Method for extracting ion-type rare earth waste residue associated aluminum uranium resources

Abstract

The application provides a method for extracting ion-type rare earth waste residue co-associated aluminum and uranium resources, which realizes the separation of aluminum and rare earth-uranium by leaching aluminum components in ion-type rare earth waste residue in a strong alkaline medium, and the aluminum forms an aluminum-containing solution of soluble metaniobate, which can be used to prepare high-value products of large-pore pseudo-boehmite; then the insoluble uranium-rich-rare earth residue is further leached in a weak alkaline medium, so that uranium forms a uranyl carbonate complex anion into the solution, and the rare earth elements are enriched in the residue, realizing efficient separation of rare earth and uranium, and the obtained rare earth-rich residue can recover rare earth elements through a process of series hydrochloric acid optimization solution, etc. The application realizes efficient recovery of valuable elements aluminum and uranium in ion-type rare earth low-emission materials, enrichment of rare earth and reduction of low-emission materials, and helps to solve the problem of difficult recovery and treatment of ion-type rare earth low-emission materials.

Description

Technical Field

[0001] This invention belongs to the field of metallurgy, and in particular relates to a method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue. Background Technology

[0002] Rare earth elements, as strategic resources, have attracted much attention due to their important applications and roles in high-tech fields. Among them, ion-adsorption rare earth mines account for approximately 80% of the global rare earth resource supply. Rare earth companies produce approximately 4,000 tons of rare earth oxides annually, while generating approximately 8,000 tons of rare earth waste. This rare earth waste contains approximately 25% Al2O3, approximately 1% rare earth oxides, and approximately 0.01% uranium, thorium, and other resources.

[0003] According to data, rare earth waste residue 238 U+ 235 U、 232 Th and 226 The specific activities of Ra were 25.8, 27.5, and 28.1 Bq / g, respectively, which are one order of magnitude higher than the standard critical level (1 Bq / g, GB 27742-2011). Therefore, they belong to low-level radioactive waste (400 Bq / g, GB9133-1996) and can be simply referred to as ionic rare earth low-level radioactive waste. It is evident that the disposal of ionic rare earth low-level radioactive waste is related to the recovery of valuable rare earth and uranium-thorium elements, radiation pollution control, and resource recycling, and thus urgently needs to be addressed.

[0004] Currently, although the volume of ionic rare earth waste is large, its disposal method mainly involves centralized stockpiling due to the low grade of rare earth elements compared to industrial development levels. Some scholars have studied a scheme that uses acid dissolution to obtain a solution containing rare earth elements, uranium, and thorium, followed by extraction for separation and recovery. This approach has achieved good yields but has not yet been industrialized. Furthermore, the above schemes often require the addition of ammonia carbonate for chemical precipitation to remove aluminum, the main impurity, during acid treatment. However, the aluminum hydroxide formed by neutralization and precipitation not only has a high water content, making it difficult to filter, but also results in significant rare earth entrainment losses, a problem that acid dissolution methods struggle to avoid.

[0005] CN102154560A discloses a method for separating and extracting uranium and thorium from rare earth slag. The method employs an alkaline leaching, uranium precipitation followed by acid leaching, and thorium precipitation separation scheme for the slag. The equipment and process of this invention are simple, easy to operate, and the raw materials are readily available, reducing environmental pollution. However, it mainly targets the slag after rare earth extraction from monazite (which has a relatively high content of uranium (0.9%) and thorium (23.09%), and lacks a suitable solution for treating ionic rare earth low-level radioactive materials with high aluminum content but low thorium and uranium content.

[0006] In summary, ionic rare earth low-level radioactive materials mainly originate from insoluble residues after dissolving rare earth oxides with hydrochloric acid, waste residues generated by adding barium chloride to remove sulfate ions from the leaching solution, or waste residues obtained by neutralizing mine wastewater and smelting separation plant wastewater with alkaline substances such as calcium oxide. Due to different processes and mineral sources, the amount and composition of ionic rare earth low-level radioactive materials vary. They are characterized by large volume, high water content, and mainly contain sulfates, hydrated aluminum polymers, as well as valuable rare earth and uranium resources. Furthermore, long-term stockpiling leads to resource waste and poses a problem of nuclear radiation pollution to the environment. Therefore, it is necessary to develop a new scheme to effectively reduce the emission of ionic rare earth low-level radioactive materials, enrich rare earths, and extract radioactive elements such as aluminum and uranium. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this invention is to provide a method for extracting associated aluminum and uranium resources from ionic rare earth waste residue. This method separates aluminum from rare earth-uranium by leaching the aluminum component in a strongly alkaline medium. The aluminum forms a soluble aluminate solution such as NaAlO2 and / or KAlO2, which can be used to prepare the high-value product macroporous pseudoboehmite γ-(AlOOH). The insoluble uranium-rich rare earth residue is then further leached in a weakly alkaline medium, causing uranium to form uranyl carbonate anions that enter the solution, while rare earth elements are enriched in the residue, achieving efficient separation of rare earth and uranium. The obtained rare earth-rich residue can be used to recover rare earth elements through a series of hydrochloric acid preferential dissolution processes. This invention achieves efficient recovery of valuable elements aluminum and uranium from ionic rare earth low-level radioactive materials, rare earth enrichment, and low-level radioactive material emission reduction, helping to solve the problem of difficult recovery and treatment of ionic rare earth low-level radioactive materials.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue, the method comprising the following steps:

[0010] Ionic rare earth waste residue is mixed with a strongly alkaline medium for the first leaching to obtain an aluminum-containing solution and uranium-rich rare earth residue.

[0011] The obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium containing carbonate and / or bicarbonate ions, and a second leaching is performed to obtain a uranium-containing solution and rare earth-rich slag.

[0012] The method for treating ionic rare earth waste (low-level radioactive materials) provided by this invention is based on the difference in solubility of rare earth, uranium, and aluminum in a strongly alkaline medium. By controlling a specific leaching medium, aluminum components are first leached in a strongly alkaline medium. Then, based on the strong complexing properties of uranium and carbonates, uranium components are further extracted in a weakly alkaline medium containing carbonate or bicarbonate ions. This achieves efficient separation of rare earth and uranium. The resulting rare earth-rich slag is then processed using mature processes such as hydrochloric acid for optimal solubility to recover rare earth. This method not only achieves the stepwise and efficient extraction of valuable elements such as aluminum and uranium, but also achieves rare earth enrichment and low-level radioactive material emission reduction, thus reducing radioactive pollution from low-level radioactive materials. It provides a green and efficient new approach for the treatment of ionic rare earth low-level radioactive materials.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0014] As a preferred technical solution of the present invention, the method further includes: treating rare earth-rich slag with hydrochloric acid preferential dissolution method to recover rare earth elements.

[0015] As a preferred embodiment of the present invention, the strongly alkaline medium includes a primary strong base, which includes sodium hydroxide and / or potassium hydroxide.

[0016] Preferably, the concentration of the primary strong base in the strongly alkaline medium is 1–500 g / L, for example, it can be 1 g / L, 5 g / L, 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L, 400 g / L, 450 g / L, or 500 g / L, etc., preferably 50–100 g / L, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0017] As a preferred technical solution of the present invention, the strongly alkaline medium further includes a calcium-fixing agent, which includes any one or a combination of at least two of sodium carbonate, potassium carbonate, sodium phosphate, or potassium phosphate. Typical but non-limiting examples of the combination include combinations of sodium carbonate and potassium carbonate, sodium carbonate and sodium phosphate, sodium carbonate and potassium phosphate, potassium carbonate and sodium phosphate, potassium carbonate and potassium phosphate, or sodium phosphate and potassium phosphate.

[0018] Preferably, the concentration of the calcium-fixing agent containing carbonate ions (such as sodium carbonate and / or potassium carbonate) in the strongly alkaline medium is 0 to 3.0 mol / L. For example, it can be 0 mol / L (i.e., without sodium carbonate and / or potassium carbonate), 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1.1 mol / L, 1.3 mol / L, 1.5 mol / L, 1.7 mol / L, 1.9 mol / L, 2.1 mol / L, 2.3 mol / L, 2.5 mol / L, 2.7 mol / L, or 3.0 mol / L, etc., preferably 0.1 to 1.0 mol / L, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0019] Preferably, in the strongly alkaline medium, the concentration of the calcium-fixing agent containing phosphate (such as sodium phosphate and / or potassium phosphate) is 0 to 1.0 mol / L. For example, it can be 0 mol / L (i.e., without sodium phosphate and / or potassium phosphate), 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, or 1.0 mol / L, etc., preferably 0.1 to 0.7 mol / L, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0020] As a preferred technical solution of the present invention, the temperature of the first dissolution is 20-100℃, such as 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 80℃, 85℃, 90℃, 95℃ or 100℃, preferably 35-95℃, but not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0021] It should be noted that the alkalinity of the system needs to be controlled during the first leaching process. The liquid-to-solid ratio and alkali concentration should be matched according to the aluminum content in the waste residue. Usually, when the aluminum leaching rate is high, the alkalinity in the solution exceeds the measurement range of the pH meter. Therefore, those skilled in the art need to make reasonable adjustments to the pH and / or alkalinity based on the leaching effect.

[0022] Preferably, the first dissolution time is 0.5 to 50 hours, for example, it can be 0.5 hours, 1 hour, 3 hours, 5 hours, 7 hours, 9 hours, 11 hours, 13 hours, 15 hours, 18 hours, 20 hours, 22 hours, 24 hours, 26 hours, 29 hours, 31 hours, 34 hours, 36 hours, 39 hours, 41 hours, 43 hours, 45 hours, 48 ​​hours or 50 hours, preferably 1 to 2 hours, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0023] Preferably, the first dissolution is carried out under stirring at a speed of 30 to 1500 r / min, for example, 30 r / min, 70 r / min, 100 r / min, 200 r / min, 300 r / min, 400 r / min, 500 r / min, 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, 1200 r / min, 1400 r / min, 1600 r / min, 1800 r / min or 2000 r / min, etc., preferably 200 to 500 r / min, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0024] As a preferred embodiment of the present invention, the weakly alkaline medium contains carbonate and / or bicarbonate ions;

[0025] Preferably, the weakly alkaline medium includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate, potassium carbonate, or potassium bicarbonate. Typical but non-limiting examples of such combinations include combinations of sodium carbonate and sodium bicarbonate, sodium carbonate and potassium carbonate, sodium carbonate and potassium bicarbonate, sodium bicarbonate and potassium carbonate, sodium bicarbonate and potassium bicarbonate, or potassium carbonate and potassium bicarbonate.

[0026] Preferably, the concentration of the weakly alkaline medium is 0.1–3 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.6 mol / L, 2.8 mol / L, or 3.0 mol / L, preferably 1–2 mol / L, but not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0027] As a preferred technical solution of the present invention, a complexing agent is added while the obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium.

[0028] Preferably, the complexing agent comprises sodium citrate and / or potassium citrate.

[0029] It should be noted that when using a complexing agent, the pH of the system obtained from the second leaching should be maintained at 7-13 before leaching, preferably 9-13.

[0030] Preferably, the amount of complexing agent added is 10% to 56% of the mass of the uranium-rich rare earth slag, for example, it can be 10%, 13%, 16%, 19%, 22%, 25%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, or 56%, etc., preferably 28% to 56%, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0031] As a preferred embodiment of the present invention, the second dissolution temperature is 25-250°C, for example, it can be 25°C, 35°C, 45°C, 55°C, 65°C, 75°C, 85°C, 95°C, 105°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C or 250°C, preferably 45-200°C, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0032] Preferably, the second dissolution time is 0.2 to 50 hours, for example, it can be 0.2 hours, 0.5 hours, 1 hour, 3 hours, 6 hours, 9 hours, 12 hours, 15 hours, 18 hours, 21 hours, 24 hours, 27 hours, 30 hours, 32 hours, 34 hours, 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours or 50 hours, preferably 0.5 to 7 hours, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0033] Preferably, the second dissolution is carried out under stirring at a speed of 100 to 450 r / min, for example, 100 r / min, 130 r / min, 160 r / min, 190 r / min, 210 r / min, 240 r / min, 270 r / min, 300 r / min, 330 r / min, 360 r / min, 390 r / min, 420 r / min or 450 r / min, etc., preferably 320 to 380 r / min, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0034] As a preferred embodiment of the present invention, ionic rare earth waste residue is mixed with a strongly alkaline medium to obtain a first leaching system. The liquid-to-solid ratio of the first leaching system is (1-100) mL:1g, for example, it can be 1mL:1g, 2mL:1g, 3mL:1g, 4mL:1g, 5mL:1g, 6mL:1g, 7mL:1g, 8mL:1g, 9mL:1g, 10mL:1g, 15mL:1g, 20mL:1g, 25mL:1g. 30mL:1g, 35mL:1g, 40mL:1g, 45mL:1g, 50mL:1g, 55mL:1g, 60mL:1g, 65mL:1g, 70mL:1g, 75mL:1g, 80mL:1g, 85mL:1g, 90mL:1g, 95mL:1g, or 100mL:1g, etc., preferably (4 to 20)mL:1g, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0035] Preferably, the obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium to obtain a second leaching system. The liquid-to-solid ratio of the second leaching system is (1-100) mL:1g, for example, it can be 1mL:1g, 2mL:1g, 3mL:1g, 4mL:1g, 5mL:1g, 6mL:1g, 7mL:1g, 8mL:1g, 9mL:1g, 10mL:1g, 15mL:1g, 20mL:1g, 25mL:1g, 30mL:1g, etc. 1g, 35mL:1g, 40mL:1g, 45mL:1g, 50mL:1g, 55mL:1g, 60mL:1g, 65mL:1g, 70mL:1g, 75mL:1g, 80mL:1g, 85mL:1g, 90mL:1g, 95mL:1g, or 100mL:1g, etc., preferably (2 to 20)mL:1g, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0036] Preferably, before the second dissolution, the pH value of the second dissolution system is controlled to be 7 to 13, for example, it can be 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5 or 13, preferably 8 to 13, but not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0037] It should be noted that the pH adjustment step before the second leaching can be performed after the addition of the complexing agent, or the pH can be adjusted first, and then the complexing agent can be added. The second pH adjustment can be performed based on the actual pH at this time, as long as the pH of the solution system before and after the second leaching is controlled between 7 and 13, so as to ensure that both uranium and aluminum have high leaching rates.

[0038] As a preferred technical solution of the present invention, the method includes the following steps:

[0039] (1) Ionic rare earth waste residue is mixed with a strong alkaline medium to obtain a first leaching system; the strong alkaline medium includes a main strong base or a main strong base and a calcium-fixing agent, the main strong base includes sodium hydroxide and / or potassium hydroxide, and the calcium-fixing agent includes an aqueous solution of at least one of sodium carbonate, sodium phosphate, potassium carbonate or potassium phosphate; wherein, in the first leaching system, the concentration of the main strong base is 1-500 g / L, the concentration of the calcium-fixing agent containing carbonate is 0-3 mol / L, the concentration of the calcium-fixing agent containing phosphate is 0-1 mol / L, and the liquid-solid ratio of the mixed system is (1-100) mL:1 g. Then, under stirring at 30-1500 r / min, the temperature is raised to 20-100℃ for the first leaching for 0.5-50 h. After solid-liquid separation, an aluminum-containing solution and uranium-rich rare earth residue are obtained.

[0040] (2) The obtained uranium-rich rare earth slag is mixed with a weak alkaline medium and a complexing agent sodium citrate and / or potassium citrate to obtain a second leaching system; the weak alkaline medium includes an aqueous solution of at least one of sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate; in the second leaching system, the concentration of the weak alkaline medium is 0.1 to 3 mol / L, the amount of complexing agent added is 10% to 56% of the mass of the uranium-rich rare earth slag, the liquid-solid ratio of the second leaching system is controlled to be (1 to 100) mL:1g, the pH value of the second leaching system is adjusted to 7 to 13, and then the second leaching is carried out at 25 to 250°C for 0.2 to 50 hours under stirring at 100 to 450 r / min. After solid-liquid separation, an aluminum-containing solution and uranium-rich rare earth slag are obtained.

[0041] (3) The obtained rare earth-rich slag is sent to the hydrochloric acid dissolution process production line to recover rare earth elements.

[0042] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0043] This invention addresses the problems of long-term stockpiling of ionic rare earth low-level radioactive materials, environmental pollution, and the waste of valuable rare earth elements and associated aluminum and uranium resources. It involves first leaching aluminum in a strongly alkaline medium to obtain a weakly alkaline uranium-rare earth-rich slag, then extracting uranium from this slag using a weakly alkaline medium containing carbonate and / or bicarbonate ions. The resulting rare earth-rich slag can be used for rare earth recovery through other mature and integrated processes, thus effectively separating and extracting aluminum, uranium, and rare earth elements. This invention achieves efficient extraction of aluminum and uranium components through stepwise extraction in different alkaline media, reducing low-level radioactive material emissions. The slag is enriched with rare earth elements at industrial processing levels. The leaching medium can be recycled after treatment, aligning with green metallurgy principles and reducing costs. The equipment used is relatively conventional, the operation is simple and easy, and it has strong practicality.

[0044] The ionic rare earth low-level radioactive materials treated by this invention can achieve a weight reduction of up to 86%, an aluminum leaching rate of up to 99%, a uranium leaching rate of up to 98%, and a rare earth enrichment factor of up to 4.0. Attached Figure Description

[0045] Figure 1 This is a schematic flowchart of the method for extracting aluminum, uranium and rare earth elements from ionic rare earth waste provided in Example 1. Detailed Implementation

[0046] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0047] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0048] The following examples and comparative examples all used the same batch of ionic rare earth waste residue, i.e., ionic rare earth low-level radioactive materials, whose main chemical components (mass percentage) are as follows: Al2O3: 42.11%, CaSO4: 44.61%, SiO2: 1.40%, Fe2O3: 0.65%, MgO: 0.03%, MnO: 0.86%, Cl: 7.19%. Further ICP analysis revealed the main elemental contents in the ionic rare earth low-level radioactive materials to be Al 18.4%, Ca 9.33%, REO (rare earth oxides) 0.9%, U 220 mg / kg, and uranium mononucleoside radioactivity specific activity ~5.6 Bq / g.

[0049] Example 1

[0050] This embodiment provides a method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue, such as... Figure 1 As shown, the method includes the following steps:

[0051] (1) Pour 80 g / L sodium hydroxide solution into a polytetrafluoroethylene three-necked flask, heat to the reaction temperature of 95°C, slowly add ionic rare earth low-level radioactive material, control the liquid-solid ratio of 8 mL: 1 g, the rotation speed of 250 r / min, the first dissolution reaction time of 60 min, and after solid-liquid separation, aluminum-containing solution and uranium-rich rare earth slag are obtained.

[0052] (2) The above-mentioned uranium-rich rare earth slag was slurryed and the pH was adjusted to 13 with (200g / L NaOH and 6mol / L HCl). The liquid-solid ratio was controlled to be 10mL:1g. Sodium citrate was added as a complexing agent, and the amount added was 28% of the weight of the uranium-rich rare earth slag. Sodium carbonate was added to reach 1.5mol / L. The temperature was set to 200℃ and the stirring speed was set to 350r / min. After reaching the temperature, the second dissolution reaction was carried out for 420min. After solid-liquid separation, uranium-containing solution and rare earth-rich slag were obtained.

[0053] In this embodiment, the method further includes using the obtained soluble aluminate solution to prepare the high-value product macroporous pseudoboehmite γ-(AlOOH); further processing the uranium-containing solution to obtain uranium products; and feeding the rare earth-rich slag into a hydrochloric acid preferential dissolution production line to recover rare earth elements and obtain rare earth products.

[0054] Further analysis using ICP revealed that the rare earth-rich slag obtained in this embodiment contained the following components by mass: Al 3.79%, REO 3.60%, U 76 mg / kg, and uranium mononucleoside radioactivity ~2 Bq / g.

[0055] Example 2

[0056] The difference from Example 1 is that the concentration of sodium hydroxide solution in step (1) is adjusted from 80 g / L to 100 g / L. Otherwise, the conditions are exactly the same as in Example 1.

[0057] Example 3

[0058] The difference from Example 1 is that the concentration of sodium hydroxide solution in step (1) is adjusted from 50 g / L to 100 g / L. Otherwise, the other conditions are exactly the same as in Example 1.

[0059] Example 4

[0060] The difference from Example 1 is that in step (1), the liquid-solid ratio is adjusted from 8 mL:1 g to 20 mL:1 g. Otherwise, the other conditions are exactly the same as in Example 1.

[0061] Example 5

[0062] The difference from Example 1 is that the liquid-solid ratio in step (1) is adjusted from 8 mL:1 g to 4 mL:1 g. Otherwise, the other conditions are exactly the same as in Example 1.

[0063] Example 6

[0064] The difference from Example 1 is that the temperature of the first dissolution in step (1) is adjusted from 95°C to 35°C. Otherwise, the other conditions are exactly the same as in Example 1.

[0065] Example 7

[0066] The difference from Example 1 is that the first dissolution time in step (1) is adjusted from 60 min to 30 min. Otherwise, the conditions are exactly the same as in Example 1.

[0067] Example 8

[0068] The difference from Example 1 is that in step (1), a mixed solution of 80 g / L sodium hydroxide and 0.1 mol / L sodium carbonate is used instead of 80 g / L sodium hydroxide solution. Otherwise, the conditions are exactly the same as in Example 1.

[0069] Example 9

[0070] The difference from Example 1 is that in step (1), a mixed solution of 80 g / L sodium hydroxide and 1 mol / L sodium carbonate is used instead of 80 g / L sodium hydroxide solution. Otherwise, the conditions are exactly the same as in Example 1.

[0071] Example 10

[0072] The difference from Example 1 is that in step (1), a mixed solution of 80 g / L sodium hydroxide and 0.1 mol / L sodium phosphate is used instead of 80 g / L sodium hydroxide solution. Otherwise, the other conditions are exactly the same as in Example 1.

[0073] Example 11

[0074] The difference from Example 1 is that in step (1), a mixed solution of 80 g / L sodium hydroxide and 0.7 mol / L sodium phosphate is used instead of 80 g / L sodium hydroxide solution. Otherwise, the other conditions are exactly the same as in Example 1.

[0075] Example 12

[0076] The difference from Example 1 is that the temperature of the second dissolution in step (2) is adjusted from 200°C to 150°C. Otherwise, the other conditions are exactly the same as in Example 1.

[0077] Example 13

[0078] The difference from Example 1 is that the temperature of the second dissolution in step (2) is adjusted from 200°C to 120°C. Otherwise, the other conditions are exactly the same as in Example 1.

[0079] Example 14

[0080] The difference from Example 1 is that the temperature of the second dissolution in step (2) is adjusted from 200°C to 90°C. Otherwise, the conditions are exactly the same as in Example 1.

[0081] Example 15

[0082] The difference from Example 1 is that the temperature of the second dissolution in step (2) is adjusted from 200°C to 25°C. Otherwise, the conditions are exactly the same as in Example 1.

[0083] Example 16

[0084] The difference from Example 1 is that in step (2), the amount of sodium carbonate added is adjusted from 1.5 mol / L to 3.0 mol / L. Otherwise, the other conditions are exactly the same as in Example 1.

[0085] Example 17

[0086] The difference from Example 1 is that in step (2), the amount of sodium carbonate added is adjusted from 1.5 mol / L to 0.1 mol / L. Otherwise, the other conditions are exactly the same as in Example 1.

[0087] Example 18

[0088] The difference from Example 1 is that the complexing agent sodium citrate is not added in step (2). Otherwise, the conditions are exactly the same as in Example 1.

[0089] Example 19

[0090] The difference from Example 1 is that in step (2), the amount of sodium citrate added as a complexing agent is adjusted from 28% to 56% of the weight of the rare earth-uranium enrichment slag. Otherwise, the other conditions are exactly the same as in Example 1.

[0091] Example 20

[0092] The difference from Example 1 is that the second dissolution time in step (2) is adjusted from 420 min to 180 min. Otherwise, the other conditions are exactly the same as in Example 1.

[0093] Example 21

[0094] The difference from Example 1 is that the second dissolution time in step (2) is adjusted from 30 min to 180 min. Otherwise, the other conditions are exactly the same as in Example 1.

[0095] Example 22

[0096] The difference from Example 1 is that in step (2), the liquid-solid ratio is adjusted from 10mL:1g to 50mL:1g. Otherwise, the other conditions are exactly the same as in Example 1.

[0097] Example 23

[0098] The difference from Example 1 is that in step (2), the liquid-solid ratio is adjusted from 10mL:1g to 20mL:1g. Otherwise, the other conditions are exactly the same as in Example 1.

[0099] Example 24

[0100] The difference from Example 1 is that in step (2), the liquid-solid ratio is adjusted from 10mL:1g to 4mL:1g. Otherwise, the other conditions are exactly the same as in Example 1.

[0101] Example 25

[0102] The difference from Example 1 is that the pH is adjusted from 13 to 14 in step (2). Otherwise, the conditions are exactly the same as in Example 1.

[0103] Example 26

[0104] The difference from Example 1 is that in step (2), the pH is adjusted from 13 to 10. Otherwise, the conditions are exactly the same as in Example 1.

[0105] Example 27

[0106] The difference from Example 1 is that in step (2), the pH is adjusted from 13 to 8. Otherwise, the conditions are exactly the same as in Example 1.

[0107] Example 28

[0108] The difference from Example 1 is that in step (2), sodium carbonate and sodium bicarbonate are used instead of pure sodium carbonate, while the total amount added remains unchanged at 1.5 mol / L, of which sodium carbonate is 0.75 mol / L and sodium bicarbonate is 0.75 mol / L. Apart from this, the other conditions are exactly the same as in Example 1.

[0109] Example 29

[0110] The difference from Example 1 is that in step (2), potassium carbonate and potassium bicarbonate are used instead of sodium antimonate, while the total amount added remains unchanged at 1.5 mol / L, of which potassium carbonate is 0.75 mol / L and potassium bicarbonate is 0.75 mol / L. Apart from this, the other conditions are exactly the same as in Example 1.

[0111] Example 30

[0112] The difference from Example 1 is that in step (2), sodium carbonate and sodium bicarbonate are used instead of pure sodium carbonate, while the total amount added remains unchanged at 1.5 mol / L, of which sodium carbonate is 0.5 mol / L and sodium bicarbonate is 1 mol / L. Apart from this, the other conditions are exactly the same as in Example 1.

[0113] Example 31

[0114] The difference from Example 1 is that in step (2), sodium bicarbonate is used instead of pure sodium carbonate, and the total amount added is kept constant at 1.5 mol / L, that is, the amount of sodium bicarbonate added is 1.5 mol / L. Apart from this, the other conditions are exactly the same as in Example 1.

[0115] Example 32

[0116] The difference from Example 1 is that in step (1), an 80 g / L sodium carbonate solution is used instead of an 80 g / L sodium hydroxide solution. Otherwise, the conditions are exactly the same as in Example 1.

[0117] Example 33

[0118] The difference from Example 1 is that in step (1), an 80 g / L sodium phosphate solution is used instead of an 80 g / L sodium hydroxide solution. Otherwise, the conditions are exactly the same as in Example 1.

[0119] Example 34

[0120] The difference from Example 1 is that in step (2), ammonium carbonate is used instead of pure sodium carbonate, while maintaining the total added amount at 1.5 mol / L.

[0121] Comparative Example 1

[0122] The difference from Example 1 is that in step (1), ammonia water is used instead of pure sodium hydroxide, while the total amount added remains unchanged at 80 g / L. Otherwise, the conditions are exactly the same as in Example 1.

[0123] The weight loss rate, leaching rate of valuable components aluminum and uranium, and rare earth enrichment factor of the ionic rare earth low-level radioactive materials in the above examples and comparative examples were determined and calculated by the following methods:

[0124] The contents of valuable components aluminum, uranium, and rare earth elements in the solid slag were tested according to standards JY / T 0567-2020 and JY / T0568-2020. The testing equipment mainly consisted of ICP-OES and ICPMS. The leaching rate of valuable components was calculated using the following formula: Leaching rate (%) = (1-m 前 W 前 / m 后 W 后 )*100%; where m 前 m 后 W represents the weight of the residue before and after leaching. 前 and W 后 These represent the content of valuable components in the residue before and after leaching.

[0125] The results are listed in Table 1.

[0126] Table 1

[0127]

[0128]

[0129] The results from the above embodiments and comparative examples show that:

[0130] As can be seen from the comparison between Example 1 and Examples 2-3, increasing the sodium hydroxide concentration in the first treatment can improve the aluminum uranium leaching rate, the low slag discharge weight reduction rate, and the rare earth enrichment rate.

[0131] As can be seen from the comparison between Examples 1 and Examples 4-5, increasing the liquid-solid ratio in the first treatment can improve the aluminum-uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0132] A comparison of Examples 1 and 6 shows that increasing the temperature in the first treatment can improve the aluminum leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate, while the uranium leaching rate decreases slightly. This may be because as the temperature increases, uranium in the strong alkaline solution is more likely to precipitate out.

[0133] A comparison of Examples 1 and 7 shows that increasing the time in the first treatment can improve the aluminum-uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0134] As can be seen from the comparison between Examples 1 and Examples 8-9, the addition of sodium carbonate in the first treatment can improve the aluminum uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0135] A comparison of Examples 1 and 10-11 shows that adding sodium phosphate in the first treatment can improve the aluminum leaching rate, the slag discharge weight reduction rate, and the rare earth enrichment rate, but the uranium leaching rate does not change much.

[0136] A comparison of Examples 1 and 12-15 shows that increasing the reaction temperature in the second treatment can improve the aluminum-uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0137] A comparison of Examples 1 and 16-17 shows that increasing the amount of sodium carbonate added in the second treatment can improve the aluminum uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0138] A comparison of Examples 1 and 18-19 shows that adding an appropriate amount of complexing agent sodium citrate to the second treatment can improve the aluminum uranium leaching rate, the low slag discharge weight reduction rate, and the rare earth enrichment rate.

[0139] A comparison of Examples 1 and 20-21 shows that extending the reaction time in the second treatment can improve the aluminum-uranium leaching rate, reduce the slag weight loss rate, and increase the rare earth enrichment rate.

[0140] A comparison of Examples 1 and Examples 22-24 shows that increasing the liquid-solid ratio in the second treatment can improve the aluminum-uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate.

[0141] A comparison of Examples 21 and 25-27 shows that increasing the pH value in the second treatment can improve the aluminum uranium leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate; however, the uranium leaching rate decreases, especially when the pH value in the second treatment is greater than 13, the uranium leaching rate decreases significantly. The reason for this is that the high alkalinity of the leaching medium promotes the precipitation of a small amount of diuranate from uranyl carbonate complex anions, resulting in a decrease in the uranium leaching rate.

[0142] A comparison of Examples 1 and Examples 28-31 shows that when the type of carbonate is changed in the weakly alkaline medium in the second treatment, the uranium leaching rate increases slightly, but the aluminum leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate decrease slightly.

[0143] A comparison of Examples 1 and 32 shows that when no strong alkaline leaching conditions were provided in the first treatment, and only the calcium-fixing agent sodium carbonate was added, the aluminum leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate decreased significantly, while the uranium leaching rate increased slightly. The reason for this is that the system did not provide sufficient alkalinity, resulting in a low aluminum leaching rate, which led to less slag weight reduction and a low rare earth enrichment rate. The strong complexing effect between carbonates and uranium promoted the increase in uranium leaching rate.

[0144] A comparison of Examples 1 and 33 shows that when the system does not provide strong alkaline leaching conditions in the first treatment and only adds sodium phosphate as a calcium-fixing agent, the aluminum leaching rate, the low slag weight reduction rate, and the rare earth enrichment rate decrease significantly, while the uranium leaching rate decreases slightly.

[0145] A comparison of Examples 1 and 34 shows that when the type of carbonate is changed in the weakly alkaline medium in the second treatment, the changes in aluminum uranium leaching rate, low slag weight loss rate and rare earth enrichment rate are not significant, but the presence of high temperature and alkaline volatile odor of ammonium carbonate is unfavorable to the operating environment.

[0146] As can be seen from the comparison between Example 1 and Comparative Example 1, when the first treatment is only weakly alkaline, the aluminum leaching rate, the low slag weight reduction rate and the rare earth enrichment rate decrease significantly, while the uranium leaching rate decreases slightly.

[0147] The technical solution provided by this invention achieves efficient recovery of valuable resources such as aluminum and uranium by using a stepwise unconventional leaching medium to enhance the leaching of aluminum and uranium from ionic rare earth low-level radioactive materials. Simultaneously, it achieves enrichment of rare earth elements and reduction of low-level radioactive materials, significantly reducing radiation hazards. This provides assistance for the treatment of ionic rare earth low-level radioactive materials in my country and alleviates the supply shortage pressure of valuable uranium resources. The leaching medium can be recycled after post-treatment, which conforms to the concept of green metallurgy and reduces costs. The equipment used is relatively conventional, the operation is simple and easy, and the application range is wide, making it highly practical.

[0148] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0149] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0150] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0151] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue, characterized in that, The method includes the following steps: Ionic rare earth waste residue is mixed with a strongly alkaline medium for the first leaching to obtain an aluminum-containing solution and uranium-rich rare earth residue. The obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium containing carbonate and / or bicarbonate ions, and a second leaching is performed to obtain a uranium-containing solution and rare earth-rich slag. The strongly alkaline medium also includes a calcium-fixing agent; The calcium-fixing agent includes any one or a combination of at least two of sodium carbonate, sodium phosphate, potassium carbonate, or potassium phosphate. The weakly alkaline medium includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate, potassium carbonate, or potassium bicarbonate.

2. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The method also includes: treating rare earth-rich slag with hydrochloric acid to recover rare earth elements.

3. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The strongly alkaline medium includes a primary strong base, which includes sodium hydroxide and / or potassium hydroxide.

4. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The concentration of the primary strong base in the strongly alkaline medium is 1~500 g / L.

5. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, The concentration of the primary strong base in the strongly alkaline medium is 50~100g / L.

6. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, In the strongly alkaline medium, the concentration of the calcium-fixing agent containing carbonate ions is 0~3.0 mol / L.

7. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, In the strongly alkaline medium, the concentration of the calcium-fixing agent containing carbonate ions is 0.1~1.0 mol / L.

8. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, In the strongly alkaline medium, the concentration of the calcium-fixing agent containing phosphate is 0~1.0 mol / L.

9. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, In the strongly alkaline medium, the concentration of the calcium-fixing agent containing phosphate is 0.1~0.7 mol / L.

10. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The temperature of the first dissolution is 20~100℃.

11. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The temperature of the first dissolution is 35~95℃.

12. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The first dissolution time is 0.5~50h.

13. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The first dissolution time is 1~2 hours.

14. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The first dissolution was carried out under stirring at a speed of 30~1500 r / min.

15. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The first dissolution was carried out with stirring at a speed of 200~500 r / min.

16. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The concentration of the weakly alkaline medium used in the second dissolution process is 0.1~3 mol / L.

17. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The concentration of the weakly alkaline medium used in the second dissolution process is 1~2 mol / L.

18. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, During the second leaching process, while mixing the obtained uranium-rich rare earth slag with a weakly alkaline medium, a complexing agent is added for further mixing.

19. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 18, characterized in that, The complexing agent used in the second dissolution includes sodium citrate and / or potassium citrate.

20. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 18, characterized in that, The amount of complexing agent added during the second leaching process is 10% to 56% of the mass of the uranium-rich rare earth slag.

21. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 18, characterized in that, The amount of complexing agent added during the second leaching process is 28% to 56% of the mass of the uranium-rich rare earth slag.

22. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The second dissolution temperature is 25~250℃.

23. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, The second dissolution temperature is 45~200℃.

24. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, The second dissolution time is 0.2~50h.

25. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, The second dissolution time is 0.5~7h.

26. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The second dissolution was carried out with stirring at a speed of 100~450 r / min.

27. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The second dissolution was carried out with stirring at a speed of 320~380 r / min.

28. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, Ionic rare earth waste residue is mixed with a strongly alkaline medium to obtain a first leaching system, wherein the liquid-to-solid ratio of the first leaching system is (1~100) mL:1g.

29. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, Ionic rare earth waste residue is mixed with a strongly alkaline medium to obtain a first leaching system, wherein the liquid-to-solid ratio of the first leaching system is (4~20) mL:1g.

30. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium to obtain a second leaching system, the liquid-to-solid ratio of which is (1~100) mL:1g.

31. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, The obtained uranium-rich rare earth slag is mixed with a weakly alkaline medium to obtain a second leaching system, the liquid-to-solid ratio of which is (2~20) mL:1g.

32. The method for extracting associated aluminum and uranium resources from ion-adsorption rare earth waste residue according to claim 1, characterized in that, In the second dissolution, the pH value of the second dissolution system is controlled to be 7~13.

33. The method for extracting associated aluminum and uranium resources from ion-type rare earth waste residue according to claim 1, characterized in that, In the second dissolution, the pH value of the second dissolution system is controlled to be 8-13.

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