To enhance the separation efficiency and accuracy of medium and low-grade uranium ores, we developed a gamma array beneficiation detection system based on 64 NaI detectors and established a reliable consistency correction method. This system adopts an 8-column × 8-row array layout, integrating a digital single-channel pulse amplitude analyzer, an FPGA data processing module and an STM32 control module, which can achieve synchronous acquisition and real-time processing of gamma-ray signals from uranium ore conveyed by belts. To address the problem of count rate deviation caused by multi-detector process differences, a mathematical model for count rate consistency analysis was constructed, and one-way analysis of variance was used for consistency evaluation. The test results show that before calibration, the F value among the detector groups reached 3 654.41, and the P value was 0, significantly deviating from the consistency standard. Then, the t-test method was adopted to locate the abnormal detectors. After calibrating the abnormal detectors, the F value dropped to 0.64, P=0.98>0.05, and there was no significant difference in the counting rates of each detector. This system effectively enhances the accuracy and stability of signal acquisition, providing efficient technical support for the pre-beneficiation of low-grade uranium ore before grinding. It has significant engineering value for expanding the utilization boundaries of mineral resources and reducing subsequent processing costs.

The Qingshankou Formation is one of the primary ore-bearing layers for uranium deposits in the Songliao Basin, where the techno-metallurgical characteristics of the ores directly determine the feasibility of in-situ leaching uranium. This study focuses on sandstone type ores in the Qingshankou Formation, employing petrographic analysis, scanning electron microscopy, energy-dispersive spectroscopy, and electron probe microanalysis to conduct techno-metallurgical research, systematically revealing the occurrence patterns of uranium minerals. The results indicate that uranium minerals in fine sandstones of the Qingshankou Formation are predominantly uraninite and pitchblende, primarily distributed along the edges of clastic particles, which facilitates contact between uranium minerals and leaching solutions. Additionally, the pores in fine sandstones are mainly intergranular, promoting uniform diffusion of leaching agents. In contrast, uranium minerals in mud breccia are primarily uraninite, mainly distributed within the mud breccia, which hinders contact between leaching solutions and uranium minerals, increasing leaching difficulty. The study suggests that the Qingshankou Formation of a uranium deposit in the Songliao Basin has the potential to become an ideal mining horizon in the region.

Against the background of digital transformation in the mining industry, long-standing issues such as data fragmentation, disjointed workflows, and insufficient collaboration mechanisms among geology, surveying, and mining disciplines have become key bottlenecks constraining improvements in production efficiency and technical management. Focusing on geology-surveying-mining collaboration, this study establishes a full-process collaborative technical system for mining production. Based on unified data standards, a layered architecture consisting of a data layer, toolset layer, collaborative operation platform layer, and mining business layer is proposed. A process-driven mechanism is employed to enable coordinated operation of core tasks such as geological modeling, surveying updates, and mining design, forming a closed-loop technical management model that covers task initiation, process control, result review, and archival sharing. Application results demonstrate that the proposed system effectively addresses common issues in traditional management modes, including data version inconsistency and poor traceability of business workflows, significantly enhances cross-disciplinary collaboration efficiency and technical management capability, and promotes the transformation of mining production management from experience-driven to process-and data-driven practices.

In order to solve the problems of cumbersome construction process, irreplaceable filter and non-convertible function of extractable liquid in complex sandstone type uranium deposits in the traditional in-situ leaching uranium well configuration (such as large-diameter gravel filling well configuration), a new type of slotted well configuration and its construction technology were proposed. The configuration adopts a one-diameter to the end method, the casing is lowered through the whole hole and the reverse grouting is cemented, and then the industrial ore section is slapped by high-pressure hydraulic sandblasting technology to open up the hydraulic connection channel inside and outside the casing. Through laboratory tests, the key technical parameters of hydraulic sandblasting joints were studied, including the effects of spray pressure, nozzle diameter and moving speed on the depth and width of the joints. The results indicate the optimal slotted performance is achieved when the injection pressure is maintained 30 MPa, the nozzle diameter is set at 3.5 mm, and the moving speed is controlled at 90 mm/min. The slotted well configuration has the advantages of simple construction process, high efficiency, less consumables and high well quality, and is suitable for the mining of complex sandstone type uranium deposits to improve the recovery rate of uranium resources.

The pregnant solution produced by the neutral in-situ leaching uranium process often contains a large amount of fine particles, which can easily lead to problems such as the decrease of ion exchange rate of subsequent ion exchange resins, the decrease of resin adsorption capacity, and frequent cleaning cycles. Aiming at the bottleneck of low removal efficiency and insufficient operation stability of traditional solid-liquid separation technology for fine particles, this study introduced a microchannel separation technology based on the coupling enhancement mechanism of microchannel adhesion separation—oscillation desorption, and carried out field pilot test. The experimental results show that the removal efficiency of particles with particle size >1 μm is higher than 94%, and the removal efficiency of particles with particle size > 5 μm is close to 100%. Under different influent turbidity (6-33 NTU) conditions, the effluent turbidity was stable at 2-9 NTU, and the removal rate was maintained 60%-75%. The operating pressure difference of the system increased slowly with the accumulation of particles. After 8 days of stable operation of the device, the removal efficiency of particles with particle size >1 μm decreased to 70%. In order to restore the separation performance of the system, the device was backwashed. After backwashing, the removal ability of particles with particle size >5 μm was quickly restored. Compared with the conventional bag filter, the particles at the out-let of the microchannel separator are mainly distributed in the sub-micron to micron scale, and the medium and large particle sizes are significantly reduced. This study provides experimental basis and technical support for the engineering application of microchannel separation technology in the pretreatment of pregnant solution of in-situ leaching uranium.

In the production process of in-situ leaching of uranium, with the increase of leaching years, the pumping capacity of the wells will be accompanied by the decline, and well washing, plugging removal and permeability enhancement have become normal operations. But the well washing frequency is high, efficiency is low, and operation is complicated. In view of the limitations of well washing, this research, based on the working principles of various well washing methods and the concept of integrated technology, designed an integrated well washing device. This device integrates various well washing techniques such as high pressure air washing, air piston washing, water piston washing, high pressure water rotary jet washing, high pressure water drilling, and chemical sedimentation washing onto a multi-functional pipe string, and is mounted on a trailer drilling rig. All kinds of washing methods are freely switched in the well, and no pipe string is proposed. The test results show that the average amount of water after well washing is increased by 153.4%, which solves the limitations of the single well washing method, and improves the efficiency and effect of well washing.

Aiming at the safety and inefficiency issues existing in the mining of Mianhuakeng mine, this study established a three-dimensional geological model of the ore body and conducted research such as stope structure parameter simulation and numerical simulation of deep-hole blasting disturbance, then obtained stope structure parameters and mining process parameters. Through on-site mining tests to verify and optimize these parameters, a pillarless sublevel deep-hole continuous mining technology was developed. This technology enables simultaneous operation of multiple processes and unmanned operation in the stope, resulting in the monthly production capacity of the stope approximately three times that of the existing horizontal slicing backfill mining technology, and a reduction in the direct mining cost of about 13%, significantly improving the mining efficiency and safety of Mianhuakeng mine.

In order to solve the problems of easy clogging by debris and uneven application of leaching agents in the micro-sprinkler tape liquid distribution system, and to enhance the uniformity and efficiency of the heap leaching process, a feasibility study on the application of a mobile sprinkling method in a certain uranium mine heap leaching was conducted. The effects of parameters such as the sprinkling volume, the moving speed of the sprinkler machine, and the instantaneous sprinkling intensity of the sprinkler machine on the permeability of the ore heap were investigated. The results show that when using a 3.6 mm aperture nozzle for sprinkling and the sprinkler machine running at a speed of 8 to 10 m/min, a uniform liquid distribution effect can be achieved with a single row of sprinkling pipelines within the flow of 6.7 to 13.8 m³/h. Compared with micro-sprinkler tape sprinkling, the use of mobile sprinkling results in a relatively uniform leaching of the ore heap, enabling uniform leaching of the ore heap, with average leaching rate of uranium (based on residue) reaching 92.55%. This study provides technical support for the industrial application of mobile sprinkling technology in uranium mine heap leaching.

Pressurization serves as a critical approach for regulating reaction rate in hydrometallurgical processes. To investigate the effects of pressure conditions on uranium leaching performance, laboratory-scale simulated heap leaching tests of uranium ore were carried out using a self-made room-temperature pressurized leaching device, with hard-rock type uranium ore from a mine in southern China as the research material. The results indicate that room-temperature pressurized leaching can accelerates the leaching reaction rate, yet it exerts no positive effect on improving the final uranium leaching rate. Pressurization exhibits a significant promoting effect on uranium leaching before the uranium leaching rate reaches 60%, and the leaching performance is optimal under a pressure of 40 kPa when the uranium leaching rate is below 85%. After 15 days of pressurized leaching, the highest uranium leaching rate reaches 94.66%, while the lowest is 85.90%. This study reveals that based on the correlation between pressure and leaching performance during room-temperature pressurized leaching, the uranium heap leaching technology can be effectively optimized by regulating pressure—a physical parameter with the advantages of controllability and low cost—thereby achieving the high-efficiency recovery of uranium resources.

To enhance the leachability of low-permeability uranium-bearing strata during in-situ leaching of uranium, biotite—a mineral commonly enriched in the Nalinggou sandstone type uranium deposit, which often leads to localized densification and impeded fluid flow—was systematically investigated for its dissolution behavior in the presence of three low-molecular-weight organic acids: citric acid, tartaric acid, and succinic acid. A comparative study was conducted through dissolution experiments and PHREEQC simulations, combined with analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The research focused on the mechanisms of structural alteration, cation release characteristics, and pore parameter evolution of biotite under varying organic acid concentrations. The results demonstrate that organic acids significantly enhance biotite dissolution, leading to increased cation release, aggravated crystal structure degradation, and expanded specific surface area and pore volume. These effects intensify with higher acid concentrations. Among the tested acids, tartaric acid exhibited the most pronounced dissolution effect, increasing the specific surface area from 4.071 8 m²/g to 9.184 5 m²/g. PHREEQC simulations revealed that organic acids effectively inhibit the precipitation of Al (OH)₃ and iron oxides by complexing with Al³⁺ and Fe³⁺, thereby prolonging the mineral dissolution process. The study indicates that low-molecular-weight organic acids can improve the permeability of uranium-bearing layers by enhancing mineral dissolution and optimizing pore structure. These findings provide a theoretical foundation and technical support for improving uranium leachability.

Based on experimental research focused on enhancing the grade of natural uranium products, reducing impurity content, and controlling moisture levels, the key factors affecting product quality were analyzed. Corresponding measures were proposed, including increasing the uranium concentration of the qualified precipitation solution, elevating the precipitation temperature, improving the washing efficiency of the precipitate slurry, and optimizing the pressure and airflow during gas-pressurized filtration. Industrial application demonstrated that after implementing these measures, the uranium grade of the product was raised from 60% to 65%, with a maximum of 67.51%, moisture content was reduced from 25%-29% to 23%-24%; and the sulfate mass fraction was below 10%. These results fully comply with the new industry acceptance standards for natural uranium products specified by the customer.

The appearance quality of nuclear fuel pellets is closely associated with the operational safety and efficiency of nuclear reactors, and must exhibit high quality before being loaded into reactors. Currently, visual inspection by human operators is employed to control the quality of nuclear fuel pellets. However, manual inspection is highly subjective, prone to visual fatigue, carries risks of false and missed detections, and lacks the capability for quantitative defect analysis. To effectively detect surface defects of UO₂ nuclear fuel pellets, an automated inspection system based on machine vision has been designed. The system adopts a modular architecture: first, preprocessing the acquired pellet images; then, utilizing image segmentation techniques tailored to the surface characteristics of the pellets to extract defect regions; subsequently, applying connectivity analysis for defect examination; and finally, employing a combined approach of Support Vector Machine (SVM) classifier and Convolutional Neural Network (CNN) for defect classification, enabling automatic identification of pellet surface defects. The results demonstrate that the system achieves high detection accuracy and efficiency, meeting the requirements of industrial automated inspection.

Addressing the persistent challenge that general safety regulations are inadequate for metal mines employing specialized processes such as in-situ leaching, this study focuses on China's dominant in-situ leaching uranium mines and proposes a safety governance framework termed "three-layer decoupling and bidirectional integration". This methodology systematically develops China's Safety Regulations for In-situ Leaching Uranium Mines and three sets of mandatory safety assessment templates by decoupling complex risks, process stages, and heterogeneous standards, and integrating on-site requirements with regulatory provisions. The innovations are reflected in: the first cross-industry transformation and process adaptation of safety standards from multiple fields such as geological exploration and chemical engineering pipelines; the use of numerical simulation technology to verify and optimize threshold values for key clauses concerning drilling stability and leakage diffusion; and the complete reconstruction of the safety assessment paradigm, establishing a "standard-evaluation" closed-loop management and control system deeply integrated with the regulations. The outcomes have been implemented as mandatory industry standards. Application data indicate that mine safety compliance inspection efficiency has improved by approximately 50%. The systematic construction method and the integrated "regulation-assessment-application" formed in this research provide a replicable solution for the safety governance of other metal mines using similar leaching processes.

Background values of groundwater are the core basis for groundwater environmental management in in-situ leaching uranium mine. Aiming at the characteristics of large sample size, strong discreteness and high spatial heterogeneity in background values monitoring of groundwater during the construction period of an in-situ leaching uranium mine, this paper established a background values determination method consisting of Grubbs outlier test, manual review, data distribution type judgment, and values range & mean calculation. A case study was carried out in mining area 1 # to obtain the background values and spatial distribution characteristics of groundwater characteristic factors. This method can effectively distinguish natural high concentration values from man-made abnormal values with objective and representative results. It can provide technical support for groundwater environmental management of in-situ leaching uranium mines and also serve as a technical reference for background values determination of similar uranium mines.

In view of the characteristics of complicated types, high salt content and strong matrix effect of associated radioactive solid wastes, and there is no relevant standard method for analyzing radionuclides in associated radioactive solid wastes. Taking molybdenum ore slag, zirconium ore slag and rare earth slag as the measurement objects, the chemical components in the samples were measured by X-ray fluorescence spectrometer, and the simulated efficiency calibration was carried out by combining with the passive efficiency calibration software. The spectrum was measured by gamma spectrometer, and the gamma spectrometry method for the analysis of radioactive nuclides in associated radioactive solid waste was established. The experimental results show that the rare earth waste residue, zirconium waste residue and background matrix samples are uniformly mixed at the ratio of 3∶7 (30 g∶70 g) and 1∶4 (20 g∶80 g), and then put into the ϕ 75 mm× 20 mm sample box for gamma spectrometry measurement. The measurement dead time accounts for 9% and the correction error of self absorption factor is less than 5%; The absolute value of the relative error is less than 5%; The maximum deviation between the passive efficiency scale and the active efficiency scale is 4.74%; When ²³⁸U is measured with 92.6 keV full energy peak, the deviation of the measured results after the interference peak correction meets the requirement of less than 30%. Compared with other methods, the relative deviations of ²³⁸U, ²³²Th and ²²⁶Ra are 1.40%-5.03%, 0.59%-6.13% and 2.30%-3.85%, respectively. When the gamma spectrometer is used to measure the associated radioactive solid wastes, this method optimizes the sample loading quality, reduces the influence of sample self absorption, and does not need to match the solid waste standard sample with the same matrix, and the measurement result is reliable. The results provide a feasible analytical scheme for peer laboratories and technical support for the formulation of relevant industry standards.

This study investigated typical enterprises engaged in the integrated beneficiation and smelting of monazite, with a focus on characterizing the behavior of thorium-232 throughout the production chain. Through systematic analysis of activity concentrations in various raw materials and products from different manufacturers, the pathways and final distribution of thorium-232 across the entire technological process were traced. Workplace monitoring of thoron concentrations was carried out to assess inhalation hazards, collectively revealing the distinct migration and enrichment patterns of thorium-232 and its associated radiological exposure risks. Through the analysis of the chemical composition in monazite ore, it is found that the REO content is the key factor influencing the activity concentration of thorium-232. The monazite dressing process primarily involves stages such as shaking table gravity separation, drying, and electromagnetic separation, while the smelting process includes magnetic separation, alkali decomposition, and hydrochloric acid preferential dissolution. Thorium-232 exhibits a pronounced tendency for selective enrichment within these sequences. Comprehensive data on chemical composition and radionuclide activity from multiple enterprises in Hainan Province demonstrate that about 92.15% of thorium-232 is concentrated into the monazite product during electromagnetic separation. Further analysis based on material chemistry and activity measurements from a smelting enterprise in Hunan Province indicates that about 96.56% of the thorium-232 is subsequently transferred and further enriched in the residue generated from the hydrochloric acid preferential dissolution stage. It is noteworthy that emissions of thorium-232 in waste gases and process waters throughout both dressing and smelting operations are negligible relative to the total inventory.

Intermediate and low level radioactive waste accounts for the vast majority of the volume in nuclear energy development and application, but has relatively low radioactivity. Its solidification treatment is a key process for ensuring environmental and public health safety. This research deeply investigated the core characteristics of intermediate and low level radioactive waste, including complex nuclide composition, associated harmful substances, and large production volume with wide distribution. It also analyzed mainstream solidification technologies, focusing on cement solidification and bitumen solidification. The principles, technical features, performance parameters, research progress, and limitations of cement solidification were elaborated. The advantages and disadvantages of bitumen solidification, as well as its domestic and international research progress and key performance indicators, were analyzed. In response to challenges such as the complexity of waste composition, stringent requirements for solidified waste forms, cost and environmental control pressures, and updated regulatory standards, future LILW solidification technologies will focus on the development of novel solidification materials, innovative solidification processes, waste minimization and resource utilization, deep integration of intelligence and automation, and strengthen international cooperation and standardization. These efforts aim to achieve more efficient, economical, environmentally friendly, and safe solutions, providing strong support for the sustainable development of nuclear energy.

Based on the Second National Census of Pollution Sources, China has successively issued a series of policy documents on radiation environmental management for associated radioactive minerals. Radiation environmental management of associated radioactive minerals have been gradually standardized, though they remain to be further clarified and refined. This study analyzes the existing regulatory requirements and the current management status. It identifies issues in areas such as industry directory management, enterprise directory management, environmental impact assessment, the storage and disposal of solid waste in the sector of associated radioactive minerals. Grounded in practices and evolving management trends, this study proposes the following recommendations: adjusting the regulatory targets in the industry directory, establishing a dynamic management mechanism for enterprise directory, clarifying the authorities for environmental impact assessment approvals, and standardizing the requirements for solid waste storage and disposal.

Aiming at the water quality characteristics of low uranium concentration, high sulfate and high suspended solids in the seepage water of a decommissioned uranium mine in southern China, as well as the problems of unstable treatment effect, easy saturation and hardening of resin, and high operation and maintenance costs in the original resin adsorption uranium removal process, combined with the seasonal dynamic change law of uranium occurrence state under the background of the mine's karst landform, the analysis of seepage water quality characteristics and the optimization of treatment process were carried out. On the basis of finding out the cyclic mode of uranium "activation and migration in rainy season, local enrichment in dry season" and the difference of occurrence states in winter and summer, a seasonal combined treatment scheme of iron-based permeable reactive barrier (PRB) was proposed, and the process flow design, engineering facility planning and seasonal process parameter optimization were completed. The designed treatment capacity of the project is 400 m³/d, which can adapt to the seasonal fluctuation characteristics of the seepage water volume and uranium occurrence form of the mine, with an expected operation cycle of 10 years, and the materials can be recycled after regeneration. The application results show that the process has a significant removal efficiency for radioactive pollutants such as natural uranium, ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po, the effluent water quality meets the standard stably for a long time, which can provide technical reference and engineering demonstration for the seepage water treatment of similar decommissioned uranium mines in karst areas.

To address the issues of low efficiency and high error rates associated with traditional manual methods for converting coordinate formats in the mineral resources national survey database, two conversion approaches and program algorithms are proposed: First, a forward conversion that transforms coordinate strings of mining areas (mines) in the database into coordinate pair text files; Second, a reverse conversion that transforms coordinate pair text files back into coordinate strings of mining areas (mines) in the database. These methods can provide data that meet format requirements for coordinate system conversion of mining areas (mines) in the database, and enable rapid rewriting of coordinate values and database updates after coordinate system conversion, thereby effectively enhancing the automation level of coordinate data processing and data management efficiency.