A system and method for modeling leaching and coal enrichment processes in a uranium-bearing source rock

Abstract

This invention relates to the field of geochemical simulation technology, and particularly to a system and method for simulating the leaching process of uranium-bearing source rocks and coal seam enrichment. The system includes: a primary dynamic leaching component, in which a background solution undergoes a dynamic leaching reaction with a uranium-bearing source rock sample under a preset oxidizing atmosphere to generate uranium-bearing leachate; a secondary coal sample seepage reaction component, in which the uranium-bearing leachate undergoes a seepage reaction with a coal sample under a reducing atmosphere; a fluid transport component, used to continuously transport the uranium-bearing leachate generated by the primary dynamic leaching component to the secondary coal sample seepage reaction component; and an atmosphere control component, used to independently regulate the oxidizing or reducing atmosphere within the primary dynamic leaching component and the secondary coal sample seepage reaction component. The technical solution of this invention can integrate and continuously simulate the entire process of uranium release from source rocks, fluid migration, and coal sample enrichment, realistically reducing the actual geological environmental gradient of uranium from surface oxidative leaching to underground reduction and enrichment.

Description

Technical Field

[0001] This invention relates to the field of geochemical simulation technology, and in particular to a simulation system and method for leaching and coal seam enrichment processes in uranium-bearing source rocks. Background Technology

[0002] Uranium enrichment in coal is typically closely related to a multi-stage process involving uranium supply from the source region, fluid migration, and coal seam reduction and precipitation. Uranium-bearing source rocks undergo leaching under the influence of groundwater, surface water, or oxidizing fluids, forming migratory uranium-bearing fluids. These fluids migrate into the coal seam along fractures, pores, and interlayer channels, where they undergo adsorption, complexation, reduction precipitation, and local enrichment under the combined influence of organic matter, sulfides, clay minerals, and the reducing environment, resulting in anomalous uranium enrichment in coal. Currently, the analysis and simulation of uranium enrichment phenomena are crucial for uranium exploration and the assessment of associated uranium resources in coal.

[0003] In existing technologies, leaching experimental devices are typically used to simulate the uranium release process from source rocks. However, these methods cannot reproduce the uranium fixation process in coal seams and are difficult to accurately reflect the actual geological environment gradient from surface oxidation and leaching to underground reduction and enrichment of uranium.

[0004] Therefore, there is an urgent need to develop a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a simulation system and method for the leaching process of uranium-bearing source rocks and the enrichment process of coal seams. It can simulate the entire process of uranium release from source rocks, fluid migration and coal sample enrichment in an integrated and continuous manner, and realistically reduce the actual geological environment gradient of uranium from surface oxidation leaching to underground reduction enrichment.

[0006] In a first aspect, the present invention provides a simulation system for the leaching and coal seam enrichment processes of uranium-bearing source rocks, comprising: A primary dynamic leaching assembly is filled with a uranium-bearing source rock sample. The primary dynamic leaching assembly is equipped with a liquid inlet, a liquid outlet, and an air inlet. A preset background solution flows into the primary dynamic leaching assembly from the liquid inlet and undergoes a dynamic leaching reaction with the uranium-bearing source rock sample under a preset oxidizing atmosphere to generate uranium-bearing leaching liquid, which flows out from the liquid outlet. The secondary coal sample seepage reaction assembly is connected to the primary dynamic leaching assembly and is filled with coal sample. The secondary coal sample seepage reaction assembly is provided with a liquid inlet, a liquid outlet and an air inlet. The uranium-containing leaching liquid flowing out of the liquid outlet of the primary dynamic leaching assembly flows into the liquid inlet of the secondary coal sample seepage reaction assembly and undergoes a seepage reaction with the coal sample under a preset reducing atmosphere to simulate the migration, adsorption, complexation, reduction and enrichment process of uranium in the coal seam. The fluid transport component is connected to the outlet of the primary dynamic leaching component and the inlet of the secondary coal sample seepage reaction component, respectively, and is used to continuously transport the uranium-containing leaching liquid generated by the primary dynamic leaching component to the secondary coal sample seepage reaction component. An atmosphere control component is connected to the air inlet of the primary dynamic leaching component and the air inlet of the secondary coal sample seepage reaction component, respectively, and is used to independently regulate the oxidizing atmosphere or reducing atmosphere in the primary dynamic leaching component and the secondary coal sample seepage reaction component.

[0007] In a second aspect, the present invention provides a method for simulating the leaching and coal seam enrichment processes of uranium-bearing source rocks, applied to the system described in the first aspect of the present invention, the method comprising: Uranium-bearing source rock samples are filled into the primary dynamic leaching assembly, and coal samples are filled into the secondary coal sample seepage reaction assembly. Start the fluid delivery assembly and the atmosphere control assembly. Use the fluid delivery assembly to allow the background solution to flow into the first-stage dynamic filtration assembly, and at the same time use the atmosphere control assembly to introduce air or oxygen into the first-stage dynamic filtration assembly. The fluid delivery assembly is used to continuously flow the uranium-containing leachate generated by the primary dynamic leaching assembly into the secondary coal sample seepage reaction assembly, while the atmosphere control assembly is used to introduce nitrogen or carbon dioxide into the secondary coal sample seepage reaction assembly. A first liquid sample is collected from the first liquid intake port of the first-stage dynamic leaching assembly to obtain the first uranium concentration of the first liquid sample. Based on the uranium content of the source rock, the proportion of leached uranium in the source rock, the organic matter content of the coal sample, the sulfide content of the coal sample, the total pore volume of the coal sample, the initial uranium content of the coal sample, and the first uranium concentration, the uranium enrichment coefficient is obtained to simulate the leaching process of the uranium source rock mass and the enrichment process of the coal seam.

[0008] This invention provides a simulation system and method for leaching and coal seam enrichment processes in uranium-bearing source rocks. By connecting a primary dynamic leaching component in series with a secondary coal sample seepage reaction component, it achieves integrated and continuous simulation of uranium release from the source rock, fluid migration, and coal enrichment processes. This solves the problem of current simulations that only focus on the leaching process, resulting in independent and unconnected leaching and adsorption devices. By incorporating an atmosphere control component, the oxidizing or reducing atmosphere within both stages can be independently adjusted, thus constructing an oxidation-reduction environmental gradient that more closely resembles actual geological processes. A fluid transport component continuously delivers the uranium-bearing leachate generated in the primary stage to the secondary stage, achieving continuous and uninterrupted coupling between the two stages. This provides a more realistic, continuous, and controllable simulation platform for uranium enrichment research in coal. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of a simulation system for leaching and coal seam enrichment processes in uranium-bearing source rock masses, provided in an embodiment of the present invention.

[0011] Figure label: 1- Primary dynamic filtration module; 11-First inert support layer; 12-Uranium-bearing source rock filling layer; 13-Second inert support layer; 2-Secondary coal sample seepage reaction assembly; 21 - First filter layer; 22 - First support layer; 23-Coal seam; 24 - Second support layer; 25 - Second filter layer; 3-Fluid transport components; 31-Storage tank; 32 - First connecting pipe; 33-Constant flow pump; 34 - Second connecting pipe; 4-Atmosphere control components; 41-First gas cylinder; 42 - Second gas cylinder; 51-First liquid intake port; 52 - Second liquid intake port. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Please refer to Figure 1 This invention provides a simulation system for leaching and coal seam enrichment processes in uranium-bearing source rocks, comprising: The first-stage dynamic leaching component 1 is filled with a uranium-bearing source rock sample. The first-stage dynamic leaching component 1 is equipped with a liquid inlet, a liquid outlet and an air inlet. The preset background solution flows into the first-stage dynamic leaching component 1 from the liquid inlet and undergoes a dynamic leaching reaction with the uranium-bearing source rock sample under a preset oxidizing atmosphere to generate uranium-bearing leaching liquid, which flows out from the liquid outlet. The secondary coal sample seepage reaction component 2 is connected to the primary dynamic leaching component 1 and is filled with coal sample. The secondary coal sample seepage reaction component 2 is equipped with a liquid inlet, a liquid outlet and an air inlet. The uranium-containing leaching liquid flowing out of the liquid outlet of the primary dynamic leaching component 1 flows into the liquid inlet of the secondary coal sample seepage reaction component 2 and undergoes a seepage reaction with the coal sample under a preset reducing atmosphere to simulate the migration, adsorption, complexation, reduction and enrichment process of uranium in the coal seam. The fluid transport component 3 is connected to the outlet of the primary dynamic leaching component 1 and the inlet of the secondary coal sample seepage reaction component 2, respectively, and is used to continuously transport the uranium-containing leaching liquid generated by the primary dynamic leaching component 1 to the secondary coal sample seepage reaction component 2. The atmosphere control component 4 is connected to the air inlet of the primary dynamic leaching component 1 and the air inlet of the secondary coal sample seepage reaction component 2, respectively, and is used to independently regulate the oxidizing atmosphere or reducing atmosphere in the primary dynamic leaching component 1 and the secondary coal sample seepage reaction component 2.

[0014] In this embodiment of the invention, the fluid delivery component 3 is disposed between the primary dynamic leaching component 1 and the secondary coal sample seepage reaction component 2, and is connected to the outlet of the primary dynamic leaching component 1 and the inlet of the secondary coal sample seepage reaction component 2, respectively. The outlet of the primary dynamic leaching component 1 is connected to the inlet of the secondary coal sample seepage reaction component 2 via the fluid delivery component 3, so that the uranium-containing leachate produced by the primary dynamic leaching component 1 can continuously and without interruption enter the secondary coal sample seepage reaction component 2. In addition, the fluid delivery component 3 is also used to deliver the background solution to the inlet of the primary dynamic leaching component 1, providing a stable liquid source for the leaching reaction. The background solution is one of deionized water, simulated groundwater, bicarbonate solution, oxygenated solution, or acidic leachate, and different geological fluid environments are simulated by adjusting the solution type, pH, and Eh conditions. The atmosphere control component 4 is connected to the air inlet of the primary dynamic leaching component 1 and the air inlet of the secondary coal sample seepage reaction component 2, respectively, forming two independent gas paths. The gas types, flow rates, and pressures of the two gas paths can be independently adjusted to maintain an oxidizing atmosphere in the primary dynamic leaching assembly 1 (achieved by introducing air or oxygen) and a reducing atmosphere in the secondary coal sample seepage reaction assembly 2 (achieved by introducing nitrogen or carbon dioxide), thus creating an environmental gradient from oxidation to reduction within the system. During the simulation, the background solution is fed into the primary dynamic leaching assembly 1 via the fluid transport assembly 3, leaching the uranium-bearing source rock sample under an oxidizing atmosphere to generate uranium-bearing leachate. The uranium-bearing leachate then enters the secondary coal sample seepage reaction assembly 2 via the fluid transport assembly 3, reacting with the coal sample under a reducing atmosphere to simulate the migration, adsorption, complexation, reduction, and enrichment processes of uranium in the coal seam.

[0015] As can be seen, by connecting the primary dynamic leaching component 1 and the secondary coal sample seepage reaction component 2 in series and independently controlling the two-stage atmosphere, the present invention realizes the integrated continuous simulation of the entire process of uranium release from the source rock, fluid migration and coal sample enrichment. An environmental gradient of oxidation and reduction is formed within the system, which can more realistically reflect the complete geological process of uranium release from the source rock to coal seam fixation.

[0016] In one embodiment of the present invention, the primary dynamic filtration component 1 is a columnar structure; The interior of the primary dynamic leaching component 1 is provided with a first inert support layer 11, a uranium-bearing source rock filling layer 12, and a second inert support layer 13 in sequence along the direction of background solution flow.

[0017] In this embodiment, the primary dynamic leaching component 1 is a vertically arranged leaching column, made of glass, plexiglass, polytetrafluoroethylene, or other corrosion-resistant transparent materials. The leaching column has a liquid inlet and an air inlet at the top, and a liquid outlet at the bottom. Inside the leaching column, from top to bottom, are arranged an upper inert support layer, a uranium-bearing source rock filling layer 12, and a lower inert support layer. The inert support layer uses quartz sand or glass beads with a particle size of 2-5 mm to prevent the loss of source rock particles and to ensure uniform distribution of the leachate. The background solution enters the leaching column through the top inlet, flows through the upper inert support layer, and is evenly distributed and has its flow rate slowed by the action of the first inert support layer 11, preventing direct impact on the source rock layer. Subsequently, the background solution enters the uranium-bearing source rock filling layer 12, and under the set oxidizing atmosphere conditions, fully contacts the source rock, leaching out the uranium element to form a uranium-bearing leachate. The uranium-containing leachate passes through the lower inert support layer, which supports the source rock while filtering out fine particulate matter. The treated uranium-containing leachate flows out from the bottom outlet.

[0018] In one embodiment of the present invention, the secondary coal sample seepage reaction component 2 is a vertically or horizontally arranged column structure; The interior of the secondary coal sample seepage reaction assembly 2 is arranged in sequence along the flow direction of the uranium-containing leachate, including a first filter layer 21, a first support layer 22, a coal sample layer 23, a second support layer 24, and a second filter layer 25. The coal sample filled in the coal sample layer 23 is either a coal sample core or coal particles.

[0019] In this embodiment, the secondary coal sample seepage reaction component 2 is a vertically or horizontally arranged seepage reaction column, with the column body made of stainless steel or polytetrafluoroethylene. The seepage reaction column is filled with a coal sample, which can be one of coal particles, compressed coal columns, or undisturbed coal cores. Inert filter layers and support layers are provided at both ends of the coal sample to prevent particle migration and ensure stable liquid flow. The seepage reaction column has an inlet at the inlet end and an outlet at the outlet end. A pressure monitoring interface is provided on the side of the column to monitor pressure changes during the seepage process and determine whether the coal sample is blocked. Uranium-containing leachate flowing from the outlet of the primary dynamic leaching component 1 flows into the secondary coal sample seepage reaction component 2 through the inlet, and undergoes a seepage reaction with the coal sample under a preset reducing atmosphere, simulating the migration, adsorption, complexation, reduction, and enrichment processes of uranium in the coal seam.

[0020] In one embodiment of the present invention, the fluid delivery assembly 3 includes: Storage tank 31 is used to store background solution; The first connecting pipe 32 is used to connect the liquid storage tank 31 to the liquid inlet of the first-stage dynamic filtration assembly 1; A constant flow pump 33 is installed on the first connecting pipe 32 to transport the background solution to the first-stage dynamic filtration assembly 1; A flow regulating valve is installed on the first connecting pipe 32 and is used to regulate the flow rate of the background solution flowing into the first-stage dynamic leaching assembly 1. The second connecting pipe 34 is used to connect the liquid outlet of the primary dynamic leaching component 1 with the liquid inlet of the secondary coal sample seepage reaction component 2.

[0021] In this embodiment, the storage tank 31 is used to store the background solution. A first connecting pipe 32 connects the storage tank 31 to the inlet of the primary dynamic leaching assembly 1. A constant flow pump 33 is installed on the first connecting pipe 32 to deliver the background solution to the primary dynamic leaching assembly 1 at a set flow rate. A flow regulating valve (not shown) is installed on the first connecting pipe 32 to regulate the flow rate of the background solution. A second connecting pipe 34 connects the outlet of the primary dynamic leaching assembly 1 to the inlet of the secondary coal sample seepage reaction assembly 2, allowing the uranium-containing leachate generated by the primary dynamic leaching assembly 1 to continuously enter the secondary coal sample seepage reaction assembly 2 for seepage reaction.

[0022] In one embodiment of the present invention, the atmosphere control component 4 includes: a first gas cylinder 41, a second gas cylinder 42, a first pressure reducing valve, a second pressure reducing valve, a first gas flow controller, a second gas flow controller, a first gas delivery pipeline, and a second gas delivery pipeline. The first gas cylinder 41 contains air or oxygen and is connected to the air inlet of the first-stage dynamic filtration assembly 1 through the first gas supply pipeline. The second gas cylinder 42 contains nitrogen or carbon dioxide and is connected to the inlet of the secondary coal sample seepage reaction component 2 through the second gas pipeline. The first pressure reducing valve and the first gas flow controller are installed on the first gas transmission pipeline; The second pressure reducing valve and the second gas flow controller are installed on the second gas pipeline.

[0023] In this embodiment, the first gas cylinder 41 contains air or oxygen and is connected to the inlet of the primary dynamic leaching assembly 1 via a first gas supply pipeline. Air serves as a standard oxidizing atmosphere, while oxygen serves as an enhanced oxidizing atmosphere. A first pressure reducing valve and a first gas flow controller are installed on the first gas supply pipeline to regulate the gas flow rate entering the primary dynamic leaching assembly 1, thereby creating an oxidizing atmosphere within the assembly. The second gas cylinder 42 contains nitrogen or carbon dioxide and is connected to the inlet of the secondary coal sample seepage reaction assembly 2 via a second gas supply pipeline. Nitrogen serves as a standard reducing atmosphere, while carbon dioxide serves as a weakly acidic reducing atmosphere. A second pressure reducing valve and a second gas flow controller are installed on the second gas supply pipeline to regulate the gas flow rate entering the secondary coal sample seepage reaction assembly 2, thereby creating a reducing atmosphere within the assembly.

[0024] It should be noted that, in order to clearly illustrate the core concept of this invention (two-stage series, independent gas control), the accompanying drawings show a simplified schematic of some pipelines. For example, the gas path connecting the atmosphere control component 4 and the first-stage dynamic filtration component 1 can be configured with multiple gas paths (such as oxygen / air and nitrogen paths) as needed, and corresponding valves can be configured for switching. Before the experiment, the air in the system is purged; after the experiment, the pipeline is purged and cleaned; or in a specific experimental procedure, an inert environment is established before starting the oxidation reaction, a reducing gas such as nitrogen can be briefly or introduced into the first-stage component at a low flow rate. Both the first gas cylinder 41 and the second gas cylinder 42 are connected to the first-stage dynamic filtration component 1 by pipelines and independently supply gas to the first-stage dynamic filtration component 1. The first gas flow controller and the second gas flow controller can also be combined into a single controller on a single pipeline. Any specific adjustments to the pipeline connection method made based on the concept of this invention to achieve independent control of the oxidation-reduction atmosphere within the two-stage components should be considered as equivalent substitutions or direct extensions of the claims of this invention and fall within the protection scope of this invention.

[0025] In one embodiment of the present invention, a first liquid sampling port 51 is provided on the primary dynamic leaching assembly 1 for sampling the uranium-containing leaching liquid flowing out of the primary dynamic leaching assembly 1. The secondary coal sample seepage reaction assembly 2 is equipped with a second liquid sampling port 52, which is used to sample the enriched liquid after seepage reaction flowing out of the secondary coal sample seepage reaction assembly 2.

[0026] In this embodiment, the primary dynamic leaching assembly 1 is provided with a first sampling port 51 for sampling the uranium-containing leachate flowing out of the primary dynamic leaching assembly 1; the secondary coal sample seepage reaction assembly 2 is provided with a second sampling port 52 for sampling the enriched liquid flowing out of the secondary coal sample seepage reaction assembly 2. A sampling point can also be added near the inlet of the secondary coal sample seepage reaction assembly 2 for periodically collecting liquid samples.

[0027] In addition, the system includes a monitoring component and a temperature control component. The monitoring component is used to monitor parameters such as fluid flow rate, pH, Eh, conductivity, and pressure online or offline. The temperature control component uses one or more of a constant temperature chamber, heating belt, or circulating water bath to provide overall temperature control for the primary dynamic leaching component 1 and the secondary coal sample seepage reaction component 2.

[0028] Furthermore, this invention provides a method for simulating the leaching and coal seam enrichment processes of uranium-bearing rock masses, applicable to a simulation system for leaching and coal seam enrichment processes of uranium-bearing rock masses. The method includes: Uranium-bearing source rock samples are filled into the primary dynamic leaching assembly, and coal samples are filled into the secondary coal sample seepage reaction assembly. Start the fluid delivery assembly and the atmosphere control assembly. Use the fluid delivery assembly to allow the background solution to flow into the first-stage dynamic filtration assembly, and at the same time use the atmosphere control assembly to introduce air or oxygen into the first-stage dynamic filtration assembly. The fluid delivery assembly is used to continuously flow the uranium-containing leachate generated by the primary dynamic leaching assembly into the secondary coal sample seepage reaction assembly, while the atmosphere control assembly is used to introduce nitrogen or carbon dioxide into the secondary coal sample seepage reaction assembly. A first liquid sample is collected from the first liquid intake port of the first-stage dynamic leaching assembly to obtain the first uranium concentration of the first liquid sample. Based on the uranium content of the source rock, the proportion of leached uranium in the source rock, the organic matter content of the coal sample, the sulfide content of the coal sample, the total pore volume of the coal sample, the initial uranium content of the coal sample, and the first uranium concentration, the uranium enrichment coefficient is obtained to simulate the leaching process of the uranium source rock mass and the enrichment process of the coal seam.

[0029] In this embodiment, the uranium-bearing source rock sample is crushed and sieved to the target particle size range, then filled into the middle packing layer of the primary dynamic leaching assembly. Inert support layers are filled on the upper and lower sides of the uranium-bearing source rock sample, respectively. The coal sample is processed into coal particles, compressed coal columns, or undisturbed coal cores, and then filled into the secondary coal sample seepage reaction assembly. Filter layers and support layers are added to both ends of the coal sample for fixation. Deionized water, simulated groundwater, bicarbonate solution, or other predetermined background solutions are added to the storage tank, and the constant flow pump is started to allow the background solution to enter the primary dynamic leaching assembly at a preset flow rate. The uranium-bearing leaching liquid generated by the primary dynamic leaching assembly is automatically introduced into the secondary coal sample seepage reaction assembly through a second connecting pipeline. Nitrogen or carbon dioxide is introduced into the secondary coal sample seepage reaction assembly to create a reducing environment, causing the uranium-bearing fluid to undergo seepage migration, adsorption complexation, reduction precipitation, and local enrichment within the coal sample. During the experiment, samples were taken at regular intervals at the outlet of the primary dynamic leaching assembly and the inlet and outlet of the secondary coal sample seepage reaction assembly. Parameters such as uranium concentration, pH, Eh, and conductivity in the liquid samples were measured to dynamically track the migration and transformation characteristics of uranium at each stage. After the experiment, coal and source rock samples were collected before and after the reaction. Based on the changes in liquid chemical parameters, a comprehensive evaluation was conducted on the release pattern of uranium in the source rock, its migration behavior in the fluid, and its enrichment mechanism in the coal samples.

[0030] In a preferred embodiment: the uranium-bearing source rock sample has a particle size of 0.25–2 mm; the coal sample is a particulate coal sample with a particle size of 0.25–1 mm, or a coal column sample with a diameter of 10–50 mm and a length of 20–100 mm; the flow rate of the background solution is 0.1–5 mL / min; the experimental temperature is 20–80 °C; and the experimental duration is 12 h–30 d.

[0031] In one embodiment of the present invention, the uranium enrichment coefficient is calculated by the following formula: This is the uranium enrichment factor. This is the first uranium concentration. The fluid flow rate of the background solution entering the primary dynamic leaching module. Uranium retention rate This represents the initial uranium content of the coal sample.

[0032] In this embodiment, the uranium enrichment coefficient reflects the degree of uranium enrichment in the coal sample. The larger the uranium enrichment coefficient, the more uranium is fixed from the uranium-containing leachate in the coal sample, and the more obvious the enrichment effect. The uranium concentration measured at the outlet of the primary dynamic leaching component is multiplied by the fluid flow rate, then multiplied by the uranium rejection rate, and integrated over time to obtain the total amount of uranium fixed by the coal sample during the experiment. The total amount of fixed uranium is divided by the initial uranium content of the coal sample before the experiment, and then one is added to obtain the uranium enrichment coefficient. The uranium rejection rate represents the proportion of uranium fixed by the coal sample in the uranium-containing leachate flowing from the primary dynamic leaching component into the secondary coal sample seepage reaction component at time t.

[0033] In one embodiment of the present invention, the first uranium concentration is calculated using the following formula: The time it takes for the background solution to flow within the primary dynamic leaching module. The oxygen flow rate flowing into the primary dynamic filtration module. For reference oxygen flow rate, To preset the reference concentration, The fluid flow rate of the background solution entering the primary dynamic leaching module. The characteristic time of source rock leaching. For source rock material factors, , Uranium content of the source rock, This is a reference value for the uranium content of the source rock. The percentage of uranium that can be leached from the source rock. This is a reference value for the percentage of uranium that can be leached from the source rock. This represents the ratio of the uranium release capacity of the background solution to that of deionized water. These are reference values ​​for background solution type parameters.

[0034] In this embodiment, the reference concentration is used as a base, multiplied sequentially by the source rock material factor, the flow rate ratio, the oxygen flow rate ratio, and a saturation function that varies with time. The source rock material factor is determined by the uranium content of the source rock, the proportion of leached uranium, and the uranium release capacity of the background solution. The flow rate ratio is the ratio of the actual fluid flow rate to the reference flow rate, and the oxygen flow rate ratio is the ratio of the oxygen flow rate introduced into the primary dynamic leaching module to the reference oxygen flow rate.

[0035] In one embodiment of the present invention, the uranium rejection rate is calculated using the following formula: To achieve the maximum theoretical rejection rate, This refers to the time it takes for the uranium-containing leachate to flow from the outlet of the primary dynamic leachate assembly to the inlet of the secondary coal sample seepage reaction assembly. This represents the total pore volume of the coal sample. The nitrogen flow rate flowing into the secondary coal sample seepage reaction assembly. For reference nitrogen flow rate, The redox potential difference between the primary dynamic leaching module and the secondary coal sample seepage reaction module. The preset reference constant, For coal sample material factors, , The organic matter content of the coal sample. This is a reference value for the organic matter content of the coal sample. The sulfide content of the coal sample. This is a reference value for the sulfide content of the coal sample. This represents the total pore volume of the coal sample. This is a reference value for the total pore volume of the coal sample.

[0036] In this embodiment, the uranium retention rate is determined jointly based on the maximum theoretical retention rate, coal sample material factor, fluid flow rate, transport lag time, total pore volume of the coal sample, nitrogen flow rate, and the redox potential difference between the two stages. This retention rate is used to evaluate the coal sample's ability to fix uranium; a higher retention rate indicates a higher proportion of uranium fixed by the coal sample in the uranium-containing leachate flowing into the secondary stage.

[0037] It is understood that the method embodiments and system embodiments provided by the present invention are based on the same inventive concept and have the same beneficial effects. The beneficial effects of the method embodiments will not be elaborated here.

[0038] In summary, this invention provides a simulation system and method for leaching and coal seam enrichment processes in uranium-bearing source rocks. By connecting a primary dynamic leaching component in series with a secondary coal sample seepage reaction component, it achieves integrated and continuous simulation of uranium release from the source rock, fluid migration, and coal enrichment processes. This solves the problem of current simulations that only focus on the leaching process, resulting in independent and unconnected leaching and adsorption devices. By incorporating an atmosphere control component, the oxidizing or reducing atmosphere within both stages can be independently adjusted, thereby constructing an oxidation-reduction environmental gradient that better reflects actual geological processes. Furthermore, by using a fluid transport component to continuously transport the uranium-bearing leachate generated by the primary component to the secondary component, continuous and uninterrupted coupling between the two stages is achieved.

[0039] The primary dynamic leaching assembly employs a vertical leaching column structure, with an inert support layer and source rock packing layer arranged from top to bottom to ensure uniform distribution of the leachate and prevent sample loss. The secondary coal sample seepage reaction assembly can be set vertically or horizontally, with an internal filter layer and support layer, and is equipped with a pressure monitoring interface to monitor pressure changes during the seepage process in real time and determine whether the coal sample is blocked. The fluid delivery assembly is equipped with a constant flow pump and flow regulating valve to precisely control the injection flow rate of the background solution. The atmosphere control assembly adopts an independent dual-gas path design; the first gas cylinder supplies air or oxygen to the primary assembly, and the second gas cylinder supplies nitrogen or carbon dioxide to the secondary assembly, with independently adjustable gas flow rates. The system also includes a liquid sampling port, monitoring components, and a temperature control component, enabling multi-node sampling, online parameter monitoring, and overall constant temperature control. This provides a more realistic, continuous, controllable, monitorable, and adjustable simulation platform for uranium enrichment research in coal.

[0040] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0041] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A simulation system for leaching and coal seam enrichment processes in uranium-bearing source rocks, characterized in that, include: A primary dynamic leaching assembly is filled with a uranium-bearing source rock sample. The primary dynamic leaching assembly is equipped with a liquid inlet, a liquid outlet, and an air inlet. A preset background solution flows into the primary dynamic leaching assembly from the liquid inlet and undergoes a dynamic leaching reaction with the uranium-bearing source rock sample under a preset oxidizing atmosphere to generate uranium-bearing leaching liquid, which flows out from the liquid outlet. The secondary coal sample seepage reaction assembly is connected to the primary dynamic leaching assembly and is filled with coal sample. The secondary coal sample seepage reaction assembly is provided with a liquid inlet, a liquid outlet and an air inlet. The uranium-containing leaching liquid flowing out of the liquid outlet of the primary dynamic leaching assembly flows into the liquid inlet of the secondary coal sample seepage reaction assembly and undergoes a seepage reaction with the coal sample under a preset reducing atmosphere to simulate the migration, adsorption, complexation, reduction and enrichment process of uranium in the coal seam. The fluid transport component is connected to the outlet of the primary dynamic leaching component and the inlet of the secondary coal sample seepage reaction component, respectively, and is used to continuously transport the uranium-containing leaching liquid generated by the primary dynamic leaching component to the secondary coal sample seepage reaction component. An atmosphere control component is connected to the air inlet of the primary dynamic leaching component and the air inlet of the secondary coal sample seepage reaction component, respectively, and is used to independently regulate the oxidizing atmosphere or reducing atmosphere in the primary dynamic leaching component and the secondary coal sample seepage reaction component.

2. The system of claim 1, wherein, The primary dynamic filtration component has a cylindrical structure; The interior of the primary dynamic leaching assembly is provided with a first inert support layer, a uranium-bearing source rock filling layer, and a second inert support layer sequentially arranged along the direction of background solution flow.

3. The system according to claim 1, characterized in that, The secondary coal sample seepage reaction assembly is a vertically or horizontally arranged column structure. The interior of the secondary coal sample seepage reaction assembly is arranged sequentially along the flow direction of the uranium-containing leachate, including a first filter layer, a first support layer, a coal sample layer, a second support layer, and a second filter layer. The coal sample layer is filled with coal sample cores or coal particles.

4. The system of claim 1, wherein, The fluid delivery assembly includes: Storage tank, used to store background solution; The first connecting pipeline is used to connect the liquid storage tank with the liquid inlet of the first-stage dynamic filtration assembly; A constant flow pump, installed on the first connecting pipeline, is used to transport the background solution to the primary dynamic leaching assembly; A flow regulating valve is installed on the first connecting pipeline to regulate the flow rate of the background solution flowing into the primary dynamic leaching assembly; The second connecting pipeline is used to connect the liquid outlet of the primary dynamic leaching component with the liquid inlet of the secondary coal sample seepage reaction component.

5. The system of claim 1, wherein, The atmosphere control assembly includes: a first gas cylinder, a second gas cylinder, a first pressure reducing valve, a second pressure reducing valve, a first gas flow controller, a second gas flow controller, a first gas delivery pipeline, and a second gas delivery pipeline. The first gas cylinder contains air or oxygen and is connected to the air inlet of the first-stage dynamic filtration assembly through the first gas delivery pipeline. The second gas cylinder contains nitrogen or carbon dioxide and is connected to the inlet of the secondary coal sample seepage reaction assembly through the second gas delivery pipeline. The first pressure reducing valve and the first gas flow controller are installed on the first gas transmission pipeline; The second pressure reducing valve and the second gas flow controller are installed on the second gas delivery pipeline.

6. The system of claim 1, wherein, The primary dynamic leaching assembly is provided with a first liquid sampling port for sampling the uranium-containing leaching liquid flowing out of the primary dynamic leaching assembly; The secondary coal sample seepage reaction assembly is equipped with a second liquid sampling port for sampling the enriched liquid after seepage reaction flowing out of the secondary coal sample seepage reaction assembly.

7. A method of modeling the leaching and coal enrichment process of a uranium-bearing source rock mass, characterized in that, Applied to the system according to any one of claims 1-6, the method comprises: Uranium-bearing source rock samples are filled into the primary dynamic leaching assembly, and coal samples are filled into the secondary coal sample seepage reaction assembly. Start the fluid delivery assembly and the atmosphere control assembly. Use the fluid delivery assembly to allow the background solution to flow into the first-stage dynamic filtration assembly, and at the same time use the atmosphere control assembly to introduce air or oxygen into the first-stage dynamic filtration assembly. The fluid delivery assembly is used to continuously flow the uranium-containing leachate generated by the primary dynamic leaching assembly into the secondary coal sample seepage reaction assembly, while the atmosphere control assembly is used to introduce nitrogen or carbon dioxide into the secondary coal sample seepage reaction assembly. A first liquid sample is collected from the first liquid intake port of the first-stage dynamic leaching assembly to obtain the first uranium concentration of the first liquid sample. Based on the uranium content of the source rock, the proportion of leached uranium in the source rock, the organic matter content of the coal sample, the sulfide content of the coal sample, the total pore volume of the coal sample, the initial uranium content of the coal sample, and the first uranium concentration, the uranium enrichment coefficient is obtained to simulate the leaching process of the uranium source rock mass and the enrichment process of the coal seam.

8. The method of claim 7, wherein, The uranium enrichment coefficient is calculated using the following formula: This is the uranium enrichment factor. The first uranium concentration, The fluid flow rate of the background solution entering the primary dynamic leaching module. Uranium retention rate This represents the initial uranium content of the coal sample.

9. The method of claim 8, wherein, The first uranium concentration is calculated using the following formula: The time it takes for the background solution to flow within the primary dynamic leaching module. The oxygen flow rate flowing into the primary dynamic filtration module. For reference oxygen flow rate, To preset the reference concentration, The fluid flow rate of the background solution entering the primary dynamic leaching module. The characteristic time of source rock leaching, For source rock material factors, , Uranium content of the source rock, This is a reference value for the uranium content of the source rock. The percentage of uranium that can be leached from the source rock. This is a reference value for the percentage of uranium that can be leached from the source rock. This represents the ratio of the uranium release capacity of the background solution to that of deionized water. These are reference values ​​for background solution type parameters.

10. The method of claim 9, wherein, The uranium rejection rate is calculated using the following formula: To achieve the maximum theoretical retention rate, This refers to the time it takes for the uranium-containing leachate to flow from the outlet of the primary dynamic leachate assembly to the inlet of the secondary coal sample seepage reaction assembly. This represents the total pore volume of the coal sample. The nitrogen flow rate flowing into the secondary coal sample seepage reaction assembly. For reference nitrogen flow rate, The redox potential difference between the primary dynamic leaching module and the secondary coal sample seepage reaction module. The preset reference constant, For coal sample material factors, , The organic matter content of the coal sample. This is a reference value for the organic matter content of the coal sample. The sulfide content of the coal sample. This is a reference value for the sulfide content of the coal sample. This represents the total pore volume of the coal sample. This is a reference value for the total pore volume of the coal sample.

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