A method for efficiently reducing fluorine ions in fluorocarbon rare earth ore

Abstract

The application discloses a kind of processing methods for efficiently reducing fluorine ion in fluorocarbon rare earth ore, comprising the following steps: newly mined carbonic acid rare earth ore is concentrated and accumulated, the carbonic acid rare earth ore is crushed and ground into powder, and particles with uniform particle size are obtained.The obtained particles are washed again, and the filter wastewater generated by washing is separately subjected to acid addition and alkali addition leaching treatment.Clean rare earth ore particles are introduced into the acid addition zone, mixed with acid, and then the mixed solution is introduced into the alkali addition zone for sufficient reaction.The precipitate CaF2 generated is collected and filtered through a filter screen to complete solid-liquid separation.The separated precipitate is treated to obtain the precipitate CaF2.The treated precipitate CaF2 is collected and stored.The application has the advantages that the carbonic acid rare earth ore can be quickly filtered and separated, and the acid addition zone and the alkali addition zone are comprehensively treated to form white precipitate CaF2.The product obtained by effectively treating and recovering fluorine ions avoids pollution of the surrounding environment caused by improper treatment.

Description

Technical Field

[0001] This invention belongs to the field of rare earth ore processing technology, and more specifically, it relates to a method for efficiently reducing fluoride ions in rare earth fluorocarbonate ores. Background Technology

[0002] Rare earth ores contain a large amount of fluoride ions, which can affect the separation and extraction of rare earth elements. Therefore, effectively reducing the fluoride ion content in rare earth ores has become an important issue for the development of the rare earth industry.

[0003] Patent document CN115927884A discloses a method for defluorinating rare earth ore leaching solutions, comprising the following steps: adding solution A to a fluoride-containing rare earth ore leaching solution, stirring and adjusting the pH value of the fluoride-containing ionic rare earth ore leaching solution, 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, followed by pressure filtration and solid-liquid separation to obtain a low-fluoride rare earth ore. This method is applicable to defluorinating leaching solutions of fluoride-containing rare earth carbonate, rare earth oxalate, mixed rare earth carbonate and oxalate, or rare earth oxide ores. This method achieves separation of fluoride from rare earth by dissolving fluoride compounds in an ammonium salt solution followed by solid-liquid separation. After treatment using this method, the fluoride content in the rare earth ore leaching solution can be significantly reduced, ensuring the smooth progress of subsequent rare earth processing and production.

[0004] While the aforementioned patents can effectively remove fluoride ions, the operation process is complex, costly, inefficient, and poses certain environmental risks. The mixed acid leaching method generates a large amount of pungent and toxic gases, which seriously affects the surrounding air quality. Furthermore, it cannot effectively treat the separated precipitates. Therefore, a more efficient, simple, and economical method is needed to reduce the fluoride ion content in rare earth ores. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a highly efficient method for reducing fluoride ions in rare earth fluorocarbonate ores. This method effectively reduces the concentration of fluoride ions without damaging the rare earth elements in the ore, thereby improving the purity and quality of the rare earth ore and meeting the needs of industrial production, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for efficiently reducing fluoride ions in rare earth fluorocarbonate ores, comprising the following steps: S1. Raw material preparation: The newly mined rare earth carbonate ore is piled up and processed in a concentrated manner; S2. Pretreatment: The rare earth carbonate ore is crushed and ground to obtain particles of uniform size. S3. Washing, leaching and filtrate treatment: The obtained particles are then washed to obtain clean rare earth ore particles. The filtrate wastewater generated from the washing is then subjected to separate acid and alkali leaching treatment. S4. Adjusting the pH value: Clean rare earth ore particles are concentrated and introduced into the acid addition zone. After mixing with acid, the mixed solution is then introduced into the alkali addition zone for complete reaction, so that Ca... 2+ and F - They combine to form CaF2, which is poorly soluble in water, thus completing the defluorination treatment; S5. Add mixed reagent: The mixed reagent is a sodium salt reagent, which is introduced into the alkali addition zone to neutralize the negative ions in the alkali addition zone and increase the Ca2+ level. 2+ The content of [specific element] makes the defluorination rate reach 93.4%; S6. Precipitation treatment: The CaF2 precipitate generated after the defluorination treatment is collected and filtered through a filter screen to complete the solid-liquid separation. S7. Precipitate treatment: The separated precipitate is treated, such as by washing and drying, to obtain the precipitate CaF2. S8. Sediment Collection: Collect and preserve the treated precipitate CaF2 for further utilization or disposal.

[0007] As an optional embodiment of the present invention, in step S4, a concentrated hydrochloric acid solution is used in the acid addition zone, and the pH value of the acid addition zone is set between 2.0 and 2.5. A lime water solution is used in the alkali addition zone, and the pH value of the alkali addition zone is set between 4.0 and 4.5.

[0008] As an optional solution of the present invention, in step S4, the fluoride ion content in the solution before treatment is 4600 mg / L, and the fluoride ion content in the solution after treatment is 200 mg / L-300 mg / L, so that the fluoride removal rate reaches 93.4%.

[0009] As an optional embodiment of the present invention, the solution concentration is maintained at 1.6 mol / L during steps S4 and S5.

[0010] As an optional embodiment of the present invention, the alkali addition zone in step S4 may also use an oxidant including hydrogen peroxide, sodium peroxide, and sodium hydrogen peroxide.

[0011] This invention provides a highly efficient method for reducing fluoride ions in rare earth fluorocarbonate ores, which has the following beneficial effects: The entire process allows for the rapid filtration and separation of rare earth carbonate ore. The combined treatment in the acid and alkali addition zones ensures the fluoride ions react fully, forming a white precipitate, CaF2. The gas produced in the alkali addition zone has no pungent odor, and the amount of toxic gas is significantly reduced, further protecting the surrounding environment. The CaF2 is then washed and dried, collected, and preserved as a precipitate, greatly reducing the fluoride ion content and effectively treating and recovering the products obtained from fluoride ion recovery, thus avoiding pollution of the surrounding environment due to improper handling. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0013] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0014] Please see Figure 1 This invention provides a technical solution: a method for efficiently reducing fluoride ions in rare earth fluorocarbonate ores, comprising the following steps: S1. Raw material preparation: The newly mined rare earth carbonate ore is piled up and processed in a concentrated manner; S2. Pretreatment: Take 50kg of rare earth fluorocarbonate ore. The rare earth fluorocarbonate ore is crushed and ground into 100-mesh particles to obtain particles of uniform size. S3. Washing, leaching and filtrate treatment: The obtained particles are then washed and stirred to obtain clean rare earth ore particles, which reduces the fluorine content of the rare earth ore. The filtrate wastewater generated from washing is then treated separately with acid and alkali leaching. S4. Adjusting the pH value: Clean rare earth ore particles are concentrated and introduced into the acid addition zone. In step S4, a concentrated hydrochloric acid solution is used in the acid addition zone. During the mixing and stirring process, the stirring time is set to 2 hours, and the stirring temperature is set between 15℃ and 85℃. Then, the mixed solution is introduced into the alkali addition zone, which uses a lime water solution. Continue stirring to ensure a complete reaction, allowing Ca to... 2+ and F - They combine to form CaF2, which is sparingly soluble in water. The chemical equation for this is Ca... 2+ + 2 F - = CaF2, producing a white precipitate, thus completing the fluoride reduction treatment. In step S4, the fluoride ion content in the solution before treatment was 4600 mg / L, and the fluoride ion content in the solution after treatment was 200 mg / L-300 mg / L. In step S4, the alkali addition zone can also use oxidants including hydrogen peroxide, sodium peroxide, and sodium hydrogen peroxide to cause the fluoride ions in the rare earth ore to undergo a redox reaction with the oxidant to generate fluorides. The reaction conditions can be a redox reaction at room temperature and pressure, but reaching 60°C or above will accelerate the redox reaction. S5. Add mixed reagent: The mixed reagent is a sodium salt reagent, which is introduced into the alkali addition zone to neutralize the negative ions in the alkali addition zone and increase the Ca2+ level. 2+ The content of [unspecified substance] resulted in a fluoride removal rate of 93.4%; the solution concentration was maintained at 1.6 mol / L during steps S4 and S5. S6. Precipitation treatment: The CaF2 precipitate generated after the defluorination treatment is collected and filtered through a filter screen to complete the solid-liquid separation. S7. Precipitate treatment: The separated precipitate is treated, such as by washing and drying, to obtain the precipitate CaF2. S8. Sediment Collection: Collect and preserve the treated precipitate CaF2 for further utilization or disposal.

[0015] In Example 2, in step S4, concentrated hydrochloric acid solution is used in the acid addition zone, and the pH value of the acid addition zone is set between 2.0 and 2.5. The pH value of the acid addition zone is tested regularly. Lime water solution is used in the alkali addition zone, and the pH value of the alkali addition zone is set between 4.0 and 4.5. The pH value of the alkali addition zone is tested regularly.

[0016] In Example 3, the fluoride ion content in the solution before treatment in step S4 was 4600 mg / L, and the fluoride ion content in the solution after treatment was 200 mg / L-300 mg / L, resulting in a fluoride removal rate of 93.4%.

[0017] In Example 4, the solution concentration was maintained at 1.6 mol / L during steps S4 and S5, and no additional water was needed for concentration adjustment by the staff, so the overall process was not affected.

[0018] In Example 5, the alkali addition zone in step S4 can also use an oxidant including hydrogen peroxide, sodium peroxide, and sodium hydrogen peroxide to mix the rare earth ore with the oxidant, so that the fluoride ions in the rare earth ore react with the oxidant to produce fluorides, resulting in less polluting gas and thus protecting the surrounding environment.

[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for efficiently reducing fluoride ions in rare earth fluorocarbonate ores, characterized in that: Includes the following steps: S1. Raw material preparation: The newly mined rare earth fluorocarbonate ore is piled up and processed in an integrated manner. S2. Pretreatment: The rare earth fluorocarbonate ore is crushed and ground to obtain particles of uniform size. S3. Washing, leaching and filtrate treatment: The obtained particles are washed to obtain clean rare earth ore particles. The filtrate wastewater generated from washing is treated separately with acid and alkali leaching. S4. Adjusting the pH value: Clean rare earth ore particles are concentrated and introduced into the acid addition zone. After mixing with acid, the mixed solution is then introduced into the alkali addition zone for complete reaction, so that Ca... 2+ and F - They combine to form CaF2, which is poorly soluble in water, thus completing the defluorination treatment; S5. Add mixed reagent: The mixed reagent is a sodium salt reagent, which is introduced into the alkali addition zone to neutralize the negative ions in the alkali addition zone and increase the Ca2+ level. 2+ The content of [specific element] makes the defluorination rate reach 93.4%; S6. Precipitation treatment: The CaF2 precipitate generated after the defluorination treatment is collected and filtered through a filter screen to complete the solid-liquid separation. S7. Precipitate treatment: The separated precipitate is washed and dried to obtain precipitate CaF2; S8. Sediment Collection: Collect and preserve the treated precipitate CaF2; In step S4, concentrated hydrochloric acid solution is used in the acid addition zone, and the pH value of the acid addition zone is set between 2.0 and 2.

5. Lime water solution is used in the alkali addition zone, and the pH value of the alkali addition zone is set between 4.0 and 4.

5.

2. The method for efficiently reducing fluoride ions in rare earth fluorocarbonate ores according to claim 1, characterized in that: In step S4, the alkali addition zone also uses an oxidizing agent, which may include hydrogen peroxide or sodium peroxide.

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