Method for extracting vanadium from vanadium-containing molten iron

Abstract

The invention relates to the technical field of metallurgy, in particular to a method for extracting vanadium from vanadium-containing molten iron, which comprises the following steps: the vanadium-containing molten iron directly flows into a bottom blowing furnace from an iron outlet; blowing oxidizing gas into the bottom of the bottom blowing furnace; three temperature measuring holes are respectively formed in the end part, the middle part and the tail part of the top of the bottom blowing furnace, and the temperature is measured once every 10-30 minutes; according to the temperature measurement result, one or more of a heating agent, a cooling agent and a flux are added from the top of the bottom blowing furnace, and the temperature in the bottom blowing furnace is controlled to be 1260-1330 DEG C; and semi-steel is discharged from a tapping hole every 10-30 minutes, and vanadium slag is dropped from a slag discharge hole every 20-60 minutes. According to the method for extracting vanadium from the vanadium-containing molten iron, oxidizing gas is blown in through bottom blowing, and a heating agent, a cooling agent and a flux are added from the top, so that the temperature of a molten pool is controlled not to exceed 1350 DEG C, it is ensured that the temperature of the molten pool is lower than the'carbon-vanadium conversion 'temperature of 1350 DEG C, the effect of'vanadium removal and carbon retention' is achieved, the carbon content of semi-steel is 3.65%-4.0%, the vanadium content of the semi-steel is 0.001%-0.02%, and the smelting requirement of the semi-steel is met.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for extracting vanadium from vanadium-containing molten iron. Background Art

[0002] There are three methods for extracting vanadium from vanadium-containing molten iron: the converter method, the ladle method and the shaking ladle method. The main method in China is the converter method. The converter vanadium extraction process is to add vanadium-containing molten iron into the converter, and then blow and extract vanadium through the top oxygen lance. The molten steel produced by the vanadium-extracting converter is called semi-steel. The converter vanadium extraction process has developed from the initial top oxygen supply mode to the top oxygen supply and bottom nitrogen supply combined blowing mode. In the combined blowing converter vanadium extraction process, there are three main factors that affect the quality of semi-steel: carbon content, vanadium content, and temperature. The evaluation indicators are: [C%] ≥ 3.2, [V%] ≤ 0.05, and semi-steel temperature T ≥ 1320℃. The carbon content of the semi-steel produced by the combined blowing converter vanadium extraction is low, and the carbon loss is large, which affects the smelting of semi-steel. The vanadium content of semi-steel still has room to decrease.

[0003] The invention patent with application number CN118406901A discloses a converter vanadium extraction method and its application. By adding a mixture of quartz sand and iron oxide balls into vanadium-containing molten iron, the composition of the molten iron is improved, and the operation and parameters of the converter vanadium extraction method are adjusted, so that the slag state of the vanadium slag is significantly improved, and the visible iron in the vanadium slag is significantly reduced, which solves the problem that the existing converter vanadium extraction method has a large amount of iron in the vanadium slag and a low slag yield after smelting, resulting in low vanadium extraction efficiency and poor effect. The patent only controls the terminal temperature of the converter vanadium extraction (1370-1380℃), and does not explain the residual vanadium in the semi-steel.

[0004] The invention patent with application number CN117802328A discloses a method for vacuum vanadium extraction from vanadium-containing molten iron. The ladle containing vanadium-containing molten iron is operated to a vacuum treatment position. Under vacuum, the vanadium-containing molten iron completes a reciprocating cycle from the ladle to the vacuum chamber. During the cycle, iron oxide balls are added through a vacuum hopper. The reciprocating cycle process can obtain good kinetic conditions, and the vanadium in the molten iron is treated to an extremely low level. At the same time, the TFe content in the obtained vanadium slag is lower than the TFe content of the vanadium slag treated in the converter, and the V2O5 in the vanadium slag is higher than the content in the vanadium slag treated in the converter. The vanadium yield can reach more than 88%. The process has a long treatment cycle, a large process temperature drop, and the process temperature is not easy to measure.

[0005] The invention patent with application number CN117512361A discloses a method for extracting vanadium from vanadium-containing molten iron and vanadium-containing slag, comprising the following steps: S1, adding vanadium-containing molten iron and a coolant into a steelmaking container, then blowing with a gun, adding iron oxides in batches during the blowing process, and obtaining vanadium-containing slag at the end of the blowing; S2, pouring out the vanadium-containing slag, crushing and grinding it to 250-400 mesh after cooling, and performing magnetic separation to obtain vanadium-containing magnetic material; the basicity of the vanadium-containing slag is 1.3-2.0, and the FeO content in the vanadium-containing slag is 9-15wt%. The processing flow of this patent is complicated.

[0006] Most of the above-mentioned smelting processes are optimizations of the converter vanadium extraction process, which cannot fundamentally solve the problem of low carbon content and high V content in the converter vanadium extraction semi-steel. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a method for extracting vanadium from vanadium-containing molten iron to solve the problems of low carbon content and high V content in the existing converter vanadium extraction semi-steel.

[0008] Based on the above purpose, the present invention provides a method for extracting vanadium from vanadium-containing molten iron, comprising the following steps: The vanadium-containing molten iron flows directly from the tap hole into the bottom-blown furnace, which is a horizontal cylindrical furnace body into which oxidizing gas is blown from the bottom, thereby replacing the traditional steelmaking converter; Oxidizing gas is blown into the bottom of the bottom-blown furnace, and heating agent, coolant and flux are added in sequence at the top; Three temperature measuring holes are set at the end, middle and tail of the bottom blowing furnace. The temperature is measured every 10 to 30 minutes. If the temperature measured at the end or middle is lower than 1260°C, a heating agent is added to increase the temperature. If the temperature measured at the end or middle is higher than 1330°C, a coolant is added to reduce the temperature. Every 10 to 30 minutes, half steel is discharged from the steel outlet, and every 20 to 60 minutes, vanadium slag is removed from the slag outlet.

[0009] Optionally, the bottom blowing furnace is a smelting device used in the non-ferrous metal smelting process, and the smelting device includes a furnace body, a gas supply system, a feeding system, a slag discharge system, a steel tapping system and a control system.

[0010] Optionally, the inclination of the bottom blowing furnace is 1°~10°, and the iron outlet side of the bottom blowing furnace is higher than the steel outlet side.

[0011] Optionally, the vanadium-containing molten iron has a furnace entry temperature of 1150-1300° C., a carbon content of 3.6%-5.0%, and a vanadium content of 0.1%-0.5%.

[0012] Optionally, the speed at which the vanadium-containing molten iron flows into the bottom blowing furnace is 0.1-5 t / min.

[0013] Optionally, the iron outlet is 10-100 cm higher than the iron outlet of the bottom blowing furnace, and the iron outlet of the vanadium-containing molten iron is directly connected to the iron outlet of the bottom blowing furnace by a groove.

[0014] Optionally, the oxidizing gas includes one or more of oxygen, compressed air, and CO2, and the amount of gas blown into the furnace bottom is 10~100Nm3 / min.

[0015] Optionally, the temperature-raising agent includes one or more of anthracite, carbon powder, ferrosilicon, and carburized rice husks; the coolant includes one or more of iron oxide scale, iron oxide balls, pure scrap steel, pig iron blocks, dust ash, slag magnetic separation or screening; and the flux is non-calcium low-melting-point substances such as manganese ore and quartz sand.

[0016] Optionally, the semi-steel discharged from the steel outlet flows directly into the ladle for direct steelmaking, and the semi-steel temperature is ≤1350°C, the C content is 3.6%~4.0%, and the vanadium content is 0.001%~0.02%.

[0017] Beneficial effects of the invention: The invention proposes a method for extracting vanadium from vanadium-containing molten iron, in which an oxidizing gas is blown into the molten iron through bottom blowing, and a heating agent, a coolant and a flux are added from the top, so as to control the molten pool temperature not exceeding 1350°C, and ensure that the molten pool temperature is lower than the "carbon-vanadium conversion" temperature of 1350°C, so as to achieve the effect of "removing vanadium and retaining carbon", and the carbon content of the semi-steel is 3.65%-4.0%, and the vanadium content of the semi-steel is 0.001%-0.02%, which meets the smelting requirements of the semi-steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A process roadmap for an embodiment of the present invention; DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0021] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should have the common meanings understood by persons having ordinary skills in the field to which the present invention belongs. Example 1

[0022] A method for extracting vanadium from vanadium-containing molten iron comprises the following steps: the vanadium-containing molten iron directly flows into a bottom-blowing furnace from a tap hole, the molten iron addition amount is 1 t / min, the vanadium content of the molten iron is 0.35%, the carbon content of the molten iron is 4.3%, the molten iron temperature is 1300°C, the speed at which the vanadium-containing molten iron flows into the bottom-blowing furnace is 0.5 t / min, the tap hole of the vanadium-containing molten iron is 20 cm higher than the tap hole of the bottom-blowing furnace, and the tap hole of the vanadium-containing molten iron is directly connected to the tap hole of the bottom-blowing furnace by a groove; oxygen is blown into the bottom of the bottom-blowing furnace at an oxygen amount of 20 Nm3 / min, and the top of the bottom-blowing furnace is measured. Three temperature measuring holes are set at the end, middle and tail respectively. The temperature is automatically measured every 30 minutes. If the temperature measured at the end or middle is lower than 1260℃, ferrosilicon is added to raise the temperature. The ferrosilicon is added according to the standard of 1000kg / 10℃. If the temperature measured at the end or middle is higher than 1330℃, pure scrap steel is added at a rate of 0.1t / min, and flux quartz sand is added at a rate of 10kg / min. Semi-steel is discharged from the steel outlet every 30 minutes, and vanadium slag is removed from the slag outlet every 60 minutes. The vanadium content of semi-steel is 0.015%, the carbon content of semi-steel is 3.8%, the temperature of semi-steel is 1343℃, and the V2O5 content of vanadium slag is 17.3%. Example 2

[0023] A method for extracting vanadium from vanadium-containing molten iron comprises the following steps: the vanadium-containing molten iron directly flows into a bottom-blowing furnace from a tap hole, the amount of molten iron added is 1 t / min, the vanadium content of the molten iron is 0.35%, the carbon content of the molten iron is 4.3%, the temperature of the molten iron is 1300°C, the speed at which the vanadium-containing molten iron flows into the bottom-blowing furnace is 0.5 t / min, the tap hole of the vanadium-containing molten iron is 60 cm higher than the tap hole of the bottom-blowing furnace, and the tap hole of the vanadium-containing molten iron is directly connected to the tap hole of the bottom-blowing furnace by a groove; compressed air is blown into the bottom of the bottom-blowing furnace, the amount of compressed air is 50 Nm3 / min, and the top of the bottom-blowing furnace is measured. Three temperature measuring holes are set at the end, middle and tail of the steel mill. The temperature is automatically measured every 40 minutes. If the temperature measured at the end or middle is lower than 1260℃, anthracite is added to increase the temperature. The anthracite is added at a standard of 1400kg / 10℃. If the temperature measured at the end or middle is higher than 1330℃, pig iron is added at a rate of 0.1t / min, and flux quartz sand is added at a rate of 10kg / min. Semi-steel is discharged from the steel outlet every 30 minutes, and vanadium slag is removed from the slag outlet every 60 minutes. The vanadium content of semi-steel is 0.016%, the carbon content of semi-steel is 3.7%, the temperature of semi-steel is 1340℃, and the V2O5 content of vanadium slag is 17.1%. Example 3

[0024] A method for extracting vanadium from vanadium-containing molten iron, comprising the following steps: the vanadium-containing molten iron directly flows into a bottom-blowing furnace from a tap hole, the amount of molten iron added is 1 t / min, the vanadium content of the molten iron is 0.33%, the carbon content of the molten iron is 4.3%, the temperature of the molten iron is 1220°C, the speed at which the vanadium-containing molten iron flows into the bottom-blowing furnace is 4 t / min, the tap hole of the vanadium-containing molten iron is 80 cm higher than the tap hole of the bottom-blowing furnace, the tap hole of the vanadium-containing molten iron is directly connected to the tap hole of the bottom-blowing furnace by a groove; compressed air is blown into the bottom of the bottom-blowing furnace, and the amount of compressed air is 80 Nm3 / min, 3 temperature measuring holes are set at the end, middle and tail of the bottom blowing furnace, and the temperature is automatically measured every 40 minutes. If the temperature measured at the end or middle is lower than 1260℃, carbon powder is added to increase the temperature, and anthracite is added according to the standard of 1800kg / 10℃. If the temperature measured at the end or middle is higher than 1330℃, pure scrap steel is added at a rate of 0.1t / min, and flux manganese ore is added at a rate of 10kg / min. Semi-steel is discharged from the steel outlet every 40 minutes, and vanadium slag is removed from the slag outlet every 60 minutes. The vanadium content of semi-steel is 0.015%, the carbon content of semi-steel is 3.7%, the temperature of semi-steel is 1345℃, and the V2O5 content of vanadium slag is 16.7%.

[0025] In Examples 1 to 3, the heating agent may also be carbonized rice husk, and the cooling agent may also be one or more of iron oxide scale, iron oxide balls, dust removal ash, slag magnetic separation or screening.

[0026] Comparative Example 1 A method for extracting vanadium from vanadium-containing molten iron comprises the following steps: adding vanadium-containing molten iron into a double-blown converter, the addition amount is 100 t / furnace, the molten iron has a vanadium content of 0.33%, a carbon content of 4.3%, a molten iron temperature of 1220°C, a converter top blowing oxygen supply intensity of 2.0 Nm3 / (min·t), an oxygen blowing time of 6 minutes, a semi-steel vanadium content of 0.040%, a semi-steel carbon content of 3.6%, a semi-steel temperature of 1395°C, and a vanadium slag V2O5 content of 15.6%.

[0027] Comparative Example 2 A method for extracting vanadium from vanadium-containing molten iron comprises the following steps: adding vanadium-containing molten iron into a double-blown converter, the addition amount is 100 t / furnace, the molten iron has a vanadium content of 0.33%, a carbon content of 4.3%, a molten iron temperature of 1220°C, a converter top blowing oxygen supply intensity of 2.0 Nm3 / (min·t), an oxygen blowing time of 7 minutes, a semi-steel vanadium content of 0.030%, a semi-steel carbon content of 3.5%, a semi-steel temperature of 1410°C, and a vanadium slag V2O5 content of 14.3%.

[0028] The vanadium content and carbon content of the semi-steel in each embodiment and comparative example are shown in Table 1.

[0029] Table 1

[0030] As can be seen from the above table, by blowing oxidizing gas into the bottom and adding heating agent, coolant and flux at the top, the molten pool temperature is controlled not to exceed 1350℃, ensuring that the molten pool temperature is lower than the "carbon-vanadium conversion" temperature, achieving the effect of "removing vanadium and retaining carbon", the carbon content of semi-steel is 3.65%~4.0%, and the vanadium content of semi-steel is 0.001%~0.02%, which meets the smelting requirements of semi-steel.

[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for extracting vanadium from vanadium-containing molten iron, characterized in that: The following steps are involved: The vanadium-containing molten iron flows directly into the bottom-blowing furnace from the tap hole; Blowing oxidizing gas into the bottom of the bottom-blown furnace; Three temperature measuring holes are set at the end, middle and tail of the bottom blowing furnace, and the temperature is measured every 10 to 30 minutes. According to the temperature measurement results, one or more of heating agent, coolant and flux are added from the top of the bottom blowing furnace to control the temperature in the bottom blowing furnace at 1260℃-1330℃. Every 10 to 30 minutes, half steel is discharged from the steel outlet, and every 20 to 60 minutes, vanadium slag is removed from the slag outlet.

2. The method according to claim 1, characterized in that: The bottom blowing furnace is a smelting device used in the non-ferrous metal smelting process, and the smelting device includes a furnace body, a gas supply system, a feeding system, a slag discharge system, a steel tapping system and a control system.

3. The method according to claim 2, characterized in that The bottom blowing furnace has an inclination of 1° to 10°, and the iron outlet side of the bottom blowing furnace is higher than the steel outlet side.

4. The method according to claim 1, characterized in that: The vanadium-containing molten iron has a furnace entry temperature of 1150-1300° C., a carbon content of 3.6%-5.0%, and a vanadium content of 0.1%-0.5%.

5. The method according to claim 1, characterized in that The speed at which the vanadium-containing molten iron flows into the bottom blowing furnace is 0.1-5 t / min.

6. The method according to claim 1, characterized in that The tap hole is 10-100 cm higher than the bottom blowing furnace tap hole, and the vanadium-containing molten iron tap hole is directly connected to the bottom blowing furnace tap hole by a groove.

7. The method according to claim 1, characterized in that The oxidizing gas includes one or more of S oxygen, compressed air, and CO2, and the amount of gas blown into the furnace bottom is 10~100Nm 3 / min.

8. The method according to claim 1, characterized in that The temperature-raising agent includes one or more of anthracite, carbon powder, ferrosilicon, and carburized rice husk; the coolant includes one or more of iron oxide scale, iron oxide balls, pure scrap steel, pig iron blocks, dust removal ash, and slag magnetic separation or screening; the flux is non-calcium low-melting-point substances such as manganese ore and quartz sand.

9. The method according to claim 1, characterized in that: The semi-steel discharged from the steel outlet directly flows into the ladle and can be directly used for steelmaking. The semi-steel temperature is ≤1350°C, the C content is 3.6%-4.0%, and the vanadium content is 0.001-0.02%.

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