阅读说明：本技术 无化工过程的高温钒渣直接冶炼氮化钒铁或钒铁的方法 (Method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process ) 是由 张计辉 于 2021-08-25 设计创作，主要内容包括：本发明提供了一种无化工过程的高温钒渣直接冶炼氮化钒铁或钒铁的方法,包括含钒铁水在转炉吹钒过程中,在接近提钒终点时从炉底或炉侧喷吹还原剂,还原渣中氧化铁；出完半钢后从提钒炉顶部加入还原剂继续还原钒渣中的氧化铁,将高温钒渣直接倒入到中频感应炉或电弧炉中或者通过保温渣罐倒入中频感应炉或电弧炉中,在中频感应炉或电弧炉中通过控制还原温度深度还原钒渣中的钒及有益金属元素,并通过控制底吹氮气量得到氮化钒铁或钒铁。本发明以高温钒渣为原料直接生产氮化钒铁,也可生产不同品位的钒铁合金,无需化工用地,而且生产工艺绿色环保,不产生化工废水,能耗明显低于传统钒化工工艺,工艺流程短。(The invention provides a method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process, which comprises the steps of blowing a reducing agent from the bottom or the side of a furnace when the vanadium-containing molten iron is close to the vanadium extraction end point in the vanadium blowing process of a converter, and reducing iron oxide in the slag; and after the semisteel is discharged, adding a reducing agent from the top of the vanadium extraction furnace to continuously reduce iron oxide in the vanadium slag, directly pouring the high-temperature vanadium slag into the medium-frequency induction furnace or the electric arc furnace or pouring the high-temperature vanadium slag into the medium-frequency induction furnace or the electric arc furnace through the heat-preservation slag tank, deeply reducing vanadium and beneficial metal elements in the vanadium slag in the medium-frequency induction furnace or the electric arc furnace by controlling the reduction temperature, and controlling the amount of bottom blowing nitrogen to obtain nitrided ferrovanadium or ferrovanadium. The method directly produces the nitrided ferrovanadium by taking the high-temperature vanadium slag as a raw material, can also produce ferrovanadium alloys with different grades, does not need chemical fields, has green and environment-friendly production process, does not produce chemical wastewater, has energy consumption obviously lower than that of the traditional vanadium chemical process, and has short process flow.)

1. A method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process is characterized by comprising the following steps:

s101, after semi-steel is discharged, adding a reducing agent from the top of a vanadium extraction converter for reduction, and simultaneously blowing the reducing agent or reducing gas or inert gas from the bottom or blowing the reducing agent or reducing gas or inert gas from the side surface of the converter;

s102, directly pouring high-temperature vanadium slag into a medium-frequency induction furnace or an electric arc furnace after vanadium extraction is finished, or pouring the high-temperature vanadium slag into the medium-frequency induction furnace or the electric arc furnace through a heat-preservation slag tank, deeply reducing vanadium and other beneficial metal elements in the vanadium slag by controlling the reduction temperature, and obtaining nitrided ferrovanadium melt or ferrovanadium melt by controlling the quantity of bottom blowing nitrogen;

and S103, injecting the nitrided ferrovanadium or ferrovanadium melt into a mold, and cooling to obtain a ferrovanadium nitride or ferrovanadium finished product.

2. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process according to claim 1, wherein the method further comprises, before step S101:

s100, in the process of blowing vanadium in the converter, blowing a reducing agent or reducing agent gas from the furnace bottom or the side surface of the furnace to the molten metal and the vanadium slag when the vanadium extraction end point is approached, or adding a reducing agent from the furnace top when the vanadium extraction end point is approached to reduce iron oxide in the slag.

3. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein in step S100, the mass of the reducing agent injected from the bottom or side of the furnace to the molten metal and the vanadium slag is 5-35% of the total iron mass in the vanadium slag, and the introduction amount of the reducing agent gas is 10-500m³And/min, adding a reducing agent from the top of the furnace, wherein the mass of the reducing agent is 5-15% of the mass of the total iron in the vanadium slag.

4. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein the reducing agent comprises one or more of coal powder particles, carbon powder particles and semi-coke powder particles, and the reducing gas is one or a combination of natural gas and coke oven gas.

5. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein the mass of the injected reducing agent in step S101 is 5-35% of the total iron mass in the vanadium slag, and the gas introduction amount of the reducing agent is 10-500m³/min。

6. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein the reduction temperature in step S102 is 1450-1650 ℃.

7. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein the nitrogen gas is introduced in an amount of 0-800m in step S102³/min。

8. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process as claimed in claim 1 or 2, wherein in step S102, the medium frequency induction furnace or the electric arc furnace is sealed by covering after leaving the electrode position, and nitrogen is blown into the furnace through the bottom lance, finally obtaining nitrided ferrovanadium melt or ferrovanadium melt with different nitrogen content.

9. The method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without chemical process according to claim 1, which is characterized by comprising the following steps:

(1) in the process of blowing vanadium in the converter, blowing a reducing agent accounting for 5-35% of the total iron mass in the vanadium slag from the furnace bottom or the furnace side when the vanadium extraction is close to the end point or blowing a reducing agent gas accounting for 10-500m3/min from the furnace side, or adding a reducing agent accounting for 5-15% of the total iron mass in the vanadium slag from the furnace top when the vanadium extraction is close to the end point;

(2) after semi-steel is discharged, one or more of blue carbon granules, coke granules and coal granule reducing agents are added from the top of the vanadium extraction converter for reduction, and the adding amount of the blue carbon granules, the coke granules and the coal granule reducing agents is 5-35% of the total iron mass in the vanadium slag;

(3) directly pouring the high-temperature vanadium slag into a medium-frequency induction furnace or an electric arc furnace or pouring the high-temperature vanadium slag into the medium-frequency induction furnace or the electric arc furnace through a heat-preservation slag tank, controlling the reduction temperature to 1450-; sealing the electrode position of the medium-frequency induction furnace or the electric arc furnace, blowing nitrogen into the furnace through a bottom spray gun, wherein the nitrogen input is 0-800m³Min, obtaining nitrided ferrovanadium or ferrovanadium solution;

(4) and pouring the ferrovanadium nitride or ferrovanadium melt into a mold, cooling to obtain a ferrovanadium nitride or ferrovanadium finished product, and further processing into small qualified blocks meeting the steelmaking requirement.

Technical Field

The invention relates to the technical field of vanadium metallurgy, in particular to a method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without a chemical process.

Background

The traditional preparation process of nitrided ferrovanadium is that vanadium slag is used as a raw material to enter a chemical plant, ferrovanadium is produced through multiple complex chemical procedures, and then the ferrovanadium is used as the raw material to carry out solid nitriding, so that the energy consumption and the cost in the production process are high. In order to shorten the process flow, researchers also directly use pure vanadium oxide produced in a vanadium chemical plant as a raw material, iron powder as an iron source and carbon powder as a reducing agent, and introduce nitrogen to prepare the ferrovanadium nitride. The vanadium oxide produced by the method is produced in a chemical process, generates a large amount of waste gas, waste water and waste residues, and generates great pollution to the environment.

In order to further shorten the process flow, researchers also directly smelt ferrovanadium by taking vanadium slag as a raw material. CN111041206A discloses a method for preparing a ferrovanadium alloy based on vanadium slag, which comprises the steps of taking vanadium slag as a raw material, adding reducing carbon and slagging auxiliary materials to carry out smelting reaction, and finally obtaining the ferrovanadium alloy. Although the method further shortens the process flow, the grade of ferrovanadium is low, the grade of vanadium is generally about 20 percent, ferrovanadium nitride can not be produced, and the physical heat of vanadium slag extracted by a converter is not fully utilized.

Disclosure of Invention

The existing ferrovanadium nitride preparation process has the problems of long production process, large vanadium loss, serious environmental pollution of three wastes, high energy consumption, high cost and the like, and is difficult to meet the strategic requirements of circular economy construction and sustainable development, more than 80 percent of various alloys of vanadium are used in the steel industry, vanadium alloy products for alloying in the steel industry do not need to be produced by chemical plants, and therefore, the need for developing a high-efficiency clean ferrovanadium nitride and ferrovanadium alloy preparation technology for fixing waste sources, reducing emission, improving the resource utilization rate and solving the environmental pollution is urgently needed.

In order to achieve the purpose, the invention adopts the following technical scheme:

s100, in the process of blowing vanadium in the converter, blowing a reducing agent or reducing agent gas from the bottom of the converter when the vanadium extraction end point is approached, or adding the reducing agent from the top of the converter when the vanadium extraction end point is approached, so as to reduce iron oxide in slag. The approach to the vanadium extraction end point can be a time point when the oxygen step reaches more than 95%, or a time point when the oxygen blowing amount required by the vanadium blowing process reaches 95%.

And S101, after the semisteel is discharged, adding a reducing agent from the top of the vanadium extraction converter for reduction.

S102, directly pouring the high-temperature vanadium slag into a medium-frequency induction furnace or an electric arc furnace or pouring the high-temperature vanadium slag into the medium-frequency induction furnace or the electric arc furnace through a heat-preservation slag pot, deeply reducing vanadium and beneficial metal elements in the vanadium slag by controlling the reduction temperature, and controlling the quantity of bottom blowing nitrogen to obtain the vanadium nitride iron or vanadium iron melt. The beneficial metal can be beneficial metal contained in vanadium slag such as Mn, Cr and the like.

And S103, pouring the ferrovanadium nitride or ferrovanadium melt into a mold, cooling to obtain a ferrovanadium nitride or ferrovanadium finished product, and further processing into small qualified blocks meeting the steel-making requirements. The mold may be a strip-shaped radial mold or the like.

In step S100 of the present invention, the reducing agent includes carbon-containing reducing agents such as carbon powder, pulverized coal, blue carbon powder, and the like. The reducing agent gas comprises one or more of natural gas and coke oven gas.

In the step S100, the mass of a reducing agent is 5-35% of the total iron mass in the vanadium slag by blowing the reducing agent from the furnace bottom or the side surface of the furnace to the molten metal and the vanadium slag, and the gas introduction amount of the reducing agent is 10-500m³And/min, adding a reducing agent from the top of the furnace, wherein the mass of the reducing agent is 5-15% of the mass of the total iron in the vanadium slag. Of course, the reducing agent of the present invention is not limited thereto, and other carbonaceous reducing agents capable of reducing vanadium may be used. The iron oxide in the slag can be completely reduced by adding the reducing agent within the above range. If the addition amount is too small, the reduction of the iron oxide is insufficient; if the amount is too much, the reducing agent is wasted.

In step S101 of the present invention, the reducing agent is a carbon-containing reducing agent such as a semi-coke granule or a semi-coke granule. The reducing agent gas comprises one or more of natural gas and coke oven gas.

In the step S101, the addition amount of the reducing agent is 5-35% of the total iron mass in the vanadium slag. If the addition amount of the reducing agent is less than 5%, the vanadium in the vanadium slag is insufficiently reduced; if the addition amount of the reducing agent is too large, the reducing agent is wasted. Therefore, the adding amount of the reducing agent is controlled to be 5-35% of the total iron mass in the vanadium slag.

The reduction temperature in step S102 of the present invention may be 1450-. In this temperature range vanadium can be reacted. Further, the reduction temperature can be 1550-1600 ℃, and the energy consumption is ensured to be low while vanadium can be reduced to the maximum extent at the temperature.

The nitrogen gas introduction amount in the step S102 of the present invention may be 0 to 800m³/min。

In the step S102, the intermediate frequency furnace or the electric arc furnace is sealed by a cover after being separated from the electrode position, a bottom nitrogen blowing device is arranged, nitrogen is blown into the furnace through a bottom spray gun, and finally the ferrovanadium melt with different nitrogen contents can be obtained.

As a preferred scheme of the invention, the method for directly smelting the nitrided ferrovanadium or ferrovanadium alloy from the high-temperature vanadium slag without the chemical process comprises the following steps:

(1) in the process of blowing vanadium in the converter, a reducing agent is injected from the bottom of the converter when the vanadium extraction is close to the end point, the injection amount of the reducing agent is 5-35% of the total iron mass in the vanadium slag, or the introduction amount of natural gas and coke oven gas is 10-500m³And/min, reducing iron oxide in the slag.

(2) After semi-steel is discharged, carbon-containing reducing agents such as blue carbon granules, coke granules or coal granules are added from the top of the vanadium extraction converter for reduction, and the mass of the carbon-containing reducing agents is 5-35% of the total iron in the vanadium slag.

(3) Directly pouring high-temperature vanadium slag into a medium-frequency induction furnace or an electric arc furnace, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to 1450-1650 ℃, removing an electrode position after the medium-frequency induction furnace or the electric arc furnace finishes reduction, covering and sealing, installing a bottom nitrogen blowing device, blowing nitrogen into the furnace through a bottom spray gun, wherein the nitrogen feeding amount is 0-800m³And/min, obtaining the nitrided ferrovanadium or ferrovanadium solution.

(4) And pouring the ferrovanadium nitride or ferrovanadium melt into a strip-shaped radial mold, cooling to obtain a ferrovanadium nitride or ferrovanadium finished product, and further processing into small qualified blocks meeting the steelmaking requirement.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) can produce both nitrided ferrovanadium and ferrovanadium alloys of different grades.

(2) The production process is green and environment-friendly, no chemical wastewater is generated, the physical heat of the high-temperature vanadium slag is fully utilized, and the energy consumption is obviously lower than that of the traditional vanadium chemical process.

(3) The process flow is short, the vanadium loss is small, chemical raw materials are not consumed, the equipment is simple, the investment is greatly reduced, and the generation amount of solid waste is small.

Detailed Description

Hereinafter, a method for directly smelting nitrided ferrovanadium or ferrovanadium from high-temperature vanadium slag without a chemical process according to the present invention will be described in detail with reference to exemplary embodiments.

Example 1

(1) The vanadium-containing molten iron contains 0.45 percent of V; 0.23% Si; 0.25% Mn; 0.18% Ti; 0.06% Cr. Carbon powder is sprayed to the bottom of the furnace at the end point of vanadium extraction of 150 tons of converter, the adding amount of the carbon powder is 25 percent of the total iron mass in the vanadium slag, and iron oxide in the slag is reduced to obtain V in the high-temperature vanadium slag₂O₅22.52% of TFe, 9.67% of SiO₂、TiO₂17.95 percent of MnO and 4.26 percent of Al2O₃MgO, CaO, etc.

(2) And adding semi-steel from the top of the vanadium extraction converter to reduce, wherein the addition amount of the semi-steel is 25% of the mass of the vanadium slag.

(3) Pouring high-temperature vanadium slag into a 20-ton electric arc furnace through a heat-preservation slag tank, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to be 1600 ℃, simultaneously spraying nitrogen at the bottom, after the reduction is finished, leaving the electric arc furnace to cover and seal an electrode position, and spraying nitrogen into the furnace through a bottom spray gun, wherein the nitrogen input amount is 450m³/min。

(4) Pouring the molten ferrovanadium or ferrovanadium nitride into a strip-shaped radial mold, cooling and processing into small qualified blocks.

The mass percentage content of vanadium in the obtained vanadium nitride ferroalloy is 51.2 percent, and the nitrogen content is 5.95 percent.

Example 2

(1) The vanadium-containing molten iron contains 0.42 percent of V; 0.24% Si; 0.26% Mn; 0.18% Ti; 0.06% Cr. Spraying natural gas to the bottom of the furnace at the end point of vanadium extraction of the 150-ton converter, wherein the introduction amount of the natural gas is 300m³Min, reducing iron oxide in the slag to obtain V in the high-temperature vanadium slag₂O₅21.76% of TFe, 9.58% of SiO₂、TiO₂17.93 percent of MnO and 5.42 percent of Al₂O₃MgO, CaO, etc.

(2) And adding semi-steel from the top of the vanadium extraction converter to reduce, wherein the addition amount of the semi-steel is 20% of the mass of the vanadium slag.

(3) Pouring the high-temperature vanadium slag into a 20-ton intermediate frequency furnace through a heat-preservation slag tank, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to 1550 ℃, sealing the intermediate frequency furnace by a cover, and introducing 380m of bottom-blown nitrogen³/min。

(4) Pouring the molten ferrovanadium or ferrovanadium nitride into a strip-shaped radial mold, cooling and processing into small qualified blocks.

The mass percentage content of vanadium in the obtained vanadium nitride ferroalloy is 48.06 percent, and the nitrogen content is 5.12 percent.

Example 3

(1) The vanadium-containing molten iron contains 0.45 percent of V; 0.20% Si; 0.25% Mn; 0.18% Ti; 0.06% Cr. Spraying coke oven gas to the bottom of the furnace at the end point of vanadium extraction in a 150-ton converter, wherein the introduction amount of the coke oven gas is 50m3/min, and reducing iron oxide in slag to obtain V in high-temperature vanadium slag₂O₅21.55% of TFe, 11.74% of SiO₂19.32% of TiO2, 4.46% of MnO, and the balance of Al₂O₃MgO, CaO, etc.

(2) After the semisteel is discharged, adding coke particles from the top of the vanadium extraction converter for reduction, wherein the adding amount of the coke particles is 15% of the total iron mass of the vanadium slag.

(3) Pouring the high-temperature vanadium slag into a 20-ton medium-frequency induction furnace, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to 1550 ℃, sealing the medium-frequency induction furnace with a cover, and blowing nitrogen into the medium-frequency induction furnace with the bottom blowing nitrogen inlet amount of 200m³/min。

(4) Pouring the molten ferrovanadium or ferrovanadium nitride into a strip-shaped radial mold, cooling and processing into small qualified blocks.

The mass percentage content of vanadium in the obtained vanadium nitride ferroalloy is 48.95 percent, and the nitrogen content is 5.52 percent.

Example 4

(1) The vanadium-containing molten iron contains 0.45 percent of V; 0.22% Si; 0.25% Mn; 0.18% Ti; 0.06% Cr. Carbon powder is sprayed to the furnace bottom at the end point of vanadium extraction of 150 tons of converter, the adding amount of the carbon powder is 15 percent of the total iron mass in the vanadium slag, and iron oxide in the slag is reduced to obtain V in the high-temperature vanadium slag₂O₅18.55% of TFe, 11.90% of SiO₂、TiO₂16.97 percent of MnO and the balance of Al₂O₃MgO, CaO, etc.

(2) After semisteel is discharged, adding coke particles from the top of the vanadium extraction converter for reduction, wherein the adding amount of the coke particles is 15% of the mass of the vanadium slag.

(3) Pouring high-temperature vanadium slag into a 20-ton intermediate frequency furnace, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to 1550 ℃, sealing the intermediate frequency furnace by a cover, adding a bottom nitrogen blowing device, blowing nitrogen into the furnace by an air gun, wherein the nitrogen inlet amount is 125m³/min。

(4) Pouring the molten ferrovanadium or ferrovanadium nitride into a strip-shaped radial mold, cooling and processing into small qualified blocks.

The mass percentage content of vanadium in the obtained vanadium nitride ferroalloy is 45.31 percent, and the nitrogen content is 2.76 percent.

Example 5

(1) The vanadium-containing molten iron contains 0.44 percent of V; 0.22% Si; 0.25% Mn; 0.18% Ti; 0.06% Cr. Carbon powder is sprayed to the bottom of the furnace at the end point of vanadium extraction of 150 tons of converter, the adding amount of the carbon powder is 30 percent of the total iron mass in the vanadium slag, and iron oxide in the slag is reduced to obtain V in the high-temperature vanadium slag₂O₅22.76% of TFe, 9.65% of SiO₂、TiO₂16.43 percent of MnO and the balance of Al₂O₃MgO, CaO, etc.

(2) And adding semi-steel from the top of the vanadium extraction converter to reduce, wherein the addition amount of the semi-steel is 25% of the mass of the vanadium slag.

(3) Pouring the high-temperature vanadium slag into a 20-ton electric arc furnace, deeply reducing vanadium in the vanadium slag by controlling the reduction temperature to be 1600 ℃, and simultaneously blowing nitrogen at the bottom for stirring to finally obtain the ferrovanadium melt.

(4) Pouring the ferrovanadium melt into a strip-shaped radial mold, and cooling to obtain a small qualified block. The mass percentage of vanadium in the obtained ferrovanadium alloy is 50.58%.

Although the present invention has been described above in connection with exemplary embodiments, it will be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the invention as defined in the appended claims.