阅读说明：本技术 采用定向凝固生产高纯金属钒的方法 (Method for producing high-purity metal vanadium by adopting directional solidification ) 是由 顾武安 韩子柯 吕学伟 王烨 潘成 钟大鹏 于 2019-11-12 设计创作，主要内容包括：本发明公开了一种采用定向凝固生产高纯金属钒的方法,属于钒金属冶炼技术领域,包括以下步骤：将定向凝固炉升温至700～800℃,加入氧化钒进行熔化,待氧化钒熔化完全后,喂入镁铝合金丝,开始定向凝固,待氧化钒反应完全后,停止喂线、加热,待样品冷却至室温后,分离得到钒粗品,将钒粗品破碎后用稀盐酸浸出即得高纯金属钒。本发明以氧化钒为原料,镁铝合金Mg<Sub>4</Sub>Al<Sub>3</Sub>为还原剂,降低了反应温度,显著降低了能耗；并且生产和分离过程同时进行,减少了工序,提高了生产效率；制备得到的金属钒纯度高于98％。(The invention discloses a method for producing high-purity metal vanadium by adopting directional solidification, which belongs to the technical field of vanadium metal smelting and comprises the following steps: heating a directional solidification furnace to 700-800 ℃, adding vanadium oxide for melting, feeding magnesium-aluminum alloy wires after the vanadium oxide is completely melted, starting directional solidification, stopping wire feeding and heating after the vanadium oxide is completely reacted, separating to obtain a vanadium crude product after a sample is cooled to room temperature, crushing the vanadium crude product, and leaching with dilute hydrochloric acid to obtain the high-purity vanadium metal. The invention takes vanadium oxide as raw material and magnesium-aluminum alloy Mg 4 Al 3 The reducing agent reduces the reaction temperature and obviously reduces the energy consumption; the production and separation processes are carried out simultaneously, so that the working procedures are reduced, and the production efficiency is improved; the purity of the prepared vanadium metal is higher than 98%.)

1. The method for producing high-purity metal vanadium by adopting directional solidification is characterized by comprising the following steps:

heating a directional solidification furnace to 700-800 ℃, adding vanadium oxide for melting, feeding magnesium-aluminum alloy wires after the vanadium oxide is completely melted, starting directional solidification, stopping wire feeding and heating after the vanadium oxide is completely reacted, separating to obtain a vanadium crude product after a sample is cooled to room temperature, crushing the vanadium crude product, and leaching with dilute hydrochloric acid to obtain the high-purity vanadium metal.

2. The method for producing high-purity vanadium metal by directional solidification according to claim 1, wherein: the vanadium oxide is vanadium trioxide and/or vanadium pentoxide; and the protective gas in the directional solidification furnace is argon.

3. The method for producing high-purity vanadium metal by directional solidification according to claim 1 or 2, wherein: the temperature of the directional solidification furnace is 750-800 ℃; preferably, the temperature of the directional solidification furnace is 750 ℃.

4. The method for producing high-purity vanadium metal by directional solidification according to claim 2, wherein: the weight percentage of aluminum in the magnesium-aluminum alloy wire is 40-60%; preferably, the magnesium-aluminum alloy wires are Mg₄Al₃Alloy wire with diameter of 3mm and density of 2.1g/cm³The linear density was 0.148 g/cm.

5. The method for producing high-purity vanadium metal by directional solidification according to claim 4, wherein: the wire feeding speed of the magnesium-aluminum alloy wires is 0.4-0.5 cm/min; preferably, the wire feeding speed of the magnesium-aluminum alloy wires is 0.43 cm/min.

6. The method for producing high-purity vanadium metal by directional solidification according to claim 2, wherein: the wire feeding time of the magnesium-aluminum alloy wires is 2-6 h.

7. The method for producing high-purity vanadium metal by directional solidification according to claim 6, wherein: the wire feeding time of the magnesium-aluminum alloy wires is 2.2-3.6 hours.

8. The method for producing high-purity vanadium metal by directional solidification according to claim 7, wherein: the reaction time of the vanadium trioxide and the magnesium-aluminum alloy wire is 2.2-2.6 hours, and the reaction time of the vanadium pentoxide and the magnesium-aluminum alloy wire is 3-3.6 hours.

9. The method for producing high-purity vanadium metal by directional solidification according to claim 1, wherein: the directional solidification speed is 10-20 mm/h; preferably, the speed of the directional solidification is 10 mm/h; the diameter of the alloy cylindrical bar blank obtained after solidification is 20-30 mm; preferably 24 mm.

10. The method for producing high-purity vanadium metal by directional solidification according to claim 1, wherein: the separation refers to cutting and separating a crude vanadium product from a sample after observing the height of vanadium at the bottom of the sample; the crushing refers to crushing the crude vanadium product to 80-150 meshes; the concentration of the dilute sulfuric acid is 5-8 mol/L.

Technical Field

The invention belongs to the technical field of vanadium metal smelting, and particularly relates to a method for producing high-purity vanadium metal by adopting directional solidification.

Background

Vanadium is a silver gray lustrous metal with a density of 6.1g/cm³The melting point is 1890 ℃, the boiling point is 3000 ℃, the total content in the crust is arranged at the 22 th site of the metal, the metal is a high-melting-point rare metal, the metal is mainly intergrowth with other metal ores, and no independent vanadium ore is found so far. Vanadium is used as a valuable strategic resource and is widely applied to the fields of automobiles, aerospace, railways, bridges, fusion reactor vessels and the like.

The existing production method of metal vanadium mainly comprises the following steps: vacuum carbothermic method, silicothermic method, thermal decomposition method of vanadium nitride, stepwise reduction method, metallothermic method, etc. Among them, the metallothermic reduction method has attracted much attention because the reaction itself generates a lot of heat, and the required starting temperature is low, and the product purity is high. The reaction of the metallothermic reduction of the oxide is the basic displacement reaction, the principle of the choice of the reductant metal being that its standard formation free enthalpy is lower than that of the reduced metal oxide, and suitable elements for oxide reduction are silicon, magnesium, aluminium and calcium. Although the standard enthalpy of formation of lithium and beryllium oxides is low, the production of metallic lithium and beryllium is difficult and the cost of using it as a metallic reducing agent can be quite high. Silicon is not an ideal reducing agent in most cases because it has a strong tendency to form stable metal silicides and the problem of silicon removal is not easily solved. Because magnesium oxide has a high melting point, the heat released by the reaction of magnesium and metal oxide is generally insufficient to form solid metal; meanwhile, since magnesium boils at a lower temperature than calcium and aluminum, a closed vessel must be used to prevent loss of magnesium, which further limits the range of application of the magnesiothermic reduction process. Compared with the aluminothermic reduction method, the calthermic reduction method is not superior at present, and the main reasons are as follows: first, the reaction needs to be carried out in a closed vessel, with its inherent limitations on scale-up; second, calcium in its pure state is relatively expensive compared to aluminum. The aluminothermic process for producing pure vanadium metal generally comprises the steps of firstly carrying out aluminothermic reduction on vanadium oxide to generate vanadium-aluminum alloy, optionally carrying out reduction reaction in an open heat-resistant container, then carrying out high-temperature vacuum aluminum removal and electron beam melting on the vanadium-aluminum alloy to remove other residual impurities to obtain the pure vanadium metal, but the vacuum aluminum removal process needs a large amount of energy.

Disclosure of Invention

The invention aims to provide a method for producing high-purity vanadium metal by adopting directional solidification, which comprises the following steps:

heating a directional solidification furnace to 700-800 ℃, adding vanadium oxide for melting, feeding magnesium-aluminum alloy wires after the vanadium oxide is completely melted, starting directional solidification, stopping wire feeding and heating after the vanadium oxide is completely reacted, separating to obtain a vanadium crude product after a sample is cooled to room temperature, crushing the vanadium crude product, and leaching with dilute hydrochloric acid to obtain the high-purity vanadium metal.

In the method for producing high-purity vanadium metal by adopting directional solidification, the vanadium oxide is vanadium trioxide and/or vanadium pentoxide; and the protective gas in the directional solidification furnace is argon.

The method for producing the high-purity vanadium metal by adopting the directional solidification comprises the following steps that the temperature of a directional solidification furnace is 750-800 ℃; preferably, the temperature of the directional solidification furnace is 750 ℃.

Wherein, in the method for producing high-purity vanadium metal by adopting directional solidification, the weight percentage of aluminum in the magnesium-aluminum alloy wire is 40-60 percent; preferably, the magnesium-aluminum alloy wires are Mg₄Al₃Alloy wire with diameter of 3mm and density of 2.1g/cm³The linear density was 0.148 g/cm.

The method for producing high-purity vanadium metal by adopting directional solidification is characterized in that the wire feeding speed of the magnesium-aluminum alloy wire is 0.4-0.5 cm/min; preferably, the wire feeding speed of the magnesium-aluminum alloy wires is 0.43 cm/min.

According to the method for producing high-purity vanadium metal by adopting directional solidification, the wire feeding time of the magnesium-aluminum alloy wire is 2-6 hours.

According to the method for producing high-purity vanadium metal by adopting directional solidification, the wire feeding time of the magnesium-aluminum alloy wire is 2.2-3.6 hours.

According to the method for producing the high-purity vanadium metal by adopting the directional solidification, the reaction time of vanadium trioxide and the magnesium-aluminum alloy wire is 2.2-2.6 hours, and the reaction time of vanadium pentoxide and the magnesium-aluminum alloy wire is 3-3.6 hours.

The method for producing high-purity vanadium metal by adopting directional solidification is characterized by comprising the following steps: the directional solidification speed is 10-20 mm/h; preferably, the speed of the directional solidification is 10 mm/h; the diameter of the alloy cylindrical bar blank obtained after solidification is 20-30 mm; preferably 24 mm.

In the method for producing high-purity metal vanadium by adopting directional solidification, the separation refers to cutting and separating a vanadium crude product from a sample after observing the height of vanadium at the bottom of the sample; the crushing refers to crushing the crude vanadium product to 80-150 meshes; the concentration of the dilute sulfuric acid is 5-8 mol/L.

The invention has the beneficial effects that:

the invention takes vanadium oxide as raw material and magnesium-aluminum alloy Mg₄Al₃The reducing agent reduces the reaction temperature and obviously reduces the energy consumption; the production and separation processes are carried out simultaneously, so that the working procedures are reduced, and the production efficiency is improved; the purity of the prepared vanadium metal is higher than 98%.

Detailed Description

Specifically, the method for producing high-purity vanadium metal by adopting directional solidification comprises the following steps:

heating a directional solidification furnace to 700-800 ℃, adding vanadium oxide for melting, feeding magnesium-aluminum alloy wires after the vanadium oxide is completely melted, starting directional solidification, stopping wire feeding and heating after the vanadium oxide is completely reacted, separating to obtain a vanadium crude product after a sample is cooled to room temperature, crushing the vanadium crude product, and leaching with dilute hydrochloric acid to obtain the high-purity vanadium metal.

In the process of the present invention, if the reaction temperature is too low, V₂O₅Not yet melted or too viscous, which would result in a reduced yield; if the reaction temperature is too high, energy loss is caused, and in addition, due to a large amount of exothermic reaction, magnesium volatilization can be caused if the reaction temperature is too high; therefore, the reaction temperature is set to be 700-800 ℃. In order to enable the purity of the prepared vanadium metal to be higher, the reaction temperature is set to be 750-800 ℃. Due to the fact thatThe purity of the vanadium metal is not obviously improved due to too high temperature, and the reaction temperature is set to 750 ℃ in consideration of comprehensive energy consumption.

If the content of aluminum in the magnesium-aluminum alloy used by the invention is too high, the local reaction temperature is too high, and alpha-Al is easily generated₂O₃If alpha-Al₂O₃Mixing into vanadium is not beneficial to separation; if the content of aluminum is too low, a high content of magnesium is easily volatilized due to a local reaction temperature which may be greater than the boiling point of magnesium, resulting in loss of magnesium. Therefore, the weight percentage of aluminum in the magnesium-aluminum alloy wire is 40-60 percent; preferably, the magnesium-aluminum alloy wires are Mg₄Al₃Alloy wire with diameter of 3mm and density of 2.1g/cm³The linear density was 0.148 g/cm.

In the process of the invention, if Mg₄Al₃Too high wire feeding speed can cause over violent reaction and too much heat generation, and can also cause the total wire feeding amount to be increased, and Al which is added in more amount can form alloy with V and is difficult to separate; if the wire feeding speed is too slow, the production efficiency is reduced, and even V is caused in severe cases₂O₅Depositing; therefore, the present invention converts Mg₄Al₃The wire feeding speed is set to be 0.4-0.5 cm/min; preferably, said Mg₄Al₃The wire feeding speed of (2) was 0.43 cm/min.

In the method, the directional solidification speed is too low, so that the production efficiency is reduced, the production time is prolonged, and unnecessary energy consumption is caused; if the directional solidification speed is too high, the reaction between the magnesium-aluminum alloy and vanadium oxide is increased, the local temperature is too high, the volatilization of magnesium is increased, and meanwhile, alpha-Al which is difficult to dissolve in acid is easily generated₂O₃. Therefore, the speed of directional solidification is 10-20 mm/h; preferably, the speed of the directional solidification is 10 mm/h.

The purity analysis of the vanadium metal prepared by the method can adopt the method in YB/T5328-2010 and the method in YB/T4218-2010.

The following examples are provided to further illustrate the embodiments of the present invention and are not intended to limit the scope of the present invention.

Mg used in the following examples₄Al₃The filament diameter of the filament is 3mm and the density is 2.1g/cm³The linear density is 0.148g/cm, and the aluminum-magnesium alloy is prepared by melting and drawing of Jisheng brand magnesium-aluminum alloy powder, wherein the magnesium-aluminum alloy powder is purchased from Hebei Jisheng aluminum powder Limited company, and then is prepared by substitute processing and drawing of aluminum processing companies in northwest of the middle aluminum group, and the processing technological parameters are as follows: the extrusion temperature is 350 ℃, the preheating temperature of the die is 350 ℃, the extrusion speed is 15mm/s, and the diameter of the outlet of the die is 3 mm.

The heating ring of the induction heating furnace used in the following embodiments is provided with a function of moving up and down, and when the heating ring moves up, the lower unheated part is equivalent to direct air cooling, and has a considerable temperature gradient, so that the function of directional solidification can be realized.