阅读说明：本技术 一种顶吹氧枪、提钒顶底复吹方法及提钒冶炼方法 (Top-blown oxygen lance, vanadium extraction top-bottom combined blowing method and vanadium extraction smelting method ) 是由 吴伟 徐瑜 肖峰 赵进宣 冉顶立 崔怀周 高琦 李相臣 赵博 于 2020-11-30 设计创作，主要内容包括：本发明涉及一种顶吹氧枪、提钒顶底复吹方法及提钒冶炼方法,属于钒钛磁铁矿冶炼技术领域,解决了现有技术中提钒转炉中钒的氧化率低、钒渣流动性差、炉渣中金属铁含量高的问题。本发明涉及的顶吹氧枪,具有n个主孔,均匀分布,具有m个副孔,位于主孔所在的面上,均匀分布于相邻主孔之间,n＝3-6,m＝n或2n。实现了提钒转炉的钒的高氧化率,炉渣内金属含量的有效控制。(The invention relates to a top-blowing oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, belongs to the technical field of vanadium-titanium magnetite smelting, and solves the problems of low vanadium oxidation rate, poor vanadium slag fluidity and high metal iron content in slag in a vanadium extraction converter in the prior art. The top-blown oxygen lance of the present invention has n main holes, m auxiliary holes and n-3-6, and is distributed homogeneously between adjacent main holes. The high oxidation rate of vanadium of the vanadium extraction converter is realized, and the metal content in the slag is effectively controlled.)

1. A top-blown oxygen lance is characterized by comprising n main holes, wherein the n main holes are uniformly distributed and have m auxiliary holes, the auxiliary holes are positioned on the plane of the main holes and are uniformly distributed between the adjacent main holes, and n is 3-6, and m is n or 2 n.

2. The top-blown oxygen lance as claimed in claim 1, wherein the main bore has a bore diameter of d₂40-55mm, and the Mach number of the blown oxygen is 1.95-2.05; the aperture of the secondary hole is d₃8-15mm, and the Mach number of the blown oxygen gas is 1.

3. A vanadium extraction top-bottom combined blowing method is characterized in that in the smelting of a vanadium extraction converter, the top-blowing oxygen lance of claim 1 or 2 is used for blowing, and the method comprises the following steps:

step 1, 0-120 seconds after the start of converting, 2-3Nm of top-blown oxygen flow³T/min, 0.8-1.0m of oxygen lance position, and bottom blowing flow rate of 0.02-0.08Nm³/min·t；

Step 2, 121-³T/min, 1.0-1.2m of oxygen lance position, and 0.06-0.2Nm of bottom blowing flow³/min·t；

Step 3, 261-³T/min, 0.8-0.9m of oxygen lance position, and bottom blowing flow rate of 0.12-0.2Nm³/min·t。

4. A vanadium extraction smelting method, characterized in that the vanadium extraction top-bottom combined blowing method of claim 3 is used in a vanadium extraction converter, and aluminum-containing materials are added when oxygen gas is blown in.

5. The vanadium extraction and smelting method according to claim 4, wherein the addition amount of the aluminum material is 1-6 kg/t.

6. The vanadium extraction smelting method according to claim 4, wherein the smelted vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.01 to 4.2 percent of C, 0.22 to 0.25 percent of Si, 0.18 to 0.22 percent of Mn, 0.10 to 0.12 percent of P, 0.10 to 0.12 percent of S, 0.12 to 0.14 percent of Ti and 0.31 to 0.34 percent of V.

7. The vanadium extraction and smelting method according to claim 4, wherein the addition amount of the iron sheet balls in the smelting process is 14-20 kg/t.

8. The vanadium extraction and smelting method according to claim 4, wherein the semisteel obtained by smelting in the converter comprises the following components in percentage by mass: 2.8 to 3.8 percent of C, 0.025 to 0.032 percent of V, 0.02 to 0.06 percent of Mn, 0.11 to 0.13 percent of P, and 0.011 to 0.025 percent of S.

9. The vanadium extraction smelting method according to claim 4, wherein the temperature at the smelting end point of the converter is 1350-. .

10. The vanadium extraction and smelting method according to claim 4, wherein the vanadium slag obtained by smelting in the converter comprises the following chemical components in percentage by mass: SiO 2₂ 12-20％，CaO 3-5％，Cr₂O₃0.8-1.5％，V₂O₅ 19-25％，Al₂O₃3.0-16.0％；FeO 20-35％，M.Fe 5-12％。

Technical Field

The invention relates to the technical field of vanadium-titanium magnetite smelting, in particular to a top-blowing oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method.

Background

In the process of extracting vanadium from the converter, vanadium-containing molten iron is added into the converter, the vanadium-containing molten iron is stirred by high-speed oxygen jet flow, and elements such as silicon, vanadium, manganese, titanium, iron and the like in the molten iron are oxidized into stable oxides to form vanadium slag of a vanadium oxide combination. It is an important method widely adopted in a plurality of molten iron vanadium extraction processes, and comprises a single-slag method, a double-slag method and a duplex method. The single slag method and the double slag method are used for extracting vanadium and smelting steel in the same converter. The former vanadium extraction slag is mixed with steel-making slag, the slag quantity is large, and V in the slag₂O₅Low content and no direct use value. In the latter, the vanadium slag obtained by vanadium extraction is poured out firstly, then semi-steel is smelted into steel, the quality of the vanadium slag is superior to that of a single slag method, but ideal industrial vanadium slag cannot be obtained, because steel-making slag stuck on a furnace lining enters the vanadium slag during vanadium extraction, the slag amount of the vanadium slag is increased, and the V is reduced₂O₅Grade and quality. The duplex method adopts two converters, one converter is specially used for extracting vanadium, vanadium slag is separately recovered, and semisteel is transferred into the other converter for slagging and steelmaking. The method can obtain high-quality vanadium slag with industrial application value. The general process comprises the steps of adding vanadium-containing molten iron into a converter, passing pure oxygen or air through a movable or fixed spray gun, and adopting different forms of top-blown converter process with oxygen, bottom-blown air and side-blown air and the like in the blowing direction of the pure oxygen or air from the spray gunA top-bottom combined blowing process combining top blowing and bottom blowing.

The core of the blowing process of the vanadium extraction converter is vanadium extraction and carbon protection, and the vanadium-containing pig iron blocks or scrap steel (the addition amount is about 20-30 percent of the added molten iron) and iron sheets (the addition amount is about 5-7 percent of the added molten iron) are added; and oxygen blowing is carried out, vanadium in the furnace is fully oxidized into vanadium oxide, and finally the vanadium oxide is separated in the form of vanadium slag. In the blowing process of the existing vanadium extraction process, the oxidation rate of molten iron vanadium is low, the melting point of the formed vanadium slag is high, and the fluidity of the formed vanadium slag is poor. Therefore, the content of residual vanadium in the semi-steel is high, the fluctuation is large, and the average residual vanadium is more than 0.037%; and the content of the metallic iron in the vanadium slag is higher, the fluctuation is larger, and the average content of the metallic iron in the slag is 23-30%.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a top-blown oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, so as to solve one of the following problems in the prior art: (1) the oxidation rate of vanadium in the vanadium extraction converter is low; (2) the vanadium slag has poor fluidity; (3) the residual vanadium content in the semisteel is high; (4) the high content of metallic iron in the slag.

In one aspect, the invention provides a top-blown oxygen lance, which is provided with n main holes, is uniformly distributed, is provided with m auxiliary holes, is positioned on the surface of the main holes, and is uniformly distributed between the adjacent main holes, wherein n is 3-6, and m is n or 2 n.

Further, the aperture of the main hole is d₂40-55mm, and the Mach number of the blown oxygen is 1.95-2.05; the aperture of the secondary hole is d₃8-15mm, and the Mach number of the blown oxygen gas is 1.

Furthermore, the central included angle of the main hole is 10-15 degrees, and the central included angle of the auxiliary hole is the same as the central included angle of the main hole.

On one hand, the invention relates to a vanadium extraction top-bottom combined blowing method, which is used for blowing by using the top blowing oxygen lance in the smelting of a vanadium extraction converter and comprises the following steps:

step 1, 0-120 seconds after the start of converting, 2-3Nm of top-blown oxygen flow³Min, oxygen lance position 0.8-1.0m, bottom blowing flow rate 0.02-0.08Nm³/min；

Step 2, 121-³Min, oxygen lance position 1.0-1.2m, bottom blowing flow rate 0.06-0.2Nm³/min；

Step 3, 261-³Min, oxygen lance position 0.8-0.9m, bottom blowing flow rate 0.12-0.2Nm³/min。

In another aspect, the present invention provides a vanadium extraction smelting method using the vanadium extraction top-bottom combined blowing method according to claim 3 in a vanadium extraction converter, wherein an aluminum-containing material is added at the beginning of blowing oxygen, and the aluminum-containing material is bauxite or bauxite.

Further, the adding amount of the aluminum material is 1-6 kg/t;

further, the mass percentage of the alumina in the slag is 5-18%.

Further, the chemical components of the smelted vanadium-containing molten iron are calculated by mass percent: 4.01 to 4.2 percent of C, 0.22 to 0.25 percent of Si, 0.18 to 0.22 percent of Mn, 0.10 to 0.12 percent of P, 0.10 to 0.12 percent of S, 0.12 to 0.14 percent of Ti and 0.31 to 0.34 percent of V.

Further, the adding amount of the iron sheet balls in the smelting process is 14-20 kg/t;

furthermore, the adding amount of the pellet ore is 2-8 kg/t.

Further, the semisteel obtained by smelting in the converter comprises the following components in percentage by mass: 2.8 to 3.8 percent of C, 0.025 to 0.032 percent of V, 0.02 to 0.06 percent of Mn, 0.11 to 0.13 percent of P, and 0.011 to 0.025 percent of S.

Further, the temperature of the smelting end point of the converter is 1350-.

Further, the vanadium slag is obtained by smelting in a converter, and the vanadium slag comprises the following chemical components in percentage by mass: SiO 2₂ 12-20％，CaO 3-5％，Cr₂O₃ 0.8-1.5％，V₂O₅ 19-25％，Al₂O₃ 3.0-16.0％；FeO 20-35％，M.Fe 5-12％。

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

(1) the oxygen lance is provided with a plurality of auxiliary holes which are positioned on the surface of the main hole and are uniformly distributed around the main hole, so that the impact area of oxygen jet flow is increased, the contact area of vanadium in molten iron and oxygen airflow is promoted, and the oxidation efficiency of the vanadium in the molten iron is improved.

(2) Compared with the published CN106282481A, the auxiliary holes are positioned on the surface of the main hole, the blowing and jetting direction of the high-pressure oxygen is aligned to the surfaces of molten iron and slag in the furnace and does not act on the furnace wall lining, and the effect of the high-pressure oxygen on the furnace wall lining is avoided.

(3) Because the flow of the oxygen blown and jetted by the auxiliary holes is smaller than that of the main holes, most of the oxygen blown and jetted by the auxiliary holes is on the surfaces of molten iron and slag, and the completely oxidized carbon monoxide is oxidized in the oxidation process of the main holes, so that the reduction of the vanadium oxide is avoided.

(4) By adding the aluminum material in the smelting process, the melting point of the vanadium slag is reduced, the fluidity of the vanadium slag at high temperature is improved, the oxidation rate of vanadium in molten iron is improved, and the separation of end-point slag and metal is facilitated.

(5) The oxygen lance nozzle has an auxiliary hole structure which is coplanar with the main hole, and the aluminum material is added to increase the fluidity of the vanadium slag, so that the reduction of the residual vanadium content of semisteel at the vanadium extraction end point (less than 0.032%) and the reduction of the metal iron content of the vanadium slag (less than 20%) are realized.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 shows the free energy change of element oxidation during vanadium extraction in a vanadium extraction furnace.

FIG. 2a is a top view of the structure of the oxygen lance with three main nozzles and three auxiliary holes.

FIG. 2b is a sectional view of the oxygen lance structure with three main nozzles and three auxiliary holes in the direction of A-A.

FIG. 3a is a top view of the structure of the oxygen lance with three main jet holes and six auxiliary holes.

FIG. 3b is a sectional view of the oxygen lance structure with three main nozzles and six auxiliary holes in the direction of A-A.

FIG. 4a is a top view of the structure of the oxygen lance with four main jet holes and four auxiliary holes.

FIG. 4b is a sectional view of the oxygen lance structure with four main nozzles and four auxiliary holes in the direction of A-A.

FIG. 4c is a sectional view of the lance structure B-B with four main nozzles and four auxiliary holes.

FIG. 5a is a top view of the structure of the oxygen lance with four main nozzles and eight auxiliary nozzles.

FIG. 5b is a sectional view of the oxygen lance structure with four main nozzles and eight auxiliary holes in the direction of A-A.

FIG. 5c is a sectional view of the oxygen lance structure B-B with four main nozzles and eight auxiliary holes.

FIG. 6 is a top-blown lance structure containing secondary holes disclosed in patent CN 106282481A.

Detailed Description

The invention provides a top-blown oxygen lance, which is provided with n main holes, is uniformly distributed, is provided with m auxiliary holes, is positioned on the surface of the main holes, and is uniformly distributed between the adjacent main holes, wherein n is 3-6, and m is n or 2 n. That is, the main hole and the auxiliary hole are positioned on the same surface, namely the bottom surface of the oxygen lance, and the openings of the main hole and the auxiliary hole are both towards the bottom surface of the furnace bottom.

The oxygen lance is provided with a main hole and an auxiliary hole, wherein the main hole blows oxygen at a large flow rate to drive oxygen into molten steel and stir the oxygen to promote oxidation of impurities in the lance, and the auxiliary hole adopts a small flow rate to mainly blow oxygen on the surfaces of the molten steel and slag. The blowing and jetting direction of the auxiliary hole adopted in the prior art is lateral and is not in the same direction with the main hole, and a large number of experiments of the inventor find that high-pressure oxygen blown and jetted laterally directly blows and jets on the furnace wall and the furnace lining, the furnace is high in temperature in the blowing process, molten iron and slag are corroded in the furnace, and the auxiliary hole is easy to damage and deform under the blowing and jetting of the oxygen. The blowing and jetting direction of the auxiliary holes is the same as that of the main holes, and the auxiliary holes face to the bottom surface of the furnace bottom and are blown and jetted on molten iron and slag, so that the damage and the influence on the furnace wall and the furnace lining are avoided.

The high-pressure oxygen of the main hole is injected into the molten iron in the furnace in a gas column mode, so that the oxygen above the molten iron is unevenly distributed, the auxiliary holes are evenly distributed around the main hole, the uniformity of the oxygen above the molten iron is effectively improved, the whole molten iron is covered by an oxygen layer, the molten iron and the slag are wrapped and immersed by oxygen atmosphere, the oxidation of vanadium is facilitated, and the oxidation rate of the vanadium is improved. Meanwhile, the oxygen blown by the auxiliary holes can oxidize reducing gases such as carbon monoxide generated by insufficient oxidation in the furnace, so that the reduction of the oxidation rate of vanadium caused by the reduction of the oxidized vanadium by the reducing gases is prevented.

Specifically, the diameter of the main hole is d₂40-55mm, and the Mach number of the blown oxygen is 1.95-2.05; the aperture of the secondary pore is d₃8-15mm, and the Mach number of the blown oxygen gas is 1.

The different functions of the auxiliary hole and the main hole are considered, the aperture and the Mach number of the auxiliary hole have special requirements, and the excessive aperture and the too large Mach number of the auxiliary hole can cause excessive outflow of oxygen from the auxiliary hole and influence on the flow of the main hole, so that the oxygen blown into molten steel by the main hole is insufficient, the stirring effect of the oxygen on the molten steel is reduced, and the oxidation rate of vanadium is seriously influenced. If the aperture and the Mach number of the secondary holes are too small, the secondary holes cannot effectively blow and jet oxygen, an oxygen layer cannot be formed on the surfaces of molten iron and slag, and the reducing gas in the furnace cannot be sufficiently oxidized. Thus, the secondary pores have a pore diameter d₃8-15mm, and the Mach number of the blown oxygen gas is 1.

Specifically, the central included angle of the main hole is 10-15 degrees, and the central included angle of the auxiliary hole is the same as the central included angle of the main hole. It should be noted that the center included angle of the main hole and the center included angle of the secondary hole mentioned in the present application refer to the included angle between the axis of the main hole and the central axis of the oxygen lance and the included angle between the axis of the secondary hole and the central axis of the oxygen lance, respectively.

As shown in FIG. 6, the openings of the secondary holes of the prior art are positioned on the side wall, the openings of the secondary holes and the main holes of the invention are positioned on the same surface and are positioned on the bottom surface, and the central included angle of the secondary holes is lower than 30 degrees. Because the auxiliary holes are positioned between the adjacent main holes, the central included angle of the auxiliary holes is the same as that of the main holes and can be 10-15 degrees. The angle can ensure that oxygen blown out from the auxiliary hole does not act on the furnace wall, the structure of the furnace wall is not influenced, and meanwhile, the oxygen of the auxiliary hole acts on molten steel and slag.

The invention also provides a top-bottom combined blowing method for extracting vanadium, which is used for blowing by using the top-blowing oxygen lance in the smelting of a vanadium extracting converter and comprises the following steps:

step 1, 0-120 seconds after the start of converting, 2-3Nm of top-blown oxygen flow³Min, oxygen lance position 0.8-1.0m, bottom blowing flow rate 0.02-0.08Nm³/min；

Step 2, 121-³Min, oxygen lance position 1.0-1.2m, bottom blowing flow rate 0.06-0.2Nm³/min；

Step 3, 261-³Min, oxygen lance position 0.8-0.9m, bottom blowing flow rate 0.12-0.2Nm³/min。

It has been found that many oxidation reactions and reduction reactions are relatively slow due to the difference in reaction rates during the blowing process. In the blowing process, some impurities are not fully oxidized, the temperature in the furnace is higher after top-blown oxygen is finished, and the reductive substances can slowly reduce the vanadium slag to cause the reduction of the final vanadium oxidation rate. Thus, the three stage top-bottom blowback process described above is employed.

The invention also provides a vanadium extraction smelting method, wherein the vanadium extraction top-bottom combined blowing method is used in a vanadium extraction converter, and an aluminum-containing material is added when oxygen begins to be blown in, wherein the aluminum-containing material is bauxite or bauxite.

In the blowing process, the oxygen sprayed by the oxygen lance oxidizes elements of the molten iron to generate the following oxides:

2C+O₂＝2CO △G0＝-273980-87.02T (1)

Ti+O₂＝TiO₂(S) △G0＝-956480+185.52T (2)

Si+O₂＝SiO₂(S) △G0＝-1302500+287.11T (3)

2Mn+O₂＝2MnO(S) △G0＝-794980+163.4T (4)

4/3V(S)+O₂＝2/3V₂O₃(S) △G0＝-774320+219.17T (5)

the standard free energy of each reaction can be calculated from reactions (1) to (5), as shown in FIG. 1. As can be seen from the figure, the oxidation sequence of the elements in the molten iron is Si, Ti, Mn, V and C within the reaction temperature range of 1300-1400 ℃. Therefore, it is feasible to oxidize off vanadium in the molten iron to generate vanadium trioxide within 1400 ℃, and to inhibit the oxidation of carbon content in the molten iron.

Meanwhile, from (1) and (5), the equation (6) for carbon-reduced vanadium oxide can be calculated as follows:

C+1/3V₂O₃＝CO+2/3V △G0＝500340-306.19T (6)

selecting V₂O₃Activity coefficient of 1.0-1.2X 10^-5。

According to the actual composition, the activity coefficient lgfc of carbon was calculated to be 0.001184, and the activity coefficient lgfv of vanadium was calculated to be 0.02156.

2/3lg(V％)-lg(C％)+26131.51/T-1/3lg(V₂O₃％)＝13.61 (7)

When V is 0.026%, V is calculated according to formula (7)₂O₃The conversion temperature was 1401 ℃ when 20.06% and 3.2% C. Therefore, the vanadium content in the molten iron can be oxidized within 1401 ℃ by adopting the large-flow oxygen supply intensity, so that the oxidation of the carbon content in the molten iron can be inhibited.

According to SiO₂-V₂O₅The ternary phase diagram of-FeO can be calculated, and the SiO of the vanadium slag component in the research can be calculated₂ 25％，FeO 50％，V₂O₅25%, and the melting temperature range is 1350-. Through calculation and research tests, after 5% -15% of alumina is added into the vanadium slag, the fluidity of the slag is increased, and the melting point of the vanadium slag is 1320-1350 ℃.

At 1300-1400 ℃, oxidizing the elements in the molten iron by oxygen in sequence to firstly oxidize impurity elements of silicon, titanium, manganese and vanadium, and finally oxidizing the main component of carbon in the steel; when the temperature reaches 1401 ℃, the carbon in the molten iron can reduce the oxidation product vanadium trioxide into vanadium again; the melting point of the vanadium slag can be reduced to 1320-1350 ℃ by adding 5-15% of alumina into the vanadium slag. Therefore, when oxygen is blown in, the aluminum-containing material is added, so that the melting point of the vanadium slag is 1320-1350 ℃, the vanadium slag is melted, and the fluidity is increased; at this temperature oxygen can oxidize the impurity elements silicon, titanium, manganese and vanadium, but not carbon; at this temperature, carbon does not reduce the oxidized product vanadium trioxide back to vanadium. Considering the industrial cost and the smelting process of extracting vanadium by a converter, bauxite or the mixture of the bauxite and the bauxite is selected as the aluminum material.

Specifically, the adding amount of the aluminum material is 1-6kg/t, and the content of the aluminum oxide in the slag is 5-18% by weight.

According to the research, after 5-18% of alumina is added into the vanadium slag, the fluidity of the slag is increased, and the melting point of the vanadium slag is 1320-1350 ℃, so that the adding amount of the aluminum material is controlled to be 1-6 kg/t.

Specifically, the smelting vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.01 to 4.2 percent of C, 0.22 to 0.25 percent of Si, 0.18 to 0.22 percent of Mn, 0.10 to 0.12 percent of P, 0.10 to 0.12 percent of S, 0.12 to 0.14 percent of Ti and 0.31 to 0.34 percent of V.

It should be noted that, the existing research shows that silicon can thermodynamically reduce vanadium trioxide, which is an oxidation product of vanadium, and also has an effect of inhibiting vanadium oxidation, and 0.05% of silicon content inhibits the oxidation of 0.14% of vanadium, so that the silicon content in molten iron is not required to be too high. According to the invention, the auxiliary hole is arranged on the oxygen lance, and the aluminum material is added into the molten iron, so that the silicon (Si 0.22-0.25%) with a large content is effectively oxidized and removed under the condition of not influencing the main effective component carbon of steel, and the oxidation of vanadium is not influenced.

Specifically, the adding amount of the iron sheet balls is 14-20kg/t and the adding amount of the pellet ore is 2-8kg/t in the smelting process.

Specifically, the semi-steel at the smelting end point comprises the following components in percentage by mass: 2.8 to 3.8 percent of C, 0.025 to 0.032 percent of V, 0.02 to 0.06 percent of Mn, 0.11 to 0.13 percent of P, and 0.011 to 0.025 percent of S.

In the semisteel at the smelting end point of the smelting method, the carbon content is kept between 2.8 and 3.8 percent, no great loss occurs, and the vanadium content is 0.025 to 0.032 percent, so that the semisteel is fully oxidized.

Specifically, the temperature at the end of the smelting is 1350-.

Specifically, the vanadium slag component at the smelting end point is characterized by comprising the following chemical components in percentage by mass: SiO 2₂ 12-20％，CaO 3-5％，Cr₂O₃ 0.8-1.5％，V₂O₅ 19-25％，Al₂O₃ 3.0-16.0％；FeO 20-35％，M.Fe 5-12％。

In the vanadium slag at the smelting end point, impurity silicon is effectively oxidized into SiO slag₂12-20%, and the added aluminum material is also mostly separated in the vanadium slag for extracting vanadium (Al)₂O₃3.0-16.0%) and vanadium is effectively oxidized into vanadium trioxide and oxidized again, finally converted into vanadium pentoxide with high conversion rate, and the formed slag is effectively separated in the form of vanadium slag.

It should be noted that, in the prior art, more than 20% of metallic iron exists in the vanadium slag at the smelting end point, i.e. the iron in the molten iron is formed into slag during the slag-making process. The iron and the vanadium slag after slagging are difficult to separate. According to the invention, the auxiliary hole is arranged on the oxygen lance, the aluminum material is added into the molten iron, and the content of metallic iron in the vanadium slag at the smelting end is effectively reduced to 5-12%, so that the waste of iron is reduced, and the difficulty of subsequent further separation is also reduced.

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Example 1

The implementation relates to a top-blown oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, wherein the method comprises the following steps:

the vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.11 percent of C, 0.23 percent of Si, 0.19 percent of Mn0.11 percent of P, 0.10 percent of S, 0.11 percent of Ti and 0.31 percent of V. The oxygen lance structure with a plurality of holes, three main spray holes and three auxiliary holes is adopted, and the structural schematic diagram is shown in figure 2. The oxygen lance main hole is provided with 3 holes, the aperture is 40mm, the Mach number is 2.01, 3 auxiliary holes are arranged around the main hole, the aperture is 8mm, and the Mach number is 1.

The vanadium extraction top-bottom combined blowing method comprises the following steps: 0-120 seconds, and the oxygen flow rate is controlled to be 2.2Nm³Min, oxygen lance position 0.85m, bottom blowing flow rate 0.03Nm³Min; at 121-³Min, oxygen lance position 1.1m, bottom blowing flow 0.08Nm³Min; 261 ℃ and 280 seconds, the oxygen flow rate is 1.8Nm³Min, oxygen lance position 0.8m, bottom blowing flow 0.12Nm³And/min, finishing converting.

When oxygen begins to be blown in, bauxite is added, the adding amount is 1kg/t, and the mass percentage of the alumina in the slag is controlled to be 5.86%. The adding amount of the iron sheet balls in the blowing process is 15.0 kg/t; the addition amount of the pellets was 5.0 kg/t.

The vanadium slag obtained by smelting in the converter comprises the following components in percentage by mass: SiO 2₂ 14％，CaO 4.24％，Cr₂O₃1.37％，Al₂O₃ 5.86％，V₂O₅20.22%, FeO 32.4%, M.Fe 6%. The semisteel comprises the following components: 2.9% of C, 0.026% of V, 0.04% of Mn, 0.11% of P, 0.015% of S and 1350 ℃. In percentage by mass

Example 2

The implementation relates to a top-blown oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, wherein the method comprises the following steps:

the vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.15% of C, 0.26% of Si, 0.21% of Mn0.12% of P, 0.11% of S, 0.12% of Ti and 0.33% of V. The oxygen lance structure with three main spray holes and six auxiliary holes is adopted, and the structural schematic diagram is shown in figure 3. The oxygen lance main hole is provided with 3 holes, the aperture is 45mm, the Mach number is 1.99, 6 auxiliary holes are arranged around the main hole, the aperture is 10mm, and the Mach number is 1.

The vanadium extraction top-bottom combined blowing method comprises the following steps: 0-120 seconds, and the oxygen flow rate is controlled to be 2.3Nm³Min, oxygen lance position 0.9m, bottom blowing flow rate 0.04Nm³Min; at 121-³Min, oxygen lance position 1.2m, bottom blowing flow 0.09Nm³Min; 261 ℃ and 280 seconds, the oxygen flow rate is 2.1Nm³Min, oxygen lance position 0.8m, bottom blowing flow 0.1Nm³And/min, finishing converting.

When oxygen begins to be blown in, bauxite is added, the adding amount is 2kg/t, and the mass percentage of the alumina in the slag is controlled to be 8.0 percent. The adding amount of the iron sheet balls in the blowing process is 15.6 kg/t; the addition amount of the pellets was 6.56 kg/t.

And at the end of converting, obtaining vanadium slag components (in mass percent): SiO 2₂ 14.15％，CaO 4.09％，Cr₂O₃1.28％，Al₂O₃ 8.0％，V₂O₅21.67%, FeO 32.4%, M.Fe 6.9%. The semisteel comprises the following components: 2.9% of C, 0.025% of V, 0.05% of Mn, 0.11% of P, 0.013% of S and 1360 ℃ of temperature.

Example 3

The implementation relates to a top-blown oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, wherein the method comprises the following steps:

the vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.14 percent of C, 0.24 percent of Si, 0.19 percent of Mn, 0.10 percent of P, 0.11 percent of S, 0.13 percent of Ti and 0.33 percent of V. The oxygen lance structure with a plurality of holes, four main spray holes and four auxiliary holes is adopted, and the structural schematic diagram is shown in figure 4. The oxygen lance main hole is provided with 4 holes, the aperture is 50mm, the Mach number is 1.99, 4 auxiliary holes are arranged around the main hole, the aperture is 12mm, and the Mach number is 1.

The vanadium extraction top-bottom combined blowing method comprises the following steps: 0-120 seconds, and the oxygen flow rate is controlled to be 2.5Nm³Min, oxygen lance position 0.8m, bottom blowing flow rate 0.04Nm³Min; at 121-³Min, oxygen lance position 1.0m, bottom blowing flow 0.09Nm³Min; 261 ℃ and 280 seconds, the oxygen flow rate is 2.2Nm³Min, oxygen lance position 0.8m, bottom blowing flow 0.12Nm³And/min, finishing converting.

When oxygen gas is blown in, bauxite is added, the adding amount is 3kg/t, and the mass percentage content of the alumina in the slag is controlled to be 10.23%. The adding amount of the iron sheet balls in the blowing process is 16 kg/t; the addition amount of the pellets was 6.0 kg/t.

At the end of converting, the obtained vanadium slag comprises the following components in percentage by mass: SiO 2₂ 14.47％，CaO 4.0％，Cr₂O₃1.08％，Al₂O₃ 10.23％，V₂O₅20.9%, FeO 31.51%, M.Fe 8.9%. The semi-steel comprises the following components: 3.1% of C, 0.027% of V, 0.06% of Mn, 0.11% of P, 0.017% of S and a temperature of 1365 ℃.

Example 4

The implementation relates to a top-blown oxygen lance, a vanadium extraction top-bottom combined blowing method and a vanadium extraction smelting method, wherein the method comprises the following steps:

the vanadium-containing molten iron comprises the following chemical components in percentage by mass: 4.09% of C, 0.23% of Si, 0.19% of Mn, 0.11% of P, 0.011% of S, 0.12% of Ti and 0.33% of V. The oxygen lance structure with four main spray holes and eight auxiliary holes is adopted, and the structural schematic diagram is shown in figure 5. The oxygen lance main hole is provided with 4 holes, the aperture is 55mm, the Mach number is 1.98, 8 auxiliary holes are arranged around the main hole, the aperture is 15mm, and the Mach number is 1.

The vanadium extraction top-bottom combined blowing method comprises the following steps: 0-120 seconds, and the oxygen flow rate is controlled to be 2.2Nm³Min, oxygen lance position 1.0m, bottom blowing flow rate 0.08Nm³Min; at 121-³Min, oxygen lance position 1.2m, bottom blowing flow 0.12Nm³Min; 261 ℃ and 280 seconds, the oxygen flow rate is 2.5Nm³Min, oxygen lance position 0.9m, bottom blowing flow 0.13Nm³And/min, finishing converting.

At the beginning of the oxygen blowing, bauxite or a bauxite mixture was added in a ratio of 1:1 in an amount of 2kg/t, respectively, and the amount of alumina in the slag was controlled to 12.5%. The adding amount of the iron sheet balls in the blowing process is 16 kg/t; the addition amount of the pellets was 5.0 kg/t.

At the end of converting, the obtained vanadium slag comprises the following components in percentage by mass: SiO 2₂ 14.8％，CaO 4.0％，Cr₂O₃0.95％，Al₂O₃ 12.5％，V₂O₅20.4%, FeO 30.5%, M.Fe 7.9%. The semisteel comprises the following components: 3.3% of C, 0.031% of V, 0.05% of Mn, 0.11% of P, 0.014% of S and 1360 ℃.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.