Method for removing fluorine and aluminum from rare earth feed liquid

Abstract

The invention provides a method for removing fluorine and aluminum from a rare earth feed liquid, which comprises the following steps: injecting the rare earth feed liquid into a base solution to carry out an overflow reaction, adding an alkaline material in the overflow reaction process to adjust the pH value of the system, and carrying out solid-liquid separation treatment on the material obtained by the overflow reaction to obtain a rare earth purified feed liquid and aluminum fluorine slag, wherein the base solution comprises defluorinated rare earth feed liquid. According to the method, the aluminum ions and the fluorine ions in the rare earth feed liquid can be synchronously and efficiently removed through a simple process, the problem that the content of the aluminum ions and the fluorine ions in the rare earth feed liquid is too high is solved, and the quality of a rare earth product is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rare earth production and relates to a method for removing fluorine and aluminum from rare earth liquid. Background Art

[0002] Rare earths are important strategic key resources, widely used in civil, aviation, aerospace and military fields, and are known as "industrial MSG".

[0003] In the process of rare earth mining and smelting, impurities such as aluminum and fluorine will always accompany the leaching and separation of rare earths. Impurity aluminum will have an important impact on the extraction and separation process of rare earths, causing emulsification of the extraction system and reduced extraction efficiency. The presence of fluoride ions will also cause rare earth fluoride to be generated during extraction and separation, which will emulsify the organic extractant and produce a flocculent three-phase product, making it difficult to separate the organic and aqueous phases and resulting in unqualified product quality. Therefore, developing a new method for removing aluminum / fluorine from rare earth liquid to obtain a rare earth purified liquid with low aluminum / fluorine content is an important way to improve the quality of rare earth products.

[0004] CN111944998A discloses a method for removing aluminum from a rare earth liquid, which uses isodecanoic acid for multi-stage continuous extraction to remove aluminum. The extraction system has low viscosity, is not easy to emulsify, has no oil-water mutual inclusion phenomenon, has a clear two-phase stratification interface, has a short phase separation time, has a good extraction and aluminum removal effect, and the extraction process is continuously operated, which reduces the frequent transfer of phases and realizes efficient and continuous aluminum removal from the rare earth liquid.

[0005] CN108642310A discloses a method for removing aluminum from a rare earth solution by complex precipitation. The rare earth solution is treated with cyclohexanecarboxylic acid as a complex precipitant, and aluminum ions contained in the rare earth solution are removed from the rare earth solution in the form of precipitation.

[0006] CN115927884A discloses a method for removing fluorine from a rare earth ore leachate, comprising the following steps: adding solution A to a fluorine-containing rare earth ore leachate, stirring and adjusting the pH value of the fluorine-containing ion-type rare earth ore leachate, obtaining solution B after clarification and solid-liquid separation, adding solution C to solution B, obtaining a precipitate after clarification and solid-liquid separation, adding solution D to the precipitate, stirring and leaching, performing filter pressing and solid-liquid separation, and obtaining a rare earth ore with a low fluorine content.

[0007] However, the current method of removing aluminum and fluorine impurities from rare earth liquid still has the disadvantages of low impurity removal efficiency and complicated process, and it is difficult to achieve simultaneous removal of aluminum and fluorine. Summary of the invention

[0008] The object of the present invention is to provide a method for removing fluorine and aluminum from a rare earth liquid. The method of the present invention can simultaneously and efficiently remove aluminum ions and fluoride ions from the rare earth liquid through a simple process, thereby solving the problem of excessively high aluminum and fluorine content in the rare earth liquid and greatly improving the quality of rare earth products.

[0009] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for removing fluorine and aluminum from a rare earth liquid, the method comprising the following steps:

[0011] Injecting rare earth feed liquid into the bottom liquid for overflow reaction, adding alkaline material to adjust the pH of the system during the overflow reaction, and performing solid-liquid separation treatment on the material obtained by the overflow reaction to obtain rare earth purified feed liquid and aluminum-fluoride slag;

[0012] Wherein, the base liquid includes defluorinated rare earth liquid.

[0013] The present invention uses a defluorinated rare earth feed liquid as a base liquid, wherein the defluorinated rare earth feed liquid is a rare earth feed liquid that has been subjected to a defluorination treatment, and the content of other elements is the same as that of the above rare earth feed liquid except for the fluorine content. By adding an alkaline material during the overflow reaction to regulate the aluminum hydrolysis process, aluminum ions are directional converted and precipitated, and fluorine ions are adsorbed in situ, thereby achieving the simultaneous removal of aluminum and fluorine in the rare earth feed liquid, while also reducing the entrainment loss of rare earth elements and improving the filtering performance of aluminum-fluorine slag.

[0014] During the overflow reaction of the present invention, the rare earth liquid can be fed continuously, which ensures the continuous implementation of the method, thereby realizing the continuous and automated removal of aluminum and fluorine impurities.

[0015] Preferably, the rare earth solution comprises rare earth compounds, aluminum ions and fluoride ions.

[0016] Preferably, the rare earth compound includes any one or a combination of at least two of oxides, hydroxides or carbonates containing rare earth elements.

[0017] Preferably, the rare earth element includes any one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium or yttrium, or a combination of at least two thereof.

[0018] Preferably, the mass concentration of the rare earth compound in the rare earth solution is 150g / L to 200g / L, for example: 150g / L, 160g / L, 170g / L, 180g / L, 190g / L or 200g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the mass concentration of aluminum ions in the rare earth solution is 4 g / L to 5 g / L, for example 4 g / L, 4.2 g / L, 4.5 g / L, 4.8 g / L or 5 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the mass concentration of fluoride ions in the rare earth solution is 1 g / L to 1.5 g / L, for example, 1 g / L, 1.1 g / L, 1.2 g / L, 1.3 g / L, 1.4 g / L or 1.5 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the pH value of the rare earth solution is 2 to 3, for example, 2, 2.2, 2.5, 2.8 or 3, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0022] Preferably, the injection rate of the rare earth solution is 10mL / min to 60mL / min, for example: 10mL / min, 20mL / min, 30mL / min, 40mL / min, 50mL / min or 60mL / min, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable, preferably 10mL / min to 50mL / min.

[0023] Preferably, the volume of the overflow reaction container is 40L to 60L, for example, 40L, 45L, 50L, 55L or 60L, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, stirring is performed during the overflow reaction.

[0025] Preferably, the stirring speed is 100 rpm to 300 rpm, for example, 100 rpm, 150 rpm, 200 rpm, 250 rpm or 300 rpm, etc., preferably 200 rpm to 300 rpm.

[0026] Preferably, the temperature of the overflow reaction is 50°C to 95°C, for example, 50°C, 55°C, 60°C, 80°C or 95°C, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably 60 to 95°C.

[0027] Preferably, the alkaline material comprises any one of aqueous ammonia, sodium carbonate solution, potassium carbonate solution, sodium bicarbonate solution, potassium bicarbonate solution or rare earth concentrate solution, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of aqueous ammonia and sodium carbonate solution, a combination of sodium carbonate solution and potassium carbonate solution, or a combination of potassium carbonate solution and sodium bicarbonate solution, etc.

[0028] Preferably, the mass concentration of the alkaline material is 5 to 20 g / L, for example, 5 g / L, 8 g / L, 10 g / L, 15 g / L or 20 g / L, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the pH of the regulating system is 3.5 to 5, for example, 3.5, 3.8, 4, 4.5 or 5, etc., preferably 4 to 4.5, and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] As a preferred embodiment of the present invention, the method comprises the following steps:

[0031] The defluorinated rare earth liquid is used as the base liquid, and the rare earth liquid is injected into the base liquid at a rate of 10 to 50 mL / min at a stirring rate of 200 to 300 rpm. At the same time, an alkaline material with a concentration of 5 to 20 g / L is used to adjust the pH of the system to 4 to 4.5, and an overflow reaction is carried out at 60 to 95° C. The material obtained by the overflow reaction is subjected to solid-liquid separation treatment to obtain rare earth purified liquid and aluminum-fluorine slag.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The method of the present invention can simultaneously and efficiently remove aluminum and fluorine from rare earth liquid by a simple process, thereby solving the problem of excessively high aluminum ion and fluorine ion content in the rare earth liquid and greatly improving the quality of rare earth products.

[0034] (2) The method for removing fluorine and aluminum from rare earth liquid of the present invention not only has mild conditions and does not require high temperature and pressure, but also will not form harmful substances with rare earth, and also has the advantages of simple process and low production cost.

[0035] (3) The continuous and synchronous aluminum-fluoride removal method of the present invention achieves the synchronous removal of aluminum and fluoride in the rare earth liquid by regulating the aluminum hydrolysis process to direct the conversion and precipitation of aluminum ions and adsorb fluorine in situ, thereby reducing the entrainment loss of rare earth elements and improving the filtration performance of aluminum-fluoride slag.

[0036] (4) The aluminum removal rate of the method of the present invention can reach more than 79.4%, the fluorine removal rate can reach more than 60.5%, and the amount of rare earth compounds entrained in the aluminum-fluorine slag can reach less than 10.4%. The depth of aluminum-fluorine removal in the rare earth liquid is closely related to the reaction temperature, pH, and feed rate. By adjusting the above conditions, the aluminum removal rate of the method can reach more than 95.2%, the fluorine removal rate can reach more than 97.2%, and the amount of rare earth compounds entrained in the aluminum-fluorine slag can reach less than 1.0%. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process flow of the method for removing fluorine and aluminum from a rare earth liquid provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0039] In the rare earth feed solution used in the examples of the present invention and the comparative examples, the mass concentration of the rare earth compound is 200 g / L, the mass concentration of the fluoride ion is 1.2 g / L, and the mass concentration of the aluminum ion is 5 g / L, wherein the rare earth compound includes lanthanum oxide, cerium oxide, lanthanum hydroxide, cerium hydroxide, lanthanum carbonate, cerium carbonate, etc. The defluorinated rare earth feed solution does not contain fluoride ions, and the contents of other substances are exactly the same as those of the rare earth feed solution.

[0040] Example 1

[0041] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0042] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, and the rare earth liquid was added into the overflow reactor at a rate of 50 mL / min under the conditions of controlling the stirring rate to 200 rpm and the reaction temperature to 60°C. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0043] Example 2

[0044] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0045] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, and the stirring rate was controlled to be 250 rpm. Under the conditions of reaction temperature of 80°C, rare earth liquid was added into the overflow reactor at a rate of 30 mL / min. At the same time, 10 g / L potassium carbonate solution was used to adjust the pH to 4.5 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0046] Example 3

[0047] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0048] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, the stirring rate was controlled to be 300 rpm, and the reaction temperature was 95°C. Rare earth liquid was added into the overflow reactor at a rate of 10 mL / min. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 4 for overflow reaction. Finally, rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0049] Example 4

[0050] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0051] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, the stirring rate was controlled to be 200 rpm, and under the condition of the reaction temperature being 50°C, rare earth liquid was added into the overflow reactor at a rate of 50 mL / min, and 5 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0052] Example 5

[0053] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0054] Defluorinated rare earth liquid was added into the overflow reactor as the base liquid, and the rare earth liquid was added into the overflow reactor at a rate of 50 mL / min under the conditions of controlling the stirring rate to 200 rpm and the reaction temperature to 100°C. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0055] Example 6

[0056] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0057] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, and the stirring rate was controlled to be 200 rpm. Under the conditions of reaction temperature of 60°C, rare earth liquid was added into the overflow reactor at a rate of 50 mL / min. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 3.5 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0058] Example 7

[0059] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0060] Defluorinated rare earth liquid was added into the overflow reactor as the base liquid, and the stirring rate was controlled to be 200 rpm. Under the conditions of reaction temperature of 60°C, rare earth liquid was added into the overflow reactor at a rate of 50 mL / min. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 5 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0061] Example 8

[0062] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0063] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, the stirring rate was controlled at 200 rpm, and the reaction temperature was 60°C. Rare earth liquid was added into the overflow reactor at a rate of 60 mL / min. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction. Finally, rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0064] Example 9

[0065] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0066] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, and the rare earth liquid was added into the overflow reactor at a rate of 50 mL / min under the conditions of controlling the stirring rate to 200 rpm and the reaction temperature to 60°C. At the same time, 30 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0067] Example 10

[0068] This embodiment provides a method for removing fluorine and aluminum from a rare earth liquid. The process flow diagram of the method is shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0069] Defluorinated rare earth liquid was added into the overflow reactor as the bottom liquid, and the rare earth liquid was added into the overflow reactor at a rate of 50 mL / min under the conditions of controlling the stirring rate to 50 rpm and the reaction temperature to 60°C. At the same time, 5 g / L sodium carbonate solution was used to adjust the pH to 4.2 for overflow reaction, and finally rare earth purified liquid and aluminum fluoride slag were obtained by solid-liquid separation.

[0070] Performance Testing:

[0071] The test results of the aluminum and fluorine removal rates of the embodiments and comparative examples and the amount of rare earth compounds entrained in the aluminum-fluorine slag are shown in Table 1, wherein the removal rate = (V 前 *C 前 -V 后 *C 后 ) / V 前 *C 前 .

[0072] Table 1

[0073] Aluminum removal rate (%) Fluoride removal rate (%) Amount of rare earth compounds entrained (%) Example 1 95.2 97.2 1.0 Example 2 96.0 97.9 0.94 Example 3 96.3 98.3 0.90 Example 4 93.7 95.2 1.20 Example 5 95.5 96.9 0.93 Example 6 79.4 82.3 1.23 Example 7 98.2 60.5 10.4 Example 8 93.3 95.7 1.89 Example 9 97.1 84.3 5.91 Example 10 87.9 60.5 7.20

[0074] As can be seen from Table 1, from Examples 1-10, the aluminum removal rate of the method of the present invention can reach more than 79.4%, the fluorine removal rate can reach more than 60.5%, the amount of rare earth compounds entrained in the aluminum-fluorine slag can reach less than 10.4%, and the depth of aluminum-fluorine removal in the rare earth liquid is closely related to the reaction temperature, pH, and feeding rate. By adjusting the above conditions, the aluminum removal rate of the method can reach more than 95.2%, the fluorine removal rate can reach more than 97.2%, and the amount of rare earth compounds entrained in the aluminum-fluorine slag can reach less than 1.0%.

[0075] By comparing Example 1 with Examples 4-5, it can be seen that in the method for removing fluorine and aluminum from a rare earth liquid according to the present invention, the temperature of the overflow reaction will affect the effect of removing fluorine and aluminum. When the temperature of the overflow reaction is controlled at 60-95°C, the effect of removing fluorine and aluminum is better. If the temperature of the overflow reaction is too low, the hydrolysis of aluminum is not complete, the removal rate is too low, and the adsorption rate of fluorine also decreases. Increasing the temperature is beneficial to the removal of aluminum and fluorine, and there is less rare earth entrainment. However, too high a temperature cannot further improve the fluorine and aluminum removal effect. On the contrary, it will cause partial loss of rare earths due to the excessively high temperature.

[0076] By comparing Example 1 with Examples 6-7, it can be seen that in the method for removing fluorine and aluminum from a rare earth liquid according to the present invention, the pH of the overflow reaction will affect the effect of removing fluorine and aluminum. When the pH of the overflow reaction is controlled at 4 to 4.5, the effect of removing fluorine and aluminum is better. If the temperature and pH of the overflow reaction are too low, the aluminum hydrolysis and precipitation will not be complete, and the fluorine removal rate will also be low. If the temperature and pH of the overflow reaction are too high, a large amount of rare earth precipitation will occur.

[0077] By comparing Example 1 and Example 8, it can be seen that in the method for removing fluorine and aluminum from the rare earth solution of the present invention, the injection speed of the rare earth solution will affect the effect of removing fluorine and aluminum. If the injection speed of the rare earth solution is too fast, it will lead to incomplete hydrolysis of aluminum in the rare earth solution, a decrease in the fluorine removal rate, and an increase in rare earth entrainment losses.

[0078] By comparing Example 1 and Example 9, it can be seen that in the method for removing fluorine and aluminum from the rare earth liquid of the present invention, the concentration of the alkaline material used will affect the effect of removing fluorine and aluminum. If the concentration of the alkaline material is too high, the hydrolysis and precipitation process of aluminum is relatively complete, but the removal rate of fluorine is reduced, and the rare earth entrainment loss is significantly increased.

[0079] By comparing Example 1 and Example 10, it can be seen that in the method for removing fluorine and aluminum from the rare earth liquid of the present invention, the stirring speed of the overflow reaction will affect the effect of removing fluorine and aluminum. If the stirring speed of the overflow reaction is too slow, it will lead to incomplete hydrolysis and precipitation of aluminum, reduce the removal rate of fluorine and aluminum, and significantly increase the rare earth entrainment loss.

[0080] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for removing fluorine and aluminum from a rare earth liquid, characterized in that: The method comprises the following steps: Injecting rare earth feed liquid into the bottom liquid for overflow reaction, adding alkaline material to adjust the pH of the system during the overflow reaction, and performing solid-liquid separation treatment on the material obtained by the overflow reaction to obtain rare earth purified feed liquid and aluminum-fluoride slag; Wherein, the base liquid includes defluorinated rare earth liquid.

2. The method according to claim 1, characterized in that The rare earth liquid comprises rare earth compounds, aluminum ions and fluoride ions; Preferably, the rare earth compound comprises any one or a combination of at least two of oxides, hydroxides or carbonates containing rare earth elements; Preferably, the rare earth element comprises any one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium or yttrium, or a combination of at least two thereof; Preferably, the mass concentration of the rare earth compound in the rare earth solution is 150 g / L to 200 g / L; Preferably, the mass concentration of aluminum ions in the rare earth solution is 4 g / L to 5 g / L; Preferably, the mass concentration of fluoride ions in the rare earth solution is 1 g / L to 1.5 g / L.

3. The method according to claim 1 or 2, characterized in that The pH of the rare earth liquid is 2-3.

4. The method according to any one of claims 1 to 3, characterized in that: The injection speed of the rare earth liquid is 10 mL / min to 60 mL / min, preferably 10 mL / min to 50 mL / min; Preferably, the volume of the overflow reaction container is 40L to 60L.

5. The method according to any one of claims 1 to 4, characterized in that: Stirring during the overflow reaction; Preferably, the stirring speed is 100 rpm to 300 rpm, preferably 200 rpm to 300 rpm.

6. The method according to any one of claims 1 to 5, characterized in that: The temperature of the overflow reaction is 50°C to 95°C, preferably 60°C to 95°C.

7. The method according to any one of claims 1 to 6, characterized in that: The alkaline material includes any one of ammonia water, sodium carbonate solution, potassium carbonate solution, sodium bicarbonate solution, potassium bicarbonate solution or rare earth concentrate solution, or a combination of at least two thereof.

8. The method according to any one of claims 1 to 7, characterized in that: The mass concentration of the alkaline material is 5-20 g / L.

9. The method according to any one of claims 1 to 8, characterized in that: The pH of the regulating system is 3.5 to 5, preferably 4 to 4.

5.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: The defluorinated rare earth liquid is used as the base liquid, and the rare earth liquid is injected into the base liquid at a rate of 10 to 50 mL / min at a stirring rate of 200 to 300 rpm. At the same time, an alkaline material with a concentration of 5 to 20 g / L is used to adjust the pH of the system to 4 to 4.5, and an overflow reaction is carried out at 60 to 95° C. The material obtained by the overflow reaction is subjected to solid-liquid separation treatment to obtain rare earth purified liquid and aluminum-fluorine slag.

Images