Method for preparing high-purity gallium oxide from bauxite by utilizing single crystal growth method

Abstract

The invention discloses a method for preparing high-purity gallium oxide from bauxite by using a single crystal growth method, which comprises the following steps: leaching the bauxite by using oxalic acid to obtain a leachate; extracting the leachate to obtain a gallium and germanium loaded organic phase; mixing the sulfuric acid solution and the leaching solution to obtain a germanium-containing loaded organic phase and gallium strip liquor; stripping germanium from the loaded organic phase through a sodium hydroxide solution; adding sodium chloride into the gallium strip liquor and electrifying to obtain crude gallium; heating the crude gallium in air to obtain gallium oxide; the pure gallium oxide is obtained by taking zirconium oxide as a thermal insulation material, heating the crucible as a heat source, oxygen and carbon dioxide as growth atmosphere, 2-8% of oxidation volume fraction, 4N-grade gallium oxide, 3N-grade iron oxide and 010-crystal-orientation single crystal seed crystals as growth raw materials through a crucible. The gallium oxide is prepared in a single crystal growth mode, the limitation of other methods on the purity of raw materials is overcome, the production cost is greatly reduced, the process is easy to implement, and the obtained product is high in purity.

Description

Technical Field

[0001] The invention relates to the technical field of metal material preparation, and in particular to a method for preparing high-purity gallium oxide from bauxite by using a single crystal growth method. Background Art

[0002] Pure gallium oxide is mainly used to synthesize gadolinium gallium garnet, which is the main magnetic storage material. With the rapid development of the information industry, its usage has increased significantly. Gallium oxide can also be used as a catalyst for organic reactions, LED phosphors, etc. In recent years, with the development and utilization of new materials, the use of gallium oxide has become more and more extensive.

[0003] There are two main methods for preparing high-purity gallium oxide: neutralization method and hydrothermal synthesis method. Both methods use 6N high-purity gallium as the basic raw material. The neutralization method uses a sodium gallate solution to neutralize to obtain gallium hydroxide precipitate, which is then washed, dried, and roasted to obtain gallium oxide. Its disadvantage is that the purity is affected by the composition of the mother liquor and the impurity content is high. The hydrothermal synthesis method requires high temperature and high pressure reaction, with low yield, and the product purity is affected by the kettle material, and the impurity content is unstable. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for preparing high-purity gallium oxide from bauxite using a single crystal growth method, aiming to solve the above technical problems.

[0005] To achieve the above object, the present invention proposes a method for preparing high-purity gallium oxide from bauxite using a single crystal growth method, comprising:

[0006] S1. Leaching bauxite with oxalic acid, and obtaining a leachate after filtering;

[0007] S2, extracting the leaching solution to obtain a gallium and germanium loaded organic phase;

[0008] S3, stripping gallium ions by mixing sulfuric acid solution and leaching solution to obtain a germanium-containing loaded organic phase and a gallium stripping solution;

[0009] S4, stripping germanium from the loaded organic phase in step S3 by sodium hydroxide solution;

[0010] S5, adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium;

[0011] S6, heating the crude gallium in air to obtain gallium oxide;

[0012] S7. Use an iridium crucible, zirconium oxide as insulation material, a medium-frequency induction heating crucible as a heat source, a growth atmosphere of oxygen and carbon dioxide, an oxidation volume fraction of 2%-8%, and growth raw materials of 4N-grade gallium oxide, 3N-grade iron oxide, and a single crystal seed crystal with a 010 crystal orientation. Mix the raw materials and fill them into the crucible. Heat up and melt the raw materials and keep them warm for 1 hour. After stabilization, the gallium oxide seed crystal with a 010 crystal orientation can be slowly lowered to contact the melt surface. After stabilization for 1 hour, shoulder release and shoulder rotation are performed. Finally, wait for the expected growth to be achieved and then get rid of the crystal and cool down to obtain pure gallium oxide.

[0013] In one embodiment, the step of extracting the leachate to obtain the gallium and germanium loaded organic phase is specifically:

[0014] N235 was selected as the extractant and kerosene as the diluent. Under an acidic environment, the leachate was subjected to three-stage countercurrent extraction at a relative ratio of 2 to obtain a loaded organic phase containing gallium and germanium.

[0015] In one embodiment, the concentration of the extractant is 20%.

[0016] In one embodiment, the pH of the acidic environment is 3-6.

[0017] In one embodiment, the concentration of the sulfuric acid solution in step S3 is 3 mol / L.

[0018] In one embodiment, the concentration of the sodium hydroxide solution in step S4 is 3.5 mol / L.

[0019] In one embodiment, the step of adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium is specifically:

[0020] Add sodium chloride to the gallium stripping solution and pass electricity for 1-2 hours to electrolyze to obtain crude gallium.

[0021] In one embodiment, the step of heating crude gallium in air to obtain gallium oxide is specifically as follows:

[0022] The crude gallium is heated to 400-600°C in air to obtain 4N grade gallium oxide.

[0023] In the technical solution of the present invention, the method for preparing high-purity gallium oxide from bauxite by single crystal growth method comprises:

[0024] S1. Leaching bauxite with oxalic acid, and obtaining a leachate after filtering;

[0025] S2, extracting the leaching solution to obtain a gallium and germanium loaded organic phase;

[0026] S3, stripping gallium ions by mixing sulfuric acid solution and leaching solution to obtain a germanium-containing loaded organic phase and a gallium stripping solution;

[0027] S4, stripping germanium from the loaded organic phase in step S3 by sodium hydroxide solution;

[0028] S5, adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium;

[0029] S6, heating the crude gallium in air to obtain gallium oxide;

[0030] S7. Use an iridium crucible, zirconium oxide as insulation material, a medium-frequency induction heating crucible as a heat source, a growth atmosphere of oxygen and carbon dioxide, an oxidation volume fraction of 2%-8%, and growth raw materials of 4N-grade gallium oxide, 3N-grade iron oxide, and a single crystal seed crystal with a 010 crystal orientation. Mix the raw materials and fill them into the crucible. Heat up and melt the raw materials and keep them warm for 1 hour. After stabilization, the gallium oxide seed crystal with a 010 crystal orientation can be slowly lowered to contact the melt surface. After stabilization for 1 hour, shoulder release and shoulder rotation are performed. Finally, wait for the expected growth to be achieved and then get rid of the crystal and cool down to obtain pure gallium oxide.

[0031] The present application adopts a single crystal growth method to prepare gallium oxide, which overcomes the limitations of other methods on raw material purity, greatly reduces production costs, and the process is easy to implement and the obtained product has high purity. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The invention provides a method for preparing high-purity gallium oxide from bauxite by using a single crystal growth method.

[0037] The method for preparing high-purity gallium oxide from bauxite by using a single crystal growth method provided in an embodiment of the present invention comprises:

[0038] S1. Leaching bauxite with oxalic acid, and obtaining a leachate after filtering;

[0039] S2, extracting the leaching solution to obtain a gallium and germanium loaded organic phase;

[0040] S3, stripping gallium ions by mixing sulfuric acid solution and leaching solution to obtain a germanium-containing loaded organic phase and a gallium stripping solution;

[0041] S4, stripping germanium from the loaded organic phase in step S3 by sodium hydroxide solution;

[0042] S5, adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium;

[0043] S6, heating the crude gallium in air to obtain gallium oxide;

[0044] S7. Use an iridium crucible, zirconium oxide as insulation material, a medium-frequency induction heating crucible as a heat source, a growth atmosphere of oxygen and carbon dioxide, an oxidation volume fraction of 2%-8%, and growth raw materials of 4N-grade gallium oxide, 3N-grade iron oxide, and a single crystal seed crystal with a 010 crystal orientation. Mix the raw materials and fill them into the crucible. Heat up and melt the raw materials and keep them warm for 1 hour. After stabilization, the gallium oxide seed crystal with a 010 crystal orientation can be slowly lowered to contact the melt surface. After stabilization for 1 hour, shoulder release and shoulder rotation are performed. Finally, wait for the expected growth to be achieved and then get rid of the crystal and cool down to obtain pure gallium oxide.

[0045] In one embodiment, the step of extracting the leachate to obtain the gallium and germanium loaded organic phase is specifically:

[0046] N235 was selected as the extractant and kerosene as the diluent. Under an acidic environment, the leachate was subjected to three-stage countercurrent extraction at a relative ratio of 2 to obtain a loaded organic phase containing gallium and germanium.

[0047] In one embodiment, the concentration of the extractant is 20%.

[0048] In one embodiment, the pH of the acidic environment is 3-6.

[0049] In one embodiment, the concentration of the sulfuric acid solution in step S3 is 3 mol / L.

[0050] In one embodiment, the concentration of the sodium hydroxide solution in step S4 is 3.5 mol / L.

[0051] In one embodiment, the step of adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium is specifically:

[0052] Add sodium chloride to the gallium stripping solution and pass electricity for 1-2 hours to electrolyze to obtain crude gallium.

[0053] In one embodiment, the step of heating crude gallium in air to obtain gallium oxide is specifically as follows:

[0054] The crude gallium is heated in the air to the soil ore for leaching. In the oxalic acid solution, gallium and germanium can form a stable complex. In contrast, it is difficult for Si to form a complex. Therefore, the oxalic acid leaching process is selected. At the same time, oxalic acid can remove iron ions in the leaching solution to avoid the influence of iron ions on subsequent processes. The leaching solution is obtained after filtration, and N235 is selected as the extractant and kerosene is the diluent. The acidic environment is selected in the extraction process to reduce the dissolution loss of the organic extractant in the aqueous solution and reduce the cost. The extractant concentration is 20%, and the leaching solution is extracted and separated at a pH of 3-6. The extraction conditions are: compared with 2, three-stage countercurrent extraction. A gallium and germanium loaded organic phase is obtained, and then a 3mol / sulfuric acid solution with a phase ratio of 1 is used to selectively strip gallium at room temperature. The loaded organic phase after stripping gallium is then stripped of germanium at room temperature using a 3.5mol / L sodium hydroxide solution with a phase ratio of 0.5. Then, sodium chloride is added to the gallium stripping solution and electricity is passed for 1-2 hours to electrolyze to obtain crude gallium with a purity of 99.99%. The crude gallium is then heated to 400-600°C in air to obtain 4N grade gallium oxide. 4N grade gallium oxide is obtained at 400-600°C.

[0055] We used oxalic acid to treat aluminum and finally used iridium as the crucible, zirconia as the insulation material, medium frequency induction heating crucible as the heat source, the growth atmosphere was oxygen and carbon dioxide, the oxidation volume fraction was 2%-8%, the growth raw materials were 4N grade gallium oxide and 3N grade iron oxide, and the single crystal seed crystal in the <010> direction was used. The raw materials were mixed and filled into the crucible. The temperature was raised to melt the raw materials and then kept warm for 1 hour. After stabilization, the high-quality gallium oxide seed crystal in the <010> direction slowly descended until it contacted the melt surface. After stabilization for 1 hour, the shoulder was released and the shoulder was turned. Finally, after waiting for the expected growth, the crystal was cooled to obtain gallium oxide with a purity of 99.999%.

[0056] Example 1

[0057] Take 100g bauxite, 200ml Bauxite is leached with oxalic acid solution at pH = 2, and after leaching, filter to obtain filter residue and leachate. ANPO extractant is selected as the leachate, kerosene is used as the diluent, and the extraction conditions are: extractant concentration 20%, pH = 3, three-stage countercurrent extraction is performed compared to 2 to obtain loaded organic liquid and raffinate, and the loaded organic is stripped with ammonia water at pH = 10 in a 1:1 ratio to obtain stripping solution. Because gallium and germanium cannot be effectively separated, there is 0.2% Ge4+ in the stripping solution. An appropriate amount of sodium chloride is added to the stripping solution and powered for 2 hours to obtain elemental gallium with a purity of 99.9%. The elemental gallium is then heated to 500° C. in air and kept warm for 2 hours to obtain 99.9% gallium oxide. 3N grade gallium oxide and 3N grade iron oxide are selected as growth materials, oxygen and carbon dioxide are selected as the atmosphere, wherein the oxygen volume fraction is 4%, and the growth raw material is separated by isomorphous growth with a single crystal seed crystal in the <010> direction to obtain 4N grade gallium oxide.

[0058] Example 2

[0059] Take 500g bauxite, 1000ml Bauxite is leached with PH=2 oxalic acid solution, and after leaching, filter to obtain filter residue and leachate. N235 extractant is selected as the leachate, kerosene is used as the diluent, and the extraction conditions are: extractant concentration 20%, PH=6, three-stage countercurrent extraction is performed with a phase ratio of 2 to obtain a loaded organic liquid and a raffinate. The loaded organic is first selectively stripped of gallium at room temperature using a 3mol / L sulfuric acid solution with a phase ratio of 1, and then stripped of germanium at room temperature using a 3.5mol / L sodium hydroxide solution with a phase ratio of 0.5. An appropriate amount of sodium chloride is added to the gallium-enriched solution and powered for 2 hours to obtain a single gallium with a purity of 99.99%. The single gallium is then heated to 500°C in air and kept warm for 2 hours to obtain 99.99% gallium oxide. 4N grade gallium oxide and 3N grade iron oxide are selected as growth materials, oxygen and carbon dioxide are selected as the atmosphere, wherein the oxygen volume fraction is 4%, and the growth raw material is separated by isomorphous growth with a single crystal seed crystal in the <010> direction to obtain 5N grade gallium oxide.

[0060] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing high-purity gallium oxide from bauxite using a single crystal growth method, characterized in that: The method for preparing high-purity gallium oxide from bauxite by single crystal growth method comprises: S1. Leaching bauxite with oxalic acid, and obtaining a leachate after filtering; S2, extracting the leaching solution to obtain a gallium and germanium loaded organic phase; S3, stripping gallium ions by mixing sulfuric acid solution and leaching solution to obtain a germanium-containing loaded organic phase and a gallium stripping solution; S4, stripping germanium from the loaded organic phase in step S3 by sodium hydroxide solution; S5, adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium; S6, heating the crude gallium in air to obtain gallium oxide; S7. Use an iridium crucible, zirconium oxide as insulation material, a medium-frequency induction heating crucible as a heat source, a growth atmosphere of oxygen and carbon dioxide, an oxidation volume fraction of 2%-8%, and growth raw materials of 4N-grade gallium oxide, 3N-grade iron oxide, and a single crystal seed crystal with a 010 crystal orientation. Mix the raw materials and fill them into the crucible. Heat up and melt the raw materials and keep them warm for 1 hour. After stabilization, the gallium oxide seed crystal with a 010 crystal orientation can be slowly lowered to contact the melt surface. After stabilization for 1 hour, shoulder release and shoulder rotation are performed. Finally, wait for the expected growth to be achieved and then get rid of the crystal and cool down to obtain pure gallium oxide.

2. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 1, characterized in that: The step of extracting the leachate to obtain the gallium and germanium loaded organic phase is specifically: N235 was selected as the extractant and kerosene as the diluent. Under an acidic environment, the leachate was subjected to three-stage countercurrent extraction at a relative ratio of 2 to obtain a loaded organic phase containing gallium and germanium.

3. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 2, characterized in that: The concentration of the extractant is 20%.

4. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 2, characterized in that: The pH of the acidic environment is 3-6.

5. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 1, characterized in that: The concentration of the sulfuric acid solution in step S3 is 3 mol / L.

6. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step S4 is 3.5 mol / L.

7. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 1, characterized in that: The step of adding sodium chloride to the gallium stripping solution and applying electricity to obtain crude gallium is specifically: Add sodium chloride to the gallium stripping solution and pass electricity for 1-2 hours to electrolyze to obtain crude gallium.

8. The method for preparing high-purity gallium oxide from bauxite using a single crystal growth method according to claim 1, characterized in that: The step of heating the crude gallium in air to obtain gallium oxide is specifically as follows: The crude gallium is heated to 400-600°C in air to obtain 4N grade gallium oxide.