Method for preparing metal through electric field assisted dissolution

Abstract

The invention discloses a method for preparing metal through electric field assisted dissolution, which comprises the following steps: by taking a transition metal electrode as a cathode and a conductive crucible as an anode, arranging a diaphragm in the conductive crucible, and dividing the conductive crucible into a first area and a second area which are mutually independent; arranging the cathode in a first zone, wherein the first zone is used as a cathode chamber; metal oxide powder is laid at the bottom of a second area, and the second area serves as an anode chamber; then adding an electrolyte solution into the anode chamber and the cathode chamber to form an electrolysis system; electrolysis parameters are set for electrolysis, under the action of an electric field, the bond action between metal and oxygen in the metal oxide is weakened, oxygen ions react with an electrolyte solution, metal ions are dissolved in the electrolyte solution, and then reduction deposition is carried out at a cathode in a metal form through a diaphragm. According to the method disclosed by the embodiment of the invention, preparation of the metal in the aqueous solution can be realized, the method can be suitable for preparation of various metals, the comprehensive yield of the metal is high, the operation process is simple, the energy consumption is low, and the method has good economical efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for preparing metal by electric field assisted dissolution. Background Art

[0002] Metals, such as copper, tin, lead, antimony, zinc, silver, nickel, iron and many other metals, exist in the form of metal oxides in nature. In order to obtain high-purity metals, electrolysis is usually used as an efficient metal production technology for metal refining. However, the traditional aqueous solution electrolysis method is often accompanied by the occurrence of hydrogen evolution reaction due to its small electrochemical window, which limits the possibility of preparing many metals (especially active metals) by aqueous solution electrolysis.

[0003] In order to overcome these limitations, hydrometallurgical technology has become an important alternative. This technology first uses appropriate solvents to leach minerals containing target metals, so that the metals are gradually enriched in the solution in the form of cations or complex anions. In this process, other impurities in the ore either remain insoluble or form precipitates and are removed. After a series of filtration, purification and other treatment steps, pure metal ion leachate is obtained. Next, the leachate is electrolyzed, and the metal ions are deposited on the cathode through the action of electric current, thereby producing the desired pure metal.

[0004] However, although hydrometallurgical technology is quite mature, it still faces some challenges:

[0005] 1. Complex pretreatment steps: In order to achieve effective enrichment of metal ions, metal salts are usually required to be acid-leached. This process not only prolongs the overall process flow, but also increases comprehensive energy consumption and production costs;

[0006] 2. Limitations in material selection: Currently, most electrolysis processes rely on metal halide salts, while research on metal oxide salts is relatively insufficient, which limits the application and development potential of electrolysis on a wider range of materials, especially in the treatment of insoluble metal oxides. Summary of the invention

[0007] In view of this, some embodiments disclose a method for preparing metal by electric field assisted dissolution, comprising:

[0008] A transition metal electrode is used as a cathode, a conductive crucible is used as an anode, and a diaphragm is arranged in the conductive crucible to divide the conductive crucible into a first area and a second area which are independent of each other;

[0009] The cathode is arranged in the first zone, and the first zone is used as a cathode chamber; the metal oxide powder is laid on the bottom of the second zone, and the second zone is used as an anode chamber; and then an electrolyte solution is added to the anode chamber and the cathode chamber to form an electrolysis system;

[0010] The electrolysis parameters are set for electrolysis. Under the action of the electric field, the bond between the metal and oxygen in the metal oxide is weakened, the oxygen ions react with the electrolyte solution, the metal ions dissolve into the electrolyte solution, and then are reduced and deposited in the form of metal at the cathode through the diaphragm.

[0011] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the conductive crucible is a graphite crucible, a nickel crucible or a platinum crucible.

[0012] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the transition metal electrode is titanium, copper, tungsten or molybdenum.

[0013] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the mass concentration of metal oxide powder in the electrolyte solution is 30-60 g / L.

[0014] Some embodiments disclose a method for preparing metals by electric field-assisted dissolution, wherein the metal oxide powder includes iron oxide, ferrous oxide, indium oxide, tin oxide, lead oxide, lead oxide, zinc oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, gallium oxide or selenium oxide.

[0015] In some embodiments of the method for preparing metal by electric field assisted dissolution, the electrolyte solution is HCl solution or H2SO4 solution.

[0016] In some embodiments of the method for preparing metal by electric field assisted dissolution, the electrolysis time of the electrolysis system is 1.5 to 3 hours, and the electrolysis current density is 0.05 to 1 A / cm 2 , the electrolysis voltage is less than 4V.

[0017] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the electrolysis current efficiency of the electrolysis system is 45-75%.

[0018] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the concentration of the electrolyte solution is 4 to 8 mol / L.

[0019] In the method for preparing metal by electric field assisted dissolution disclosed in some embodiments, the comprehensive yield of the product of the electrolysis system is 97.5-99.9%.

[0020] The method for preparing metal by electric field assisted dissolution disclosed in the embodiment of the present invention is that metal oxide powder is dissolved by electric field assisted acid leaching in an acidic solution environment and electrolytic deposition is performed at the same time, so as to realize the preparation of metal in aqueous solution; the embodiment of the present invention sets a diaphragm in the conductive crucible to separate the conductive crucible into a mutually independent anode chamber and cathode chamber, and the diaphragm has selective permeability, so that impurity ions in the metal oxide cannot migrate from the anode chamber to the cathode chamber through the diaphragm, thereby improving the purity of the metal reduced in the cathode chamber. The method for preparing metal by electric field assisted dissolution disclosed in the embodiment of the present invention can be applied to the preparation of a variety of metals, has a high comprehensive yield of metals, a simple operation process, low energy consumption, is environmentally friendly, and has good economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Example 1 Schematic diagram of electrolysis for preparing metals by electric field assisted dissolution.

[0022] Reference numerals

[0023] 1 Graphite Crucible 2 Titanium

[0024] 3 Diaphragm 4 Indium oxide powder

[0025] 5 HCl solution DETAILED DESCRIPTION

[0026] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0027] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0028] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0029] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0030] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0031] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be arbitrarily combined, and the obtained technical solutions belong to the contents disclosed in the embodiments of the present application. It should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like mentioned in the present application indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the technical features and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention, unless it conflicts with the context. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance, unless it conflicts with the context.

[0032] In some embodiments, the method for preparing metal by electric field assisted dissolution comprises:

[0033] A transition metal electrode is used as a cathode, a conductive crucible is used as an anode, a diaphragm is arranged in the conductive crucible, and the conductive crucible is divided into a first area and a second area which are independent of each other; a cathode is arranged in the first area, and the first area is used as a cathode chamber; metal oxide powder is laid on the bottom of the second area, and the second area is used as an anode chamber; then an electrolyte solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the first area and the second area are isolated from each other by a diaphragm, and generally, the diaphragm is made of yttrium oxide material and has selective permeability, and metal ions can migrate from the anode area to the cathode area through the diaphragm under the action of an electric field to be reduced to metal, and impurity ions in the metal oxide cannot migrate from the anode area to the cathode area through the diaphragm;

[0034] The electrolysis parameters are set for electrolysis. Under the action of the electric field, the bond between the metal and oxygen in the metal oxide is weakened, the oxygen ions react with the electrolyte solution, the metal ions dissolve into the electrolyte solution, and then are reduced and deposited in the form of metal at the cathode through the diaphragm. During the electrolysis process, the action of the electric field promotes the weakening of the bond between the metal and oxygen in the metal oxide, the hydrogen ions in the electrolyte solution can react with the oxygen ions in the metal oxide more quickly, and the oxygen ions in the metal oxide are consumed, which promotes the metal ions in the metal oxide to dissolve into the electrolyte solution in the form of free ions. The metal ions entering the electrolyte solution are reduced, nucleated, and grown at the cathode through the diaphragm to be deposited in the form of metal.

[0035] In some embodiments, the conductive crucible is a graphite crucible, a nickel crucible, or a platinum crucible.

[0036] In some embodiments, the transition metal electrode is titanium, copper, tungsten, or molybdenum.

[0037] In some embodiments, the mass concentration of the metal oxide powder in the electrolyte solution is 30-60 g / L.

[0038] In some embodiments, the metal oxide powder includes iron oxide, ferrous oxide, indium oxide, tin oxide, lead oxide, lead oxide, zinc oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, gallium oxide, or selenium oxide.

[0039] In some embodiments, the electrolyte solution is a HCl solution or a H2SO4 solution.

[0040] In some embodiments, the electrolysis time of the electrolysis system is 1.5 to 3 hours, and the electrolysis current density is 0.05 to 1 A / cm 2 , the electrolysis voltage is less than 4V.

[0041] In some embodiments, the electrolysis current efficiency of the electrolysis system is 45-75%.

[0042] In some embodiments, the concentration of the electrolyte solution is 4 to 8 mol / L.

[0043] In some embodiments, the comprehensive yield of the product of the electrolysis system is 97.5-99.9%.

[0044] The technical details are further illustrated below in conjunction with embodiments.

[0045] Example 1

[0046] Figure 1 Schematic diagram of electrolysis for preparing metal by electric field assisted dissolution disclosed in Example 1.

[0047] Example 1 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0048] A graphite crucible 1 is used as an anode and titanium 2 is used as a cathode; wherein a diaphragm 3 is provided in the graphite crucible 1 to divide the graphite crucible 1 into an anode chamber and a cathode chamber;

[0049] Indium oxide powder 4 is laid on the bottom of the anode chamber, titanium is placed in the cathode chamber, and then a 4 mol / L HCl solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of indium oxide powder to HCl solution is 1:10;

[0050] Connect the power supply and set the current density to 0.05A / cm 2 After electrolysis for 1.5 hours, metallic indium was obtained at the cathode, the comprehensive yield of the product was 97.8%, and the current efficiency was 48%.

[0051] Example 2

[0052] Example 2 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0053] A graphite crucible is used as an anode and copper is used as a cathode; wherein a diaphragm is provided in the graphite crucible to divide the graphite crucible into an anode chamber and a cathode chamber;

[0054] Indium oxide powder is laid on the bottom of the anode chamber, copper is placed in the cathode chamber, and then a 4 mol / L HCl solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of indium oxide powder to HCl solution is 1:12;

[0055] Connect the power supply and set the current density to 0.05A / cm 2 After electrolysis for 1.5 hours, metallic indium was obtained at the cathode, the comprehensive yield of the product was 98.2%, and the current efficiency was 51%.

[0056] Example 3

[0057] Example 3 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0058] A nickel crucible is used as an anode and copper is used as a cathode; wherein a diaphragm is provided in the nickel crucible to divide the nickel crucible into an anode chamber and a cathode chamber;

[0059] The tin oxide powder is laid on the bottom of the anode chamber, the copper is placed in the cathode chamber, and then a 6 mol / L HCl solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of the tin oxide powder to the HCl solution is 1:15;

[0060] Connect the power supply and set the current density to 0.05A / cm 2 After electrolysis for 1.5 hours, metallic tin was obtained at the cathode, the comprehensive yield of the product was 98.5%, and the current efficiency was 54%.

[0061] Example 4

[0062] Example 4 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0063] A nickel crucible is used as an anode and titanium is used as a cathode; wherein a diaphragm is provided in the nickel crucible to divide the nickel crucible into an anode chamber and a cathode chamber;

[0064] Tin oxide powder is laid on the bottom of the anode chamber, titanium is placed in the cathode chamber, and then a 6 mol / L H2SO4 solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of tin oxide powder to H2SO4 solution is 1:15;

[0065] Connect the power supply and set the current density to 0.05A / cm 2 After electrolysis for 2 hours, metallic tin was obtained at the cathode, the comprehensive yield of the product was 98.8%, and the current efficiency was 59%.

[0066] Example 5

[0067] Example 5 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0068] A platinum crucible is used as an anode and titanium is used as a cathode; wherein a diaphragm is provided in the platinum crucible to divide the platinum crucible into an anode chamber and a cathode chamber;

[0069] Zinc oxide powder is laid on the bottom of the anode chamber, titanium is placed in the cathode chamber, and then 8 mol / L HCl solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of zinc oxide powder to HCl solution is 1:15;

[0070] Connect the power supply and set the current density to 0.05A / cm 2, electrolysis for 2 hours, metallic zinc was obtained at the cathode, the comprehensive yield of the product was 99.2%, and the current efficiency was 63%.

[0071] Example 6

[0072] Example 6 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0073] A platinum crucible is used as an anode and titanium is used as a cathode; wherein a diaphragm is provided in the platinum crucible to divide the platinum crucible into an anode chamber and a cathode chamber;

[0074] Zinc oxide powder is laid on the bottom of the anode chamber, titanium is placed in the cathode chamber, and then H2SO4 solution with a concentration of 8 mol / L is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of zinc oxide powder to H2SO4 solution is 1:15;

[0075] Connect the power supply and set the current density to 0.2A / cm 2 , electrolysis was carried out for 2.5 hours, and metallic zinc was obtained at the cathode. The comprehensive yield of the product was 99.5% and the current efficiency was 70%.

[0076] Example 7

[0077] Example 7 discloses a method for preparing metal by electric field assisted dissolution, which specifically comprises:

[0078] A platinum crucible is used as an anode and tungsten is used as a cathode; wherein a diaphragm is provided in the platinum crucible to divide the platinum crucible into an anode chamber and a cathode chamber;

[0079] Zinc oxide powder is laid on the bottom of the anode chamber, tungsten is placed in the cathode chamber, and then H2SO4 solution with a concentration of 8 mol / L is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of zinc oxide powder to H2SO4 solution is 1:15;

[0080] Connect the power supply and set the current density to 0.5A / cm 2 After electrolysis for 3 hours, metallic zinc was obtained at the cathode, the comprehensive yield of the product was 99.8%, and the current efficiency was 68%.

[0081] Example 8

[0082] Example 8 discloses a method for preparing metal by electric field assisted dissolution, which specifically includes:

[0083] A platinum crucible is used as an anode and molybdenum is used as a cathode; wherein a diaphragm is provided in the platinum crucible to divide the platinum crucible into an anode chamber and a cathode chamber;

[0084] Zinc oxide powder is laid on the bottom of the anode chamber, molybdenum is placed in the cathode chamber, and then 8 mol / L HCl solution is added to the anode chamber and the cathode chamber to form an electrolysis system; wherein the mass ratio of zinc oxide powder to HCl solution is 1:15;

[0085] Connect the power supply and set the current density to 0.8A / cm 2 After 3 hours of electrolysis, metallic zinc was obtained at the cathode, the comprehensive yield of the product was 99.9%, and the current efficiency was 73%.

[0086] Based on Examples 1 to 8, it can be seen that in the method for preparing metal by electric field-assisted dissolution disclosed in the embodiments of the present invention, the greater the concentration of the electrolyte solution, the greater the current density, and the longer the electrolysis time, the higher the comprehensive yield of the product and the higher the current efficiency.

[0087] Comparative Example 1

[0088] Comparative Example 1 discloses a method for preparing metal by dissolution, comprising:

[0089] Indium oxide powder was laid on the bottom of a beaker, and a 4 mol / L HCl solution was added into the beaker. After immersion for 12 hours, the leaching solution was transferred into a graphite crucible. The mass ratio of indium oxide powder to HCl solution was 1:10.

[0090] The leaching solution is electrolyzed using a graphite crucible as an anode and titanium as a cathode;

[0091] Connect the power supply and set the current density to 0.05A / cm 2 , electrolysis for 1.5h;

[0092] Metal indium was obtained on the cathode, with a comprehensive product yield of 87.8% and a current efficiency of 47%.

[0093] Comparative Example 2

[0094] Comparative Example 2 discloses a method for preparing metal by dissolution, comprising:

[0095] Using a graphite crucible as an anode and titanium as a cathode, indium oxide powder is laid on the bottom of the graphite crucible, an aqueous solution is added into the graphite crucible, and a cathode is placed in the aqueous solution above the indium oxide powder;

[0096] Connect the power supply and set the current density to 0.05A / cm 2 , electrolysis for 1.5h;

[0097] There was no metal precipitation on the cathode, only a small amount of white precipitation in the solution, and the indium oxide powder produced only a small amount of weight loss.

[0098] The method for preparing metal by electric field assisted dissolution disclosed in the embodiment of the present invention is that metal oxide powder is dissolved by electric field assisted acid leaching in an acidic solution environment and electrolytic deposition is performed at the same time, so as to realize the preparation of metal in aqueous solution; the embodiment of the present invention sets a diaphragm in the conductive crucible to separate the conductive crucible into a mutually independent anode chamber and cathode chamber, and the diaphragm has selective permeability, so that impurity ions in the metal oxide cannot migrate from the anode chamber to the cathode chamber through the diaphragm, thereby improving the purity of the metal reduced in the cathode chamber. The method for preparing metal by electric field assisted dissolution disclosed in the embodiment of the present invention can be applied to the preparation of a variety of metals, has a high comprehensive yield of metals, a simple operation process, low energy consumption, is environmentally friendly, and has good economic efficiency.

[0099] The technical solutions disclosed in the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the present invention. Any conventional changes, substitutions or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing metal by electric field assisted dissolution, characterized in that: include: A transition metal electrode is used as a cathode, a conductive crucible is used as an anode, and a diaphragm is arranged in the conductive crucible to divide the conductive crucible into a first area and a second area which are independent of each other; The cathode is arranged in the first zone, and the first zone is used as a cathode chamber; the metal oxide powder is laid on the bottom of the second zone, and the second zone is used as an anode chamber; and then an electrolyte solution is added to the anode chamber and the cathode chamber to form an electrolysis system; The electrolysis parameters are set for electrolysis. Under the action of the electric field, the bond between the metal and oxygen in the metal oxide is weakened, the oxygen ions react with the electrolyte solution, the metal ions dissolve into the electrolyte solution, and then are reduced and deposited in the form of metal at the cathode through the diaphragm.

2. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The conductive crucible is selected from graphite crucible, nickel crucible or platinum crucible.

3. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The transition metal electrode is titanium, copper, tungsten or molybdenum.

4. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The mass concentration of the metal oxide powder in the electrolyte solution is 30 to 60 g / L.

5. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The metal oxide powder includes iron oxide, ferrous oxide, indium oxide, tin oxide, lead oxide, lead oxide, zinc oxide, copper oxide, silver oxide, nickel oxide, manganese oxide, gallium oxide or selenium oxide.

6. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The electrolyte solution is HCl solution or H2SO4 solution.

7. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The electrolysis time of the electrolysis system is 1.5 to 3 hours, and the electrolysis current density is 0.05 to 1 A / cm 2 , the electrolysis voltage is less than 4V.

8. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The electrolysis current efficiency of the electrolysis system is 45-75%.

9. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The concentration of the electrolyte solution is 4-8 mol / L.

10. The method for preparing metal by electric field assisted dissolution according to claim 1, characterized in that: The comprehensive yield of the product of the electrolysis system is 97.5-99.9%.

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