A method for preparing rare earth oxide powder with excellent physical properties
By adjusting the pH value of the rare earth salt solution and adding oxalic acid to fix the powder, the oxalic acid solution reacts with rare earth cations, the problem of strong volatility of the oxalic acid solution is solved, the yield of rare earth oxides is increased and the cost of oxalic acid is reduced.
Patent Information
- Application Number
- CN202310235166.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-13
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2043-03-13
AI Technical Summary
In the existing rare earth oxide powder preparation methods, the oxalic acid solution has strong volatile properties, resulting in a decrease in oxalic acid rare earth salt, reducing the production of rare earth oxides and increasing production costs.
By adjusting the pH value of the rare earth salt solution to the acidic state, adding oxalic acid fixed powder to dissolve it to form an oxalic acid solution, quickly reacting with rare earth cations to form a rare earth oxalate, avoiding the volatility of the oxalic acid solution and reducing the amount of oxalic acid.
The production of rare earth oxides is improved, the cost of oxalic acid is reduced, and the method effectively avoids volatility problems and improves the efficiency of the preparation process.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of rare earth oxide powder preparation, in particular to a method for preparing rare earth oxide powder with excellent physical properties. Background Art
[0002] Rare earth elements have been widely used in the fields of petroleum, chemical industry, metallurgy, textile, ceramics, glass, permanent magnet materials, etc. With the progress of science and technology and the continuous breakthrough of application technology, the value of rare earth oxides will become increasingly greater. With the development of science and technology, rare earth oxides, as the raw materials of new materials, have been more and more widely used, and the preparation of rare earth oxides has developed towards the direction of special physical and chemical forms, such as the preparation of rare earth oxides and rare earth composite powders with different particle sizes and different specific surface areas.
[0003] In the prior art, when preparing rare earth oxide powders, rare earth oxides are obtained by oxidizing rare earth metals in air, or burning rare earth hydroxides and rare earth salts containing volatile acid radicals (such as oxalates, carbonates, nitrates, sulfates, etc.) in air. In industry, rare earth oxides are generally prepared by burning rare earth oxalates in air. However, in the existing method of burning oxalates, due to the strong volatility of oxalic acid solution, the oxalic acid solution evaporates more during the preparation of oxalate solution, thereby reducing the amount of rare earth oxalate salt formed, thereby reducing the output of rare earth oxides to a certain extent and increasing the production cost. Therefore, it is necessary to invent a method for preparing rare earth oxide powders with excellent physical properties to solve the above problems. Summary of the invention
[0004] 1. Technical issues to be resolved
[0005] In view of the deficiencies in the prior art, the present invention provides a method for preparing rare earth oxide powder with excellent physical properties. The pH value of a mixed rare earth salt solution is adjusted by an oxalic acid solution to maintain the solution in an acidic state. At the same time, oxalic acid fixing powder is added to dissolve the oxalic acid solid powder to form an oxalic acid solution, so that the oxalic acid solution reacts rapidly with rare earth cations to form rare earth oxalate after being dissolved, thereby effectively avoiding the volatilization problem caused by directly adding the oxalic acid solution, while increasing the reaction of oxalic acid with rare earth ions and reducing the amount of oxalic acid used, which not only increases the output of rare earth oxides, but also reduces the use cost of oxalic acid.
[0006] (II) Technical solution
[0007] In order to achieve the above-mentioned effect of reducing the cost of using oxalic acid, the present invention provides the following technical solution: a method for preparing rare earth oxide powder with excellent physical properties, comprising the following steps:
[0008] S1. Preparation of rare earth solution
[0009] 80-100 g of REO solid is crushed, and then the crushed REO fixed powder is put into a mixing kettle, and 80-100 liters of water are added, and the mixture is stirred thoroughly. Then, oxalic acid solution is added to the solution, and stirred simultaneously until the pH value of the mixed solution is adjusted to 2-3, and then the adjusted rare earth solution is transferred from the mixing kettle for use.
[0010] S2. Preparation of rare earth oxalate
[0011] The mixture in step S1 is placed in a heating kettle, the mixed solution is heated to 80-90 degrees Celsius, the fixed oxalic acid is placed in a grinder, the fixed oxalic acid is crushed into oxalic acid powder, and then solid oxalic acid powder is added to the mixed solution, and mixed and stirred until oxalate rare earth precipitate is formed.
[0012] S3, rare earth oxalate treatment
[0013] The rare earth oxalate mixture in step S2 is allowed to stand and settle for 30 minutes, then the upper solution is extracted, the lower sediment is retained, the lower sediment is filtered, and the filtered sediment is rinsed with pure water for 3-5 times, then the rinsed sediment is taken out for use, the drying box is turned on, and preheated at 200 degrees Celsius for 10 minutes, then the wet rare earth oxide is transferred to the drying box, the temperature of the drying box is increased to 300 degrees Celsius, and dried for 30 minutes, then the dried rare earth oxide is taken out from the drying box and cooled to room temperature.
[0014] S4. Preparation of rare earth oxide solid
[0015] The dried rare earth oxide in step S3 is placed in a quartz boat, which is then placed in a decomposition furnace and heated and calcined at 800-900 degrees Celsius for 2 hours. After the heating and calcination is completed, the crucible is naturally cooled to room temperature to prepare a rare earth oxide solid.
[0016] S5. Preparation of rare earth oxide powder
[0017] The rare earth oxide solid in step S4 is placed in a grinder, and the grinder is turned on to grind the rare earth oxide solid for 30 minutes.
[0018] Preferably, in step S1, when adjusting the pH value, the temperature needs to be controlled at 20-25 degrees Celsius. During the adjustment process, the mixed liquid needs to be stirred continuously, and the oxalic acid solution needs to be added in small amounts multiple times.
[0019] Preferably, in step S2, the chemical equation of the reaction is:
[0020] 2RE 3+ +3H2C2O4——→RE2(C2O4)3↓+6H + .
[0021] Preferably, in step S2, the weight of the added oxalic acid is 1.2-1.4 times the weight of the rare earth oxide.
[0022] Preferably, in step S3, the temperature during the precipitation process needs to be at room temperature, and the temperature of the drying box during the drying process of the wet rare earth cannot be lower than 300 degrees Celsius and cannot be higher than 360 degrees Celsius.
[0023] Preferably, in step S4, air needs to be continuously injected into the decomposition furnace during the calcination process, and the reaction equation of the rare earth solid during the calcination process is:
[0024]
[0025] Preferably, in step S5, the diameter of the rare earth oxide powder particles after grinding is required to be 30-40 nm, and the grinder needs to be kept sealed during the grinding process.
[0026] (III) Beneficial effects
[0027] Compared with the prior art, the present invention provides a method for preparing rare earth oxide powder with excellent physical properties, which has the following beneficial effects:
[0028] The method for preparing rare earth oxide powder with excellent physical properties comprises the following steps: adjusting the pH value of a mixed rare earth salt solution by using an oxalic acid solution to maintain the solution in an acidic state, and simultaneously adding oxalic acid fixing powder to dissolve the oxalic acid solid powder to form an oxalic acid solution, so that the oxalic acid solution reacts rapidly with rare earth cations to form rare earth oxalate after being dissolved, thereby effectively avoiding the volatilization problem caused by directly adding the oxalic acid solution, reducing the amount of oxalic acid used while increasing the reaction of oxalic acid with rare earth ions, thereby not only increasing the output of rare earth oxides, but also reducing the use cost of oxalic acid. DETAILED DESCRIPTION
[0029] The following will combine the contents in 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.
[0030] Embodiment 1:
[0031] The present invention provides a technical solution: a method for preparing rare earth oxide powder with excellent physical properties, comprising the following steps:
[0032] S1. Preparation of rare earth solution
[0033] 80 grams of REO solid was crushed, and then the crushed REO fixed powder was put into a mixing kettle, 80 liters of water was added, and the mixture was stirred thoroughly. Then oxalic acid solution was added to the solution and stirred simultaneously until the pH value of the mixed solution was adjusted to 2.5. Then the adjusted rare earth solution was transferred out of the mixing kettle for use.
[0034] When adjusting the pH value, the temperature needs to be controlled at 20 degrees Celsius. During the adjustment process, the mixed liquid needs to be stirred continuously, and the oxalic acid solution needs to be added in small amounts multiple times.
[0035] S2. Preparation of rare earth oxalate
[0036] The mixture in step S1 is easily placed in a heating kettle, and the mixed solution is heated to 80 degrees Celsius. Fixed oxalic acid, which is 1.2 times the weight of the rare earth oxide, is placed in a pulverizer, and the fixed oxalic acid is crushed into oxalic acid powder. Then, solid oxalic acid powder is added to the mixed solution, and mixed and stirred until an oxalate rare earth precipitate is formed.
[0037] The chemical equation for the reaction is:
[0038] 2RE 3+ +3H2C2O4——→RE2(C2O4)3↓+6H + .
[0039] S3, rare earth oxalate treatment
[0040] The rare earth oxalate mixture in step S2 is allowed to stand and settle for 30 minutes, then the upper solution is extracted, the lower sediment is retained, the lower sediment is filtered, and the filtered sediment is rinsed with pure water for 4 times, then the rinsed sediment is taken out for use, the drying box is turned on, and preheated at 200 degrees Celsius for 10 minutes, then the wet rare earth oxide is transferred to the drying box, the temperature of the drying box is increased to 300 degrees Celsius, and dried for 30 minutes, then the dried rare earth oxide is taken out from the drying box and cooled to room temperature.
[0041] The temperature during the precipitation process must be at room temperature, and the temperature of the drying box during the drying of wet rare earths must not be lower than 300 degrees Celsius and must not be higher than 360 degrees Celsius.
[0042] S4. Preparation of rare earth oxide solid
[0043] The dried rare earth oxide in step S3 is placed in a quartz boat, and then the quartz boat is placed in a decomposition furnace and heated and calcined at 900 degrees Celsius for 2 hours. After the heating and calcination is completed, the crucible is naturally cooled to room temperature to prepare a rare earth oxide solid.
[0044] During the calcination process of the decomposition furnace, air needs to be continuously injected, and the reaction equation of the rare earth solid during the calcination process is:
[0045]
[0046] S5. Preparation of rare earth oxide powder
[0047] The rare earth oxide solid in step S4 is placed in a grinder, and the grinder is turned on to grind the rare earth oxide solid for 30 minutes.
[0048] The diameter of the rare earth oxide powder particles after grinding is required to be 30 nm, and the grinder needs to be kept sealed during the grinding process.
[0049] Embodiment 2:
[0050] The present invention provides a technical solution: a method for preparing rare earth oxide powder with excellent physical properties, comprising the following steps:
[0051] S1. Preparation of rare earth solution
[0052] 90 grams of REO solid was crushed, and then the crushed REO fixed powder was put into a mixing kettle, 90 liters of water was added, and the mixture was fully stirred. Then, oxalic acid solution was added to the solution and stirred simultaneously until the pH value of the mixed solution was adjusted to 3. Then, the adjusted rare earth solution was transferred from the mixing kettle for use.
[0053] When adjusting the pH value, the temperature needs to be controlled at 20 degrees Celsius. During the adjustment process, the mixed liquid needs to be stirred continuously, and the oxalic acid solution needs to be added in small amounts multiple times.
[0054] S2. Preparation of rare earth oxalate
[0055] The mixture in step S1 is easily placed in a heating kettle, and the mixed solution is heated to 80 degrees Celsius. Fixed oxalic acid, which is 1.2 times the weight of the rare earth oxide, is placed in a pulverizer, and the fixed oxalic acid is crushed into oxalic acid powder. Then, solid oxalic acid powder is added to the mixed solution, and mixed and stirred until an oxalate rare earth precipitate is formed.
[0056] The chemical equation for the reaction is:
[0057] 2RE 3++3H2C2O4——→RE2(C2O4)3↓+6H + .
[0058] S3, rare earth oxalate treatment
[0059] The rare earth oxalate mixture in step S2 is allowed to stand and settle for 30 minutes, then the upper solution is extracted, the lower sediment is retained, the lower sediment is filtered, and the filtered sediment is rinsed with pure water for 5 times, then the rinsed sediment is taken out for use, the drying box is turned on, and preheated at 200 degrees Celsius for 10 minutes, then the wet rare earth oxide is transferred to the drying box, the temperature of the drying box is increased to 300 degrees Celsius, and dried for 30 minutes, then the dried rare earth oxide is taken out from the drying box and cooled to room temperature.
[0060] The temperature during the precipitation process must be at room temperature, and the temperature of the drying box during the drying of wet rare earths must not be lower than 300 degrees Celsius and must not be higher than 360 degrees Celsius.
[0061] S4. Preparation of rare earth oxide solid
[0062] The dried rare earth oxide in step S3 is placed in a quartz boat, and then the quartz boat is placed in a decomposition furnace and heated and calcined at 900 degrees Celsius for 2 hours. After the heating and calcination is completed, the crucible is naturally cooled to room temperature to prepare a rare earth oxide solid.
[0063] During the calcination process of the decomposition furnace, air needs to be continuously injected, and the reaction equation of the rare earth solid during the calcination process is:
[0064]
[0065] S5. Preparation of rare earth oxide powder
[0066] The rare earth oxide solid in step S4 is placed in a grinder, and the grinder is turned on to grind the rare earth oxide solid for 30 minutes.
[0067] The diameter of the rare earth oxide powder particles after grinding is required to be 35 nm, and the grinder needs to be kept sealed during the grinding process.
[0068] Embodiment three:
[0069] The present invention provides a technical solution: a method for preparing rare earth oxide powder with excellent physical properties, comprising the following steps:
[0070] S1. Preparation of rare earth solution
[0071] 100 g of REO solid was crushed, and then the crushed REO fixed powder was put into a mixing kettle, and 100 liters of water was added, and the mixture was stirred thoroughly. Then oxalic acid solution was added to the solution and stirred simultaneously until the pH value of the mixed solution was adjusted to 2. Then the adjusted rare earth solution was transferred out of the mixing kettle for use.
[0072] When adjusting the pH value, the temperature needs to be controlled at 20 degrees Celsius. During the adjustment process, the mixed liquid needs to be stirred continuously, and the oxalic acid solution needs to be added in small amounts multiple times.
[0073] S2. Preparation of rare earth oxalate
[0074] The mixture in step S1 is easily placed in a heating kettle, the mixed solution is heated to 90 degrees Celsius, fixed oxalic acid that is 1.4 times the weight of the rare earth oxide is placed in a grinder, the fixed oxalic acid is crushed into oxalic acid powder, and then solid oxalic acid powder is added to the mixed solution, and mixed and stirred until an oxalate rare earth precipitate is formed.
[0075] The chemical equation for the reaction is:
[0076] 2RE 3+ +3H2C2O4——→RE2(C2O4)3↓+6H + .
[0077] S3, rare earth oxalate treatment
[0078] The rare earth oxalate mixture in step S2 is allowed to stand and settle for 30 minutes, then the upper solution is extracted, the lower sediment is retained, the lower sediment is filtered, and the filtered sediment is rinsed with pure water for 5 times, then the rinsed sediment is taken out for use, the drying box is turned on, and preheated at 200 degrees Celsius for 10 minutes, then the wet rare earth oxide is transferred to the drying box, the temperature of the drying box is increased to 300 degrees Celsius, and dried for 30 minutes, then the dried rare earth oxide is taken out from the drying box and cooled to room temperature.
[0079] The temperature during the precipitation process must be at room temperature, and the temperature of the drying box during the drying of wet rare earths must not be lower than 300 degrees Celsius and must not be higher than 360 degrees Celsius.
[0080] S4. Preparation of rare earth oxide solid
[0081] The dried rare earth oxide in step S3 is placed in a quartz boat, and then the quartz boat is placed in a decomposition furnace and heated and calcined at 900 degrees Celsius for 2 hours. After the heating and calcination is completed, the crucible is naturally cooled to room temperature to prepare a rare earth oxide solid.
[0082] During the calcination process of the decomposition furnace, air needs to be continuously injected, and the reaction equation of the rare earth solid during the calcination process is:
[0083]
[0084] S5. Preparation of rare earth oxide powder
[0085] The rare earth oxide solid in step S4 is placed in a grinder, and the grinder is turned on to grind the rare earth oxide solid for 30 minutes.
[0086] The diameter of the rare earth oxide powder particles after grinding is required to be 40 nm, and the grinder needs to be kept sealed during the grinding process.
[0087] The method for preparing rare earth oxide powder with excellent physical properties comprises the following steps: adjusting the pH value of a mixed rare earth salt solution by using an oxalic acid solution to maintain the solution in an acidic state, and simultaneously adding oxalic acid fixing powder to dissolve the oxalic acid solid powder to form an oxalic acid solution, so that the oxalic acid solution reacts rapidly with rare earth cations to form rare earth oxalate after being dissolved, thereby effectively avoiding the volatilization problem caused by directly adding the oxalic acid solution, reducing the amount of oxalic acid used while increasing the reaction of oxalic acid with rare earth ions, thereby not only increasing the output of rare earth oxides, but also reducing the use cost of oxalic acid.
[0088] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing rare earth oxide powder with excellent physical properties, characterized in that: The following steps are involved: S1. Preparation of rare earth solution 80-100 g of REO solid is crushed, and then the crushed REO fixed powder is put into a mixing kettle, and 80-100 liters of water is added, and the mixture is fully stirred and mixed, and then oxalic acid solution is added to the solution, and stirred simultaneously until the pH value of the mixed solution is adjusted to 2-3, and then the adjusted rare earth solution is transferred from the mixing kettle for standby use; S2. Preparation of rare earth oxalate The mixture in step S1 is placed in a heating kettle, the mixed solution is heated to 80-90 degrees Celsius, the fixed oxalic acid is placed in a grinder, the fixed oxalic acid is crushed into oxalic acid powder, and then the solid oxalic acid powder is added to the mixed solution, and mixed and stirred until an oxalic acid rare earth precipitate is formed; S3, rare earth oxalate treatment The rare earth oxalate mixed solution in step S2 is allowed to settle for 30 minutes, then the upper solution is extracted, the lower sediment is retained, the lower sediment is filtered, and the filtered sediment is rinsed with pure water for 3-5 times, then the rinsed sediment is taken out for standby use, the drying box is turned on, and preheated at 200 degrees Celsius for 10 minutes, then the wet rare earth oxide is transferred to the drying box, the temperature of the drying box is raised to 300 degrees Celsius, and the drying is carried out for 30 minutes, then the dried rare earth oxide is taken out from the drying box, and cooled to room temperature; S4. Preparation of rare earth oxide solid The dried rare earth oxide in step S3 is placed in a quartz boat, and then the quartz boat is placed in a decomposition furnace and heated and calcined at 800-900 degrees Celsius for 2 hours. After the heating and calcination is completed, the crucible is naturally cooled to room temperature to prepare a rare earth oxide solid; S5. Preparation of rare earth oxide powder The rare earth oxide solid in step S4 is placed in a grinder, and the grinder is turned on to grind the rare earth oxide solid for 30 minutes.
2. The method for preparing a rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In step S1, when adjusting the pH value, the temperature needs to be controlled at 20-25 degrees Celsius. During the adjustment process, the mixed liquid needs to be stirred continuously, and the oxalic acid solution needs to be added in small amounts multiple times.
3. The method for preparing a rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In step S2, the chemical equation of the reaction is: <h2 style=";text-align:left;direction:ltr">2RE<h2 style=";text-align:left;direction:ltr"> 3+ <h2 style=";text-align:left;direction:ltr"> +3H2C2O4——→RE2(C2O4)3↓+6H<h2 style=";text-align:left;direction:ltr"> + <h2 style=";text-align:left;direction:ltr"> 。 4. The method for preparing rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In step S2, the weight of the added oxalic acid is 1.2-1.4 times the weight of the rare earth oxide.
5. The method for preparing rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In step S3, the temperature during the precipitation process must be at room temperature, and the temperature of the drying box during the drying of the wet rare earth cannot be lower than 300 degrees Celsius and cannot be higher than 360 degrees Celsius.
6. The method for preparing rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In step S4, air needs to be continuously injected into the decomposition furnace during the calcination process, and the reaction equation of the rare earth solid during the calcination process is:
7. The method for preparing rare earth oxide powder with excellent physical properties according to claim 1, characterized in that: In the step S5, the diameter of the rare earth oxide powder particles after grinding is required to be 30-40 nm, and the grinder needs to be kept sealed during the grinding process.
Citation Information
Patent Citations
Methods of synthesizing an oxidant and applications thereof
AU2001280529A1
Method for preparing rare earth oxide with large particles
CN101780970A