CN116265619A

CN116265619A - Method for preparing high-melting-point metal by double-chamber molten salt electrolysis

Info

Publication number: CN116265619A
Application number: CN202111553824.8A
Authority: CN
Inventors: 赵中伟; 雷云涛; 赵天瑜; 伏虎; 孙丰龙; 何季麟
Original assignee: Zhengzhou University; Central South University
Current assignee: Zhengzhou University; Central South University
Priority date: 2021-12-17
Filing date: 2021-12-17
Publication date: 2023-06-20

Abstract

The invention relates to a method for preparing high-melting-point metal by double-chamber molten salt electrolysis, belonging to the field of high-melting-point metal smelting. The method is implemented by using a double-chamber electrolytic cell, wherein anode molten salt is filled in an anode chamber and an anode is inserted, cathode molten salt is filled in a cathode chamber and a cathode is inserted in the cathode chamber, and liquid alloy is also filled at the bottom of the electrolytic cell. Under the condition of power-on operation, the oxidation reaction of the anode is consumed and generates high-melting-point metal ions, and the reduction reaction of the cathode surface generates high-melting-point metal products. The invention has the advantages of continuous production, wide electrolytic raw materials, high product purity, strong operation adaptability and the like.

Description

Method for preparing high-melting-point metal by double-chamber molten salt electrolysis

Technical Field

The invention belongs to the field of high-melting-point metal smelting, and particularly relates to a method for preparing high-melting-point metal by double-chamber molten salt electrolysis.

Background

Titanium, zirconium and hafnium are elements of group IVB of the periodic Table, and their metal melting points are as high as 1668 ℃, 1852 ℃ and 2227 ℃, respectively, which are rare high-melting metals, and they also have good chemical corrosion resistance and mechanical properties, and even show some unusual characteristics, so materials of titanium, zirconium and hafnium are required in many high-precision fields. For example, titanium and titanium alloys, which are light weight, high strength and corrosion resistant, are widely used in the high tech fields of aerospace, biomedical, electronic information, etc.; zirconium metal is widely used as cladding material of nuclear fuel and structural material of reactor by virtue of its small thermal neutron capture surface and excellent corrosion resistance; hafnium is often used as a control rod and emergency shutdown rod for nuclear reactors.

Titanium, zirconium and hafnium, which exhibit similar physicochemical properties, have similar smelting schemes:

the current main process for industrially producing metallic titanium is the Kroll method: in rutile or high-state slag (containing TiO) ₂ Iron-making slag of 80% or more) as a raw material, tiO at high temperature ₂ Reduction by carbon and chlorination by chlorine to obtain crude TiCl ₄ Purifying and removing coarse TiCl by chemical method and rectification method ₄ V, si, al, fe, and the like, to obtain refined TiCl ₄ Reducing with metal Mg, vacuum distilling to remove MgCl ₂ And Mg impurity to obtain the titanium sponge product. In order to prepare high-purity titanium or recycle unqualified titanium sponge, a purification process such as electrolytic refining or iodination is additionally required. The Kroll process is also the dominant process for producing zirconium sponge and hafnium sponge.

The Kroll process, although widely used and mature in process, faces a number of problems: the process is complex, the production period is long, the intermittent operation is performed, and the production efficiency is low; cumbersome purification and impurity removal procedures are required to purify crude MCl ₄ (m=ti, zr, or Hf, the same applies below); MCl (micro-channel logic) ₄ And Cl ₂ The paint has corrosiveness and easy diffusibility and has larger pollution; MO (MO) ₂ Is reduced to chloridize, MCl ₄ Is used for refining and molten salt electrolysis of MgCl ₂ The cost is high and the energy consumption is high. In addition, the magnesium reduction process does not have the refining and impurity removing functions, and in order to prepare titanium, zirconium or hafnium metal products meeting certain purity, a process of deep separation of similar elements is additionally required.

Before and after 2000, cambridge university proposed FFC process for directly preparing metallic titanium from titanium oxide. The method uses TiO ₂ The powder is shaped and sintered to be used as a cathode, graphite is used as an anode, and CaCl is used as a cathode ₂ The base molten salt is electrolyte, and TiO is in the electrolysis process ₂ When reduced to metallic titanium, oxygen ions enter the molten salt and migrate to the anode to react with the graphite electrode. The method has the advantages of short flow, low cost, no generation of corrosive gas and the like, but has no impurity removal function, and metal impurities (such as Fe, si and Al) in the raw materials remain in the metallic titanium product as is; o in the titanium dioxide block in the late electrolysis stage ^2- The impurities cannot be effectively removed, so that the oxygen content in the product is higher; as electrolysis proceeds, the current efficiency continues to decrease and the energy consumption increases.

The MER process is proposed in the United states to convert TiO ₂ Stirring, compression molding, heat treating to form composite anode, and electrolyzing carbon steel as cathode in NaCl-KCl molten salt to obtain metal titanium. Features of the MER process: the raw material applicability is wider, the operation is simple, but carbon residues exist in long-time electrolysis, so that the cathode and anode are easy to short-circuit, and the metal titanium product in the same room is polluted; in addition, the composite anode may be broken and slag is dropped in the electrolytic process, and the titanium powder separated from the cathode falls to the bottom of the tank, so that the recovery rate of titanium is reduced.

The USTB process is proposed in China, the equipment and principle are similar to those of the MER process, but the USTB process adopts TiC _x O _y And waiting for titanium compound solid solution anode to improve anode stability in the electrolytic process. However, full solid solution cations of technical sizeThe preparation is extremely difficult; the anode slag and cathode powder are inevitably dropped in the electrolysis process; impurities (e.g., mn, V, al) that behave electrochemically similarly to titanium are difficult to remove effectively; the precipitated carbon powder or anode slag drifts to the cathode, which is easy to pollute the cathode product and cause the grade reduction of metallic titanium.

Currently, the fused salt electrolysis process of zirconium and hafnium is similar to the fused salt electrolysis process of titanium.

In summary, although various characteristic molten salt electrolysis methods for titanium zirconium hafnium have been proposed, they have the following problems to be overcome to various extents:

(1) the smelting raw materials have higher purity requirements;

(2) the electrolytic process has no impurity removing function or limited refining impurity removing capability;

(3) the metal products are easy to be polluted by nonmetallic impurities such as carbon, oxygen and the like;

(4) the process is long, the steps are tedious, the time consumption is long, and the energy consumption is high.

Based on this, a new method and apparatus for extracting high melting point metals by molten salt electrolysis are needed to solve the above problems.

Disclosure of Invention

The invention aims to provide a method for extracting high-melting-point metal by a molten salt electrolysis method, which has the advantages of low raw material requirement, simple flow, strong operation adaptability, high purity of metal products and the like.

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

the method is suitable for a double-chamber electrolytic tank, and the double-chamber electrolytic tank comprises an electrolytic tank body and an insulating partition plate; the insulating partition plate is arranged at the upper part in the double-chamber electrolytic cell and divides the double-chamber electrolytic cell into an anode chamber, a cathode chamber and a communication area; the communication area is positioned at the bottom of the electrolytic tank body and is respectively communicated with the anode chamber and the cathode chamber;

the communicating area is filled with liquid alloy; anode fused salt is filled in the anode chamber, and an anode is immersed in the anode fused salt; the cathode chamber is filled with cathode fused salt, and the cathode is immersed in the cathode fused salt; the anode molten salt and the cathode molten salt are not contacted with each other, and two ends of the liquid alloy are respectively contacted with the anode molten salt and the cathode molten salt; wherein the anode contains raw materials of metal elements to be smelted; the liquid alloy is an alloy of liquid metal to be smelted and auxiliary metal;

the method comprises the following steps: connecting the anode with the positive electrode of the power supply, and connecting the cathode with the negative electrode of the power supply; and electrifying and electrolyzing to generate metal products on the cathode.

The metal to be smelted is high-melting point metal with melting point higher than 1500 ℃ and comprises titanium, zirconium, hafnium, vanadium, niobium, tantalum and the like, and the metals have similar chemical/smelting characteristics: the chemical property is active, the oxygen affinity is provided, the raw materials exist in the form of oxide, and the raw materials can form a compound with certain conductivity with nonmetallic elements such as carbon, nitrogen, sulfur and the like.

Preferably, the metal to be smelted is titanium, zirconium or hafnium.

The raw materials of the metal element to be smelted comprise: coarse metals to be smelted, alloys of the metals to be smelted and compounds of the metal elements to be smelted.

The crude metal to be smelted refers to metal to be smelted with low purity. For titanium zirconium hafnium smelting, different grades of titanium sponge, titanium powder, titanium ingots, waste/residual titanium and titanium materials are included; zirconium sponge, zirconium powder, spent/residual zirconium; hafnium sponge, hafnium powder, waste/hafnium residues; .

The alloy of the metal to be smelted mainly refers to waste alloy materials to be recycled, such as Ti-6Al-4V (TC 4), ti-5Al-2.5Sn (TA 7), zirconium alloy cladding materials or other alloys taking the metal to be smelted as a main component.

The compound of the metal element to be smelted consists of the metal element to be smelted and nonmetallic elements, wherein the nonmetallic elements comprise one or more of oxygen, carbon, nitrogen and sulfur.

Preferably, the compound of the metal element to be smelted is MO _x (1≤x≤2)、MC、MC _y O _1-y (0<y<1)、MN、MO _x N _1-x (0<x<1)、MC _y N _1-y (0<y<1)、MC _x O _y N _1-x-y (0<x+y<1)、MS _z (0.5≤z≤3)、MC _y S _1-y (0<y<1) Wherein M is Ti, zr or Hf, as follows.

More specifically, the MO _x (1.ltoreq.x.ltoreq.2) comprises MO, M ₃ O ₅ 、M ₄ O ₇ 、M ₂ O ₃ 、M ₅ O ₉ 、M ₆ O ₁₁ 、M ₇ O ₁₃ 、M ₈ O ₁₅ 、M ₉ O ₁₇ 、MO ₂ The method comprises the steps of carrying out a first treatment on the surface of the The MC _y O _1-y (0<y<1) Comprises MC _0.5 O _0.5 I.e. M ₂ CO or MO.MC, MC _0.2 O _0.8 、MC _0.6 O _0.4 The method comprises the steps of carrying out a first treatment on the surface of the The MC _y N _1-y (0<y<1) Comprises MC _0.5 N _0.5 、MC _0.6 N _0.4 The method comprises the steps of carrying out a first treatment on the surface of the The MC _x O _y N _1-x-y (0<x+y<1) Comprises MC _0.25 O _0.25 N _0.5 The method comprises the steps of carrying out a first treatment on the surface of the The MS (MS) _z (0.5.ltoreq.z.ltoreq.3) comprises M ₂ S、MS、M ₂ S ₃ 、M ₃ S ₄ 、M ₅ S ₈ 、MS ₂ 、MS ₃ The method comprises the steps of carrying out a first treatment on the surface of the The MC _y S _1-y (0<y<1) Comprises MC _0.5 S _0.5 I.e. M ₂ CS or MC.MS.

The anode contains raw materials of the metal elements to be smelted, and the raw materials are subjected to oxidation reaction in the electrifying process to generate metal ions to be smelted. For example, some typical oxidation reactions are:

m (crude metal or alloy) -ne ^- →M ⁿ⁺

MO ₂ +C-ne ^- →M ⁿ⁺ +CO/CO ₂ ↑

MO-ne ^- →M ⁿ⁺ +O ₂ ↑

MC-ne ^- →M ⁿ⁺ +C↑

MC+MO ₂ -ne ^- →M ⁿ⁺ +CO/CO ₂ ↑

MC _0.5 O _0.5 -ne ^- →M ⁿ⁺ +CO↑

MN-ne ^- →M ⁿ⁺ +N ₂ ↑

MC _0.25 O _0.25 N _0.5 -ne ^- →M ⁿ⁺ +CO↑+N ₂ ↑

MS ₂ -ne ^- →M ⁿ⁺ +S ₂ ↑

Preferably, the anode further comprises a current collector, wherein the current collector is added as a part of the anode or as a component of the anode, and the material of the current collector comprises at least one of a carbon material, a metal to be smelted, an alloy of the metal to be smelted and an inert metal. Compounding and/or mixing of the current collector can improve the compound (such as TiO) containing some metal elements to be smelted with poor conductivity ₂ ) To suppress local overheating and breakage phenomena due to poor conductivity, or to fix or hold the anode.

Preferably, the anode further comprises a regulator for regulating the ratio of oxygen element to other nonmetallic elements in the anode.

Preferably, the regulator comprises an oxygen enrichment regulator and an oxygen consumption regulator; the modifier is provided to avoid insufficient reaction (relatively poor conductivity or electrical activity of the oxygen-enriched compound of the metal element to be smelted) due to excess oxygen, or large precipitation of carbon powder due to insufficient oxygen.

Preferably, the oxygen enrichment regulator comprises an oxide of the metal to be smelted; the oxygen consumption regulator comprises carbon powder or/and a compound of metal elements to be smelted, wherein the compound of the metal elements to be smelted contains one or more nonmetallic elements of carbon, nitrogen and sulfur.

For carbon powder, the carbon powder can be used as a current collector to be mixed into the anode to enhance conductivity, and can also be used as an oxygen consumption regulator to react with the oxide of the metal to be smelted at high temperature to form carbon monoxide or carbon dioxide gas, so that solid oxygen element is consumed. The purpose of controlling the amount of carbon powder added is to improve conductivity as much as possible while avoiding carbon powder precipitation due to excessive carbon.

For TiC, for example _0.5 O _0.5 Wherein the molar ratio of the carbon element to the oxygen element is already 1, and TiC _0.5 O _0.5 Has good conductivity, so that carbon powder current collector/regulator does not need to be mixed; for TiC with certain conductivity _0.2 O _0.8 TiC can be directly used without mixing carbon powder current collector/regulator _0.2 O _0.8 As anode to make electrolytic reaction, carbon powder current collector/regulator can be mixed to promote TiC _0.2 O _0.8 More completely react but the mixing amount does not exceed TiC _0.2 O _0.8 0.6 times the molar amount of (a); for TiO with poor conductivity ₂ Carbon powder/modifier may be mixed in, but the mixing amount does not exceed TiO ₂ Twice the molar amount; for TiC, then, for example, tiO may be added as _x (1.ltoreq.x.ltoreq.2) or TiC _y O _1-y (0<y<0.5 Oxygen-enriched regulator to avoid excessive carbon element and massive carbon powder precipitation. The same is true for the compounds of Zr and Hf.

It is worth mentioning that the current collector and the modifier are preferred, and that the addition or non-addition should be selected depending on the composition and properties of the anode.

The cathode is metal which is difficult to alloy with the metal to be smelted, stainless steel, nickel, molybdenum, tungsten, platinum and the like.

The auxiliary metal can form an alloy with the metal to be smelted, wherein the melting point of the alloy is lower than 1100 ℃, and the alloy comprises one or more of Cu, ga, in, au, ag, pb, sn, sb, bi, zn.

Preferably, the auxiliary metal is Cu or/and Sn.

More preferably, when the metal to be smelted is titanium, the liquid alloy adopts Ti-Cu alloy with 15-60 at% of Ti or Ti-Sn alloy with 5-25 at% of Ti; when the metal to be smelted is zirconium, the liquid alloy adopts Zr-Cu alloy with 30-70at% of Zr content; when the metal to be smelted is hafnium, the liquid alloy adopts Hf-Cu alloy with the Hf content of 10-45 at%.

The anode molten salt or the cathode molten salt consists of alkali metal halide or/and alkaline earth metal halide, and the halide of the metal element to be smelted is dissolved.

Preferably, the alkali metal halide is one or more of LiX, naX, KX; the alkaline earth metal halide is MgX ₂ ，CaX ₂ Wherein x=f or/and Cl.

These alkali metal halides and alkaline earth metal halides serve as supporting electrolytes and serve to dissolve ions containing the metal element to be smelted, and both alkali metal ions and alkaline earth metal ions are more difficult to reduce than ions of the smelted metal element.

In addition to the halides mentioned above, fluorides or chlorides of rubidium, cesium, strontium, barium can also be used for adjusting the physical properties of melting point and density of molten salt, and adjusting the valence state of metal ions to be smelted, but they have higher cost and greater toxicity.

The halide of the metal element to be smelted is used for providing metal ions to be smelted in a dissociated state or a complex state, and the halide of the metal element to be smelted is MX _n 、Na _m MX ₆ 、K _m MX ₆ Wherein M=Ti, zr or Hf, X=F or/and Cl, 2.ltoreq.n.ltoreq.4, 2.ltoreq.m.ltoreq.3. For example, MX _n Comprises MCl ₂ 、MCl ₃ 、MCl ₄ 、MF ₂ 、MF ₃ 、MF ₄ ；Na _m MX ₆ Comprises Na ₂ MCl ₆ 、Na ₃ MCl ₆ 、Na ₂ MF ₆ 、Na ₃ MF ₆ 。

Further, the content of the metal element to be smelted in the anode molten salt or the cathode molten salt is 1-10wt%.

In molten salt, the content of metal elements (ions) to be smelted is too low, side reactions of impurity ions are easy to cause, the content of metal elements (ions) to be smelted is too high, volatilization loss of the metal elements (ions) to be smelted in a halide form is easy to cause, and therefore, the concentration of the metal elements (ions) to be smelted is generally controlled to be 1-10wt%.

Further, the anode molten salt and the cathode molten salt may be the same or different in composition.

Further, the method for preparing the high-melting-point metal by double-chamber molten salt electrolysis further comprises the following steps:

step 3, post-treatment; when the metal product is subjected to wet post-treatment, namely, the metal product mixed with molten salt is cleaned by adopting an aqueous solution, the cathode molten salt is only composed of chloride, so that the residues of certain indissolvable fluorides and the emission of fluorine-containing wastewater are avoided.

The normal operation temperature of the double-chamber electrolytic tank is 800-1100 ℃. The anode current density is 0.01-1.5A/cm ² Or controlling the cathode current density to be 0.01-5.0A/cm ² 。

Furthermore, the power-on electrolysis mode is not limited, and can be arbitrarily selected in the modes of voltage transformation, constant voltage, current transformation and constant current.

Preferably, the electrified electrolysis mode is constant voltage, constant current and unidirectional pulse.

The reaction principle during power-on can be summarized as:

an oxidation reaction occurs in an anode chamber containing metal elements to be smelted, and metal ions to be smelted are generated and enter anode molten salt; the metal ions to be smelted in the anode molten salt undergo a reduction reaction at the interface of the anode molten salt and the liquid alloy to generate corresponding metal atoms, and enter the liquid alloy; in the cathode chamber, metal atoms to be smelted in the liquid alloy undergo oxidation reaction at the interface of the liquid alloy and the cathode molten salt to generate corresponding metal ions, and the corresponding metal ions enter the cathode molten salt; in the cathode molten salt, metal ions to be smelted undergo a reduction reaction on the surface of the cathode and generate a metal product to be smelted.

The specific principle of the method for preparing high-melting-point metal by double-chamber molten salt electrolysis is as follows:

taking titanium metal as an example for illustration: in the electrified state, in the anode chamber, titanium ions in the anode molten salt undergo a reduction reaction at the interface of the anode molten salt and the liquid alloy, and titanium atoms are generated and enter the liquid alloy, wherein the reaction equation is as follows:

Ti ⁿ⁺ +ne ^- ti (liquid alloy)

Metal impurities more reactive than titanium will oxidize out of the anode and enter the anode molten salt in an ionic state, but it is more difficult for the reduction reaction to occur and enter the liquid alloy than titanium ions, so that such impurities are effectively trapped in the anode molten salt. For metallic impurities and their compounds (e.g., fe, al, V) that are slightly more inert than titanium, oxidation reactions generally do not occur and are difficult to enter into the molten salt, even if under anodic polarization, oxidation reactions occur and enter into the anodic molten salt, which is then reduced to metal at the liquid alloy interface and dissolved into the liquid alloy.

In the cathode chamber, titanium atoms in the liquid alloy undergo oxidation reaction at the interface of the liquid alloy and the cathode molten salt and generate titanium ions to enter the cathode molten salt, and the titanium ions in the cathode molten salt undergo reduction reaction on the surface of the cathode to generate metallic titanium products, wherein the reaction equations are respectively as follows:

ti (liquid alloy) -ne ^- →Ti ⁿ⁺

Ti ⁿ⁺ +ne ^- →Ti

For impurities entering the liquid alloy, because of low concentration and low electrochemical activity of Fe, al, V and other impurity atoms which are more inert than titanium, oxidation reaction is difficult to occur and the impurities enter the cathode molten salt, namely the impurities are continuously enriched in the liquid alloy, and the purity of the cathode product metallic titanium is not influenced; among them, the impurity atoms such as Na, K, etc., which are more active than titanium, are difficult to precipitate at the cathode due to the difference in deposition potential even if they are oxidized at the interface to generate cations and enter the molten salt of the cathode.

It can be seen that the metal impurities, whether more active or more inert than titanium, can be effectively removed through multiple electrochemical reaction interfaces and melt dissolution so as to produce a metal titanium cathode product with higher purity (purity not less than 99.9%). For zirconium smelting, the device has good interception effect on Hf, and a metal zirconium product with the Hf content not more than 0.01% can be separated out from a cathode, so that the chemical component requirement of the zirconium alloy pipe for the fuel cladding of the nuclear power plant is met. For hafnium smelting, a nuclear grade hafnium product may also be obtained.

Along with the long-term operation of the electrolytic tank, when the impurity content of the liquid alloy is continuously enriched and reaches a certain degree, the liquid alloy needs to be purified.

For nonmetallic impurities, free carbon, oxygen-containing compounds and dropped anode slag in the anode chamber are not in contact with cathode molten salt and cathode in the cathode chamber in space, so that the problem of high impurity content of C, O and the like in metal products and the problem of short circuit of carbon powder contacting with conductive agents caused by the problem can be avoided.

The invention has adaptability to the anode slag dropping/breaking phenomenon in the electrolytic process. For anode slag/blocks containing metals to be smelted and alloys thereof, metal atoms to be smelted can be dissolved into liquid alloy, and the effect of electrolytic refining can still be achieved by means of electrochemical interface reaction of a cathode chamber. For anode slag/block containing a compound of a metal element to be smelted, it floats at the interface of the anode molten salt and the liquid alloy, and then undergoes a reduction reaction to form titanium atoms and dissolve into the liquid alloy, such as TiO ₂ The following reactions occur at the interface:

TiO ₂ -4e ^- ti (liquid alloy) +2O ^2-

Dissociated O ^2- Enters into the anode molten salt and migrates to the anode, and then oxidation reaction occurs to generate gas escape. Therefore, the phase structure of the compound containing the metal element to be smelted is not critical, i.e. it is not limited to solid solution form, but may be near solid solution or composite material form.

The invention has adaptability to the dropping phenomenon of products in the electrolysis process. The falling of the product is generally attributable to chemical factors, which are the disproportionation reaction of metal ions to be smelted in molten salt to produce metal simple substances, or physical factors, which are the falling of the metal product at the cathode due to weak bonding. In the center of the prior art, the dropped product settles at the bottom of the electrolytic cell to be difficult to recycle, and even if recycled, the product is inferior in quality and needs to be further subjected to a purification process. The product powder falling from the molten salt or the cathode can be absorbed by the liquid alloy at the bottom of the electrolytic tank, then the product powder continuously participates in the reaction according to the electrochemical mechanism, and finally the metal product is separated out from the cathode.

The beneficial effects of the invention are as follows:

(1) Continuous production and short process. The anode is utilized to directly produce high-melting-point metal, in particular to titanium zirconium hafnium by a molten salt electrolysis method, and the deep purification and impurity removal procedure (such as vanadium impurity removal in titanium smelting and zirconium hafnium deep separation in zirconium smelting) is not needed in the production flow. The continuous operation of molten salt electrolysis can be realized by putting a plurality of anodes in the electrolytic tank to realize the timely taking out of the residual anode and the timely adding of the new anode, or by adopting a continuous feeding mode into the basket type anode, and the production efficiency is high. In the electrolysis process, the fluctuation of the molten salt composition and the liquid alloy composition is small, and the electrolysis process has sustainability and can be operated for a long time.

(2) The electrolytic raw materials are wide. The high-purity titanium with higher purity can be obtained by double-chamber electrolysis with metallic titanium as a raw material; the waste titanium material and titanium alloy can be recovered, in particular to titanium alloy which is difficult to be treated by the traditional electrolytic refining method; the compound containing the metal element to be smelted is used as a soluble anode, a novel way for smelting titanium is provided, which is different from the existing method, and the titanium compound adopts TiO such as rutile or high titanium slag ₂ The high-content material is directly prepared and synthesized by carbonization, nitridation, vulcanization, electro-deoxidation and other methods, and the production cost is low. The same is true for zirconium, hafnium and other refractory metals.

(3) The purity of the product is high, and the byproducts are easy to treat. Impurity ions with different electrochemical behaviors can be effectively controlled in molten salt or liquid alloy, multiple electrochemical interface reactions and the dissolution of different melts ensure the purity of cathode product metal, and the purity can reach 99.99% or more under the optimized condition. The gas evolved by anodic electrolysis is not corrosive, wherein CO ₂ And N ₂ Is nontoxic and harmless, and CO is converted into CO after oxidation/combustion ₂ ，S ₂ The sulfur-containing compounds can be returned to the vulcanizing process of the oxide raw material of the metal element to be smelted.

(4) The operation adaptability is strong. In the electrolysis process, the soluble anode continuously provides metal ions to be smelted for molten salt so as to maintain the concentration balance of the metal to be smelted in each melt in the electrolytic tank, and meanwhile, the defects of low solubility of tetrachloride or oxide raw materials and extremely severe feeding operation requirements in the molten salt electrolysis method are avoided. The dropped residue can still participate in the reaction at the interface of the liquid alloy or be blended into the liquid alloy and then participate in the reaction at the interface, so that the yield is improved, and correspondingly, the solid solution or the composite anode can be adopted. The metal powder which is disproportionated and separated out in the electrolyte or the cathode falls off is dissolved in the liquid alloy and continuously participates in the reaction, so that the loss rate is reduced. The liquid alloy has strong depolarization effect, for polyvalent metal, the incomplete reduction of high-price metal ions to be smelted and the current consumption caused by the incomplete reduction are relieved in the anode chamber, and low-price metal ions to be smelted are easier to generate in the cathode chamber, so that the metal ions to be smelted are favorable for being separated out as coarse-grained metal products on the surface of the cathode.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic cross-sectional view of an electrolytic cell according to an embodiment of the invention;

reference numeral 1: 1-an anode; 2-anode molten salt; 3-liquid alloy; 4-an electrolytic tank body; 5-cathode molten salt; 6-metal product; 7-cathode; 8-insulating spacers.

FIG. 2 is a schematic illustration of other anode or cathode forms that may be used in the present invention;

wherein (a) is a basket type anode, (b) is an integrated anode, and (c) is a rotary cathode

Reference numeral 2: 9-an inert metal basket; 10-coarse metal to be smelted, alloy of the metal to be smelted or/and compound of metal elements to be smelted of powder or block; 11-anode without current collector connection; 12-cathode turntable; 13-a rotating shaft; 14-scraper.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, based on the examples herein, which are within the scope of the invention as defined by the claims, will be within the scope of the invention as defined by the claims.

The method for preparing high-melting-point metal by double-chamber molten salt electrolysis is implemented by using a double-chamber electrolytic cell shown in fig. 1, wherein a cell body 4 of the electrolytic cell is divided into an anode chamber and a cathode chamber by an insulating partition plate 8, the bottom in the cell body 4 of the electrolytic cell is a communicating region, the anode chamber is filled with anode molten salt 2 and is inserted with an anode 1, the anode 1 is connected with a power supply anode through a current collector such as a graphite rod or a metal rod to be smelted or an inert metal rod, the cathode chamber is filled with cathode molten salt 5 and is inserted with a cathode 7, and the communicating region is filled with liquid alloy 3; the anode molten salt 2 and the cathode molten salt 5 are connected through a liquid alloy 3 without being contacted with each other, and the liquid alloy 3 is used for constructing an electrochemical reaction interface of metal ions to be smelted/metal atoms to be smelted and is used as a transmission medium of the metal atoms to be smelted;

under the condition of electrifying operation, the temperature is 800-1100 ℃, and the anode current density is 0.01-1.5A/cm ² Or controlling the cathode current density to be 0.01-5.0A/cm ² . The oxidation reaction of the anode 1 is consumed to generate metal ions to be smelted, and the reduction reaction of the surface of the cathode 7 is generated to generate metal products 6.

In addition to the cell shown in fig. 1, the structure of the cell can also be designed in various forms, such as a U-shaped cell. In addition, the shape of the electrolytic cell can be varied, for example, the bottom of the electrolytic cell is not limited to a trapezoidal bottom, but can be round bottom or flat bottom.

The electrolytic cell capable of realizing the physical separation of the anode molten salt and the cathode molten salt and the conduction of the liquid alloy can be applied to the method of the invention.

Fig. 1 shows only a conventional electrode form, but other electrode forms are possible, for example, fig. 2 (a) and (b) show a basket anode and a unitary anode, respectively. The basket type anode is characterized in that an inert metal basket 9 is used for containing an anode, coarse metal to be smelted, alloy of the metal to be smelted or/and compound 10 of metal elements to be smelted, which are contained in the inert metal basket 9, are in conductive contact with the inert metal basket 9 and are subjected to oxidation reaction, raw materials of the coarse metal to be smelted, the alloy of the metal to be smelted or/and the compound 10 of the metal elements to be smelted, which are contained in the inert metal basket 9, are only needed to be periodically thrown into in the electrolysis process, and anode residues can be cleaned after the electrolysis is finished. The integrated anode is the anode 11 without current collector connection, and the anode 11 without current collector connection can be used as the anode by directly connecting the positive line with the crude metal to be smelted, the alloy of the metal to be smelted and some compounds of metal elements to be smelted with good conductivity. Fig. 2 (c) shows a rotary cathode, in which a metal product to be smelted is separated from the surface of the cathode turntable 12 in the electrolysis process, meanwhile, the cathode turntable 12 is driven by the rotating shaft 13 to continuously rotate, the metal product to be smelted on the surface of the cathode turntable 12 is separated and collected by the scraper 14, the cathode turntable 12 with a new surface returns to the cathode chamber to continue electrolysis, and meanwhile, the rotation of the cathode turntable 12 can play a role of stirring, reduce concentration polarization and promote mass transfer. Of course, the cathode turntable 12 may be designed in a variety of shapes, such as a sector, a cylinder, etc.

Example 1

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-KCl-TiCl ₂ (wherein the molar ratio of NaCl to KCl is 1:1 and the titanium ion content is 9.9 wt%) and inserting industrial sponge titanium as an anode. The cathode chamber contains cathode fused salt which is NaCl-KCl-TiCl ₂ (wherein the molar ratio of NaCl to KCl was 1:1 and the titanium ion content was 5.4 wt%), and a titanium sheet was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Sn alloy with the Ti content of 14at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 800 ℃ and argon atmosphere, and the initial cathode current density is controlled to be 0.05A/cm ² And (5) taking out cathode product metallic titanium after electrolysis for 24 hours. After analysis, the purity of titanium was 99.99%.

Example 2

TiO is prepared from high-titanium slag and graphite powder as raw materials ₂ Uniformly mixing the C in a molar ratio of 1:2 in a ball mill, and sintering the mixture into blocks at 1400 ℃ in inert atmosphere after compression molding to serve as an anode.

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is CaCl ₂ -KCl-CaF ₂ -K ₃ TiF ₆ (wherein CaCl) ₂ 、KCl、CaF ₂ The molar ratio of (2) to (3) is 6:3.5:0.5, the titanium ion content is 2.3 wt%), and the anode is inserted; the cathode chamber contains cathode fused salt which is NaCl-NaF-TiF ₃ (wherein the molar ratio of NaCl to NaF is 6:4 and the titanium ion content is 4.3 wt%) and a tungsten wire is inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which comprises Ti-Sn-Cu alloy with the Ti content of 11at% and the Sn content of 16at%, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 1000 ℃ and argon atmosphere, and the initial anode current density is controlled to be 0.1A/cm ² And (5) taking out cathode product metallic titanium after electrolysis for 12 h. After analysis, the purity of titanium was 99.94%.

Example 3

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-KCl-MgCl ₂ -TiCl ₂ (wherein NaCl, KCl, mgCl) ₂ The molar ratio of (3:6:1), the titanium ion content was 8.4 wt%), and TiC was intercalated _0.25 O _0.25 N _0.5 The material is used as an anode; the cathode chamber contains cathode molten salt, which is NaCl-KCl-LiCl-TiCl ₂ (wherein the molar ratio of NaCl, KCl, liCl is 5:4:1 and the titanium ion content is 10.0 wt%) and a titanium plate is interposed as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Sn alloy with the Ti content of 18at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 880 ℃ and argon atmosphere, and the initial anode current density is controlled to be 0.3A/cm ² And (5) taking out cathode product metallic titanium after electrolysis for 12 h. After analysis, the purity of titanium was 99.99%.

Example 4

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-Na ₂ TiCl ₆ (wherein the titanium ion content is 1.0 wt%) and inserting a scrap Ti-6Al-4V (TC 4) alloy as an anode; the cathode chamber contains cathode molten salt, which is KCl-LiF-MgF ₂ -TiCl ₃ (wherein KCl, liCl, mgF) ₂ The molar ratio of (3) to (2) was 7.5:2.3:0.2, the titanium ion content was 3.6 wt%), and a molybdenum wire was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Cu alloy with the Ti content of 35at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the conditions of constant temperature of 970 ℃ and argon atmosphere, and the initial anode current density is controlled to be 0.01A/cm ² And (5) taking out cathode product metallic titanium after electrolysis for 24 hours. After analysis, the purity of titanium was 99.96%.

Example 5

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-KCl-CaCl ₂ -KCl-K ₂ TiF ₆ -TiCl ₂ (wherein CaCl) ₂ Molar ratio to KCl is 1:1, K ₂ TiF ₆ With TiCl ₂ The molar ratio of (2) was 1:4, the titanium ion content was 5.5 wt%), and TiO was intercalated ₂ Taking the sintered material (molar ratio of 1:1) with TiC as an anode; the cathode chamber contains cathode fused salt which is CaCl ₂ -KCl-TiCl ₂ (wherein the molar ratio of NaCl to KCl was 1:1 and the titanium ion content was 5.8 wt%), and a titanium rod was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Cu alloy with the Ti content of 30at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 950 ℃ and argon atmosphere, and the initial anode current density is controlled to be 0.5A/cm ² And (5) taking out cathode product metallic titanium after electrolysis for 12 h. After analysis, the purity of titanium was 99.96%.

Example 6

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition isCaCl ₂ -LiCl-TiCl ₂ (wherein CaCl) ₂ Molar ratio to LiCl is 6:4, titanium ion content is 3.2 wt%), and TiS is intercalated ₂ The material is used as an anode; the cathode chamber contains cathode fused salt, which is KCl-LiF-TiCl ₃ -TiCl ₂ (wherein the molar ratio of KCl to LiF is 7.5:2.5, tiCl) ₃ With TiCl ₂ The molar ratio of (2) was 1:1, the titanium ion content was 8.5 wt%), and a titanium sheet was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Sn alloy with the Ti content of 20at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 850 ℃ and argon atmosphere, and the initial anode current density is controlled to be 1.0A/cm ² And (5) taking out cathode product metallic titanium after 10h electrolysis. After analysis, the purity of titanium was 99.97%.

Example 7

In the double-chamber electrolytic tank, anode molten salt is contained in the anode chamber, and its composition is KCl-TiF ₃ (wherein the titanium ion content is 1.7 wt%) and inserting a platinum wire basket containing scrap Ti-5Al-2.5Sn (TA 7) alloy particles into the platinum wire basket to serve as an anode; the cathode chamber is filled with cathode fused salt, and the composition of the cathode fused salt is KCl-TiF ₃ -TiF ₄ (wherein TiF ₃ With TiF ₄ The molar ratio of (2) was 1:1, the titanium ion content was 1.0 wt%), and a stainless steel rod was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Sn alloy with the Ti content of 16at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 900 ℃ and argon atmosphere, and the initial cathode current density is controlled to be 0.2A/cm ² And (5) taking out cathode product metallic titanium after 10h electrolysis. After analysis, the purity of titanium was 99.91%.

Example 8

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-LiF-TiCl ₂ (wherein the molar ratio of NaCl to LiF is 1:1, the titanium ion content is 6.5 wt%) and TiC is intercalated _0.5 O _0.5 The material is used as an anode; the cathode chamber contains cathode fused saltThe composition of the catalyst is NaCl-LiCl-TiCl ₂ (wherein the molar ratio of NaCl to LiCl was 8:2 and the titanium ion content was 7.1 wt%) and a titanium plate was interposed as a cathode. The bottom of the double-chamber electrolytic tank is filled with a liquid alloy which is Ti-Cu alloy with the Ti content of 27at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the conditions of constant temperature of 920 ℃ and argon atmosphere, and the initial anode current density is controlled to be 1.5A/cm ² And (5) after 8 hours of electrolysis, taking out cathode product metallic titanium. After analysis, the purity of titanium was 99.95%.

Example 9

The only difference between this embodiment and embodiment 7 is that: the original constant current electrolysis mode is changed into a pulse electrolysis mode, and the current density of the cathode is 0.8A/cm due to the pulse current intensity ² The pulse width is 30s and the pulse duty cycle is 50%. The remaining conditions were the same.

And (5) after electrolysis for 12 hours, taking out cathode product metallic titanium. After analysis, the purity of titanium was 99.95%.

Example 10

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is NaCl-KCl-K ₂ ZrF ₆ (wherein the molar ratio of NaCl to KCl is 1:1 and the zirconium ion content is 8.3 wt%) and inserting industrial sponge zirconium as a zirconium-containing anode. The cathode chamber is filled with cathode molten salt, and the composition of the cathode molten salt is NaCl-ZrCl ₂ (wherein the zirconium ion content was 5.6 wt%) and a zirconium piece was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with liquid alloy which is Zr-Cu alloy with 40at% Zr content, and the liquid alloy can ensure that the anode molten salt and the cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 1000 ℃ and argon atmosphere, and the initial cathode current density is controlled to be 0.3A/cm ² And (5) after electrolysis for 12 hours, taking out cathode product zirconium metal. After analysis, the purity of zirconium was 99.99%, and the content of hafnium was less than 0.01%.

Example 11

In the double-chamber electrolytic tank, anode molten salt is contained in the anode chamber, and its composition is NaF-KF-K ₂ ZrF ₆ (wherein the molar ratio of NaF to KF is 4:6, zirconium ion content was 10.0 wt%), and ZrC was intercalated _0.25 O _0.25 N _0.5 The material is used as a zirconium-containing anode; the cathode chamber is filled with cathode fused salt to form KCl-K ₃ ZrCl ₆ -K ₂ ZrCl ₆ (wherein K ₃ ZrCl ₆ And K is equal to ₂ ZrCl ₆ The molar ratio of (2) was 5:1, the zirconium ion content was 4.3 wt%), and a zirconium rod was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with liquid alloy which is made of Zr-Cu alloy with the Zr content of 47.5at percent, and the liquid alloy can ensure that the anode molten salt and the cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of constant temperature of 950 ℃ and argon atmosphere, and the initial cathode current density is controlled to be 0.7A/cm ² And (5) after 10 hours of electrolysis, taking out cathode product zirconium metal. After analysis, the purity of zirconium was 99.99%.

Example 12

In the double-chamber electrolytic tank, anode molten salt is contained in the anode chamber, and the composition of the anode molten salt is NaCl-ZrCl ₂ (wherein the content of zirconium ions is 3.6 wt%) and inserting a platinum wire basket containing crushed waste zirconium alloy into the platinum wire basket to serve as an anode; the cathode chamber contains cathode molten salt composed of NaCl-KCl-BaCl ₂ -ZrF ₂ (wherein NaCl, KCl, baCl) ₂ The molar ratio of (2) was 4.5:4.5:1, the zirconium ion content was 1.0 wt%), and a tungsten rod was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with liquid alloy which is Zr-Sn alloy with 6at% Zr content, and the liquid alloy can ensure that the anode molten salt and the cathode molten salt are not contacted and mixed.

Constant-current electrolysis is carried out under the condition of inert atmosphere at the constant temperature of 900 ℃, and the initial cathode current density is controlled to be 0.01A/cm ² And (5) taking out cathode product zirconium metal after electrolysis for 24 hours. After analysis, the purity of zirconium is 99.93%, the content of impurity Sn is 0.04%, and the content of impurity Hf is less than 0.01%, so that the zirconium can be used as a raw material for producing nuclear fuel cladding materials.

Example 13

In the double-chamber electrolytic tank, anode molten salt is contained in the anode chamber, and its composition is KF-K ₂ HfF ₆ (wherein the content of hafnium ions is 7.1 wt%) and inserting HfC _0.25 O _0.25 N _0.5 The material is used as a hafnium compound anode; the cathode chamber is filled with cathode fused salt which is formed by NaF-KCl-K ₂ HfCl ₆ (wherein the molar ratio of NaF to KCl was 4:1 and the hafnium ion content was 8.5 wt%) and a hafnium rod was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with liquid alloy which is composed of Hf-Cu alloy with the Hf content of 38at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Electrifying and electrolyzing at 1100 deg.C under argon atmosphere, and controlling initial cathode current density to 0.5A/cm ² And (5) taking out cathode product metal hafnium after 10h electrolysis. After analysis, the purity of hafnium was 99.99%.

Example 14

Hafnium dioxide and graphite powder according to HfO ₂ Uniformly mixing the C in a molar ratio of 1:2 in a ball mill, and sintering the mixture into blocks at 1400 ℃ in an inert atmosphere after compression molding to serve as a hafnium compound anode.

In the double-chamber electrolytic tank, anode molten salt is contained in anode chamber, its composition is CaCl ₂ -CaF ₂ -HfF ₄ (wherein CaCl) ₂ With CaF ₂ The molar ratio of (2) is 1:1, the hafnium ion content is 10 wt%), and the hafnium compound anode is inserted; the cathode chamber contains cathode fused salt which is NaF-NaCl-Na ₂ HfF ₆ (wherein the molar ratio of NaF to NaCl was 4:1 and the hafnium ion content was 3.2 wt%) and a tungsten wire was inserted as a cathode. The bottom of the double-chamber electrolytic tank is filled with liquid alloy which is composed of Hf-Cu alloy with the Hf content of 38at percent, and the liquid alloy can ensure that anode molten salt and cathode molten salt are not contacted and mixed.

Electrifying and electrolyzing at 1100 deg.C under inert atmosphere, and controlling initial cathode current density to 2.0A/cm ² And (5) after 5h of electrolysis, taking out cathode product metal hafnium. After analysis, the purity of hafnium was 99.7%.

Comparative example 1

The comparative example uses a common electrolytic cell, i.e., anode and cathode are inserted into the same molten salt, without liquid alloy. The difference between this comparative example and example 1 is that: the molten salt composition is NaCl-KCl-TiCl ₂ (wherein the molar ratio of NaCl to KCl is 1:1, and the titanium ions containThe amount was 5.4 wt%) with the same balance.

And (5) taking out cathode product metallic titanium after electrolysis for 24 hours. After analysis, the purity of titanium was 99.92%.

Comparative example 2

The comparative example uses a common electrolytic cell, i.e., anode and cathode are inserted into the same molten salt, without liquid alloy. The difference between this comparative example and example 2 is that: the molten salt composition is NaCl-NaF-TiF ₃ (wherein the molar ratio of NaCl to NaF is 6:4, the titanium ion content is 4.3 wt%), the other conditions are the same.

And (5) after electrolysis for 12 hours, taking out cathode product metallic titanium. After analysis, the purity of titanium was 99.31%.

The bottom of the electrolytic tank is provided with anode slag and titanium powder which fall from the anode and the cathode respectively.

Comparative example 3

The comparative example uses a common electrolytic cell, i.e., anode and cathode are inserted into the same molten salt, without liquid alloy. The difference between this comparative example and example 7 is that: the fused salt composition is KCl-TiF ₃ -TiF ₄ (wherein TiF ₃ With TiF ₄ The molar ratio of (2) was 1:1, the titanium ion content was 1.0 wt%), the other conditions were the same.

And (5) taking out cathode product metallic titanium after 10h electrolysis. After analysis, the purity of titanium was 98.85%.

Comparative example 4

The comparative example uses a common electrolytic cell, i.e., anode and cathode are inserted into the same molten salt, without liquid alloy. The difference between this comparative example and example 8 is that: the molten salt composition is NaCl-LiF-TiCl ₂ (wherein the molar ratio of NaCl to LiF is 1:1, the titanium ion content is 6.5 wt%), the other conditions are the same.

And (5) after 8 hours of electrolysis, taking out cathode product metallic titanium. After analysis, the purity of titanium was 99.82%.

Comparative example 5

The comparative example uses conventional electricityThe solution tank, that is, the anode and the cathode are inserted into the same molten salt, and no liquid alloy exists. The present comparative example differs from example 10 in that: the molten salt composition is NaCl-KCl-K ₂ ZrF ₆ (wherein the molar ratio of NaCl to KCl is 1:1, the zirconium ion content is 8.3 wt.%), the other conditions being the same.

And (5) after electrolysis for 12 hours, taking out cathode product zirconium metal. After analysis, the purity of zirconium was 99.94% and the content of hafnium was 0.02%.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention.

Claims

1. The method for preparing the high-melting-point metal by double-chamber molten salt electrolysis is characterized by being suitable for a double-chamber electrolytic tank, wherein the double-chamber electrolytic tank comprises an electrolytic tank body and an insulating partition plate; the insulating partition plate is arranged at the upper part in the double-chamber electrolytic cell and divides the double-chamber electrolytic cell into an anode chamber, a cathode chamber and a communication area; the communication area is positioned at the bottom of the electrolytic tank body and is respectively communicated with the anode chamber and the cathode chamber;

2. The method for producing a high-melting point metal by double-chamber molten salt electrolysis according to claim 1, wherein the raw materials of the metal element to be smelted include: coarse metals to be smelted, alloys of the metals to be smelted and compounds of metal elements to be smelted;

3. The method for producing a refractory metal by two-compartment molten salt electrolysis according to claim 1, wherein the anode further comprises a current collector added as a component of the anode or as a constituent of the anode, and the current collector is made of at least one of a carbon material, a metal to be smelted, an alloy of the metal to be smelted, and an inert metal.

4. The method for producing a refractory metal by double-chamber molten salt electrolysis according to claim 1, wherein the anode further comprises a regulator for regulating the ratio of oxygen element to other nonmetallic elements in the anode;

the regulator comprises an oxygen enrichment regulator and an oxygen consumption regulator; the oxygen enrichment regulator comprises an oxide of metal to be smelted; the oxygen consumption regulator comprises carbon powder or/and a compound of metal elements to be smelted, wherein the compound of the metal elements to be smelted contains one or more nonmetallic elements of carbon, nitrogen and sulfur.

5. The method for producing a high-melting metal by double-chamber molten salt electrolysis according to any one of claims 1 to 4, wherein the auxiliary metal is Cu or/and Sn.

6. The method for preparing high-melting-point metal by double-chamber molten salt electrolysis according to any one of claims 1 to 4, wherein the metal to be smelted is titanium, zirconium or hafnium.

7. The method for producing a refractory metal by double-chamber molten salt electrolysis according to any one of claims 1 to 4, wherein the anode molten salt or the cathode molten salt is composed of an alkali metal halide or/and an alkaline earth metal halide and a halide of a metal element to be smelted is dissolved.

8. The method for producing a high-melting metal by double-chamber molten salt electrolysis according to claim 7, wherein the alkali metal halide is one or more of LiX, naX, KX; the alkaline earth metal halide is MgX ₂ ，CaX ₂ One or more of the following; the halide of the metal element to be smelted is MX _n 、Na _m MX ₆ 、K _m MX ₆ Wherein M=Ti, zr or Hf, X=F or/and Cl, 2.ltoreq.n.ltoreq.4, 2.ltoreq.m.ltoreq.3.

9. A method for producing a refractory metal by double-chamber molten salt electrolysis according to any one of claims 1 to 4,

the content of the metal element to be smelted in the anode molten salt or the cathode molten salt is 1-10wt%;

when the metal to be smelted is titanium, the liquid alloy adopts Ti-Cu alloy with 15-60 at% of Ti or Ti-Sn alloy with 5-25 at% of Ti; when the metal to be smelted is zirconium, the liquid alloy adopts Zr-Cu alloy with 30-70at% of Zr content; when the metal to be smelted is hafnium, the liquid alloy adopts Hf-Cu alloy with the Hf content of 10-45 at%.

10. The method for producing a high-melting metal by double-chamber molten salt electrolysis according to any one of claims 1 to 4, wherein the normal operation temperature of the double-chamber electrolytic cell is 800 to 1100 ℃; the anode current density is 0.01-1.5A/cm ² Or controlling the cathode current density to be 0.01-5.0A/cm ² 。