steel to an LF refining furnace, wherein the amount of lime added in each ton of steel is 0.5-2.5kg, and the amount of fluorite is 0-2kg, measuring the temperature, sampling, analyzing the components of the molten steel, confirming that vanadium elements and other alloy elements meet the component control requirements of steel, and carrying out component fine adjustment according to the content of the alloy elements; adjusting the temperature to be 50-70 ℃ above the liquidus temperature of the corresponding steel grade, and carrying out soft blowing stirring treatment to finish molten steel treatment;

6) continuous casting: and (5) continuously casting the molten steel obtained in the step (5) to obtain the target vanadium-containing steel.

2. The smelting method for increasing vanadium and smelting steel according to claim 1, wherein in the step 1, the deoxidizer is one or a combination of silicon iron, silicon manganese, high-carbon ferromanganese, aluminum or carbon.