Inhibitor for suppressing slag splashing in the late stage of ferrovanadium smelting and method for suppressing splashing

Abstract

The present invention provides an inhibitor for suppressing slag splashing in the late stage of ferrovanadium smelting, comprising lime and metallic iron, wherein the mass ratio of the lime to the metallic iron is 80-150:20-50. The present invention also provides a method for suppressing slag splashing in the late stage of ferrovanadium smelting, wherein a ferrovanadium alloy molten pool and a ferrovanadium smelting slag layer are obtained through refining in a smelting furnace, and then the following steps are performed: (1) stopping power to the smelting furnace, removing the electrodes, and adding the inhibitor comprising lime and metallic iron to the ferrovanadium smelting slag layer; (2) allowing the smelting furnace to stand, allowing the lime to undergo an endothermic reaction with the ferrovanadium smelting slag; and (3) energizing and heating the smelting furnace again, causing the lime to melt on the surface of the ferrovanadium smelting slag layer to form a covering layer. The method described in the present invention has a short process flow, strong operability, and excellent slag splashing suppression effect.

Description

Technical Field

[0001] The present invention relates to the technical field of vanadium alloy smelting, in particular to an inhibitor for suppressing splashing of high-temperature slag in a smelting furnace in the late stage of ferrovanadium smelting, and also to a method for suppressing splashing of high-temperature slag. Background Art

[0002] Ferrovanadium (FV) alloys exhibit a dual strengthening mechanism of grain refinement and precipitation strengthening, reducing the steel's sensitivity to overheating and improving its strength and wear resistance. They are widely used in vanadium-containing microalloyed steels. Currently, the production of ferrovanadium alloys primarily utilizes the aluminothermic process, using powdered vanadium trioxide and flake vanadium pentoxide. The slag phase primarily consists of a ternary Al2O3-CaO-MgO slag system with a melting point of 1700-2000°C. At high temperatures, the upper slag layer often experiences splashing.

[0003] In existing ferrovanadium smelting, large amounts of aluminum are added during the injection and refining stages for deep reduction. This aluminum tends to float to the upper layer of the hot slag and burn violently, contributing to the deep reduction of vanadium oxides in the middle and upper layers of the slag. However, due to the rapid increase in the temperature of the upper slag layer, the slag splashes, and in severe cases, it is prone to explosions. Slag splashing can easily cause injuries to personnel and burn damage to smelting flat cars, smelting rails, lifting booms, motors, and various equipment within the smelting chamber, seriously hindering the normal operation of ferrovanadium smelting production.

[0004] Patent application number 201610808106.3 discloses a method for smelting FeV80 by the electric aluminothermic method. By evenly spreading ferrovanadium fine powder on the bottom of a straight furnace and adding ferrovanadium fine powder to the smelting raw materials containing V2O5, a molten ferrovanadium alloy layer is formed at the bottom of the furnace during the smelting process, avoiding direct contact between the knotted layer at the bottom of the furnace and the smelting slag layer; at the same time, ferrovanadium fine powder is added to the smelting raw materials containing V2O5 to absorb excess heat, so as to achieve the purpose of reducing the MgO content in the ferrovanadium smelting slag and improving the slag system characteristics. The method comprises the following steps: (1) evenly spreading vanadium iron fine powder on the bottom of the furnace and compacting it; wherein the vanadium iron fine powder is 10-15% of the total mass of V2O3 and V2O5; (2) adding uniformly mixed smelting raw materials V2O5, aluminum powder, iron particles and lime, as well as vanadium iron fine powder into the furnace, and energizing the arc for smelting; wherein the mass ratio of V2O5 to vanadium iron fine powder is 4:1-2; (3) after a molten pool is formed in the furnace, adding uniformly mixed smelting raw materials V2O3, aluminum powder, iron particles and lime, and continuing smelting with electricity; (4) stopping the power supply and performing blowing after the smelting is completed; (5) continuing the power supply for refining after the blowing is completed; (6) after the refining is completed, the furnace body is allowed to cool, the furnace is dismantled, the alloy cake is water quenched, and crushed to obtain FeV80 alloy. However, the application does not yet involve a technical solution for suppressing slag splashing in the late stage of vanadium iron smelting.

[0005] Patent application CN108913894B discloses a self-stirring process for vanadium-ferroalloy smelting. After the autothermal reaction is complete, a spherical stirring agent is added to the molten pool. Secondary self-stirring is achieved by pouring the slag and metal into an ingot mold for self-stirring, thereby reducing the vanadium content in the slag. However, the problem of slag splashing has not been effectively addressed.

[0006] Patent application publication number CN110747359A discloses a ferrovanadium smelting method that increases the aluminum ratio to produce ferrovanadium. Aluminum powder and a slag-forming agent are added during the ferrovanadium smelting and refining process. This method primarily improves the reaction conditions from the perspective of ingredient proportioning. However, the density of the refined material is lower than that of the slag, making it prone to floating on the surface of the slag. Aluminum powder has a flash point of approximately 550°C and easily burns on the slag surface. Therefore, this application still faces the technical issue of slag splashing.

[0007] Judging from the technologies disclosed in the prior art, current vanadium-ferrometallurgy smelting technology mainly focuses on strengthening stirring, injection refining, and optimizing the aluminum ratio in the early and middle stages of smelting. However, no technical solutions have been reported to suppress slag splashing in the later stages of vanadium-ferrometallurgy. Summary of the Invention

[0008] In view of the deficiencies of the prior art, the present invention aims to provide an inhibitor for suppressing slag splashing in the late stage of ferrovanadium smelting, and also provides a method for suppressing slag splashing in the late stage of ferrovanadium smelting using the inhibitor.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The invention provides an inhibitor for inhibiting slag splashing in the late stage of ferrovanadium smelting. The inhibitor comprises lime and metallic iron, wherein the mass ratio of the lime to the metallic iron is 80-150:20-50.

[0011] Furthermore, the lime includes at least one of active lime, calcined lime, and passivated lime.

[0012] Furthermore, the mass contents of the main components in the active lime, the calcined lime, and the passivated lime are: CaO ≥ 85%, CaO + MgO ≥ 88%, S ≤ 0.05%, P ≤ 0.05%, the activity of calcium oxide ≥ 300 ml / mol, and the remainder is iron, SiO2, and manganese.

[0013] Furthermore, the metallic iron is at least one of iron particles and steel scraps, and the particle size of the metallic iron is ≤15 mm.

[0014] The present invention also provides a method for suppressing slag splashing in the late stage of ferrovanadium smelting.

[0015] After refining in the smelting furnace to obtain the vanadium-ferroalloy molten pool and the vanadium-ferroalloy slag layer, the following steps are performed:

[0016] (1) Stop powering the smelting furnace, remove the electrodes, and add the above-mentioned inhibitors including lime and metallic iron to the vanadium-ferrometallurgical slag layer;

[0017] (2) The smelting furnace is left to stand, and an endothermic reaction occurs between the lime and the vanadium-iron smelting slag;

[0018] (3) The smelting furnace is powered on and heated again, so that the lime melts on the surface of the vanadium-ferrometallurgical slag layer to form a covering layer.

[0019] Furthermore, in step (1), the amount of lime added is 80-150 kg, and the amount of metallic iron added is 20-50 kg.

[0020] Furthermore, in step (2), the smelting furnace is left to stand for 1-3 minutes.

[0021] Furthermore, in step (3), the smelting furnace is powered on again for heating for 5 to 15 minutes.

[0022] Furthermore,

[0023] Before step (1), the following steps are also included:

[0024] (0-1) Put the raw materials required for smelting vanadium iron alloy FeV50 or FeV80 into the smelting furnace;

[0025] (0-2) Electric furnace arc heating smelting to form vanadium-ferroalloy molten pool and vanadium-ferroalloy smelting slag layer;

[0026] After step (3), the following steps are also included:

[0027] (4) After the smelting is completed, the smelting furnace is lifted out and left to cool.

[0028] Furthermore,

[0029] In step (0-2), the arc heating smelting temperature is 2000-2400°C, and the electric current is applied for smelting for 20-90 minutes to form a vanadium-ferroalloy molten pool;

[0030] In step (4), the smelting furnace is left to cool for 20 to 24 hours.

[0031] Compared with the prior art, the beneficial technical effects of the present invention are:

[0032] The inhibitor of the present invention comprises a mixed raw material composed of lime and metallic iron. The inhibitor is added to the vanadium smelting slag layer in the smelting furnace in the later stage of vanadium smelting. Then, electric heating is applied to form a covering layer on the upper layer of the slag to suppress the splashing of the high-temperature slag of vanadium smelting, thereby avoiding injuries to personnel caused by slag splashing, and preventing burns of smelting flat cars, smelting tracks, lifting cantilevers, motors, and various equipment in the smelting room. In addition, the addition of lime has a certain auxiliary effect in diluting the viscosity of the vanadium smelting slag, and the metallic iron plays a role in quickly reducing the temperature of the upper layer of slag and enhancing the sedimentation of residual vanadium in the slag. The method described in the present invention has a short process flow, strong operability, and has an excellent effect of suppressing slag splashing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a flow chart of the method for suppressing slag splashing in the late stage of ferrovanadium smelting according to the present invention;

[0035] Figure 2 This is a schematic diagram of the conditions in the smelting furnace when lime is added to the ferrovanadium smelting slag layer in the smelting furnace to form a covering layer in the late stage of ferrovanadium smelting. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0037] The present invention provides an inhibitor for suppressing slag splashing in the later stages of ferrovanadium smelting. The inhibitor comprises lime and metallic iron. The inhibitor is obtained by weighing and uniformly mixing the lime and metallic iron in a mass ratio of 80-150:20-50. In a preferred embodiment, the lime comprises at least one of active lime, calcined lime, and passivated lime. The mass contents of the main components of the active lime, calcined lime, and passivated lime are: CaO ≥ 85%, CaO + MgO ≥ 88%, S ≤ 0.05%, P ≤ 0.05%, and a calcium oxide activity ≥ 300 ml / mol, with the remainder being iron, SiO2, manganese, etc. In a preferred embodiment, the metallic iron is at least one of iron granules and steel scraps, and the particle size of the metallic iron is ≤ 15 mm.

[0038] like Figure 1As shown, the present invention also provides a method for suppressing slag splashing in the late stage of ferrovanadium smelting. It should be understood by those skilled in the art that the term "late stage of ferrovanadium smelting" refers to "after refining". Figure 2 As shown, in a smelting furnace 1 (the inner layer of the smelting furnace 1 is a refractory material layer 5), a ferrovanadium alloy molten pool 2 and a ferrovanadium smelting slag layer 3 located above the ferrovanadium alloy molten pool 2 are obtained through refining. Then, the method performs the following steps:

[0039] (1) Stop energizing the smelting furnace 1, remove the electrodes, and add the above-mentioned inhibitors including lime and metallic iron to the vanadium-ferrometallurgical slag layer 3.

[0040] The amount of lime and metallic iron added is adjusted based on the charge structure and slag thickness. In a preferred embodiment, the amount of lime added is 80-150 kg, with preferred amounts being 80 kg, 90 kg, 100 kg, 110 kg, 120 kg, 130 kg, 140 kg, and 150 kg. The amount of metallic iron added is 20-50 kg, with preferred amounts being 20 kg, 25 kg, 30 kg, 35 kg, 40 kg, 45 kg, and 50 kg.

[0041] (2) The smelting furnace 1 is allowed to stand, and an endothermic reaction occurs between the lime and the high-temperature vanadium-ferrometallurgical slag. In a preferred embodiment, the smelting furnace 1 is allowed to stand for 1-3 minutes;

[0042] (3) The smelting furnace 1 is powered on and heated again, so that the lime melts on the surface of the ferrovanadium smelting slag layer 3 to form a covering layer 4.

[0043] The time for reheating the smelting furnace is adjusted according to the charge structure, slag layer thickness, and the amount of lime and metallic iron added. In a preferred embodiment, the time for reheating the smelting furnace is 5 to 15 minutes, preferably 5 minutes, 7 minutes, 9 minutes, 11 minutes, 13 minutes, or 15 minutes.

[0044] Those skilled in the art should also understand that, before step (1), the following steps are also included: (0-1) the raw materials required for smelting vanadium-ferroalloy FeV50 or FeV80 are put into the smelting furnace. (0-2) the electric furnace is arc-struck and heated to form a vanadium-ferroalloy molten pool and a vanadium-ferroalloy slag layer. In a preferred embodiment, the temperature of the arc-struck heating smelting is 2000-2400°C, and the electric smelting is carried out for 20 to 90 minutes to form the vanadium-ferroalloy molten pool. After step (3), the following steps are also included: (4) after the smelting is completed, the smelting furnace is lifted out and allowed to cool. In a preferred embodiment, the smelting furnace is allowed to cool for 20 to 24 hours.

[0045] Example 1

[0046] Conventional ferrovanadium (FeV80) ingredients include flake vanadium pentoxide, powdered vanadium trioxide, residual alloy cold material of the same grade, aluminum granules, iron granules, and active lime. FeV80 is smelted using the electrothermal method. Arc heating is performed at a temperature of 2000°C for 90 minutes to form a ferrovanadium alloy molten pool and a ferrovanadium slag layer. After the injection refining is completed, the furnace is de-energized, the electrodes are removed, and active lime and metallic iron are weighed and mixed at a mass ratio of 150 kg:50 kg. The mixture is then added to the ferrovanadium slag layer in the furnace. The furnace is then allowed to stand for one minute to allow the active lime to undergo an endothermic reaction with the high-temperature ferrovanadium slag. The furnace is then heated again for 15 minutes to promote surface melting of the active lime and form a coating. After the smelting is completed, the furnace is allowed to cool and dismantle, yielding the ferrovanadium FeV80 alloy. Experimental results show that the method for suppressing vanadium-ferrometallurgical slag splashing of the present invention can prevent slag splashing, thereby avoiding personal injury and equipment burning caused by high-temperature hot slag splashing.

[0047] Example 2

[0048] The only difference between this embodiment and embodiment 1 is that the lime in the inhibitor used in this embodiment is calcined lime.

[0049] Example 3

[0050] The only difference between this embodiment and embodiment 1 is that the lime in the inhibitor used in this embodiment is passivated lime.

[0051] Example 4

[0052] Ferrovanadium (FeV80) ingredients include flake vanadium pentoxide, residual alloy cold material of the same grade, aluminum granules, iron granules, and active lime. Arc heating smelting is performed at a temperature of 2200°C for 50 minutes to form a ferrovanadium alloy molten pool and a ferrovanadium slag layer. After the injection refining is completed, the furnace is de-energized, the electrodes are removed, and active lime and metallic iron are weighed and mixed at a mass ratio of 120 kg:40 kg. The mixture is then added to the ferrovanadium slag layer in the furnace. The furnace is allowed to stand for 2 minutes to allow the active lime to undergo an endothermic reaction with the high-temperature ferrovanadium slag. The furnace is then heated again for 9 minutes to promote surface melting of the active lime and form a coating layer. After smelting, the furnace is allowed to cool and dismantle, yielding the ferrovanadium FeV80 alloy. Experimental results show that given the high heat content of this charge structure, moderate electrode heating can effectively prevent slag splashing, thereby preventing injuries and equipment damage caused by hot slag splashing.

[0053] Example 5

[0054] The only difference between this embodiment and embodiment 4 is that the lime in the inhibitor used in this embodiment is calcined lime.

[0055] Example 6

[0056] The only difference between this embodiment and embodiment 4 is that the lime in the inhibitor used in this embodiment is passivated lime.

[0057] Example 7

[0058] Ferrovanadium (FeV80) ingredients include flake vanadium pentoxide, other vanadium-containing materials, aluminum granules, iron granules, and active lime. Arc heating is performed at a temperature of 2400°C for 20 minutes to form a ferrovanadium alloy molten pool and a ferrovanadium slag layer. After the injection refining is completed, the furnace is de-energized, the electrodes are removed, and active lime and metallic iron are weighed and mixed at a mass ratio of 80 kg:20 kg. The mixture is then added to the ferrovanadium slag layer in the furnace. The furnace is allowed to stand for 3 minutes to allow the active lime to undergo an endothermic reaction with the high-temperature ferrovanadium slag. The furnace is then heated again for 5 minutes to promote surface melting of the active lime and form a coating. After smelting, the furnace is allowed to cool and dismantle, yielding the ferrovanadium alloy FeV80. Experimental results show that this charge structure, with its high heat content, can prevent slag splashing with a short heating period, thus preventing injuries to personnel and equipment damage caused by hot slag splashing.

[0059] Example 8

[0060] The only difference between this embodiment and embodiment 7 is that the lime in the inhibitor used in this embodiment is calcined lime.

[0061] Example 9

[0062] The only difference between this embodiment and embodiment 7 is that the lime in the inhibitor used in this embodiment is passivated lime.

[0063] The present invention utilizes the characteristics of lime's light density and low melting temperature and metallic iron's rapid heat absorption to reduce the slag temperature. In the later stage of ferrovanadium smelting, lime and metallic iron are added to the ferrovanadium smelting slag layer in the smelting furnace, so that a covering layer is formed on the ferrovanadium smelting slag layer, thereby playing a role in suppressing the splashing of the high-temperature ferrovanadium smelting slag.

[0064] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0065] It should be pointed out in particular that the various components or steps in the above-mentioned embodiments can be cross-linked, replaced, added, or deleted with each other. Therefore, the combinations formed by these reasonable permutations and combinations should also fall within the scope of protection of the present invention, and the scope of protection of the present invention should not be limited to the embodiments.

[0066] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to limit the scope of the disclosure of the present invention (including the claims) to these examples. Within the spirit of the present invention, the technical features of the above embodiments or different embodiments may be combined, and many other variations exist in different aspects of the present invention as described above, which are not provided in detail for the sake of clarity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for suppressing slag splashing in the late stage of ferrovanadium smelting, characterized in that: After refining in the smelting furnace to obtain the vanadium-ferroalloy molten pool and the vanadium-ferroalloy slag layer, the following steps are performed: (1) stopping powering the smelting furnace, removing the electrodes, and adding an inhibitor comprising lime and metallic iron to the vanadium-ferrometallurgical slag layer, wherein the mass ratio of the lime to the metallic iron is 80-150:20-50; (2) The smelting furnace is left to stand, and an endothermic reaction occurs between the lime and the vanadium-iron smelting slag; (3) The smelting furnace is powered on and heated again, so that the lime melts on the surface of the vanadium-ferrometallurgical slag layer to form a covering layer.

2. The method according to claim 1, characterized in that In step (1), the amount of lime added is 80-150 kg, and the amount of metallic iron added is 20-50 kg.

3. The method according to claim 1, characterized in that In step (2), the smelting furnace is left to stand for 1-3 minutes.

4. The method according to claim 1, wherein In step (3), the smelting furnace is powered on again for heating for 5 to 15 minutes.

5. The method according to claim 1, wherein Before step (1), the following steps are also included: (0-1) Put the raw materials required for smelting vanadium iron alloy FeV50 or FeV80 into the smelting furnace; (0-2) Electric furnace arc heating smelting to form vanadium-ferroalloy molten pool and vanadium-ferroalloy smelting slag layer; After step (3), the following steps are also included: (4) After the smelting is completed, the smelting furnace is lifted out and left to cool.

6. The method according to claim 5, characterized in that In step (0-2), the arc heating smelting temperature is 2000-2400°C, and the electric current is applied for smelting for 20-90 minutes to form a vanadium-ferroalloy molten pool; In step (4), the smelting furnace is left to cool for 20 to 24 hours.

7. The method according to claim 1, characterized in that The lime includes at least one of active lime, calcined lime and passivated lime.

8. The method according to claim 7, characterized in that The mass contents of the main components of the active lime, the calcined lime, and the passivated lime are: CaO ≥ 85%, CaO + MgO ≥ 88%, S ≤ 0.05%, P ≤ 0.05%, the activity of calcium oxide ≥ 300 ml / mol, and the remainder is iron, SiO2, and manganese.

9. The method according to claim 1, characterized in that The metallic iron is at least one of iron particles and steel scraps, and the particle size of the metallic iron is ≤15 mm.

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