Composite microorganism for synergistically driving uranium and polymetallic resources leaching and leaching method

Abstract

The application discloses a composite microorganism for cooperatively driving uranium and polymetallic resources leaching and a leaching method. The composite microorganism for cooperatively driving uranium and polymetallic resources leaching comprises acid-producing microorganisms, auxiliary ore-dissolving microorganisms, surfactant-producing bacteria and metal-oxidizing microorganisms. The leaching method of uranium and polymetallic resources comprises the following steps: adding the acid-producing microorganisms and the auxiliary ore-dissolving microorganisms to leach the ore, pre-reacting with the ore, adding the surfactant-producing bacteria, secondarily reacting, and adding the metal-oxidizing microorganisms. The application constructs a multi-strain combined system composed of fungi, actinomycetes and functional metal-oxidizing leaching microorganisms. Through the spatial cooperation and functional coupling of different microbial metabolites, efficient stripping and extraction of uranium and associated metals under mild environmental conditions are realized. The leaching method is green and low-carbon, can simultaneously extract polymetallic resources, has high permeability, significantly improves leaching rate and has strong process stability.

Description

Technical Field

[0001] This invention belongs to the field of bioleaching technology, and particularly relates to composite microorganisms and leaching methods for synergistically driving the leaching of uranium and polymetallic resources. Background Technology

[0002] Traditional uranium leaching often employs strong acid (sulfuric acid) and oxidant (potassium permanganate, iron salts, hydrogen peroxide, etc.) processes. However, this process has the following significant drawbacks in practical applications: (1) High environmental risk: The extensive use of strong acid can easily cause severe equipment corrosion and the spread of acidic wastewater pollution in the mining area. (2) Limited processing efficiency: Traditional processes have low efficiency in the simultaneous recovery of uranium and polymetallic (such as Cu, Ni, etc.) composite resources, and the leaching rate is greatly affected by fluctuations in the physicochemical properties of the ore. (3) Difficulty in ore liberation: Single chemical agents are difficult to penetrate into the micropores of the ore, resulting in the inability of the encapsulated uranium oxides to dissolve effectively.

[0003] Microorganisms, under specific conditions, can produce organic acids, iron carriers, surfactants, and redox metabolites, which can be used for ore dissociation and metal release, constructing green and low-cost bioleaching systems. Current bioleaching research mostly employs single-functional strains, making it difficult to simultaneously handle multiple tasks such as acidolysis, redox reactions, and interface enhancement, and thus unable to cope with mineral resources with complex compositions. In actual mineral and metallurgical systems, high concentrations of specific metal elements often have significant toxic effects on single-functional microorganisms, thereby inhibiting their metabolic activity and leaching efficiency. Leaching systems dominated by single strains typically struggle to maintain optimal physiological activity and stable functional output, especially under complex mineral interfaces and multi-metal coexistence conditions. Summary of the Invention

[0004] The purpose of this invention is to provide a composite microorganism and leaching method for synergistically driving the leaching of uranium and polymetallic resources. The multi-species synergistic system can significantly improve system stability and leaching efficiency through metabolic complementarity and niche division of labor.

[0005] This invention provides a composite microorganism for synergistically driving the leaching of uranium and polymetallic resources, including acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms.

[0006] In the aforementioned composite microorganisms, the acid-producing microorganisms are one or more of Cladosporium, Corylus, and Paecilomyces.

[0007] In the aforementioned composite microorganisms, the auxiliary mineral-dissolving microorganisms are one or more of the following: *Streptococcus pyogenes*, *Pandora bacillus*, *Masses*, and *Aeromonas*.

[0008] In the aforementioned composite microorganisms, the surfactant-producing bacteria are one or more of the following: Oligotrophomonas, Rifsonia, and Mycobacterium.

[0009] In the aforementioned composite microorganisms, the metal-oxidizing microorganisms are one or more of the following: Microbacterium, Thiobacillus, Leptospira, Aspergillus, and Penicillium.

[0010] In the above-mentioned composite microorganisms, the volume ratio of the acid-producing microorganisms, the mineral-dissolving microorganisms, the surfactant-producing bacteria and the metal-oxidizing microorganisms is (1-2):1:(1-2):(1-5).

[0011] The multi-strain synergistic system of this invention achieves efficient leaching of uranium and its associated metals through the following four dimensions: Acidolysis and Complexation Effects: Acid-producing microorganisms can secrete small-molecule organic acids such as oxalic acid, citric acid, malic acid, and succinic acid during metabolism. On the one hand, these organic acids release H+... + Ions lower the pH of the system, resulting in proton-driven dissolution of the crystal lattice of uranium minerals and associated minerals, promoting mineral structure destruction and the release of metal ions; on the other hand, organic acid anions can react with the dissolved uranyl ions (UO2). 2+ This forms stable water-soluble complexes, enhancing the coordination stability of uranium in solution and reducing the likelihood of hydrolysis or precipitation under fluctuating pH conditions, thereby improving uranium mobility and sustained leaching capacity. Similarly, ore-dissolving microorganisms can secrete siderophores and related organic ligands, which enhance the leaching of uranium by binding U(VI) and Fe. 3+ The strong complexation of metal ions can promote the dissolution and weathering of iron oxides and associated minerals, and to some extent participate in the formation of UO2. 2+ The coordination stabilization process of uranyl ions. Furthermore, the iron-supported metal complexation process may alter the mineral interface microenvironment, indirectly enhancing mineral dissolution kinetics and metal migration capabilities, thereby synergistically strengthening the leaching process of uranium and associated metals. In addition, the biofilm formed by the acid-producing microorganisms and mineral-dissolving microorganisms selected in this invention is rich in polysaccharides, effectively buffering environmental toxicity under extreme conditions such as strong acids, strong alkalis, and heavy metal contamination, constructing a microenvironment conducive to the survival and leaching of subsequent functional microorganisms. Because they play a leading regulatory role in the system, acid-producing microorganisms and mineral-dissolving microorganisms should be preferentially added during the leaching process to create suitable leaching conditions. Simultaneously, metal-oxidizing microorganisms oxidize Fe... 2+ Or sulfide minerals form Fe 3+ and H + It maintains an acidic environment, increases the redox potential (Eh) of the system, promotes the transformation of U(IV) to U(VI) in the mineral lattice, and enhances the mineral oxidation and dissolution process, so that the acidolysis, complexation process and mineral oxidation reaction form a synergistic strengthening effect.

[0012] Biocatalyzed exfoliation: In addition to the secretion of siderophores and organic ligands, assisting leaching microorganisms can also secrete various extracellular enzymes, including proteases, polysaccharide hydrolases, and lipid hydrolases. These enzymes can degrade natural organic matter, biofilm matrix (EPS), and other organic impurities attached to the ore surface, thereby exposing the active sites of the mineral and maintaining the reactivity of the mineral surface. During bioleaching, the mineral surface often forms a "passivation layer" due to the accumulation of metal hydrolysis products, secondary precipitates, or microbial metabolites, which restricts the mass transfer of protons, oxidants, and complexing agents into the mineral interior. The continuous secretion of extracellular enzymes helps to disrupt or reconstruct this interfacial layer structure, reduce diffusion resistance, and enhance the contact efficiency between the solution and the mineral interface, thereby maintaining the kinetic continuity of the leaching reaction and avoiding a decrease in the leaching rate due to interfacial deactivation. In addition, the degradation of organic matter mediated by extracellular enzymes can also release small molecule soluble organic carbon, providing metabolic substrates for other heterotrophic microorganisms in the system, forming a metabolic feedback network, and further enhancing community stability and leaching efficiency. Meanwhile, the process continuously exposes the fresh reaction surface of the minerals, providing more active sites for metal-oxidizing microorganisms and further promoting the oxidative leaching reaction.

[0013] Surfactant-producing bacteria can secrete biosurfactants such as surfactants, iturobrine, rhamnolipids, mannolipids, polysaccharides, and extracellular polymers during their metabolism. These amphiphilic molecules can significantly reduce the surface tension of solutions and the solid-liquid interfacial tension, and improve the wettability of mineral surfaces, thereby enhancing the penetration of leachate into ore particles and microfractures. In actual ore systems, some uranium minerals are often encapsulated by clay minerals, siliceous cements, or secondary minerals, forming diffusion-restricted "encapsulated mineral" structures. Biosurfactants can improve the efficiency of leaching agents, microbial metabolites, and complexing ligands into the mineral interior by lowering the interfacial energy barrier and promoting capillary penetration of liquids in micropores and fractures, making it easier for encapsulated uranium oxides or uranium silicates to be exposed to the reaction environment. In addition, biosurfactants such as surfactants, iturobrine, and rhamnolipids may also promote the dissolution and migration of some metal ions by forming micelles or complexed microenvironments, and to a certain extent regulate the surface charge of minerals and the adhesion behavior of microorganisms, thereby synergistically enhancing the mineral dissolution and metal release processes. Among the surfactant-producing bacteria selected in this invention, the biofilms formed by *Oligotrophomonas*, *Rifonsonia*, and *Mycobacterium* show a high degree of enrichment of type C cytochrome, low intracellular resistance, and strong extracellular electron uptake capacity, thus enabling them to more effectively promote the production of U(IV) and Fe. 2+ This process also facilitates the oxidation of sulfides and improves bioleaching efficiency. Furthermore, these microorganisms can synergistically interact with subsequent metal-oxidizing microorganisms to further enhance the overall leaching capacity of the system.

[0014] Metal-oxidizing microorganisms in leaching systems mainly oxidize U(IV) and Fe in minerals. 2+Sulfides or other low-valence metallic elements, to form U(VI), Fe 3+ Or other species with oxidizing capabilities, thereby significantly increasing the redox potential (Eh) of the system. In this process, Fe... 3+ It can also act as an important indirect oxidant in electron transfer reactions at mineral interfaces, further promoting the transformation of U(IV) to U(VI) and other low-valence metals to soluble high-valence states in the mineral lattice. Simultaneously, by continuously maintaining the oxidative environment of the system, metal-oxidizing microorganisms can form a coupling effect with the acidolysis and complexation processes produced by acid-producing microorganisms. This allows the mineral dissolution process to be synergistically driven by acidolysis, complexation, and oxidation reactions, thereby significantly improving the leaching efficiency of uranium and its associated metals.

[0015] The present invention also provides a leaching method for uranium and polymetallic resources, which involves bioleaching using any of the above-mentioned composite microorganisms. First, the acid-producing microorganisms and the auxiliary dissolving microorganisms are added and mixed evenly with the ore for a pre-reaction of 12-24 hours. Then, the surfactant-producing bacteria are added, and after a second reaction of 8-24 hours, the metal-oxidizing microorganisms are added.

[0016] In the above leaching method, the mass ratio of each bacterial solution in the composite microorganism to the ore is 1:(100000-5000000), the reaction pH is maintained at 1.0-9.0, and the temperature is 10-60 ℃.

[0017] The leaching methods described above include heap leaching, column leaching, stirred leaching, or in-situ leaching.

[0018] In the above leaching method, the ore includes uranium ore, U-polymetallic associated ore, tailings heaps, or industrial metallurgical slag. This is particularly true for complex and difficult-to-process low-grade ores, as well as high-salt and highly toxic ores.

[0019] This invention constructs a multi-species synergistic system composed of fungi, actinomycetes, and functional metal oxidizing leaching microorganisms. Through spatial synergy and functional coupling of different microbial metabolites, efficient stripping and extraction of uranium and its associated metals are achieved under mild environmental conditions. Compared with single-strain leaching systems, this multi-species synergistic system significantly improves system stability and metal leaching efficiency through metabolic complementarity, niche specialization, and interfacial process coupling, and enhances the adaptability of the microbial community to high-concentration metal ion toxicity stress. On the one hand, organic acids, chelating ligands, and biosurfactants produced by some strains can promote the destruction of mineral interface structures, enhancing the complexation stability and migration ability of metal ions; on the other hand, these metabolites can also be utilized by other microorganisms as carbon sources, electron donors, or energy sources, thus forming a stable metabolic coupling network. Lead microorganisms such as acid-producing microorganisms and auxiliary leaching microorganisms effectively buffer environmental toxicity through extracellular polymers, constructing a microenvironment conducive to the survival and leaching of subsequent functional strains. C-type cytochromes in the biofilm of surfactant-producing bacteria mediate extracellular electron uptake, which can more effectively promote the leaching of U(IV) and Fe. 2+ This process involves the oxidation of sulfides and improves bioleaching efficiency. Simultaneously, metal-oxidizing microorganisms can further oxidize U(IV) and Fe... 2+ Or sulfide minerals form U(VI), Fe 3+ It also produces acidic products, increases the redox potential of the system, and promotes the transformation of metal valence states. Under the synergistic effect of multiple microorganisms, it can jointly promote the continuous enhancement of mineral dissolution, metal release, and subsequent metal resource enrichment processes.

[0020] The technical effects of the leaching method of the present invention are as follows: Green and low-carbon: The use of biological organic acids to replace strong inorganic acids significantly reduces acid consumption and acidic wastewater treatment costs, and the equipment has low corrosivity.

[0021] Multi-metal simultaneous extraction: It can simultaneously achieve the effective leaching of multiple metal resources such as U, Mo, Cu, Ni, Zn, Cd, Pb, Cr, and rare earth element REE, thereby improving the comprehensive utilization rate of resources.

[0022] Highly efficient permeability: The introduction of strains that produce surfactants solves the problem that leachate is difficult to penetrate deep into the ore in traditional processes.

[0023] Significantly improved leaching rates: Experiments have shown that when treating U-Mo polymetallic ores, the uranium leaching rate can reach 96.9% and the molybdenum leaching rate can reach 91.1%; when treating U-Cu-REE polymetallic ores, the uranium leaching rate can reach 95.4%, the copper leaching rate can reach 87.2%, and the rare earth leaching rate can reach 92.5%; when treating UV polymetallic ores, the uranium leaching rate can reach 87.1% and the vanadium leaching rate can reach 92.0%.

[0024] High process stability: Through metabolic complementarity and niche specialization, multi-strain synergistic systems typically exhibit strong environmental adaptability and process stability in complex mineral and metallurgical environments. Different strains can respectively undertake functions such as organic acid secretion, metal redox, interfacial activity regulation, resource complexation and migration, and organic matter degradation, thereby forming a multi-level metabolic coupling network. This network can buffer, to some extent, the biotoxic impact caused by high concentrations of heavy metal ions, acidity fluctuations, and changes in mineral composition. Furthermore, the synergistic effect of multiple strains helps maintain the dynamic activation state of the mineral surface, reducing the accumulation of secondary precipitates, extracellular polymers, and mineral debris at the interface, thus mitigating mass transfer limitations caused by surface passivation or localized deposition. Compared with single-strain leaching systems, this system is more conducive to maintaining the stability of long-term continuous leaching processes and reduces the risk of localized blockage or decreased leaching efficiency due to deposit formation. Attached Figure Description

[0025] Figure 1 This refers to the survival status during the bioleaching experiment in Example 3.

[0026] Figure 2 The images shown are scanning electron microscope (SEM) images of the morphological evolution during the leaching of uranium-vanadium polymetallic ore in Example 5. A is the sterile control group, B is the SEM image at the beginning of the reaction (t=0 d), C is the SEM image after the reaction has proceeded to 20 d, and D is a magnified view of a part.

[0027] Figure 3 Example 6 illustrates the leaching effect on uranium-molybdenum polymetallic ore.

[0028] Figure 4 The leaching effect of uranium-molybdenum polymetallic ore was compared with that of Comparative Example 1. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0030] The composite microorganisms used for synergistically driving the leaching of uranium and polymetallic resources include acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria and metal-oxidizing microorganisms, with a volume ratio of (1-2):1:(1-2):(1-5), preferably 2:1:2:5.

[0031] Acid-producing microorganisms can secrete high concentrations of low-molecular-weight organic acids such as oxalic acid, citric acid, malic acid, and succinic acid, which promote the cleavage of U(IV) mineral structures through acid hydrolysis and complexation; and provide usable organic carbon sources and complexing ligands for other strains of the present invention; their biofilms are rich in polysaccharides, which can effectively buffer environmental toxicity under extreme environments such as strong acid, strong alkali and heavy metal contamination, and construct a microenvironment conducive to the survival and leaching of subsequent functional strains; preferably one or more of Cladosporium, Corylus, and Paecilomyces.

[0032] The ore-dissolving microorganisms can produce siderophores, various extracellular enzymes and organic acids, which promote the destruction of the ore matrix and the activation of the mineral surface; their metabolites can be further utilized by other microbial species of the present invention to enhance the overall metabolic flux of the system; similarly, their biofilms are rich in polysaccharides, which can play a leading regulatory role in creating suitable leaching conditions; preferably, one or more of the following are selected: *Streptococcus solani*, *Pandora bacillus*, *Masses*, and *Aeromonas*.

[0033] Surfactant-producing bacteria metabolize and produce biosurfactants such as surfactants, ituronidin, rhamnolipids, mannolipids, biopolysaccharides, and extracellular polymers. These biosurfactants reduce the solid-liquid interfacial tension and enhance the penetration of the leaching agent into the ore pores. Simultaneously, they promote the migration and complexation stability of metal ions in solution, creating conditions for subsequent metal-oxidizing microbial leaching. Their biofilms are enriched with type C cytochromes, have low intracellular resistance, and strong extracellular electron uptake capacity, enabling them to more effectively promote the leaching of U(IV) and Fe. 2+ And the oxidation process of sulfides, and improve the bioleaching efficiency; preferably one or more of oligotrophomonas, Rifsonia, and mycobacteria.

[0034] Metal-oxidizing microorganisms oxidize U(IV) and Fe in minerals 2+ Sulfides or other low-valence metallic elements, to form U(VI), Fe 3+ Or other species with oxidizing capabilities, thereby significantly increasing the redox potential (Eh) of the system. In this process, Fe... 3+ It can also act as an important indirect oxidizing agent to further promote the transformation of U(IV) to U(VI) and other low-valence metals to soluble high-valence states in mineral lattices. Furthermore, in the oxidation of Fe... 2+ The process of sulfide formation may generate acidic products, maintaining an acidic environment in the system and providing suitable growth and metabolic conditions for acid-producing microorganisms. The preferred microorganisms are one or more of the following: Microbacterium, Thiobacillus, Leptospira, Aspergillus, and Penicillium.

[0035] Through the synergistic effect of the above-mentioned multiple microbial species, a multi-stage coupled leaching and recovery process of "acid hydrolysis-complexation-permeation-oxidation" can be formed, realizing the continuous enhancement of mineral crushing, metal release, valence state regulation and selective enrichment, thereby significantly improving the leaching efficiency and subsequent recovery stability of uranium and its associated metal resources.

[0036] A leaching method for uranium and polymetallic resources involves bioleaching using any of the aforementioned composite microorganisms. The initial mass ratio of each microbial solution to ore in the composite microorganism is 1:(100,000-5,000,000). The reaction pH is maintained at 1.0-9.0, and the temperature is 10-60 °C. Leaching methods include heap leaching, column leaching, stirred leaching, or in-situ leaching. This leaching method can be used to leach metal resources such as U, Mo, Cu, Ni, Zn, Cd, Pb, Cr, and rare earth elements (REEs).

[0037] The leaching method may specifically include the following steps: The ore is crushed to a particle size of 0.5-10 mm. The ore includes uranium ore, U-polymetallic associated minerals, tailings, or industrial metallurgical slag.

[0038] Inoculate with compound microorganisms in a specified ratio. The inoculation sequence is as follows: first, add acid-producing microorganisms and mineral-dissolving microorganisms, mix them evenly with the ore, and pre-react for 12-24 hours. Then, add surfactant-producing bacteria, and after a second reaction of 8-24 hours, add metal-oxidizing microorganisms. The preferred reaction time for the first stage is 12-16 hours, and the preferred reaction time for the second stage is 8-12 hours.

[0039] Under conditions of 10-60 ℃ and pH 1.0-9.0, the reaction is carried out with aeration and periodic stirring. The reaction can be carried out in an intermittent or continuous manner, and the leaching cycle is 3-30 days.

[0040] Collect and enrich uranium-containing leachate.

[0041] Example 1: Bioleaching Experiment of U-Mo Polymetallic Ores In this embodiment, the acid-producing microorganism is Cladosporium buddingum (Cladosporium buddingum). Cladosporium cladosporioides CICC41760 was purchased from the China Industrial Microbial Culture Collection Center; the auxiliary mineral-dissolving microorganism was *Streptococcus faecalis* (…). Herbaspirillum seropedicae DSM 6446 was purchased from the German Microbial Culture Collection (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH); the surfactant-producing bacterium was Rifonsears (…). Leifsonia sp. CICC 25134 was purchased from the China Industrial Microbial Culture Collection Center; the metal oxidizing microorganism was *Thiobacillus acidophilus* (sp. CICC 25134). Acidithiobacillus ferrooxidans(ATCC 23270) was purchased from the American Center for Type Culture Collection.

[0042] (1) Material preparation: Select 1 kg of hard rock uranium-molybdenum polymetallic ore containing 0.15% U and 0.08% Mo, crush it to a particle size of 4 mm, and prepare 1 L of suspension.

[0043] (2) Inoculation: Add the microorganisms in the following order: acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing microorganisms, and metal-oxidizing microorganisms. Specifically, add *Cladosporium* first. C. cladosporioides and the spirulina H. seropedicae After being mixed evenly with the ore and reacted for 14 hours, Rifonsonia bacteria were added. Leifsonia After reacting for another 10 hours, *Thiobacillus ferrooxidans* was added. A. ferrooxidans The four bacterial strains were mixed in a ratio of 2:1:2:5, with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0044] (3) Operation: The initial pH was set to 4.0, the temperature was kept constant at 30 °C, and the reaction was continued for 20 days.

[0045] (4) Monitoring: During the reaction, the pH fluctuation range was maintained between 2.2 and 4.0, there was no sludge blockage, and the system had good fluidity, as shown in Table 1.

[0046] (5) Results: The uranium leaching rate reached 96.9% and the molybdenum leaching rate reached 91.1%.

[0047] Table 1

[0048] Data analysis shows that in the multi-species synergistic leaching system constructed in this embodiment, as the reaction time increases, the pH of the system gradually decreases from 4.0 to 2.2, the redox potential (Eh) increases from +223 mV to +416 mV, the concentration of rhamnolipids continues to rise, and the concentrations of uranium and molybdenum increase synchronously. This indicates that the system can form an acidification-oxidation-interface enhancement coupling environment that is conducive to the release of uranium and molybdenum during the reaction process.

[0049] Specifically, in the initial stage of the reaction (0-5 days), acid-producing microorganisms and mineral-dissolving microorganisms first act on the ore surface, increasing the acidity of the system and promoting the loosening of the mineral surface. Simultaneously, Eh begins to rise, indicating that metal oxidation-related reactions have been gradually activated. In the middle stage of the reaction (5-10 days), the concentration of rhamnolipin increased from 45 mg / L to 123 mg / L, the uranium concentration from 421 mg / L to 1153 mg / L, and the molybdenum concentration from 188 mg / L to 457 mg / L. This indicates that the surfactant-producing bacteria significantly enhance the wetting, dispersion, and mass transfer at the mineral-solution interface, contributing to increased mineral surface exposure and the efficiency of metal ion migration into the liquid phase. In the later stage of the reaction (10-20 days), Eh further increases to +416 mV, and the rhamnolipin concentration increases to 154 mV. The concentrations of uranium and molybdenum continued to rise and stabilize after reaching mg / L, indicating that the oxidation capacity of the system was further enhanced after the participation of Acidithiobacillus ferrooxidans. This, together with the acidification and interfacial activation effects formed in the early stage, continuously promoted the decomposition of uranium- and molybdenum-containing minerals and the release of target metals.

[0050] Throughout the entire operation, the system pH remained consistently within the range of 2.2-4.0 without drastic fluctuations, and no significant sludge blockage or deterioration of fluidity was observed. This indicates that the multi-strain synergistic system possesses good process stability and self-regulating ability, eliminating the need for frequent external acid additions for pH correction. Ultimately, after 20 days of reaction, the uranium leaching rate reached 96.9%, and the molybdenum leaching rate reached 91.1%, demonstrating that the multi-strain synergistic system described in this invention can efficiently achieve simultaneous leaching of target metals in U-Mo polymetallic ores, exhibiting high leaching efficiency and engineering application potential.

[0051] Example 2: Bioleaching Experiments of U-Polymetallic Ores Using Different Treatment Processes This embodiment uses hard rock type U-polymetallic ore as the object and conducts a 20-day comparative experiment. The composite microorganisms used in this embodiment are the same as those in Embodiment 1.

[0052] (1) Material preparation: Select 1 kg of hard rock uranium-polymetallic ore containing 0.19% U, 0.06% Cu and 0.11% REE, crush it to 4 mm particle size and prepare 1 L suspension.

[0053] (2) Inoculation: Set up experimental groups and inoculate the above 4 strains into the experimental group reactor in a ratio of 2:1:2:5, that is, first add acid-producing microorganisms (Bacillus buddingus). Cladosporium cladosporioides CICC 41760) and auxiliary mineral-dissolving microorganisms (Syndrome affinis) Herbaspirillum After the seropedicae DSM 6446 was mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria (Rifsonia) were added. Leifsoniasp. CICC 25134), after reacting for another 10 hours, metal-oxidizing microorganisms (sp. CICC 25134) were added. Acidithiobacillus ferrooxidans ATCC 23270), with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0054] A control group was set up, with 1 g / L sulfuric acid and 0.5 g / L manganese dioxide added to the sterile strong acid control group A. A single fungus ( Cladosporium cladosporioides CICC 41760), single bacteria ( DSM 6446 Herbaspirillum seropedicae sp. CICC 25134, Leifsonia ATCC 23270 was introduced into control groups B, C, D, and E, respectively, with an initial bacterial density of 10⁻⁶. 8 CFU / mL; In addition, two-strain controls (any two of the above four strains added in a predetermined ratio, with a control group FK) and three-strain controls (any three of the above four strains added in a predetermined ratio, with a control group LO) were set up. The specific settings are as follows: Control group F: Cladosporium buddingii Acidithiobacillus ferrooxidans + *Plasmodium spp.* C. cladosporioides The cultures were sequentially introduced into the experimental group reactors at a 2:1 ratio, with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0055] Control group G: Cladosporium buddingii H. seropedicae +Rifons C. cladosporioides sp. were added to the experimental group reactor in a 1:1 ratio, i.e., acid-producing microorganisms were added first. Leifsonia After being mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria were added. C. cladosporioides sp., with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0056] Control group H: Cladosporium buddingii Leifsonia +Acidophilic ferrooxidase A. C. cladosporioides The acid-producing microorganisms were added to the experimental reactor in a 2:5 ratio, meaning they were added first. C. ferrooxidans After being mixed evenly with the ore and reacted for 14 hours, metal-oxidizing microorganisms were introduced. cladosporioides The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0057] Control group I: *Syngonium filamentosa*A. ferrooxidans +Rifons H. seropedicae sp. were added to the experimental group reactor in a 1:2 ratio, i.e., auxiliary mineral-dissolving microorganisms were added first. Leifsonia After being mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria were added. H. seropedicae sp., with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0058] Control group J: *Syngonium filamentosa* Leifsonia +Acidophilic ferrooxidase H. seropedicae The microorganisms were added to the experimental reactor in a 1:5 ratio, meaning that the auxiliary mineral-dissolving microorganisms were added first. A. ferrooxidans After being mixed evenly with the ore and reacted for 14 hours, metal-oxidizing microorganisms were introduced. H. seropedicae The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0059] Control group K: Rifonsonia A. ferrooxidans sp. + Acidiotrophoblastic acidophilus Leifsonia The surfactant-producing bacteria were introduced into the experimental group reactors sequentially at a 2:5 ratio, meaning the surfactant-producing bacteria were added first. A. ferrooxidans After the sp. is mixed evenly with the ore and reacted for 10 hours, metal-oxidizing microorganisms are introduced. Leifsonia The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0060] Control group L: Cladosporium buddingii A. ferrooxidans + *Plasmodium spp.* C. cladosporioides +Rifons H. seropedicae sp. were introduced into the experimental group reactor in a 2:1:2 ratio, i.e., acid-producing microorganisms were added first. C. Leifsonia and mineral-dissolving microorganisms cladosporioides After being mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria were added. H. seropedicae sp., with an initial density of 10 per strain. 7 -10 8 CFU / mL.

[0061] Control group M: Cladosporium buddingii Leifsonia + *Plasmodium spp.* C. cladosporioides +Acidophilic ferrooxidase H. seropedicae The acid-producing microorganisms were introduced into the experimental reactor in a 2:1:5 ratio, meaning they were added first. A. ferrooxidans and mineral-dissolving microorganisms C. cladosporioides After being mixed evenly with the ore and reacted for 14 hours, metal-oxidizing microorganisms were introduced.H. seropedicae The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0062] Control group N: Cladosporium buddingii A. ferrooxidans +Rifons C. cladosporioides sp. + Acidiotrophoblastic acidophilus Leifsonia The acid-producing microorganisms were introduced into the experimental reactor in a 2:2:5 ratio, meaning they were added first. A. ferrooxidans After being mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria were added. C. cladosporioides After reacting for another 10 hours, metal-oxidizing microorganisms are introduced. Leifsonia The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0063] Control group O: *Syngonium filamentosa* A. ferrooxidans +Rifons H. seropedicae sp. + Acidiotrophoblastic acidophilus Leifsonia The microorganisms were introduced into the experimental reactor in a 1:2:5 ratio, meaning that the auxiliary mineral-dissolving microorganisms were added first. H. A. ferrooxidans After being mixed evenly with the ore and reacted for 14 hours, surfactant-producing bacteria were added. seropedicae After reacting for another 10 hours, metal-oxidizing microorganisms are introduced. Leifsonia The initial density of each strain was 10. 7 -10 8 CFU / mL.

[0064] (3) Operation: Same as Example 1, the experimental results are shown in Table 2.

[0065] Table 2

[0066] Results Analysis: Compared with traditional strong acid chemical leaching, single-strain treatment, dual-strain combination, and triple-strain combination, the four-strain synergistic leaching system described in this invention showed the best results in leaching uranium, copper, and rare earth metals. Specifically, the experimental group achieved a uranium leaching rate of 95.4%, a copper leaching rate of 87.2%, and a rare earth leaching rate of 92.5%, significantly higher than the control groups. This indicates that the multi-strain sequential inoculation system constructed in this invention can form a more effective synergistic leaching mechanism in complex polymetallic ores.

[0067] First, compared with the traditional strong acid method, the system of this invention can still achieve higher uranium, copper, and rare earth leaching rates without the addition of strong chemical agents such as sulfuric acid and manganese dioxide. Specifically, the uranium leaching rate increased from 78.5% to 95.4%, the copper leaching rate increased from 65.0% to 87.2%, and the rare earth leaching rate significantly increased from 15.2% to 92.5%. This indicates that this invention not only achieves efficient recovery of uranium resources but also significantly promotes the release of associated copper and rare earth resources, especially in rare earth release, where it has a clear advantage over the traditional strong acid method. This is because the traditional strong acid method mainly relies on low pH and external strong oxidants to chemically damage minerals, resulting in a relatively simple action mode. In contrast, the system of this invention, through the synergistic effect of multiple stages—acid production, solubilization, interface strengthening, and metal oxidation—can continuously act on the mineral surface and its microenvironment, thus facilitating the simultaneous release of multiple metal components from complex minerals.

[0068] Secondly, based on the results of single-strain and double-strain controls, it was difficult for any single strain or any combination of two strains to achieve the same leaching effect as the experimental group. Among the single-strain groups, the strain with relatively stronger leaching ability was... A. ferrooxidans However, its uranium leaching rate was only 32.7%, indicating that oxidation alone is insufficient to efficiently destroy complex ore systems; the leaching rates of the other single-bacterial groups were even lower, suggesting that relying solely on a single mechanism such as acid production, surfactant generation, or assisted dissolution is insufficient to achieve deep leaching of polymetallic ores. Among the dual-bacterial groups, with... A. ferrooxidans C. cladosporioides + A. ferrooxidans The combined performance was relatively good, but the leaching rates of uranium, copper, and rare earth elements were only 47.7%, 40.1%, and 17.2%, respectively. This indicates that although acidification and oxidation are key steps, the overall leaching efficiency is still significantly limited when there is a lack of interfacial strengthening and auxiliary solubilizing effects.

[0069] Furthermore, the results of the three-bacterial control group show that different combinations of functional bacteria have varying effects on the release of different metals. For example, the control group M ( C. cladosporioides + H. seropedicae + A. ferrooxidans The leaching effect on rare earth elements was better, with a leaching rate of 84.2%; the control group N ( C. cladosporioides + Leifsonia sp.+ A. ferrooxidans The leaching effect on uranium and copper was strong, with uranium and copper leaching rates reaching 84.6% and 76.3%, respectively; the control group O ( H. seropedicae + Leifsonia sp.+ A. ferrooxidansThe leaching rate for rare earth elements reached 72.4%. These results indicate that different strains play complementary roles in acidification and mineralization, mineral surface wetting and dispersion, mineral fracture penetration, metal oxidation, and interfacial mass transfer. Only when all four types of functional bacteria participate in the system and are inoculated in a predetermined order can the metabolic specialization and functional synergy of each strain over time be maximized, ensuring a continuous connection between ore surface activation, mineral structure destruction, metal oxidation release, and enhanced mass transfer processes, thereby achieving the highest overall leaching efficiency.

[0070] Therefore, the multi-strain synergistic system described in this invention is not a simple superposition of the effects of individual strains, but rather a dynamically evolving leaching microenvironment constructed through the relay effect of different functional strains at different reaction stages. This achieves efficient, mild, and multi-target synergistic leaching of complex hard-rock U-polymetallic ores. While significantly improving the recovery rate of uranium and associated metals, this system avoids the dependence on large amounts of external acid and strong chemical oxidants required by traditional strong acid methods, thus reducing acid consumption and subsequent wastewater treatment pressure. It exhibits good environmental friendliness and promising industrial application prospects.

[0071] Example 3: Survival of multiple bacterial strains in the bioleaching experiment of U-polymetallic ore The survival rates of strains B, C, D, and E in the experimental group and single-strain control group of Example 2 were determined, and the results are as follows: Figure 1 As shown.

[0072] It can be seen that, compared with single-strain leaching systems, the multi-strain synergistic system constructed in this invention exhibits stronger tolerance to heavy metal toxicity in complex mineral environments. Different strains, through metabolic complementarity and niche specialization, can reduce the biotoxicity of free metal ions to a certain extent and maintain the community's metabolic activity and the sustainability of interfacial reactions, thereby improving the stability of the leaching process. This synergistic effect helps to continuously promote mineral dissolution and metal release, demonstrating the potential advantages of multi-strain collaborative systems in the efficient leaching of metal resources.

[0073] Example 4 This embodiment uses hard-rock UV polymetallic ore as the object and conducts a 20-day comparative experiment. In this embodiment, the acid-producing microorganism is *Paecilomyces wanensis* (…). Paecilomyces variotii CCTCC AF 2019001 was purchased from the China Center for Type Culture Collection; the auxiliary dissolving microorganism was Aeromonas hydrophila (CCTCC AF 2019001). Aeromonas hydrophila ATCC7966) was purchased from the American Center for Type Culture Collection; the surfactant-producing bacterium was *Oligotrophomonas rhizophila* (ATCC7966). Stenotrophomonas rhizophila ATCC BAA-473 was purchased from the American Center for Type Culture Collection; the metal oxidizing microorganism was Bacillus rubrum XS6-1 ( Microbacterium testaceumXS6-1CGMCC 28318 is deposited at the China General Microbiological Culture Collection Center on August 31, 2023.

[0074] (1) Material preparation: Select 1 kg of hard rock uranium-vanadium polymetallic ore containing 0.13% U and 0.24% V, crush it to 4 mm particle size, and prepare 1 L suspension.

[0075] (2) Inoculation: Add the acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms in that order. Specifically, add the acid-producing microorganisms first. P. variotii and mineral-dissolving microorganisms A. hydrophila After being mixed evenly with the ore and reacted for 12 hours, surfactant-producing bacteria were added. S. rhizophila After reacting for another 8 hours, metal-oxidizing microorganisms were added. ​ XS6-1. The ratio of the four bacterial strains was 2:1:2:5, and the initial density of each strain was 10. 7 -10 8 CFU / mL.

[0076] (3) Operation: The initial pH was set to 6.0, the temperature was kept constant at 20 °C, and the reaction was continued for 20 days.

[0077] (4) Monitoring: There was no sludge blockage during the reaction process and the system had good fluidity, as shown in Table 3.

[0078] Table 3

[0079] Results Analysis: In the multi-species synergistic leaching system constructed in this embodiment, as the reaction time increased, the concentrations of citric acid, iron carrier, and rhamnolipid in the system continued to increase, while the concentrations of uranium and vanadium increased synchronously. This indicates that the system can gradually establish a coupled leaching environment of "organic acid activation-complexation migration-interface enhancement-selective oxidation" under near-neutral initial conditions, thereby achieving efficient release of uranium and vanadium from hard rock UV polymetallic ores.

[0080] Specifically, in the initial stage of the reaction (0-5 days), acid-producing microorganisms... ​ With auxiliary mineral-dissolving microorganisms ​First, the strain colonized and acted on the ore surface. The citric acid concentration in the system rose to 4.8 mM, and the iron carrier concentration reached 289.5 µM, indicating that the strain had begun to secrete organic acids and metal complex metabolites, producing a preliminary activation effect on the uranium- and vanadium-bearing minerals on the ore surface. During this stage, the uranium concentration rose to 674 mg / L, and the vanadium concentration rose to 1027 mg / L, with the vanadium release exceeding that of uranium. This indicates that under the synergistic effect of organic acid complexation and iron carrier, some vanadium components in the ore more easily entered the liquid phase, demonstrating that the complexation and migration process significantly promoted vanadium release.

[0081] During the mid-reaction period (5-10 days), the concentration of citric acid in the system further increased from 4.8 mM to 6.7 mM, the concentration of iron support increased from 289.5 µM to 364.2 µM, and the concentration of rhamnolipin increased from 45 mg / L to 120 mg / L; simultaneously, the concentration of uranium increased from 674 mg / L to 1027 mg / L, and the concentration of vanadium increased from 1002 mg / L to 1993 mg / L. These results indicate that with the increase of surfactant-producing bacteria... ​ After addition, the wetting, dispersion, and interfacial mass transfer capabilities of mineral particles are significantly enhanced, which helps to expand the mineral-solution interface and accelerate the penetration of organic acids and iron carriers into mineral microcracks and reaction sites, thereby promoting the continuous release of uranium and vanadium from the ore lattice or surface active sites. In particular, vanadium is more easily maintained in the liquid phase in a soluble form in the presence of complexing agents, thus exhibiting a faster accumulation growth trend.

[0082] In the later stages of the reaction (10-20 days), the citric acid concentration continued to rise to 9.2 mM, the siderophore concentration to 479.7 µM, and the rhamnolipid concentration to 155 mg / L, indicating that the activation of organic acids, ligand complexation, and interfacial enhancement were still ongoing within the system. Simultaneously, with the development of metal-oxidizing microorganisms... ​ The effect of XS6-1 was further enhanced, with some low-valence or structurally bound uranium and vanadium in the ore being continuously activated and released into the solution, ultimately reaching a uranium concentration of 1132 mg / L and a vanadium concentration of 2208 mg / L. Compared with the intermediate stage, the rate of increase in uranium and vanadium concentrations slowed down in the later stage, indicating that the system had approached leaching equilibrium at 20 days, but still maintained a high leaching level.

[0083] Mechanistically, the efficient vanadium release in this embodiment is closely related to its complexation and migration characteristics. Vanadium can exist in various states in ores. In the presence of organic acids and iron carriers, its solubility can be increased through coordination complexation, and its re-adsorption or re-precipitation on the mineral surface can be reduced, thereby enhancing its stability and migration in the liquid phase. Simultaneously, the continuous accumulation of rhamnose further strengthens the mineral interface reaction and mass transfer process, allowing the complexation release and migration of vanadium to continue. Therefore, the multi-strain synergistic system described in this invention has a significant promoting effect on the leaching of vanadium from vanadium-bearing uranium ores.

[0084] In summary, this embodiment demonstrates that a multi-species synergistic system constructed sequentially from acid-producing microorganisms, ore-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms can achieve continuous and efficient release of uranium and vanadium from hard-rock UV polymetallic ores under relatively mild conditions of initial pH 6.0 and temperature 20 °C. This system significantly improves the leaching efficiency of UV polymetallic ores through the synergistic effects of multiple mechanisms, including organic acid activation, iron carrier complexation and migration, surfactant-enhanced interfacial mass transfer, and selective activation by metal-oxidizing microorganisms, demonstrating promising prospects for green leaching applications.

[0085] Example 5 The results of monitoring ore-microorganism interactions and ore morphology during the bioleaching process of uranium-vanadium polymetallic ore in Example 4 are as follows: ​ As shown.

[0086] It can be seen that the dynamic evolution of the ore surface from relatively intact and dense to fragmented, loose and enhanced with biological attachment during the bioleaching process of uranium-vanadium polymetallic ore indicates that there is a significant interfacial interaction between microorganisms and ore, accompanied by the continuous destruction of mineral structure and the advancement of leaching reaction.

[0087] Specifically, ​ In the sterile control group shown in A, the ore surface was relatively intact, with a clear lamellar structure, relatively flat edges, and a relatively dense surface. Only a small amount of natural debris was attached, indicating that no significant erosion or dissociation occurred on the ore surface under conditions without the participation of microorganisms. ​ B represents the surface morphology of the ore at the initial reaction stage (t=0 d). At this time, the main body of the ore still maintains a relatively complete blocky structure, the surface is relatively flat, and only a small number of original cracks or attached particles appear, indicating that the leaching reaction is still in the initial stage and the modification effect of microorganisms on the mineral surface is not yet significant.

[0088] After the reaction had proceeded for 20 days, ​ C indicates that the ore has undergone significant fragmentation, with the original large blocky structure destroyed into numerous fine particles and irregular debris, suggesting that under the continuous action of microorganisms, the surface structure of the ore has become significantly loose, brittle, and gradually disintegrated. Meanwhile,​ D is ​ The magnified view of C further shows that a large number of rod-shaped or short rod-shaped microbial cells are attached to the surface of the ore and are in close contact with the mineral particles. Cell aggregation can be seen in some areas, indicating that microorganisms can colonize and accumulate on the surface of the ore, thereby enhancing the acidification, complexation, oxidation and interfacial mass transfer processes of the mineral surface through local metabolic activities.

[0089] The above results demonstrate that the multi-species synergistic leaching system constructed in this invention does not solely rely on chemical reactions in the solution phase. Instead, it induces gradual cleavage, erosion, and fragmentation of the ore surface through direct attachment and interfacial interactions of microorganisms on the ore surface. This continuously increases the reaction surface area and exposes new active sites, ultimately promoting the release of target metals such as uranium and vanadium from the ore into the liquid phase. In other words, ​ The morphological changes shown confirm, at the microscopic level, the synergistic leaching mechanism of "microbial attachment - mineral surface activation - structural destruction - metal release".

[0090] Example 6: Effect of inoculum ratio on uranium-molybdenum ore leaching efficiency This example uses hard-rock uranium-molybdenum polymetallic deposits as the subject, and a comparative experiment was conducted over a period of 20 days. The bacterial strain used in this example is the same as that in Example 1.

[0091] (1) Material preparation: Same as in Example 1.

[0092] (2) Inoculation method: Each group of strains was added in the inoculation sequence described in Example 1, that is, acid-producing microorganisms and mineral-dissolving microorganisms were added first, and after being mixed evenly with the ore and reacted for 14 hours, surfactant-producing microorganisms were added, and after reacting for another 10 hours, metal-oxidizing microorganisms were added. Except for the different addition ratios between strains, all other conditions were the same as in Example 1.

[0093] (3) Operating conditions: Same as in Example 1.

[0094] (4) The ratio of the experimental group to the control group was set as follows: Experimental group: Acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms were sequentially introduced into the reaction system in a ratio of 1:1:1:1.

[0095] Control group P: Acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms were sequentially introduced into the reaction system in a ratio of 0.5:1:2:5.

[0096] Control group Q: Acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms were sequentially introduced into the reaction system in a ratio of 2:6:2:5.

[0097] Control group R: Acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms were sequentially introduced into the reaction system in a ratio of 2:1:0.5:5.

[0098] Control group S: Acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms were sequentially introduced into the reaction system in a ratio of 2:1:2:12.

[0099] (5) Different inoculation ratios of different bacterial strains have a significant impact on the leaching effect of uranium and molybdenum, such as ​ As shown.

[0100] Results Analysis: When the bacterial composition, inoculation order, and operating conditions remained consistent, changing only the ratio of the four functional bacterial strains affected the leaching effect of uranium-molybdenum ore. In Example 1, the strain ratio was 2:1:2:5, achieving a uranium leaching rate of 96.9% and a molybdenum leaching rate of 91.1% after 20 days. In Example 6, the experimental group used a strain ratio of 1:1:1:1, achieving a uranium leaching rate of 90.5% and a molybdenum leaching rate of 85.2% after 20 days, significantly better than the control groups. This indicates that the strain ratio defined in this invention can effectively coordinate the functions of acid activation, ore dissolution assistance, interface enhancement, and metal oxidation, and is most conducive to the synergistic effect of the multi-bacterial system.

[0101] In contrast, the uranium and molybdenum leaching rates of each control group decreased to varying degrees, indicating that when the addition ratio of any functional strain exceeds the scope of this invention, the overall leaching effect of the system will be affected. Among them, the leaching effect of control group P was the lowest, indicating that when the proportion of acid-producing microorganisms is too low, the initial acidification and ore surface activation are insufficient, significantly limiting the subsequent leaching process. Although control groups Q, R, and S still maintained a certain leaching capacity, they were all significantly lower than those of the example, indicating that whether the proportion of auxiliary dissolving microorganisms is too high, the proportion of surfactant-producing bacteria is too low, or the proportion of metal-oxidizing microorganisms is too high, it will disrupt the dynamic balance between the functional modules in the multi-bacterial system to varying degrees.

[0102] In summary, the inoculation ratio of the strains specified in this invention has a clear technical effect, and a reasonable ratio configuration is one of the key conditions for achieving efficient and synergistic leaching of uranium-molybdenum polymetallic ores.

[0103] Example 7: Effect of stepwise inoculation interval on uranium-molybdenum ore leaching efficiency This example uses hard-rock uranium-molybdenum polymetallic deposits as the subject, and a comparative experiment was conducted over a period of 20 days. The bacterial strain used in this example is the same as that in Example 1.

[0104] (1) Material preparation: Same as in Example 1.

[0105] (2) Inoculation conditions: All strains were added according to the inoculation sequence described in Example 1, i.e., acid-producing microorganisms and auxiliary mineral-dissolving microorganisms were added first, followed by surfactant-producing microorganisms, and finally metal-oxidizing microorganisms. The ratio of the four strains (acid-producing microorganisms: auxiliary mineral-dissolving microorganisms: surfactant-producing microorganisms: metal-oxidizing microorganisms) was 2:1:2:5, and the initial density of each strain was controlled at 10. 7 -10 8 Within the CFU / mL range, only the reaction interval between the two inoculations was adjusted, and all other conditions were the same as in Example 1.

[0106] (3) Operating conditions: Same as in Example 1.

[0107] (4) The time interval between the experimental group and the control group is set as follows: Control group T: First, acid-producing microorganisms and mineral-dissolving microorganisms are added and mixed evenly with the ore. After reacting for 4 hours, surfactant-producing bacteria are added, and after reacting for another 10 hours, metal-oxidizing microorganisms are added.

[0108] Control group U: First, acid-producing microorganisms and mineral-dissolving microorganisms are added and mixed evenly with the ore. After reacting for 14 hours, surfactant-producing bacteria are added, and after reacting for another 2 hours, metal-oxidizing microorganisms are added.

[0109] Control group V: First, add acid-producing microorganisms and mineral-dissolving microorganisms, mix them evenly with the ore and react for 4 hours, then add surfactant-producing bacteria, and after another 2 hours of reaction, add metal-oxidizing microorganisms.

[0110] Experimental Group A: First, acid-producing microorganisms and mineral-dissolving microorganisms are added and mixed evenly with the ore. After reacting for 24 hours, surfactant-producing bacteria are added, and after reacting for another 12 hours, metal-oxidizing microorganisms are added.

[0111] Experimental Group B: First, acid-producing microorganisms and mineral-dissolving microorganisms are added and mixed evenly with the ore. After reacting for 16 hours, surfactant-producing bacteria are added, and after reacting for another 24 hours, metal-oxidizing microorganisms are added.

[0112] (5) Different step-inoculation intervals have a significant impact on the leaching effect of uranium and molybdenum, as shown in Table 4.

[0113] Table 4

[0114] Results Analysis: Under the condition that the bacterial composition, inoculation order, and inoculation ratio remained consistent, changing only the stepwise inoculation interval between different functional strains significantly affected the leaching effect of uranium-molybdenum ore. In Example 1, the uranium leaching rate and molybdenum leaching rate reached 96.9% and 91.1%, respectively, which were significantly higher than those of the control groups. This indicates that the interval setting is more conducive to the temporal connection and synergistic effect of different functional strains in the multi-bacterial system.

[0115] Specifically, in control group T, shortening the first-stage interval to 4 hours reduced uranium and molybdenum leaching rates to 64.9% and 54.6%, respectively; in control group U, shortening the second-stage interval to 2 hours reduced uranium and molybdenum leaching rates to 69.2% and 57.8%, respectively; while control group V, by simultaneously shortening the intervals between the first and second stages, further reduced uranium and molybdenum leaching rates to 51.3% and 40.4%, the lowest among all groups. These results indicate that insufficient initial reaction time hinders the acid-producing and ore-dissolving microorganisms from fully completing the acidification, activation, and local dissolution of the ore surface. Furthermore, surfactant-producing bacteria struggle to establish sufficient interfacial enhancement effects, resulting in subsequent addition of metal-oxidizing microorganisms failing to continuously promote uranium and molybdenum release based on adequate pretreatment, thus significantly reducing the leaching efficiency.

[0116] In contrast, the experimental group in Example 7 maintained a relatively high leaching level, but it was lower than that in Example 1. This indicates that moderately extending the reaction time of a certain stage does not significantly weaken the leaching capacity of the system like excessively shortening it, but it also cannot further improve the leaching effect. The reason may be that after the reaction time of a certain stage is too long, the functional effect corresponding to that stage has basically reached saturation, and further extension cannot significantly enhance the overall synergy of the system. Instead, it weakens the sequential advantage of the successive relay and dynamic coupling of each functional strain.

[0117] In summary, the stepwise inoculation interval of this invention can better match the progress rhythm of different functional processes such as acid activation, assisted leaching, interface strengthening, and metal oxidation, and is one of the key process conditions for achieving efficient synergistic leaching of uranium-molybdenum polymetallic ores. Whether the stepwise inoculation interval is too short or too long, it will weaken the synergistic effect of the multi-bacterial system to varying degrees, thereby reducing the leaching efficiency of uranium and molybdenum.

[0118] Comparative Example 1: Effect of inoculation sequence on uranium-molybdenum ore leaching efficiency This comparative example uses hard-rock uranium-molybdenum polymetallic ore as the object and conducts a 5-day comparative experiment. The compound microorganisms used in this comparative example are the same as those in Example 1, the only difference being the order in which the strains are added.

[0119] (1) Material preparation: Same as in Example 1.

[0120] (2) Inoculation: The total amount of the four strains added in each comparative example was consistent with that in Example 1. The strain ratio (acid-producing microorganisms: mineral-dissolving microorganisms: surfactant-producing microorganisms: metal-oxidizing microorganisms) was 2:1:2:5, and the initial density of each strain was 10. 7 -10 8 CFU / mL. Except for the order of bacterial inoculation, all other conditions were the same as in Example 1.

[0121] (3) Operation: The initial pH was set to 4.0, the temperature was kept constant at 30 °C, and the reaction was continued for 5 days.

[0122] (4) Different vaccination sequences are set as follows: Comparative Example 1-A: First, metal-oxidizing microorganisms are added to the ore suspension. ​ After reacting with the ore for 14 hours, acid-producing microorganisms are added. ​ and mineral-dissolving microorganisms ​ After reacting for another 10 hours, surfactant-producing bacteria were finally added. ​ sp.

[0123] Comparative Example 1-B: First, surfactant-producing bacteria are added to the ore suspension. ​ After reacting with the ore for 10 hours, acid-producing microorganisms are added. ​ and mineral-dissolving microorganisms ​ After reacting for another 14 hours, metal-oxidizing microorganisms were finally added. ​ .

[0124] Comparative Example 1-C: First, acid-producing microorganisms are added to the ore suspension. ​ After reacting with the ore for 14 hours, metal-oxidizing microorganisms are added. ​ After reacting for another 10 hours, add mineral-dissolving microorganisms. ​ and surfactant-producing bacteria ​ sp.

[0125] Comparative Example 1-D: First, add mineral-dissolving microorganisms to the ore suspension. ​ and surfactant-producing bacteria ​ After reacting with the ore for 14 hours, acid-producing microorganisms are added. ​ ​ After reacting for another 10 hours, metal-oxidizing microorganisms were finally added. ​ ​ .

[0126] Comparative Example 1-E: acid-producing microorganisms ​ Mineral-dissolving microorganisms ​ ​ Surfactant-producing bacteria ​ sp. and metal oxidation microorganisms ​ ​ Add the minerals to the ore suspension at a ratio of 2:1:2:5 all at once, mix thoroughly, and then proceed with the subsequent reaction.

[0127] (5) The inoculation sequence of different bacterial strains has a significant impact on the leaching effect of uranium and molybdenum, such as ​ As shown.

[0128] Results analysis: The inoculation sequence of different microbial strains significantly affected the leaching efficiency of uranium and molybdenum. In Example 1, the concentrations of both uranium and molybdenum leachates were the highest, indicating that the sequential inoculation method of "first acid-producing microorganisms and auxiliary mineral-dissolving microorganisms, then surfactant-producing microorganisms, and finally metal-oxidizing microorganisms" is most conducive to establishing a continuous leaching microenvironment, thereby obtaining the best leaching effect.

[0129] In contrast, the concentrations of uranium and molybdenum leaching solutions in each comparative example were significantly reduced, indicating that disrupting the order of bacterial addition weakens the synergistic effect of different functional strains in ore surface activation, interface enhancement, and metal oxidation release. Specifically, Comparative Examples 1-A and 1-B showed poor leaching effects, suggesting that premature addition of metal-oxidizing microorganisms or surfactant-producing bacteria is detrimental to the establishment of the initial acidification and solubilization environment. Comparative Examples 1-C and 1-D showed some improvement, but were still inferior to Example 1. Comparative Example 1-E was better than some of the out-of-order groups, but still inferior to Example 1, indicating that simultaneous addition of strains at once is insufficient to achieve the synergistic effect of stepwise inoculation.

[0130] In summary, the sequential inoculation method of the strains used in Example 1 of this invention has significant advantages, proving that the synergistic leaching of multiple strains depends not only on the strain composition, but also significantly on the rational addition order of each functional strain.

[0131] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A composite microorganism for synergistically driving the leaching of uranium and polymetallic resources, characterized in that, This includes acid-producing microorganisms, mineral-dissolving microorganisms, surfactant-producing bacteria, and metal-oxidizing microorganisms.

2. The composite microorganism according to claim 1, characterized in that, The acid-producing microorganisms are one or more of Cladosporium, Corylus, and Paecilomyces.

3. The composite microorganism according to claim 1, characterized in that, The auxiliary mineral-dissolving microorganisms are one or more of the following: spirulina, pandora bacilli, muscarinic bacteria, and aeromonas.

4. The composite microorganism according to claim 1, characterized in that, The surfactant-producing bacteria are one or more of the following: Oligotrophomonas, Rifsonia, and Mycobacterium.

5. The composite microorganism according to claim 1, characterized in that, The metal-oxidizing microorganisms are one or more of the following: Microbacterium, Thiobacillus, Leptospira, Aspergillus, and Penicillium.

6. The composite microorganism according to claim 1, characterized in that, The volume ratio of the acid-producing microorganism, the mineral-dissolving microorganism, the surfactant-producing bacteria and the metal-oxidizing microorganism is (1-2):1:(1-2):(1-5).

7. A leaching method for uranium and polymetallic resources, characterized in that, Bioleaching is performed using the composite microorganisms described in any one of claims 1-6. First, the acid-producing microorganisms and the auxiliary dissolving microorganisms are added and mixed evenly with the ore for a pre-reaction of 12-24 hours. Then, the surfactant-producing bacteria are added, and after a second reaction of 8-24 hours, the metal-oxidizing microorganisms are added.

8. The leaching method according to claim 7, characterized in that, The mass ratio of each bacterial solution in the composite microorganism to the ore is 1:(100000-5000000), the reaction pH is maintained at 1.0-9.0, and the temperature is 10-60 ℃.

9. The leaching method according to claim 7, characterized in that, Leaching methods include heap leaching, column leaching, stirred leaching, or in-situ leaching.

10. The leaching method according to claim 9, characterized in that, The ore includes uranium ore, U-polymetallic associated ore, tailings heaps, or industrial metallurgical slag.

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