A highly efficient method for separating and recovering rare earth elements and leaching agents from rare earth leachate.

Abstract

This invention discloses a highly efficient method for recovering rare earth elements and leaching agents from ion-adsorption rare earth ore leaching mother liquor, comprising: obtaining ion-adsorption rare earth ore leaching mother liquor → pretreatment of leaching mother liquor (sedimentation, flocculation, filtration) → activation of rare earth element chemical bonds in leaching mother liquor → activation of functional groups on the surface of the transformation material → reconstruction of rare earth element chemical bonds in mother liquor and recovery of leaching agent → breaking of rare earth element chemical bonds in the transformation material and recovery of rare earth concentrate. This invention achieves efficient simultaneous recovery of rare earth elements and leaching agents from the rare earth leaching mother liquor through selective separation, increasing the concentration of rare earth mother liquor, reducing the circulating water volume in the rare earth recovery stage, and shortening the leaching agent circulation time. The rare earth recovery stage and the circulating leaching stage form two independent water systems, avoiding mutual interference between the two stages, saving land costs, and reducing the risk of leaching agent contamination exposure. The independent rare earth recovery stage can employ various precipitation processes, effectively preventing the return of industrial wastewater from the recovery stage to the mining area.

Description

Technical Field

[0001] This invention belongs to the fields of mining, mineral processing, and hydrometallurgical utilization, and specifically relates to an efficient method for separating and recovering rare earth elements and leaching agents from rare earth leachates. Background Technology

[0002] Because the rare earth content in ion-adsorption rare earth ores is generally low (0.05–0.2 wt%), it is extremely difficult to improve its industrial grade using traditional gravity separation, magnetic separation, electrostatic separation, and flotation techniques. Therefore, the current mainstream process is based on cation exchange extraction, using cationic leaching agents such as ammonium salts (ammonium sulfate), magnesium salts (magnesium sulfate), and calcium salts (calcium chloride) to leach rare earth elements in situ to obtain a high-concentration rare earth mother liquor. Subsequently, the rare earth elements in the mother liquor undergo impurity removal precipitation, solid-liquid separation, and roasting to obtain rare earth oxide concentrate products, which are then further extracted and separated into rare earth products. In this mainstream process, the rare earth leaching mother liquor separation and recovery stage involves a large amount of industrial water recycling, resulting in significant land costs and pollution exposure risks. Taking the traditional ammonium salt in-situ leaching process with an annual output of 2000 tons of rare earth concentrate as an example, the daily processing capacity is 8000 m³. 3 Rare earth leaching mother liquor needs to undergo approximately 8 hours of ammonium bicarbonate impurity removal and 6 hours of ammonium bicarbonate precipitation in batches before recyclable leaching agent and rare earth concentrate crude product can be obtained. In this process, the daily industrial circulating water volume is approximately 8000 m³. 3 The ammonia nitrogen concentration was approximately 2000 ppm, far exceeding the ammonia nitrogen limit for Class III surface water in GB 3838-2002 standard, and the treatment cost was as high as 300,000 yuan per year. Magnesium salt in-situ leaching-precipitation and calcium salt in-situ leaching processes also face similar bottlenecks, as the separation and recovery stages involve a large amount of industrial water circulation and high concentrations of inorganic salts (Mg). 2+ Ca 2+ SO4 2- Exposure Risks. In recent years, researchers have developed a magnesium salt in-situ leaching-centrifugal extraction process to further improve the recovery efficiency of high-value rare earth elements in the rare earth leaching mother liquor separation and recovery stage. This process efficiently and rapidly achieves the enrichment of high-concentration rare earth mother liquor, but the integrated centrifugal extraction unit is expensive and has high subsequent operating costs, increasing the direct cost by about 30% per ton of REO. In addition, the highly toxic extract and the raffinate directly returned to the mining area will further increase the risk of exposure to mine ecological environment pollution.

[0003] Therefore, in order to solve the high cost problem and pollution exposure risk caused by the large amount of industrial recycled water in the leaching mother liquor separation and recovery stage of the current ion-adsorption rare earth mining process, this invention discloses a method for efficient separation and recovery of rare earth and leaching agent in rare earth leachate. By separating the rare earth recovery stage and the circulating leaching stage into two independent hydrometallurgical systems, the recovery cost of rare earth concentrate products can be effectively reduced while realizing the rapid reuse of leaching agent. Summary of the Invention

[0004] The purpose of this invention is to provide a highly efficient method for separating and recovering rare earth elements and leaching agents from rare earth leachates, effectively solving the common defects and bottlenecks in the separation and recovery of rare earth leachate mother liquor in inorganic salt mining processes based on the principle of cation exchange extraction, such as ammonium salts, magnesium salts, and calcium salts.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A highly efficient method for recovering rare earth elements and leaching agents from ion-type rare earth ore leaching mother liquor includes the following steps:

[0007] S1. Obtain mother liquor from ion-adsorption type rare earth ore leaching;

[0008] S2. Pretreatment of leachate mother liquor (sedimentation, flocculation, filtration);

[0009] S3. Activation of rare earth element chemical bonds in the leaching mother liquor;

[0010] S4. Activation of functional groups on the surface of transforming materials;

[0011] S5. Reconstruction of rare earth element chemical bonds in mother liquor and recovery of leaching agent;

[0012] S6. Breaking of chemical bonds in rare earth elements in transformation materials and recovery of rare earth concentrate products.

[0013] Furthermore, in step S1, the source of the ion-type rare earth ore leaching mother liquor may include leaching mother liquor obtained by traditional cation exchange leaching processes such as ammonium salt, magnesium salt, calcium salt and aluminum salt;

[0014] Further, in step S2, the purpose of the sedimentation treatment is to remove large particles of silt, gravel, and other insoluble substances through natural sedimentation, with a sedimentation time of 2-5 hours; the purpose of the flocculation treatment is to remove suspended matter and most colloidal matter, and the flocculants used include, but are not limited to, organic polymeric flocculants such as sodium polyacrylate, dimethyl diallyl ammonium chloride, and polyacrylamide, with a flocculation time of 2-5 hours; the purpose of the filtration treatment is to further remove suspended matter and colloidal matter to ensure the high-efficiency operation of subsequent conversion materials, and the filtration methods used include, but are not limited to, bag filtration, multi-media filtration, and glass filter media filtration.

[0015] Furthermore, in step S3, the activation of rare earth element chemical bonds in the leaching mother liquor is achieved by introducing a pH adjuster to stabilize the pH value of the leaching mother liquor, ensuring the high-efficiency operation of the subsequent conversion materials. The pH adjuster includes, but is not limited to, conventional agents such as hydrochloric acid, sulfuric acid, sodium hydroxide, and potassium hydroxide, and the stable pH value of the mother liquor is 2–7.

[0016] Further, in step S4, the activation method of the functional groups on the surface of the transformation material is to rinse with conventional industrial water such as pure water, soft water, or tap water. The activation time is 0.5 to 2 hours, the rinsing rate is 2 to 8 BV / h, and the activation ambient temperature is 10 to 40°C. The transformation material includes, but is not limited to, adsorbent materials with styrene, acrylic acid, phenolic resin, epoxy resin, vinylpyridine, urea-formaldehyde resin, and vinyl chloride as the framework structure and acidic groups such as sulfonic acid groups, carboxylic acid groups, and phosphate groups, and chelating groups such as amino acid groups, amino phosphate groups, and sulfur groups as functional groups.

[0017] Further, in step S5, the process of reconstructing the rare earth element chemical bonds in the mother liquor refers to passing the pretreated activated mother liquor from steps S3 and S2 through the activated transformation material in step S4 at a flow rate of 1 to 10 BV / h, with the reaction environment temperature being 10 to 40°C. Step S6 is executed immediately after the transformation material is saturated with rare earth elements.

[0018] Further, in step S5, the leaching agent recovery refers to directly collecting the rare earth mother liquor filtrate after the activated and transformed material. Specifically, the recovered leaching agent solution needs to be adjusted to pH 3-5 before continued use. Based on this, the first water circulation system of the present invention is formed: rare earth leaching mother liquor → recovered leaching agent (liquid) → in-situ leaching solution → rare earth leaching mother liquor, as shown in the appendix. Figure 1 As shown.

[0019] Furthermore, in step S6, the breaking of rare earth element chemical bonds in the transformation material is achieved by using a strong acid solution of a certain concentration to disrupt the chemical bonds formed between the functional groups on the surface of the transformation material and the rare earth elements. Specifically, the strong acid solution includes, but is not limited to, hydrochloric acid and sulfuric acid, with a concentration of 2–15 wt%, a rinsing time of 0.5–2 h, a rinsing rate of 2–8 BV / h, and an activation temperature of 10–40 °C.

[0020] Further, in step S6, the recovery of the concentrate product is achieved through a traditional impurity removal and precipitation operation on the strong acid leaching solution (containing a high concentration of rare earth elements). Specifically, the impurity removal agents include, but are not limited to, carbonates, bicarbonates, and calcium oxide, with a removal pH of 4.0–4.5 and a temperature of 5–40°C; the precipitating agents include, but are not limited to, carbonates, bicarbonates, and organic precipitants, with a precipitation pH of 4.6–7.0 and a temperature of 5–40°C. Based on this, the second water circulation system of the present invention is formed: strong acid leaching solution → impurity removal and precipitation supernatant → mine water → strong acid leaching solution, as shown in the appendix. Figure 2 As shown.

[0021] This invention addresses the problems faced by current in-situ mining processes using a single water circulation system for ion-type rare earth ammonium / magnesium / calcium salts, including large industrial circulating water volumes, high pollution risks, and low leaching agent reuse efficiency. It constructs a highly efficient method for recovering rare earth elements and leaching agents from the leaching mother liquor based on the principle of rare earth element chemical bond reconstruction and breaking. On one hand, this invention utilizes the high exchange capacity of the transition material to effectively achieve the reconstruction process of rare earth element chemical bonds in the leaching mother liquor (egRe(H2O)). n (SO4) m +Mat→Mat-Re+SO4 2- A high-concentration rare earth element enrichment process is achieved through the addition of H2O; subsequently, a high-concentration rare earth solution (e.g., Mat-Re + H2O) is obtained by breaking the chemical bonds of rare earth elements. + →+Re 3+ +Mat-H); finally, rare earth concentrate products are obtained through traditional impurity removal and precipitation processes. In this process, the circulating water volume of the leaching mother liquor in the subsequent impurity removal and precipitation stage can be reduced to 2% to 5%, and the concentration of rare earth elements can be increased by 20 to 100 times, forming an independent water circulation system. On the other hand, this invention utilizes the highly efficient and rapid elution capability of the transforming material for rare earth elements in the leaching mother liquor, which can effectively realize the separation process of rare earth elements from the leaching agent (egRe(H2O)). n(aq) +NH 4+(aq) +Mat (S) →Mat-Re (S) +NH 4+(aq) +H2O (aq) In this process, the leaching agent circulation time can be reduced to 30%–50% of the original process time, forming another independent water circulation system. In summary, the independent operation of the two water circulation systems for leaching agent reuse and rare earth concentrate product recovery can effectively reduce the risk of leaching agent pollution exposure in the hydrometallurgical stage of mining and improve the efficiency of the ore mining stage.

[0022] This invention has at least the following technical effects:

[0023] (1) The rare earth and the leaching agent in the rare earth leaching mother liquor are selectively separated to achieve efficient synchronous recovery, which increases the concentration of rare earth mother liquor, reduces the circulating water volume in the rare earth recovery process, and effectively shortens the leaching agent circulation time.

[0024] (2) The rare earth recycling process and the circulating leaching process form two independent water systems, which effectively avoids mutual interference between the two processes, saves the land cost of the hydrometallurgical workshop, and reduces the risk of exposure to leaching agent pollution.

[0025] (3) A variety of precipitation processes can be used for the independent rare earth recycling process, such as oxalic acid precipitation, ammonium bicarbonate precipitation and hydroxide precipitation, which can effectively prevent industrial wastewater from flowing back to the mining area during the recycling process. Attached Figure Description

[0026] Figure 1 The water circulation system 1 described in this invention;

[0027] Figure 2 This refers to the water circulation system 2 described in this invention. Detailed Implementation

[0028] To make the technical objectives, technical solutions, and technical effects of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art in conjunction with the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] The weights of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope disclosed in the embodiments of this invention. Specifically, the weights mentioned in the embodiments of this invention can be well-known units of mass in the chemical industry, such as μg, mg, g, and kg.

[0030] Example 1:

[0031] Use 3% ammonium sulfate (C) under suitable conditions (NH4+)Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (0.82%) to obtain a rare earth concentration of 0.5 g / L, which was then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of amino acid-based styrene adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After activation, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentration of rare earth elements in the solution was detected by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the concentration of ammonium ions in the solution was detected by ion chromatography (IC). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 35 BV, the leaching time was 3.5 h, the rare earth concentration in the residual liquid was 30 mg / L, the ammonium ion concentration was 0.74%, the rare earth element recovery rate was 99.5%, and the leaching agent loss rate was 9.8%. Subsequently, the ammonium ion concentration in the residual liquid was replenished to 0.82%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 95.7%. Based on this, the first independent water circulation system was formed, with a circulation volume of 35 BV and a time of 3.5 h.

[0032] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 8.7 g / L, and the rare earth element elution rate was 99.4%. Finally, the rare earth concentrate was recovered through a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h. The rare earth recovery rate was 98.6%. Based on this, a second independent water circulation system was established, with a circulation volume of 2 BV and a time of 2h.

[0033] Comparative Example 1:

[0034] Use 3% ammonium sulfate (C) under suitable conditions (NH4+)Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ore (0.82%) to obtain a rare earth concentration of 0.5 g / L. The 35 BV leaching mother liquor from Example 1 was then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was stirred and activated at 30°C for 0.5 hours. Subsequently, rare earth concentrate was recovered directly through a conventional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 5 hours, and the precipitation stage was allowed to stand for 5 hours, resulting in a total rare earth recovery rate of 89.5%. Based on this, an independent water circulation system was established, with a circulating water volume of 35 BV and a time consumption of 10 hours.

[0035] Example 2:

[0036] Use 3% ammonium sulfate (C) under suitable conditions (NH4+) Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (0.82%) to obtain a rare earth concentration of 0.5 g / L, and then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of aminophosphate-based styrene-based adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After the adsorbent was activated, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentration of rare earth elements in the solution was detected by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the concentration of ammonium ions in the solution was detected by ion chromatography (IC). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 32 BV, the leaching time was 3.2 h, the rare earth concentration in the residual liquid was 30 mg / L, the ammonium ion concentration was 0.72%, the rare earth element recovery rate was 97.1%, and the leaching agent loss rate was 12.2%. Subsequently, the ammonium ion concentration in the residual liquid was replenished to 0.82%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this time, the rare earth leaching rate was 91.2%. Based on this, the first independent water circulation system was formed, with a circulation volume of 32 BV and a time of 3.2 h.

[0037] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 8.0 g / L, and the rare earth element elution rate was 98.1%. Finally, the rare earth concentrate was recovered using a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h, with a rare earth recovery rate of 96.6%. Based on this, a second independent water circulation system was established, with a circulation water volume of 2 BV and a time of 2h.

[0038] Example 3:

[0039] Use 5% magnesium sulfate (C) under suitable conditions (Mg2+) Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (1.0%) to obtain a rare earth concentration of 0.5 g / L, and then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added uniformly to the leaching mother liquor. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of amino acid-based styrene-based adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After the adsorbent was activated, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentrations of rare earth elements and magnesium ions in the solution were detected using inductively coupled plasma atomic emission spectrometry (ICP-OES). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 30 BV, and the leaching time was 3 hours. The rare earth concentration in the residual liquid was 30 mg / L, the magnesium ion concentration was 0.88%, the rare earth element recovery rate was 98.1%, and the leaching agent loss rate was 12%. Subsequently, the magnesium ion concentration in the residual liquid was replenished to 1.0%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 92.1%. Based on this, the first independent water circulation system was formed, with a circulation volume of 30 BV and a time of 3.0 hours.

[0040] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 7.5 g / L, and the rare earth element elution rate was 99.2%. Finally, the rare earth concentrate was recovered through a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h. The rare earth recovery rate was 98.6%. Based on this, a second independent water circulation system was established, with a circulation volume of 2 BV and a time of 2h.

[0041] Example 4:

[0042] Use 5% calcium chloride (C) under suitable conditions (Ca2+) Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (1.8%) to obtain a rare earth concentration of 0.5 g / L, and then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added uniformly to the leaching mother liquor. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of amino acid-based styrene-based adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After the adsorbent was activated, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentrations of rare earth elements and calcium ions in the solution were detected using inductively coupled plasma atomic emission spectrometry (ICP-OES). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 20 BV, and the leaching time was 2 hours. The rare earth concentration in the residual liquid was 30 mg / L, the calcium ion concentration was 1.5%, the rare earth element recovery rate was 92.3%, and the leaching agent loss rate was 16.7%. Subsequently, the calcium ion concentration in the residual liquid was replenished to 1.8%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 89.4%. Based on this, the first independent water circulation system was formed, with a circulation volume of 20 BV and a time of 2 hours.

[0043] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 5.0 g / L, and the rare earth element elution rate was 98.1%. Finally, the rare earth concentrate was recovered using a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h, with a rare earth recovery rate of 95.6%. Based on this, a second independent water circulation system was established, with a circulation water volume of 2 BV and a time of 2h.

[0044] Example 5:

[0045] Use 3% ammonium sulfate (C) under suitable conditions (NH4+)Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (0.82%) to obtain a rare earth concentration of 0.5 g / L, and then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of sulfonate-based styrene-based adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After the adsorbent was activated, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentration of rare earth elements in the solution was detected by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the concentration of ammonium ions in the solution was detected by ion chromatography (IC). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 20 BV, and the leaching time was 2 hours. The rare earth concentration in the residual liquid was 30 mg / L, the ammonium ion concentration was 0.70%, the rare earth element recovery rate was 96.1%, and the leaching agent loss rate was 12.2%. Subsequently, the ammonium ion concentration in the residual liquid was replenished to 0.82%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 97.3%. Based on this, the first independent water circulation system was formed, with a circulation volume of 20 BV and a time of 2 hours.

[0046] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 5.0 g / L, and the rare earth element elution rate was 93.1%. Finally, the rare earth concentrate was recovered using a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h, with a rare earth recovery rate of 97.7%. Based on this, a second independent water circulation system was established, with a circulation water volume of 2 BV and a time of 2h.

[0047] Example 6:

[0048] Use 3% ammonium sulfate (C) under suitable conditions (NH4+)Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (0.82%) to obtain a rare earth concentration of 0.5 g / L, and then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of carboxylic acid-based styrene adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After the adsorbent was activated, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentration of rare earth elements in the solution was detected by inductively coupled plasma atomic emission spectrometry (ICP-OES), and the concentration of ammonium ions in the solution was detected by ion chromatography (IC). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 28 BV, taking 2.8 hours. The rare earth concentration in the residual liquid was 30 mg / L, the ammonium ion concentration was 0.72%, the rare earth element recovery rate was 94.2%, and the leaching agent loss rate was 12.2%. Subsequently, the ammonium ion concentration in the residual liquid was replenished to 0.82%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 91.9%. Based on this, the first independent water circulation system was formed, with a circulation volume of 28 BV and a time of 2.8 hours.

[0049] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 7.0 g / L, and the rare earth element elution rate was 98.1%. Finally, the rare earth concentrate was recovered through a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h. The rare earth recovery rate was 97.9%. Based on this, a second independent water circulation system was established, with a circulation volume of 2 BV and a time of 2h.

[0050] Example 7:

[0051] Use 3% ammonium sulfate (C) under suitable conditions (NH4+)Rare earth leaching mother liquor was obtained by leaching ion-adsorption rare earth ores (0.82%) to obtain a rare earth concentration of 0.5 g / L, which was then allowed to stand for 3 hours for later use. A 0.02% sodium polyacrylate solution was prepared and added to the leaching mother liquor at a uniform rate. After flocculation and standing for 3 hours, the solution was filtered. A small amount of sulfuric acid was added to the filtered leachate to adjust the pH to 4.5, and the solution was activated by stirring at 30°C for 0.5 hours. A certain volume of phosphate-based styrene-based adsorbent was packed into a elution column, and ultrapure water was passed through the working column at a flow rate of 5 BV / h to activate the adsorbent for 1 hour. After activation, the leaching mother liquor was passed through the elution column at a flow rate of 10 BV / h at a reaction temperature of 25°C. The conversion residue was collected, and the concentration of rare earth elements in the solution was detected by inductively coupled plasma atomic emission spectrometry (ICP-OES), while the concentration of ammonium ions in the solution was detected by ion chromatography (IC). After the adsorption bed of the leaching column was penetrated, the flow rate of the solution through the leaching column was 25 BV, taking 2.5 hours. The rare earth concentration in the residual liquid was 30 mg / L, the ammonium ion concentration was 0.69%, the rare earth element recovery rate was 92.7%, and the leaching agent loss rate was 15.6%. Subsequently, the ammonium ion concentration in the residual liquid was replenished to 0.82%, the leaching process was repeated, and the rare earth leaching mother liquor was collected. At this point, the rare earth leaching rate was 93.7%. Based on this, the first independent water circulation system was formed, with a circulation volume of 25 BV and a time of 2.5 hours.

[0052] Subsequently, the transformation material was leached with 5% hydrochloric acid under suitable conditions, and the hydrochloric acid eluent was collected. The leaching flow rate was 4 BV / h, the leaching time was 0.5h, and the ambient temperature was 10–40℃. The concentration of rare earth elements in the eluent was detected using ICP-OES. At this point, the volume of hydrochloric acid passing through the leaching column was 2 BV, the rare earth concentration was 6.25 g / L, and the rare earth element elution rate was 94.4%. Finally, the rare earth concentrate was recovered using a traditional impurity removal and precipitation process. The impurity removal stage was allowed to stand for 1h, and the precipitation stage was allowed to stand for 1h. The rare earth recovery rate was 93.1%. Based on this, a second independent water circulation system was established, with a circulation volume of 2 BV and a time of 2h.

[0053] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for efficient recovery of rare earth elements and leaching agent from ion-type rare earth ore leaching mother liquor, comprising the following steps: S1. Obtain ion-adsorption type rare earth ore leaching mother liquor. This ion-adsorption type rare earth ore leaching mother liquor is the leaching mother liquor obtained by cation exchange leaching process, and the cations include: Ammonium ions, magnesium ions, calcium ions, and aluminum ions; S2. The leachate mother liquor is pretreated by sedimentation for 2-5 hours, flocculation for 2-5 hours, and filtration to obtain pretreated mother liquor; The flocculants used in the flocculation process include: sodium polyacrylate, dimethyl diallyl ammonium chloride, and polyacrylamide; S3. Add a small amount of pH adjuster to the pretreatment mother liquor to activate it, and obtain the activated mother liquor; S4. Activation of functional groups on the surface of the transformation material to obtain activated transformation material. The transformation material includes: adsorbent materials with styrene, acrylic acid, phenolic resin, epoxy resin, vinylpyridine, urea-formaldehyde, and vinyl chloride as the framework structure, sulfonic acid group, carboxylic acid group, and phosphate group as acidic groups and amino acid group, amino phosphate group, and sulfur group as functional groups. S5. Reconstruct the chemical bonds of rare earth elements in the activated mother liquor, and recover the leaching agent at the same time; S6. Breaking of rare earth element chemical bonds in transformation materials and recovery of rare earth concentrate products. Breaking of rare earth element chemical bonds in transformation materials includes: rinsing the transformation materials with a strong acid concentration of 2~15wt% to break the chemical bonds formed between the functional groups on the surface of the transformation materials and the rare earth elements. The rinsing time is 0.5~2h, the rinsing rate is 2~8BV / h, and the activation temperature is 10~40℃.

2. The efficient recycling method according to claim 1, wherein: The filtration methods described in step S2 include: bag filtration, multi-media filtration, and glass filter media filtration.

3. The efficient recycling method according to claim 1, wherein: The pH adjuster mentioned in step S3 includes: hydrochloric acid, sulfuric acid, sodium hydroxide, and potassium hydroxide; The pH adjuster adjusts the pH of the mother liquor to 2-7.

4. The efficient recycling method according to claim 1, wherein: The activation of the functional groups on the surface of the transformation material in step S4 is as follows: activating by rinsing with industrial water for 0.5~2h, with a rinsing rate of 2~8BV / h and an activation ambient temperature of 10~40℃.

5. The efficient recycling method according to claim 1, wherein: Step S5, which involves reconstructing the rare earth element chemical bonds in the activated mother liquor, includes: The activation mother liquor is passed through the activation transformation material at a flow rate of 1~10 BV / h, and the reaction environment temperature is 10~40℃. Step S6 is executed immediately after the transformation material is saturated with rare earth elements.

6. The efficient recycling method according to claim 1, wherein: The recovery of the leaching agent in step S5 includes: directly collecting the rare earth mother liquor filtrate after the activated and transformed material; The pH of the recovered leachate needs to be adjusted to 3-5.

7. The efficient recycling method according to claim 1, wherein: Step S6, the recovery of concentrate products, includes: removing impurities and precipitating the strong acid leaching solution; The impurity removal agents include: carbonates, bicarbonates, and calcium oxide; the pH for impurity removal is 4.0~4.5, and the temperature is 5~40℃; Precipitants include carbonates, bicarbonates, and organic precipitants; the precipitation pH is 4.6~7.0, and the temperature is 5~40℃.

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