A process for the in-situ leaching mining of a uranium-rhenium-scandium triad

Abstract

The present application belongs to the field of hydrometallurgy, and discloses a treatment method for uranium-rhenium-scandium trinity in-situ leaching mining, wherein a leaching reagent is injected into a mineral layer through a liquid injection well, and then the leaching reagent containing uranium, rhenium and scandium is pumped out through a liquid pumping well, filtered, and subjected to column adsorption; then the obtained uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin are respectively eluted by using a corresponding eluent; the eluted liquid after column adsorption is collected, the uranium-containing eluted liquid is acidified, precipitated by adding alkali, and subjected to pressure filtration to obtain a uranium product; the rhenium-containing eluted liquid is subjected to a rhenium removal capturing agent, an equal volume of ammonia water is added, stirred and contacted, and then allowed to stand to separate into layers, the water phase is collected, evaporated and concentrated, and allowed to stand to crystallize to obtain an ammonium rhenate product; and the scandium-containing eluted liquid is added with oxalic acid, subjected to precipitation and calcination to obtain a scandium oxide product. The treatment method has the advantages of simple operation, easy large-scale production, high leaching efficiency, and good industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgy, and particularly relates to a method for in-situ leaching mining of uranium, rhenium, and scandium. Background Technology

[0002] Uranium is generally considered a rare metal. Although it is abundant in the Earth's crust, far more so than mercury, bismuth, and silver, its discovery was delayed considerably compared to elements like mercury due to the difficulty of extraction. As the last naturally occurring radioactive element in the periodic table, metallic uranium plays a vital role in our world. For example, the heat released during its radioactive decay, along with its neighbor thorium, provides a significant amount of energy to the Earth's core and continuously or unpredictably alters the thinner layers of the Earth's crust.

[0003] Scandium and its compounds have a wide range of applications due to their unique properties. Metallic scandium has a high melting point, low specific gravity, and is strong, making it suitable as a structural material for aerospace, rockets, and aircraft. In electronics, replacing some of the iron oxide in ferrite with scandium oxide can improve coercivity, thereby enhancing the performance of computer memory components. Scandium can also be used as an activator for oxide cathodes in electron cathode tubes, significantly increasing thermionic emission and extending the cathode life. In the metallurgical industry, scandium is commonly used as an additive in alloys to improve their strength, hardness, and heat resistance.

[0004] Rhenium is a rare element with an abundance of only 1 × 10⁻⁶ in the Earth's crust. -9 Rhenium, with its unique and excellent physicochemical properties such as high melting point, high boiling point, high density, excellent ductility, formability, and catalytic activity, has enormous application prospects in petrochemical, aerospace, metallurgy, and defense fields, leading to a supply shortage in the market. The difficulty in rhenium extraction and separation, coupled with the rarefied nature of rhenium and its alloys, has driven up its price, attracting significant attention. Therefore, research on rhenium extraction and separation has become a top priority in rhenium research.

[0005] Currently, the main processes for extracting and recovering uranium, rhenium, and scandium involve leaching and extraction. Leaching methods primarily include hydrochloric acid leaching and sulfuric acid leaching, while extraction methods mainly include solvent extraction, precipitation, ion exchange, and liquid membrane extraction. The use of hydrochloric acid or sulfuric acid leaching often leads to significant environmental problems, and conventional extraction methods also have various drawbacks. Therefore, developing a comprehensive in-situ leaching method for the extraction of uranium, rhenium, and scandium is of paramount importance. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention focuses on the exploration of leaching reagents for uranium-rhenium-scandium ore. Ordinary leaching agents are difficult to use for leaching low-grade uranium-rhenium-scandium ore. While hydrochloric acid and sulfuric acid have leaching effects, the leaching rates are low, and leaching with hydrochloric acid or sulfuric acid brings significant environmental problems. This invention aims to provide a three-in-situ leaching method for the mining of uranium-rhenium-scandium ore.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for in-situ leaching mining of uranium, rhenium, and scandium includes the following steps:

[0009] (1) Leaching: The leaching reagent is injected into the ore layer through the injection well, and then the leaching reagent containing uranium, rhenium and scandium is extracted through the pumping well;

[0010] (2) Pretreatment: The leaching reagent containing uranium, rhenium and scandium in step (1) is filtered;

[0011] (3) Adsorption: Using uranium-oriented adsorption resin as adsorbent, the leaching reagent containing uranium, rhenium, and scandium filtered in step (2) is adsorbed through a packed column; and then adsorbed through rhenium-oriented adsorption resin and scandium-oriented adsorption resin respectively.

[0012] (4) Desorption: The uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin obtained in step (3) are then eluted with uranium desorbent, rhenium desorbent and scandium desorbent respectively. The desorption volume is 1-5 BV, and the eluent after passing through the column is collected.

[0013] (5) Obtaining products: Uranium-containing eluent is acidified, precipitated with alkali, and filtered under pressure to obtain uranium products; rhenium-containing eluent is treated with a rhenium removal agent, then an equal volume of ammonia is added, stirred and contacted, allowed to stand and separate into layers, the aqueous phase is collected, evaporated and concentrated, and allowed to stand and crystallize to obtain ammonium rheniumate products; scandium-containing eluent is treated with oxalic acid, precipitated and calcined to obtain scandium oxide products.

[0014] Furthermore, the leaching reagent in step (1) is a mixed solution of [R3NH][HSO4], (NH4)2SO4 and [R3NH][SCN], where R3N is any one of TOA, TiOA, and N235, and the concentration ranges of [R3NH][HSO4], (NH4)2SO4 and [R3NH][SCN] are 3-8%, 4-10%, and 2-6%, respectively. The amount used is 3-5 times the amount of uranium, rhenium and scandium contained in the sandstone scandium ore layer.

[0015] Furthermore, the uranium-directed adsorption resin mentioned in step (3) is one of D201 or D301.

[0016] Furthermore, the particle size of the scandium-directed adsorption resin described in step (3) is 0.4-0.9 mm.

[0017] Furthermore, the adsorption flow rate in step (3) is 3-5 BV / h.

[0018] Furthermore, the diameter-to-height ratio of the packing column described in step (3) is 1:5-10.

[0019] Furthermore, the rinsing flow rate in step (4) is 2-4 BV / h.

[0020] Furthermore, the operating temperature for both adsorption in step (3) and desorption in step (4) is 5-45℃.

[0021] Furthermore, the uranium desorbent in step (4) is a mixed solution of sodium chloride and sodium bicarbonate, with concentrations of 2-5% and 1-2% for sodium chloride and sodium bicarbonate, respectively.

[0022] The rhenium desorbent is any one or a mixture of two of ammonia and ammonium thiocyanate, with a concentration of 4-8%;

[0023] The scandium desorbent is hydrochloric acid or sulfuric acid, with a concentration of 3-10%, and the amount used is 3-8 times the scandium content of sandstone scandium ore layers.

[0024] Furthermore, the specific steps for obtaining the product described in step (5) are as follows:

[0025] The uranium-containing eluent is acidified with hydrochloric acid to a pH of 4.5-5.0 for 1-3 hours; sodium hydroxide is added for precipitation for 1 hour, and the precipitate is aged for 12-24 hours. The precipitate filtration pressure is 0.3-0.8 MPa.

[0026] Add an equal volume of ammonia water with a concentration of 3-9% to the rhenium-containing eluent, stir for 1-5 hours, let stand for 0.5-1 hour, evaporate and concentrate at 70-100℃, stop heating when a small amount of liquid remains, let the residual heat stand to crystallize, and dry to obtain ammonium perrylate product.

[0027] White scandium oxide powder can be obtained by adding oxalic acid at a concentration of 1.35 times the amount of scandium to the scandium leaching solution and calcining it at 750-900 degrees Celsius for 1-2 hours.

[0028] The advantages of this invention compared to the prior art are:

[0029] This invention addresses the exploration of leaching reagents for uranium-rhenium-scandium ore. Ordinary leaching agents are difficult to use for low-grade uranium-rhenium-scandium ore. While hydrochloric acid and sulfuric acid have leaching effects, the leaching rates are low, and leaching with hydrochloric acid or sulfuric acid causes significant environmental problems. This invention provides a three-in-situ leaching method for uranium-rhenium-scandium ore. This method has the advantages of simple operation, ease of large-scale production, and high leaching efficiency, and has significant industrial application value. Detailed Implementation

[0030] The following specific embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Any modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and substance of the present invention should be covered within the scope of the claims of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0031] Example 1: Preparation of rhenium-oriented adsorption resin

[0032] The rhenium-directed adsorption resin described in this embodiment is a graphene resin, prepared through the following steps:

[0033] 1. Preparation of carboxylated graphene: 2 parts of graphene oxide were dispersed in water to form a transparent colloidal solution, and then 150 parts of NaOH were added. After dissolution, 20 parts of bromoacetic acid were added, and the mixture was stirred and refluxed at 60°C for 9 hours. After the reaction was completed, the pH was adjusted to 2.8 with HCl, filtered, and the product was washed with deionized water until neutral to obtain carboxylated graphene.

[0034] 2. Preparation of graphene resin: 80 parts of D201 anion exchange resin and 4 parts of carboxylated graphene were added to a reaction vessel, and then a catalyst was added. The reaction was carried out at 70°C for 8 hours, then cooled to room temperature and washed three times with water to obtain graphene resin.

[0035] Example 2: Preparation of Scandium Directional Adsorption Resin

[0036] At room temperature, 12 parts of 1-methylimidazole and 15 parts of bromobutane were refluxed under sealed conditions for 24 hours. After the reaction was completed, 12 parts of ammonium perrylate solution were added, and the mixture was refluxed for 2 hours. The mixture was washed three times with deionized water. The washed product was then rotary evaporated under vacuum for 3 hours to obtain a rhenium ionic liquid. Then, 25 parts of the rhenium ionic liquid and 10 parts of secondary carbon amine N1923 were added to a three-necked flask as the active component. The temperature was raised to 70°C, and 15 parts of styrene and 0.1 parts of benzoyl peroxide were added as chain initiators. The ultrasonic device was turned on, and the mixture was suspended and copolymerized in the three-necked flask at 70°C. After the particle size of the suspended matter reached 15 nm, 6 parts of carboxymethyl chitosan were added for ultrasonic suspension copolymerization. 7 parts of dichloromethane were added to the beads obtained after the reaction to induce a swelling reaction. The temperature was raised to 90°C, and 10 parts of concentrated sulfuric acid were added dropwise. The mixture was then subjected to a sulfonation reaction under ultrasonication to obtain a scandium directional adsorption resin.

[0037] Example 3: Treatment method for in-situ leaching mining of uranium, rhenium, and scandium

[0038] (1) Leaching: 3% [N235H][HSO4], 5% [N235H][SCN] and 4% (NH4)2SO4 leaching reagents are injected into the ore layer through injection wells, and then the leaching reagents containing uranium, rhenium and scandium are extracted through pumping wells;

[0039] (2) Pretreatment: The solution containing uranium, rhenium and scandium is filtered;

[0040] (3) Adsorption: Then, using uranium-oriented adsorption resin as adsorbent, the solution containing uranium, rhenium and scandium is subjected to column adsorption. The diameter-to-height ratio of the packing column is 1:5, the operating temperature is 20℃, and the adsorption tail liquid is adsorbed by rhenium-oriented resin and then passed through scandium-oriented adsorption resin.

[0041] (4) Desorption: The obtained uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin were then eluted with their respective desorbents. The uranium desorbent was a mixed solution of sodium chloride and sodium bicarbonate, with a concentration of 2% for both sodium chloride and sodium bicarbonate; the rhenium desorbent was ammonia solution with a concentration of 4%; and the scandium desorbent was hydrochloric acid with a concentration of 5%. The desorption volume was 4 BV, the operating temperature was 20°C, and the eluent after passing through the column was collected.

[0042] (5) Obtaining the product: The uranium-containing leaching solution is acidified with hydrochloric acid to pH 4.5 for 1 hour; sodium hydroxide is added to precipitate for 1 hour, the precipitate is aged for 12 hours, and the precipitate filtration pressure is 0.3 MPa;

[0043] Add an equal volume of 3% ammonia water to the rhenium-containing eluent, stir for 1 hour, let stand for 0.5 hours, evaporate and concentrate at 70°C, stop heating when a small amount of liquid remains, let stand to crystallize with residual heat, and dry to obtain ammonium perrylate product;

[0044] White scandium oxide powder can be obtained by adding oxalic acid with a scandium content of 1.35 times that of scandium to the eluent and calcining it at 750 degrees Celsius for 2 hours.

[0045] The overall recovery rates of uranium, rhenium, and scandium are all above 85%.

[0046] Example 4: Treatment method for in-situ leaching mining of uranium, rhenium, and scandium

[0047] (1) Leaching: 5% [TOAH][HSO4], 5% [TOAH][SCN] and 2% (NH4)2SO4 leaching reagents are injected into the ore layer through injection wells, and then the leaching reagents containing uranium, rhenium and scandium are extracted through pumping wells;

[0048] (2) Pretreatment: The solution containing uranium, rhenium and scandium is filtered;

[0049] (3) Adsorption: Then, using uranium-oriented adsorption resin as adsorbent, the solution containing uranium, rhenium and scandium is subjected to column adsorption process. The diameter-to-height ratio of the packing column is 1:6, the operating temperature is 20℃, the adsorption tail liquid is adsorbed by rhenium-oriented resin, and then passed through scandium-oriented adsorption resin.

[0050] (4) Desorption: The obtained uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin were then eluted with their respective desorbents. The uranium desorbent was a mixed solution of sodium chloride and sodium bicarbonate, with concentrations of 4% and 2% for sodium chloride and sodium bicarbonate, respectively; the rhenium desorbent was ammonium thiocyanate with a concentration of 4%; and the scandium desorbent was sulfuric acid with a concentration of 5%. The desorption volume was 4 BV, the operating temperature was 20°C, and the eluent after passing through the column was collected.

[0051] (5) Obtaining the product: The uranium-containing leaching solution is acidified with hydrochloric acid to pH 5.0 for 3 hours; sodium hydroxide is added to precipitate for 1 hour, the precipitate is aged for 24 hours, and the precipitate filtration pressure is 0.8 MPa;

[0052] Add an equal volume of 9% ammonia water to the rhenium-containing eluent, stir for 1 hour, let stand for 0.5 hours, evaporate and concentrate at 100°C, stop heating when a small amount of liquid remains, let stand to crystallize with residual heat, and dry to obtain ammonium perrylate product.

[0053] White scandium oxide powder can be obtained by adding oxalic acid with a scandium content of 1.35 times that of scandium to the eluent and calcining it at 900 degrees Celsius for 1 hour.

[0054] The overall recovery rates of uranium, rhenium, and scandium are all above 85%.

[0055] Example 5: Treatment method for in-situ leaching mining of uranium, rhenium, and scandium

[0056] (1) Leaching: The leaching reagents [TiOAH][HSO4], [TiOAH][SCN] and (NH4)2SO4 are injected into the ore layer through injection wells, and then the leaching reagents containing uranium, rhenium and scandium are extracted through pumping wells;

[0057] (2) Pretreatment: The solution containing uranium, rhenium and scandium is subjected to filtration process;

[0058] (3) Adsorption: Then, using uranium-oriented adsorption resin as adsorbent, the solution containing uranium, rhenium and scandium is subjected to column adsorption process. The diameter-to-height ratio of the packing column is 1:10, the operating temperature is 30℃, and the adsorption tail liquid is adsorbed by rhenium-oriented resin and then passed through scandium-oriented adsorption resin.

[0059] (4) Desorption: The obtained uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin were then eluted with their respective desorbents. The uranium desorbent was a mixed solution of sodium chloride and sodium bicarbonate, with concentrations of 5% and 1% respectively. The rhenium desorbent was a mixed solution of 4% ammonium thiocyanate and 5% ammonia. The scandium desorbent was 5% sulfuric acid. The desorption volume was 4 BV, the operating temperature was 20°C, and the eluent after passing through the column was collected.

[0060] (5) Obtaining the product: The uranium-containing leaching solution is acidified with hydrochloric acid to pH 4.8 for 2 hours; sodium hydroxide is added for precipitation for 1 hour, the precipitation is aged for 20 hours, and the precipitation filtration pressure is 0.5 MPa;

[0061] Add an equal volume of 5% ammonia water to the rhenium-containing eluent, stir for 3 hours, let stand for 0.5 hours, evaporate and concentrate at 80°C, stop heating when a small amount of liquid remains, let stand to crystallize with residual heat, and dry to obtain ammonium perrylate product;

[0062] White scandium oxide powder can be obtained by adding oxalic acid at a concentration of 1.35 times the amount of scandium to the scandium leaching solution and calcining it at 900 degrees Celsius for 1.5 hours.

[0063] The overall recovery rates of uranium, rhenium, and scandium are all above 85%.

[0064] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for in-situ leaching mining of uranium, rhenium, and scandium, characterized in that, Includes the following steps: (1) Leaching: The leaching reagent is injected into the ore layer through the injection well, and then the leaching reagent containing uranium, rhenium and scandium is extracted by the pumping well. The leaching reagent is a mixed solution of [R3NH][HSO4], (NH4)2SO4 and [R3NH][SCN], where R3N is any one of TOA, TiOA and N235. (2) Pretreatment: The leaching reagent containing uranium, rhenium and scandium in step (1) is filtered; (3) Adsorption: Using uranium-oriented adsorption resin as adsorbent, the leaching reagent containing uranium, rhenium, and scandium filtered in step (2) is adsorbed through a packed column; then it is adsorbed through rhenium-oriented adsorption resin and scandium-oriented adsorption resin respectively. (4) Desorption: The uranium-loaded saturated resin, rhenium-loaded saturated resin and scandium-loaded saturated resin obtained in step (3) are then eluted with uranium desorbent, rhenium desorbent and scandium desorbent respectively. The desorption volume is 1-5 BV. The eluent after passing through the column is collected. (5) Obtaining products: Uranium-containing eluent is acidified, precipitated with alkali, and filtered under pressure to obtain uranium products; rhenium-containing eluent is treated with a rhenium removal agent, then an equal volume of ammonia is added, stirred and contacted, allowed to stand and separate into layers, the aqueous phase is collected, evaporated and concentrated, and allowed to stand and crystallize to obtain ammonium rheniumate products; scandium-containing eluent is treated with oxalic acid, precipitated and calcined to obtain scandium oxide products.

2. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The concentration ranges of [R3NH][HSO4], (NH4)2SO4 and [R3NH][SCN] are 3-8%, 4-10% and 2-6%, respectively, and the dosage is 3-5 times that of uranium, rhenium and scandium in sandstone-type scandium deposits.

3. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The uranium-directed adsorption resin mentioned in step (3) is one of D201 and D301.

4. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The particle size of the scandium-directed adsorption resin in step (3) is 0.4-0.9 mm.

5. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The adsorption flow rate in step (3) is 3-5 BV / h.

6. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The diameter-to-height ratio of the packing column in step (3) is 1:5-10.

7. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The rinsing flow rate in step (4) is 2-4 BV / h.

8. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The operating temperature for both step (3) adsorption and step (4) desorption is 5-45 ℃.

9. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The uranium desorbent mentioned in step (4) is a mixed solution of sodium chloride and sodium bicarbonate, with concentrations of 2-5% and 1-2% for sodium chloride and sodium bicarbonate, respectively. The rhenium desorbent is any one or a mixture of two of ammonia and ammonium thiocyanate, with a concentration of 4-8%; The scandium desorbent is hydrochloric acid or sulfuric acid, with a concentration of 3-10%, and the amount used is 3-8 times the scandium content of sandstone scandium ore layers.

10. The method for in-situ leaching mining of uranium, rhenium, and scandium as described in claim 1, characterized in that, The specific steps for obtaining the product described in step (5) are as follows: The uranium-containing eluent is acidified with hydrochloric acid to a pH of 4.5-5.0 for 1-3 hours; sodium hydroxide is added for precipitation for 1 hour, and the precipitate is aged for 12-24 hours. The precipitate filtration pressure is 0.3-0.8 MPa. Add an equal volume of ammonia water with a concentration of 3-9% to the rhenium-containing eluent, stir for 1-5 hours, let stand for 0.5-1 hours, evaporate and concentrate at 70-100℃, stop heating when a small amount of liquid remains, let the residual heat stand to crystallize, and dry to obtain ammonium rheniumate product; White scandium oxide powder can be obtained by adding oxalic acid at a concentration of 1.35 times the amount of scandium to the scandium leaching solution and calcining it at 750-900 degrees Celsius for 1-2 hours.