Method for heap leaching extraction of uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter

Abstract

The invention discloses a method for heap leaching extraction of uranium and vanadium from organic matter-rich low-grade uranium-iron-vanadium polymetallic ore, and belongs to the technical field of hydrometallurgy. The method for heap leaching extraction of uranium and vanadium from the low-grade uranium-iron-vanadium polymetallic ore rich in organic matter comprises the steps that the low-grade uranium-iron-vanadium polymetallic ore is crushed, concentrated sulfuric acid is added for mixing, and an ore acid mixture is obtained; atomizing water, spraying the atomized water into the mineral acid mixture, and carrying out a pre-leaching reaction to obtain a primary treatment mixture; carrying out granulation treatment on the primary treatment mixture to obtain spherical ore grains; the spherical ore grains are subjected to film coating treatment and then subjected to constant-temperature curing, and a secondary treatment mixture is obtained; and heap building is conducted on the secondary treatment mixture, leaching treatment is conducted on the heap through a sulfuric acid solution, leaching liquid is collected, and uranium and vanadium in the leaching liquid are extracted and recycled. According to the method, all links are continuously connected, the technological process is shortened, the operation cost is reduced, and efficient leaching of uranium and vanadium in the low-grade uranium-iron-vanadium polymetallic ore is achieved.

Description

Technical Field

[0001] This application belongs to the field of hydrometallurgical technology, and in particular relates to a method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ores rich in organic matter through heap leaching. Background Technology

[0002] This low-grade polymetallic uranium-iron-vanadium ore, rich in organic matter, is a type of black shale and a unique sedimentary rock. It is rich in organic matter, clay minerals, and fine-grained sulfides (such as pyrite), and has a dark gray to black appearance with a relatively high specific gravity. It is typically enriched in multiple elements, including uranium, vanadium, molybdenum, nickel, cobalt, and platinum group elements, making it an important resource for uranium and vanadium extraction. The primary uranium minerals are mainly pitchblende and smaller quantities of uraninite, uranium crystalline minerals, and pitchblende-thorium. Secondary uranium minerals include uranium black and various types of uranium mica. Vanadium minerals are mainly silicate minerals such as vanadium-calcium uranium ore, vanadium-potassium uranium ore, and vanadium mica, or associated with limonite and pyrite. Due to the complex forms of uranium and vanadium in different ores, most uranium minerals are fine-grained and poorly liberated, often encapsulated by gangue minerals such as quartz and pyrite that are difficult to leach. Vanadium often exists in a homogeneous form within the mica lattice, requiring lattice disruption, making uranium and vanadium difficult to leach from the ore.

[0003] Research on the extraction of uranium, vanadium, or vanadium alone from black shale in my country began in the 1960s. The main methods included sodium roasting-water leaching, calcification roasting-acid or alkali leaching, and oxidative roasting-acid or alkali leaching. However, roasting processes suffer from severe environmental pollution, high energy consumption, and low uranium leaching rates due to the tendency of uranium-bearing minerals to sinter. With increasing environmental requirements, fully hydrometallurgical processes have gradually been developed. For example, the prior art disclosed in application publication number CN 112553463 A discloses a leaching method for uranium-vanadium ore from black shale, including: crushing and grinding the ore sample, mixing it evenly with water and sulfuric acid; adding water or dilute sulfuric acid to the matured material, controlling the liquid-to-solid volume-to-mass ratio, adding an iron inhibitor for neutralization, adjusting the pH to 1-3, and leaching at 80-100℃; vacuum filtering the leached slurry to obtain leachate and filter cake; and countercurrent washing of the filter cake with dilute sulfuric acid in 3-10 stages, with the first stage wash water incorporated into the leachate.

[0004] However, the existing hydrometallurgical process has the following problems: First, during the leaching process, inhibitors are added to neutralize and adjust the pH, and iron alum is formed in the leaching solution to remove iron while uranium and vanadium are lost; Second, the mineral itself has a high organic matter and clay content, and stirring during leaching accelerates the mudification of the slurry. In addition, the iron alum generated during the leaching process makes the solid-liquid separation performance of the leaching slurry worse, the filtration speed is slow, the filter cake cannot be directly washed on the tray, and an additional three-stage countercurrent washing is required. The processing steps are long, the concentration of qualified solution is reduced, which is not conducive to the subsequent recovery of uranium and vanadium. Summary of the Invention

[0005] This application discloses a method for extracting uranium and vanadium from organic-rich, low-grade uranium-iron-vanadium polymetallic ores by heap leaching, aiming to solve the technical problems of low leaching efficiency, complex processes, and high operating costs in existing hydrometallurgical processes.

[0006] To achieve the above objectives, the technical solution of this application is: The first aspect of this application provides a method for heap leaching uranium and vanadium from organic-rich, low-grade uranium-iron-vanadium polymetallic ore, the method comprising: Low-grade uranium-iron-vanadium polymetallic ore is crushed to a particle size of -15 mm to -4 mm. Concentrated sulfuric acid is added to the crushed ore particles and mixed to obtain a mineral-acid mixture. Water is atomized and sprayed into the mineral acid mixture for a pre-leaching reaction to obtain a primary treatment mixture. The primary processed mixture is granulated to obtain spherical mineral particles; The spherical mineral particles are coated and then solidified at a constant temperature to obtain a secondary processed mixture. The secondary treatment mixture is piled up, and the pile is leached with sulfuric acid solution. The leachate is collected, and uranium and vanadium in the leachate are extracted and recovered.

[0007] In conjunction with the first aspect, preferably, the low-grade uranium-iron-vanadium polymetallic ore is crushed to a particle size of -15 mm to -4 mm. When concentrated sulfuric acid is added to the crushed mineral particles and mixed, the mass ratio of concentrated sulfuric acid to mineral particles is 0.5~0.01:1; After mixing, the concentrated sulfuric acid and mineral particles are allowed to stand for 10-30 minutes.

[0008] In conjunction with the first aspect, preferably, the step of spraying atomized water into the mineral acid mixture for pre-leaching reaction involves using water at a rate of 3% to 20% of the mass of the mineral acid mixture.

[0009] Preferably, in conjunction with the first aspect, the diameter of the spherical mineral particles is 5 mm to 20 mm.

[0010] In conjunction with the first aspect, preferably, during the constant temperature curing process, the temperature is 50~200 ℃ and the curing time is 1 h~48 h.

[0011] Preferably, in conjunction with the first aspect, the secondary processed mixture is piled up to a height of 1.5 m to 5 m.

[0012] Preferably, in conjunction with the first aspect, when the sulfuric acid solution is used to leach the heap, the concentration of the sulfuric acid solution is 5 g / L to 10 g / L.

[0013] Preferably, in conjunction with the first aspect, when leaching the pile with sulfuric acid solution, a top-feed method is used, employing atomized spraying or drip irrigation, with a spray intensity of 10 L / min. m -2 h -1 ~100 L m -2 h -1 .

[0014] In conjunction with the first aspect, preferably, when the secondary treatment mixture is piled up and leached with sulfuric acid solution, the determination of the end of leaching includes: when the concentration of uranium and vanadium in the leaching solution is less than 50 mg / L, it can be determined as the leaching endpoint.

[0015] In conjunction with the first aspect, preferably, the secondary treatment mixture is piled up, and when the pile is leached with sulfuric acid solution, after the leaching is completed, the slag is sampled and analyzed, then neutralized with lime and transferred to the tailings silo.

[0016] Compared with the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: The heap leaching method provided in this application achieves efficient extraction of uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ores through a continuous processing flow of crushing-acid mixing-pre-leaching-granulation-solidification-heap building-leaching-unloading. First, crushing reduces ore particle size, increasing the contact area with acid. Acid mixing and pre-leaching activate uranium and vanadium minerals in the ore, allowing for initial dissolution of the target elements. Granulation, solidification, and heap building processes form high-strength particles with uniform pore structure, enabling uniform penetration of the leaching agent and ensuring sufficient contact between each ore layer and the leaching agent, further significantly improving the extraction efficiency of uranium and vanadium. Simultaneously, the continuous connection of each stage eliminates the need for intermediate transfers, greatly shortening the process flow, reducing construction and operating costs, and achieving efficient leaching of uranium and vanadium from organic-rich low-grade uranium-iron-vanadium polymetallic ores. Furthermore, compared with existing technologies, it eliminates the ore fine grinding and leaching slurry solid-liquid separation processes, adopts heap leaching technology, is suitable for processing low-grade uranium and vanadium resources, requires less equipment investment, has strong processing capacity, has significant economic benefits and practicality, and is more suitable for large-scale industrial production applications. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a process flow diagram of the method for extracting uranium and vanadium by heap leaching according to an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0021] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0023] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0024] It should be noted that all raw materials and / or reagents in the embodiments of this application were purchased on the market or prepared according to conventional methods known to those skilled in the art.

[0025] In a first aspect, embodiments of this application provide a method for extracting uranium and vanadium from organic-rich, low-grade uranium-iron-vanadium polymetallic ore by heap leaching, the method comprising: Low-grade uranium-iron-vanadium polymetallic ore is crushed, and concentrated sulfuric acid is added to the crushed ore particles to mix them, resulting in a mineral-acid mixture. Water is atomized and sprayed into the mineral acid mixture for a pre-leaching reaction to obtain a primary treatment mixture. The primary processed mixture is granulated to obtain spherical mineral particles; The spherical mineral particles are coated and then solidified at a constant temperature to obtain a secondary processed mixture. The secondary treatment mixture is piled up, and the pile is leached with sulfuric acid solution. The leachate is collected, and uranium and vanadium in the leachate are extracted and recovered.

[0026] It should be noted that, firstly, the ore is crushed to significantly reduce particle size and increase specific surface area, creating sufficient contact conditions for subsequent acid penetration and reaction. Then, acid mixing ensures thorough mixing of the ore and acid solution, and the pre-leaching process activates the uranium and vanadium minerals present in the ore, promoting initial dissolution of uranium and vanadium and avoiding the problem of poor internal element reaction caused by "direct pile leaching" in traditional processes. Based on this, the pre-leached ore undergoes granulation and solidification treatment to form high-strength, uniformly porous granular materials. This allows for the construction of a stable pile without the risk of collapse during subsequent pile building. This pile structure ensures uniform penetration of the leaching agent, allowing each layer of ore to fully contact and react with the leaching agent, completely solving the defects of short-circuiting and incomplete local leaching in traditional pile leaching, ultimately significantly improving the leaching rate and recovery rate of uranium and vanadium.

[0027] Meanwhile, the entire process eliminates the need for intermediate transfers or prolonged settling, achieving continuous and seamless integration. On one hand, it avoids the loss of uranium and vanadium during process intervals and eliminates the waiting time in traditional step-by-step processes, significantly shortening the overall production cycle. On the other hand, continuous operation reduces labor and energy costs, and the solidified reactor body is easily removed from the reactor later, with high tailings treatment efficiency, further reducing overall process costs. Furthermore, this process is suitable for processing low-grade uranium and vanadium resources, requiring minimal equipment investment and having a low operational threshold. It provides a practical and feasible technical solution for the efficient industrial development of uranium and vanadium resources, possessing broad industrial application value.

[0028] It should be noted that this application employs heap leaching to leach low-grade uranium-iron-vanadium polymetallic ores rich in organic matter, reducing the ore particle size requirements during the leaching process and decreasing crushing and grinding costs. The use of acid treatment-atomized water pre-leaching-granulation-solidification effectively improves the ability to break down mica, quartz, pyrite, and other minerals in the ore, optimizes the leaching environment for uranium and vanadium minerals, and enhances the leaching performance of uranium and vanadium under large-particle ore conditions. The pre-leaching-granulation-solidification process solves the problems of clay minerals in the ore swelling and forming mud upon contact with water, easily clogging the heap, and the high viscosity and poor fluidity of the organic-rich leaching solution, which prevents heap leaching. The heap leaching process eliminates solid-liquid separation and washing steps, significantly shortening the process flow, reducing construction and operating costs, and greatly improving ore processing capacity and efficiency. The overall process is suitable for processing low-grade uranium-vanadium resources, requiring less equipment investment, offering strong processing capacity, a short process flow, and high processing efficiency, making it suitable for large-scale industrial applications.

[0029] In this embodiment, the low-grade uranium-iron-vanadium polymetallic ore is crushed to a particle size of -15 mm to -4 mm. When concentrated sulfuric acid is added to the crushed ore particles for mixing, the preferred mass ratio of concentrated sulfuric acid to ore particles is 0.5 to 0.01:1. After mixing, the concentrated sulfuric acid and ore particles are allowed to stand for 10 to 30 minutes. By controlling the mass ratio of concentrated sulfuric acid to ore particles and the standing time, the pre-activation rate of uranium and vanadium minerals in the ore particles can be improved. This avoids insufficient leaching affecting subsequent extraction efficiency, as well as avoiding ore particle agglomeration or acid waste caused by excessive concentrated sulfuric acid. It also prevents excessive leaching from leading to the loss of target elements in subsequent processes.

[0030] In this embodiment, the amount of water sprayed into the mineral-acid mixture for pre-leaching reaction is 3% to 20% of the mass of the mineral-acid mixture. By controlling the amount of water added during pre-leaching, it is ensured that the water fully penetrates into the mineral particles, thereby improving the pre-dissolution efficiency of uranium and vanadium minerals. It also maintains a suitable acidity environment within the system, preventing concentrated sulfuric acid from corroding equipment or damaging the mineral particle structure due to excessively high local concentrations.

[0031] In this embodiment, the diameter of the spherical mineral particles is preferably 5 mm to 20 mm. The spherical mineral particles are coated with a high-temperature resistant PP or polytetrafluoroethylene film to prevent moisture evaporation and drying of the ore. A constant temperature device is used to maintain the temperature of the mineral particles at 50–200 °C, with a curing time of 1–48 h. This effectively solves the problems of clay minerals in the ore swelling and becoming muddy upon contact with water, easily clogging the pile, and the high viscosity and poor fluidity of the leachate from the ore rich in organic matter, which prevents heap leaching.

[0032] In this embodiment, the secondary treatment mixture is piled up, with a preferred pile height of 1.5 m to 5 m. The pile is then leached with a sulfuric acid solution, preferably with a concentration of 5 g / L to 10 g / L. The solution is applied from the top, using either atomized spraying or drip irrigation, with a preferred spray intensity of 10 L / m. -2 h -1 ~100 L m -2 h -1 By controlling these experimental parameters, it is possible to ensure sufficient and uniform contact between the sulfuric acid leaching agent and the ore particles within the heap, while maintaining the stability of the heap. This balances leaching efficiency and cost, ultimately achieving efficient recovery of uranium and vanadium, meeting the requirements of a continuous heap leaching process. Furthermore, the heap leaching process eliminates solid-liquid separation and washing steps, significantly shortening the process flow, reducing construction and operating costs, and greatly improving ore processing capacity and efficiency. The overall process is suitable for processing low-grade uranium and vanadium resources, requiring minimal equipment investment, offering high processing capacity, a short process flow, and high efficiency, making it suitable for large-scale industrial applications.

[0033] It should be noted that the leachate after heap leaching is collected in the bottom pool for sampling, analysis, and uranium and vanadium extraction and recovery. The leaching agent can be prepared by diluting concentrated sulfuric acid with water or by using raffinate. When the uranium and vanadium concentrations in the leachate are below 50 mg / L, the leaching endpoint is reached. The ore heap is then washed with production water, using 5%–10% of the ore mass. After washing, the ore heap is kept dry for at least 24 hours. The slag is then sampled, analyzed, neutralized with lime, and transferred to the tailings storage area.

[0034] It should be noted that this application uses a single sulfuric acid system with low acidity, thereby reducing the consumption of acid and alkali reagents. The raffinate after extraction and separation can be directly used as a dilution source for the sulfuric acid solution used for leaching in the preparation of the leaching agent, without the need to add a large amount of fresh water. At the same time, the trace sulfuric acid remaining in the raffinate can be further utilized, reducing the amount of new acid added, significantly reducing the water and acid consumption costs of the entire process, and reducing wastewater discharge, thus taking into account both economic efficiency and environmental protection.

[0035] The technical solution of this application will be further described below with reference to specific embodiments.

[0036] Example 1 This embodiment provides a method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ores rich in organic matter through heap leaching, such as... Figure 1 The process flow diagram shown specifically includes: A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.596%, a uranium content of 0.035%, an organic carbon content of 2.29%, and a total iron content of 6.16%. This ore is processed using the following method: (1) Crushing: The ore is crushed to -5 mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0037] (2) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.08. Mix evenly using a mixer and let stand for 15 min.

[0038] (3) Pre-leaching: Spray atomized water into the acid-mixed ore and continue stirring to carry out pre-leaching. The amount of water is 8% of the ore mass. After all the water is added, continue stirring for 10 minutes until all the water has reacted completely.

[0039] (4) Granulation: The pre-leached ore is prepared into spherical mineral particles using a granulator with a diameter of about 7 mm to 8 mm.

[0040] (5) Curing: The spherical mineral particles are coated with a high-temperature resistant polytetrafluoroethylene film and cured in a kiln at a constant temperature of 120 ℃ for 24 h.

[0041] (6) Stacking: The ore is stacked using a mobile belt stacker to a height of 2 m.

[0042] (7) Leaching: The ore pile was leached with a 5 g / L sulfuric acid solution as the leaching agent. The leaching was carried out by drip irrigation and continuous spraying at a spraying intensity of 30 L / L. m -2 h -1 The leachate is collected from the bottom pool and then sampled for analysis and uranium and vanadium extraction and recovery. The leaching agent can be prepared using raffinate water for acid adjustment.

[0043] (8) Washing out of the pile: After leaching for 7 days, the ore pile is washed with production water at a rate of 6% of the ore mass. After washing, the ore pile is kept dry for 24 hours. After the slag is sampled and analyzed, lime is added to neutralize it and the slag is transferred to the tailings silo.

[0044] After the above process, the leaching rate of vanadium slag was 72.12%, and the leaching rate of uranium slag was 92.86%.

[0045] Example 2 A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.387%, a uranium content of 0.062%, an organic carbon content of 1.56%, and a total iron content of 8.23%. The ore is processed according to the following process: (1) Crushing: The ore is crushed to -8 mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0046] (2) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.12. Mix evenly using a mixer and let stand for 10 min.

[0047] (3) Pre-leaching: Spray atomized water into the acid-mixed ore and continue stirring to carry out pre-leaching. The amount of water is 11% of the ore mass. After all the water is added, continue stirring for 15 minutes until all the water has reacted completely.

[0048] (4) Granulation: The pre-leached ore is prepared into spherical mineral particles using a granulator with a diameter of about 9 mm to 10 mm.

[0049] (5) Curing: The spherical mineral particles are coated with a high-temperature resistant polytetrafluoroethylene film and cured in a kiln at a constant temperature of 100 ℃ for 20 h.

[0050] (6) Stacking: The ore is stacked using a mobile belt stacker to a height of 3 m.

[0051] (7) Leaching: The ore pile was leached with a 10 g / L sulfuric acid solution as the leaching agent. The leaching was carried out by drip irrigation and continuous spraying at a spraying intensity of 50 L / L. m -2 h -1 The leachate is collected from the bottom pool and then sampled for analysis and uranium and vanadium extraction and recovery. The leaching agent can be prepared using raffinate water for acid adjustment.

[0052] (8) Washing out of the pile: After leaching for 6 days, the ore pile is washed with production water at a rate of 8% of the ore mass. After washing, the ore pile is kept dry for 24 hours. After the slag is sampled and analyzed, lime is added to neutralize it and the slag is transferred to the tailings silo.

[0053] After the above process, the leaching rate of vanadium slag was 68.77%, and the leaching rate of uranium slag was 92.61%.

[0054] Example 3 A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.427%, a uranium content of 0.072%, an organic carbon content of 2.86%, and a total iron content of 5.44%. The ore is processed according to the following process: (1) Crushing: The ore is crushed to -4 mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0055] (2) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.1. Mix evenly using a mixer and let stand for 20 min.

[0056] (3) Pre-leaching: Spray atomized water into the acid-mixed ore and continue stirring to carry out pre-leaching. The amount of water is 14% of the ore mass. After all the water is added, continue stirring for 20 minutes until all the water has reacted completely.

[0057] (4) Granulation: The pre-leached ore is prepared into spherical mineral particles using a granulator with a diameter of about 6 mm to 7 mm.

[0058] (5) Curing: The spherical mineral particles are coated with a high-temperature resistant polytetrafluoroethylene film and cured in a kiln at a constant temperature of 90 ℃ for 36 h.

[0059] (6) Stacking: The ore is stacked using a mobile belt stacker to a height of 2.5 m.

[0060] (7) Leaching: The ore pile was leached with a 5 g / L sulfuric acid solution as the leaching agent. The leaching was carried out by drip irrigation and continuous spraying at a spraying intensity of 60 L / L. m -2 h -1 The leachate is collected from the bottom pool and then sampled for analysis and uranium and vanadium extraction and recovery. The leaching agent can be prepared using raffinate water for acid adjustment.

[0061] (8) Washing out of the pile: After leaching for 8 days, the ore pile is washed with production water at a rate of 5% of the ore mass. After washing, the ore pile is kept dry for 24 hours. After the slag is sampled and analyzed, lime is added to neutralize it and the slag is transferred to the tailings silo.

[0062] After the above process, the leaching rate of vanadium slag was 70.39%, and the leaching rate of uranium slag was 93.75%.

[0063] Meanwhile, to verify the preparation process of the above embodiments, this application provides the following comparative examples for detailed explanation.

[0064] Comparative Example 1 A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.596%, a uranium content of 0.035%, an organic carbon content of 2.29%, and a total iron content of 6.16%. This ore is processed using the following method: (1) Crushing: The ore is crushed to -1 mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0065] (2) Grinding: Dry grinding to -100 mesh using a ball mill.

[0066] (3) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.12; add water with a mass fraction of 13% of the ore and mix evenly.

[0067] (4) Heat preservation: use polytetrafluoroethylene high temperature resistant film for coating, and cure in the kiln at a constant temperature of 120 ℃ for 3 hours.

[0068] (5) Leaching: Add water, the ratio of leaching liquid to solid is 1:1, stir at room temperature for 1 h.

[0069] After filtration and washing, the leaching slurry had a leaching rate of 63.71% based on vanadium slag and a leaching rate of 92.44% based on uranium slag.

[0070] Comparative Example 2 A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.387%, a uranium content of 0.062%, an organic carbon content of 1.56%, and a total iron content of 8.23%. The ore is processed according to the following process: (1) Crushing: The ore is crushed to -1mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0071] (2) Grinding: Dry grinding to -100 mesh using a ball mill.

[0072] (3) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.12; add water with a mass fraction of 13% of the ore and mix evenly.

[0073] (4) Heat preservation: use polytetrafluoroethylene high temperature resistant film for coating, and cure in the kiln at a constant temperature of 120℃ for 3 hours.

[0074] (5) Leaching: Add water, the ratio of leaching liquid to solid is 1:1, stir at room temperature for 1 hour.

[0075] After filtration and washing, the leaching slurry had a leaching rate of 58.26% based on vanadium slag and a leaching rate of 93.31% based on uranium slag.

[0076] Comparative Example 3 A certain low-grade polymetallic ore rich in organic matter has a vanadium pentoxide content of 0.427%, a uranium content of 0.072%, an organic carbon content of 2.86%, and a total iron content of 5.44%. The ore is processed according to the following process: (1) Crushing: The ore is crushed to -1mm particle size using a three-stage closed-circuit crushing process using a jaw crusher, cone crusher and vibrating screen.

[0077] (2) Grinding: Dry grinding to -100 mesh using a ball mill.

[0078] (3) Acid treatment: Add concentrated sulfuric acid with a mass fraction of more than 98% to the ore, with an acid-ore mass ratio of 0.12; add water with a mass fraction of 13% of the ore and mix evenly.

[0079] (4) Heat preservation: use polytetrafluoroethylene high temperature resistant film for coating, and cure in the kiln at a constant temperature of 120℃ for 3 hours.

[0080] (5) Leaching: Add water, the ratio of leaching liquid to solid is 1:1, and stir at room temperature for 1 h.

[0081] After filtration and washing, the leaching slurry had a leaching rate of 62.65% based on vanadium slag and a leaching rate of 94.52% based on uranium slag.

[0082] Table 1 Comparison of effects between the examples and comparative examples.

[0083] The process flow used in Example 1 of this application only involves crushing and does not require further grinding and refining. Grinding and refining requires additional equipment such as ball mills. Omitting this step reduces equipment purchase and maintenance costs, and the grinding process consumes a large amount of electrical energy. By omitting grinding and refining, this application can reduce production energy consumption and shorten the process time. In the comparative example, using finer-grained ore for acid treatment would result in a large amount of acid being wasted. For example, comparing the data of Example 1 and Comparative Example 1 for treating 1 ton of ore: the acid-ore mass ratio in Example 1 is 0.08, i.e., the amount of concentrated sulfuric acid added is 80 kg, while the acid-ore mass ratio in the comparative example is 0.12, i.e., the amount of concentrated sulfuric acid added is 120 kg. Therefore, compared with the comparative example, the amount of concentrated sulfuric acid used in this application is reduced by about 33.3%. If calculated according to industrial production scale, acid consumption can be significantly reduced. At the same time, the leaching effect of Example 1 maintains good stability, the uranium leaching rate does not change significantly, while the vanadium slag leaching rate increases slightly.

[0084] Therefore, the heap leaching method provided in this application achieves efficient extraction of uranium and vanadium through a continuous processing flow of crushing-acid mixing-pre-leaching-granulation-solidification-heap building-leaching-unloading. By seamlessly connecting each stage, no intermediate transfer is required, significantly shortening the process flow, reducing construction and operating costs, and enabling efficient leaching of uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ores rich in organic matter. Furthermore, this integrated process is suitable for processing low-grade uranium and vanadium resources, requires minimal equipment investment, has high processing capacity, and possesses significant economic and practical advantages, making it more suitable for large-scale industrial production applications.

[0085] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0086] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ores rich in organic matter through heap leaching, characterized in that, The method includes: Low-grade uranium-iron-vanadium polymetallic ore is crushed, and concentrated sulfuric acid is added to the crushed ore particles to mix them, resulting in a mineral-acid mixture. Water is atomized and sprayed into the mineral acid mixture for a pre-leaching reaction to obtain a primary treatment mixture. The primary processed mixture is granulated to obtain spherical mineral particles; The spherical mineral particles are coated and then solidified at a constant temperature to obtain a secondary processed mixture. The secondary treatment mixture is piled up, and the pile is leached with sulfuric acid solution. The leachate is collected, and uranium and vanadium in the leachate are extracted and recovered.

2. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, The low-grade uranium-iron-vanadium polymetallic ore is crushed to a particle size of -15 mm to -4 mm. When concentrated sulfuric acid is added to the crushed mineral particles and mixed, the mass ratio of concentrated sulfuric acid to mineral particles is 0.5~0.01:1; After mixing, the concentrated sulfuric acid and mineral particles are allowed to stand for 10-30 minutes.

3. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, The water is atomized and sprayed into the mineral acid mixture for pre-leaching reaction, and the amount of water used is 3% to 20% of the mass of the mineral acid mixture.

4. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, The diameter of the spherical mineral particles is 5 mm to 20 mm.

5. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, During the constant temperature curing process, the temperature is 50~200 ℃ and the curing time is 1 h~48 h.

6. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, The secondary processed mixture is piled up to a height of 1.5 m to 5 m.

7. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, When leaching the heap with sulfuric acid solution, the concentration of the sulfuric acid solution is 5 g / L to 10 g / L.

8. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, When leaching the heap with sulfuric acid solution, a top-feed method is used, employing atomized spraying or drip irrigation, with a spray intensity of 10 L / m. -2 h -1 ~100 L m -2 h -1 .

9. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, When the secondary treatment mixture is piled up and leached with sulfuric acid solution, the determination of the end of leaching includes: The leaching endpoint can be determined when the concentration of uranium and vanadium in the leaching solution is below 50 mg / L.

10. The method for extracting uranium and vanadium from low-grade uranium-iron-vanadium polymetallic ore rich in organic matter by heap leaching according to claim 1, characterized in that, When the secondary treatment mixture is piled up and leached with sulfuric acid solution, after leaching is completed, the slag is sampled and analyzed, then neutralized with lime and transferred to the tailings silo.

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