Preparation method and equipment of high-purity gallium oxide for fluorescent powder

Abstract

The invention discloses a preparation method of high-purity gallium oxide for fluorescent powder, and belongs to the technical field of gallium oxide preparation. The invention discloses a preparation method and equipment of high-purity gallium oxide for fluorescent powder, and the preparation method comprises the following steps: S1, adding ammonia water into a gallium sulfate or ammonium gallium sulfate solution, neutralizing to precipitate gallium hydroxide, S2, washing and filtering the gallium hydroxide precipitate to obtain a gallium hydroxide solid, and S3, drying and roasting the gallium hydroxide solid to obtain gallium oxide. Preparation equipment of high-purity gallium oxide for fluorescent powder comprises a magnetic inner barrel, an adding hard tube and an induction coil, the magnetic inner barrel is located on the inner side of a non-magnetic outer barrel, a heating space is formed between the non-magnetic outer barrel and the magnetic inner barrel, the induction coil and an electric heating tube are arranged on the inner side of the heating space, and the induction coil is located on the outer side of the side wall of the magnetic inner barrel. The electric heating pipe is positioned below the magnetic inner barrel; the method has the advantages that the requirements on basic raw materials are reduced, and the purity of gallium oxide is improved.

Description

Technical Field

[0001] The invention relates to the technical field of gallium oxide preparation, and in particular to a method and equipment for preparing high-purity gallium oxide for phosphor. Background Art

[0002] Gallium oxide itself is a wide-bandgap semiconductor gem with a bandgap width ranging from 4.2eV to 4.9eV. Its electrical and optical properties are extraordinary, and it can withstand temperature changes without changing its quality. It is resistant to acid and alkali corrosion. It is widely used in gas sensing, ultraviolet detection, thin-film electroluminescence, and transparent conductive films. Its development prospects and application potential are unlimited. As a brilliant element in LED phosphors, gallium oxide is constantly expanding its application fields with the in-depth exploration of new materials, showing an unprecedented broad prospect.

[0003] With the vigorous development of the semiconductor industry, the strategic position of high-purity gallium oxide compounds in the modern and defense industries has become increasingly prominent. Its wide application and profound impact demonstrate its importance and extraordinaryness.

[0004] There are three main processes for preparing high-purity gallium at present: First, add a highly concentrated hot aqueous solution of sodium bicarbonate to a hot aqueous solution of gallium trichloride and boil until all the hydroxide of gallium is precipitated. Wash the precipitate with hot water until there is no Cl-, and calcine it at above 600°C to obtain gallium oxide; second, use high-purity metallic gallium as the anode, dissolve it in a 5% to 20% sulfuric acid solution, add ammonia water to the solution, cool it, repeatedly crystallize ammonium gallium sulfate, dry it at 105°C, and calcine it at 800°C under excess oxygen to obtain gallium oxide; third, weigh high-purity gallium and put it into a three-necked flask, add high-purity nitric acid to dissolve all the gallium, then filter it, pour the filtrate into a three-necked flask, move it to an electric furnace for evaporation, and when it is concentrated to near crystallization, move the solution to a large evaporating dish and evaporate it to dryness. The evaporated gallium nitrate is placed for calcination, and the finished product is taken out after cooling to obtain high-purity gallium oxide. The purity of these gallium oxide preparations is not high, and the preparation process is cumbersome. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that the preparation method of gallium oxide in the prior art has low purity and complicated process flow, and to propose a preparation method and equipment of high-purity gallium oxide for phosphor.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing high-purity gallium oxide for phosphor, comprising the following steps: S1. Adding ammonia water to the gallium sulfate or ammonium gallium sulfate solution to neutralize it, so that gallium hydroxide is precipitated; S2, washing and filtering the gallium hydroxide precipitate to obtain gallium hydroxide solid; S3, drying and calcining the gallium hydroxide solid to obtain gallium oxide.

[0007] Furthermore, the preparation steps of the gallium sulfate solution in step S1 are as follows: S101. Add liquid gallium and sulfuric acid into a container, place it in a constant temperature water bath, stir and add hydrogen peroxide to obtain a gallium sulfate solution.

[0008] Furthermore, the liquid gallium in step S101 is 4N metallic gallium.

[0009] Furthermore, the sulfuric acid in step S101 is diluted with 98% concentrated sulfuric acid to obtain a 50% to 80% sulfuric acid solution.

[0010] Furthermore, the preparation steps of the ammonium gallium sulfate solution in step S1 are as follows: S102, adding high-purity water and ammonium sulfate to the gallium sulfate solution in step S101 to prepare an ammonium gallium sulfate solution, and cooling and crystallizing; S103, separating the crystals and adding high-purity water to obtain an ammonium gallium sulfate solution.

[0011] Furthermore, in step S102, chemically pure ammonium sulfate is added at a molar ratio of ammonium sulfate to gallium sulfate of 1.2-1.5:1.

[0012] A preparation device for high-purity gallium oxide for phosphor, comprising a magnetic inner barrel for containing the solution in step S1 for reaction, a hard tube for adding reagents into the magnetic inner barrel, and an induction coil for heating the magnetic inner barrel; The magnetic inner barrel is located inside the non-magnetic outer barrel, a heating space is formed between the non-magnetic outer barrel and the magnetic inner barrel, an induction coil and an electric heating tube are arranged inside the heating space, the induction coil is located outside the side wall of the magnetic inner barrel, and the electric heating tube is located below the magnetic inner barrel; A first conveying pipe is arranged at the bottom of the magnetic inner barrel, and a second conveying pipe is arranged at the bottom of the non-magnetic outer barrel.

[0013] Furthermore, a lifting plate, a stirring shaft, and stirring blades are provided above the magnetic inner barrel; the lifting plate is installed on the working end of the lifting unit; the stirring shaft is rotatably installed on the lifting plate; stirring blades are provided at the lower part of the stirring shaft; the stirring shaft and stirring blades are lifted or lowered from the inside of the magnetic inner barrel by the lifting unit and the lifting plate.

[0014] Furthermore, a drainage through hole is opened inside the stirring shaft, and a filter screen is arranged at the bottom opening of the drainage through hole.

[0015] Furthermore, the magnetic inner barrel comprises a heat-resistant glass barrel and a magnetic metal interlayer, and the magnetic metal interlayer is embedded and installed in the side wall of the heat-resistant glass barrel.

[0016] Compared with the prior art, the present invention provides a method and equipment for preparing high-purity gallium oxide for phosphor, which has the following beneficial effects: The present invention discloses a method and equipment for preparing high-purity gallium oxide for phosphors. 1. Gallium oxide is prepared by using gallium sulfate or ammonium gallium sulfate, and a purification process of washing and filtering is added in the middle. 4N metal gallium can be used as a basic raw material. Compared with the production method in the prior art, the limitation of raw material purity in the traditional method is overcome, the production cost is greatly reduced, and the process operation is simple and easy to implement. 2. The present invention takes a unique approach and innovatively uses a mixed solution of sulfuric acid and hydrogen peroxide to react with metal gallium. This method has a low threshold, rapid reaction, and greatly reduces time costs. At the same time, the fine control of the hydrogen peroxide solution not only simplifies the operation process, but also shortens the production cycle.

[0017] Other advantages, objectives and features of the present invention will be described in part in the following description; and in part, will be apparent to those skilled in the art based on an examination of the following; or, may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the reaction flow of Example 1 of the present invention; Figure 2 This is a schematic diagram of the reaction flow of Example 2 of the present invention; Figure 3 This is a schematic diagram of the image analysis results of the gallium oxide product of Example 1 of the present invention; Figure 4 This is a schematic diagram of the image analysis results of the gallium oxide product of Example 2 of the present invention; Figure 5 It is a front view schematic diagram of the cross-sectional effect of the non-magnetic outer barrel of the present invention; Figure 6 For the present invention Figure 5 A schematic diagram of the structure enlargement of part A; Figure 7 It is a schematic diagram of the support frame structure of the present invention.

[0019] In the figure: 1. Non-magnetic outer barrel; 2. Magnetic inner barrel; 201. Heat-resistant glass barrel; 202. Magnetic metal interlayer; 3. Induction coil; 4. Heating space; 5. First conveying pipe; 6. Second conveying pipe; 7. Electric heating pipe; 8. Lifting unit; 9. Lifting plate; 10. Driving motor; 11. Stirring shaft; 12. Stirring blade; 13. Drainage hole; 14. Adding hard pipe; 15. Adding hose; 16. Suction hose; 17. Filter; 18. Support frame. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0021] Reference Figure 1-7 The present invention provides a method for preparing high-purity gallium oxide for phosphor, comprising the following steps: S1. Adding ammonia water to the gallium sulfate or ammonium gallium sulfate solution to neutralize it, so that gallium hydroxide is precipitated; S2, washing and filtering the gallium hydroxide precipitate to obtain gallium hydroxide solid; S3, drying and calcining the gallium hydroxide solid to obtain gallium oxide.

[0022] The preparation steps of the gallium sulfate solution in step S1 are as follows: S101. Add liquid gallium and sulfuric acid into a container, place it in a constant temperature water bath, stir and add hydrogen peroxide, the hydrogen peroxide is used as a catalyst to increase the reaction rate of gallium and sulfuric acid, and obtain a gallium sulfate solution.

[0023] In step S101 , the liquid gallium is 4N metallic gallium.

[0024] In step S101, sulfuric acid is diluted with 98% concentrated sulfuric acid to obtain a 50% to 80% sulfuric acid solution.

[0025] In step S101, the temperature of the constant temperature water bath is 80-95°C, and the insulation time is 10-30 minutes.

[0026] In step S101, the stirring rate is 200-300 r / min, and hydrogen peroxide is slowly added at a ratio of sulfuric acid to hydrogen peroxide of 1:0.3-0.8.

[0027] When gallium sulfate is used to prepare gallium oxide, gallium metal and sulfuric acid are reacted to generate gallium sulfate, and a neutralizer (ammonia water) is added to adjust the pH value of the system to 6-7, so that the gallium in the system is precipitated in the form of gallium hydroxide. Solid gallium hydroxide is then obtained through filtration and washing, and finally high-purity gallium oxide for phosphors is obtained through drying and roasting.

[0028] The steps for preparing the ammonium gallium sulfate solution in step S1 are as follows: S102, adding high-purity water and ammonium sulfate to the gallium sulfate solution in step S101 to prepare an ammonium gallium sulfate solution, and cooling and crystallizing; S103, separating the crystals and adding high-purity water to obtain an ammonium gallium sulfate solution.

[0029] In step S102, the cooling crystallization temperature is 0-4°C and the crystallization time is 2-6 hours.

[0030] In step S102, high-purity water is added at a ratio of 1:2 between the reaction metal and the high-purity water.

[0031] In step S102, chemically pure ammonium sulfate is added at a molar ratio of ammonium sulfate to gallium sulfate of 1.2-1.5:1.

[0032] In step S103, the crystals are dissolved in high-purity water at a ratio of 1:4.

[0033] In step S3, gallium hydroxide is dried at 130-150° C. for 2-4 hours.

[0034] In step S3, the gallium hydroxide solid is calcined at 800-900° C. for 3-5 hours.

[0035] When ammonium gallium sulfate is used to prepare gallium oxide, gallium metal and sulfuric acid are reacted to generate gallium sulfate, which is then polymerized and crystallized with ammonium sulfate in an aqueous solution to precipitate ammonium gallium sulfate crystals. The ammonium gallium sulfate crystals are recrystallized to obtain high-purity ammonium gallium sulfate crystals, and aqueous ammonia is added to adjust the pH value of the system to 6-7 to precipitate gallium in the system in the form of gallium hydroxide. Solid gallium hydroxide is then obtained through filtration and washing, and finally high-purity gallium oxide for phosphors is obtained through drying and roasting.

[0036] A preparation device for high-purity gallium oxide for phosphor, comprising a magnetic inner barrel 2 for containing the solution in step S1 for reaction, and an adding hard tube 14 for adding reagents into the magnetic inner barrel 2, wherein the adding hard tube 14 is fixedly mounted on a lifting plate 9, and an outlet at the bottom of the adding hard tube 14 faces the inner side of the magnetic inner barrel 2, and the top of the adding hard tube 14 is connected to an adding hose 15, and there are a plurality of adding hard tubes 14, which are respectively used to add hydrogen peroxide, ammonia water, dilute sulfuric acid, etc. into the magnetic inner barrel 2, and an induction coil 3 for heating the magnetic inner barrel 2; The magnetic inner barrel 2 is located on the inner side of the non-magnetic outer barrel 1, and the non-magnetic outer barrel 1 and the magnetic inner barrel 2 are fixedly connected by a support frame 18, so that the magnetic inner barrel 2 and the non-magnetic outer barrel 1 are both barrel structures with top openings, and a heating space 4 is formed between the non-magnetic outer barrel 1 and the magnetic inner barrel 2. The heating space is used to hold water, and the reaction in the magnetic inner barrel 2 is heated by a constant temperature water bath. An induction coil 3 and an electric heating tube 7 are installed on the inner side of the heating space 4, and the induction coil 3 and the electric heating tube 7 are fixed to the inner wall of the non-magnetic outer barrel 1 through a fixing frame. The non-magnetic outer barrel 1 can be made of non-magnetic, high-temperature resistant hard materials, such as stainless steel, ceramics, high-temperature resistant glass, etc.

[0037] The induction coil 3 is located outside the side wall of the magnetic inner barrel 2 , and the magnetic inner barrel 2 is electromagnetically heated by the induction coil 3 to roast the reactants in the magnetic inner barrel 2 .

[0038] The electric heating tube 7 is located below the magnetic inner barrel 2. When water bath heating is required, water is added into the heating space 4 and the water is heated by the electric heating tube 7. A first delivery pipe 5 is installed at the bottom of the magnetic inner barrel 2 . The first delivery pipe 5 passes through the side wall of the non-magnetic outer barrel 1 and the side wall of the magnetic inner barrel 2 , and is used to pass high-purity water into the magnetic inner barrel 2 .

[0039] A second delivery pipe 6 is installed at the bottom of the non-magnetic outer barrel 1. The second delivery pipe 6 is also divided into two sections. One end is a second water inlet section, which runs through the side wall of the non-magnetic outer barrel 1 and is used to introduce water for water bathing into the heating space 4. The other end is a second water outlet section, which is used to discharge water for water bathing.

[0040] A lifting plate 9, a stirring shaft 11, and a stirring blade 12 are installed above the magnetic inner barrel 2. The lifting plate 9 is installed on the working end of the lifting unit 8. The lifting unit 8 can select a vertically installed hydraulic cylinder, electric cylinder or other telescopic equipment. The stirring shaft 11 is rotatably installed on the lifting plate 9. The top of the stirring shaft 11 protrudes from the top of the lifting plate 9. A driven gear is mounted on the stirring shaft 11. A driving motor 10 is installed on one side of the stirring shaft 11. A driving gear is installed on the working end of the driving motor 10. The driving gear is meshed with the driven gear, and the stirring shaft 11 is driven to rotate by the driving motor 10.

[0041] A stirring blade 12 is installed at the lower part of the stirring shaft 11. The stirring shaft 11 and the stirring blade 12 are lifted or lowered from the inside of the magnetic inner barrel 2 by the lifting unit 8 and the lifting plate 9, and are used for stirring during the reaction process.

[0042] A drainage hole 13 is provided inside the stirring shaft 11, and the top of the drainage hole 13 is connected to a suction hose 16, which is connected to an external liquid pump. A filter screen 17 is installed at the bottom opening of the drainage hole 13. When it is necessary to filter out the clear liquid in the magnetic inner barrel 2, the stirring shaft 11 is inserted into the clear liquid in the magnetic inner barrel 2 and sucked out through the drainage hole 13. When sucking the clear liquid, the filter screen 17 prevents precipitation and crystallization from entering the drainage hole 13.

[0043] The magnetic inner barrel 2 includes a heat-resistant glass barrel 201 and a magnetic metal interlayer 202. The heat-resistant glass barrel 201 is made of high-temperature resistant glass or quartz glass, and its high-temperature resistance is above 1100 degrees. The magnetic metal interlayer 202 is embedded in the side wall of the heat-resistant glass barrel 201. When the induction coil 3 is energized, the induction coil 3 performs electromagnetic induction heating on the magnetic metal interlayer 202, and further roasts the gallium hydroxide in the heat-resistant glass barrel 201 to obtain high-purity gallium oxide.

[0044] Example 1 Step 1: Weigh 200g of metal gallium and dissolve it into liquid, pour the used 60% sulfuric acid and metal gallium into the magnetic inner barrel 2, introduce water into the heating space 4 through the second delivery pipe 6, start the electric heating pipe 7 to heat the water in the heating space 4, place the reaction of sulfuric acid and metal gallium in a constant temperature water bath at 85°C, keep warm for 30 minutes, start the drive motor 10 to drive the stirring shaft 11 and the stirring blade 12 to rotate, control the lifting unit 8 to drive the stirring blade 12 to extend into the reaction solution in the magnetic inner barrel 2, start stirring, the stirring rate is 200r / min, and slowly add 30% hydrogen peroxide at a ratio of sulfuric acid to hydrogen peroxide of 1:0.6 to start the reaction; Step 2: according to the ratio of reaction metal to high-purity water of 1:2, high-purity water is added through the hard tube 14, and chemically pure ammonium sulfate solid is added to the gallium sulfate solution according to the molar ratio of ammonium sulfate to gallium sulfate of 1.2:1, and the driving motor 10 is turned on again for stirring to prepare an ammonium gallium sulfate solution, and the solution is placed in a 0°C freezer for cooling and crystallization for 3 hours; Step 3: Separate the crystals from step 2 from the supernatant, wash the surface of the crystals with high-purity water, dissolve the crystals in high-purity water at a ratio of 1:4, and add chemically pure ammonia water to the solution to adjust the solution pH to 7; Step 4: adding high-purity water to wash the precipitate, stirring for 30 minutes, allowing the precipitate to stand, filtering out the supernatant, repeating the process three times, and then filtering and separating to obtain gallium hydroxide; Step 5: Place gallium hydroxide in an oven at 150° C. and dry for 2 hours to obtain solid gallium hydroxide, and place the solid gallium hydroxide in a high-temperature furnace at 900° C. and calcine for 3 hours to obtain gallium oxide.

[0045] The purity of the gallium oxide obtained above reaches 99.999%.

[0046] Example 2 Step 1: Weigh 100g of metallic gallium and dissolve it into liquid state, pour the used 70% sulfuric acid and metallic gallium into a reaction vessel, place it in a constant temperature water bath at 90°C, keep warm for 15 minutes, start stirring, stirring at a rate of 200r / min, and slowly add 30% hydrogen peroxide at a ratio of sulfuric acid to hydrogen peroxide of 1:0.8 to start the reaction; Step 2: Add chemically pure ammonia water to the gallium sulfate solution to adjust the solution pH to 7; Step 3: adding high-purity water to wash the precipitate, stirring for 30 minutes, allowing the precipitate to stand, filtering out the supernatant, repeating the process three times, and then filtering and separating to obtain gallium hydroxide; Step 4: Place gallium hydroxide in an oven at 130° C. and dry for 4 hours to obtain solid gallium hydroxide, and place the solid gallium hydroxide in a high-temperature furnace at 800° C. and calcine for 4 hours to obtain gallium oxide.

[0047] The purity of the gallium oxide obtained above reaches 99.999%.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0050] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing high-purity gallium oxide for phosphor, characterized in that: Here are the steps: S1. Adding ammonia water to the gallium sulfate or ammonium gallium sulfate solution to neutralize it, so that gallium hydroxide is precipitated; S2, washing and filtering the gallium hydroxide precipitate to obtain gallium hydroxide solid; S3, drying and calcining the gallium hydroxide solid to obtain gallium oxide.

2. The method for preparing high-purity gallium oxide for phosphor according to claim 1, characterized in that: The preparation steps of the gallium sulfate solution in step S1 are as follows: S101. Add liquid gallium and sulfuric acid into a container, place it in a constant temperature water bath, stir and add hydrogen peroxide to obtain a gallium sulfate solution.

3. The method for preparing high-purity gallium oxide for phosphor according to claim 2, characterized in that: The liquid gallium in step S101 is 4N metallic gallium.

4. The method for preparing high-purity gallium oxide for phosphor according to claim 2, characterized in that: The sulfuric acid in step S101 is diluted with 98% concentrated sulfuric acid to obtain a 50% to 80% sulfuric acid solution.

5. The method for preparing high-purity gallium oxide for phosphor according to claim 2, characterized in that: The steps for preparing the ammonium gallium sulfate solution in step S1 are as follows: S102, adding high-purity water and ammonium sulfate to the gallium sulfate solution in step S101 to prepare an ammonium gallium sulfate solution, and cooling and crystallizing; S103, separating the crystals and adding high-purity water to obtain an ammonium gallium sulfate solution.

6. The method for preparing high-purity gallium oxide for phosphor according to claim 5, characterized in that: In step S102, chemically pure ammonium sulfate is added at a molar ratio of ammonium sulfate to gallium sulfate of 1.2-1.5:

1.

7. The preparation device for high-purity gallium oxide for phosphor according to any one of claims 1 to 6, characterized in that: It comprises a magnetic inner barrel (2) for containing the solution in step S1 for reaction, an adding hard tube (14) for adding reagents into the magnetic inner barrel (2), and an induction coil (3) for heating the magnetic inner barrel (2); The magnetic inner barrel (2) is located on the inner side of the non-magnetic outer barrel (1), a heating space (4) is formed between the non-magnetic outer barrel (1) and the magnetic inner barrel (2), an induction coil (3) and an electric heating tube (7) are arranged on the inner side of the heating space (4), the induction coil (3) is located on the outer side of the side wall of the magnetic inner barrel (2), and the electric heating tube (7) is located below the magnetic inner barrel (2); A first conveying pipe (5) is provided at the bottom of the magnetic inner barrel (2), and a second conveying pipe (6) is provided at the bottom of the non-magnetic outer barrel (1).

8. The device for preparing high-purity gallium oxide for phosphor according to claim 7, characterized in that: A lifting plate (9), a stirring shaft (11), and a stirring blade (12) are arranged above the magnetic inner barrel (2); the lifting plate (9) is mounted on the working end of the lifting unit (8); the stirring shaft (11) is rotatably mounted on the lifting plate (9); a stirring blade (12) is arranged at the bottom of the stirring shaft (11); the stirring shaft (11) and the stirring blade (12) are lifted or lowered from the inside of the magnetic inner barrel (2) by the lifting unit (8) and the lifting plate (9).

9. The device for preparing high-purity gallium oxide for phosphor according to claim 8, characterized in that: A liquid drainage through hole (13) is provided inside the stirring shaft (11), and a filter screen (17) is provided at the bottom opening of the liquid drainage through hole (13).

10. The preparation equipment for high-purity gallium oxide for phosphor according to claim 8, characterized in that: The magnetic inner barrel (2) comprises a heat-resistant glass barrel (201) and a magnetic metal interlayer (202); the magnetic metal interlayer (202) is embedded and installed in the side wall of the heat-resistant glass barrel (201).

Images