In response to the issues such as significant differences in dynamic water levels among different drilling wells in a test mining area, insufficient groundwater recharge, unbalanced unit extraction, and varying leaching rates, this study employs automated monitoring of dynamic water levels as a focal point. By carrying out dynamic groundwater level monitoring, we aimed to achieve a visualized system for groundwater dynamics. Utilizing computer digital processing and simulation technology for the analysis of monitoring data, we established a quality control system centered on numerical simulation of the leach flow field, study of flow field characteristics, optimization of extraction flow rates, and regulation of groundwater levels. We developed scientific techniques for flow field regulation, enabling reasonable distribution of leaching agents, reducing areas of dead zones in leaching, enhancing the smoothness of the flow field in the mining area, and improving unit extraction conditions, thereby laying a solid foundation for intelligent and refined analysis of the mining area.

With the continuous improvement of automation levels in uranium mines, the reliability of electrical control systems has become a key factor in ensuring production safety and efficiency. This paper addresses the abnormal failure issues of the frequency converter control system in a uranium mining project in Xinjiang and proposes a PLC-based frequency converter communication control and hardwired backup redundancy control scheme. By comparing and analyzing the technical characteristics of terminal control and communication control, a redundant architecture combining Modbus RTU and terminal control is designed and implemented. Practical application shows that this scheme effectively solves the control failure issues caused by communication interference in the original system. The mean time between failures (MTBF) of the system has increased from 168 h before the transformation to over 2 000 h, and the control response time has been shortened to less than 100 ms. The research content provides an important reference for the design of high-reliability control systems in the uranium mining industry, especially for production scenarios with complex electromagnetic environments and stringent reliability requirements.

To address pipeline blockage issues in the negative-pressure pneumatic conveying of uranium dioxide at a uranium company, this study employed a combined approach of CFD-DEM coupled simulation and field experiments. By examining particle flow patterns, gas-phase pressure distribution, and system pressure drop, the underlying mechanism of pipeline blockage was elucidated. The validity of the simulation model was confirmed through comparative analysis of field measurements and numerical results. The findings demonstrate that increasing the elbow curvature radius from 200 mm to 500 mm and the bend diameter ratio from 2.50 to 6.25 significantly reduced local pressure losses during conveying. As a result, particle flow stability improved, with the peak gas-phase pressure dropping to 27.2 kPa and the overall system pressure drop decreasing markedly, thereby restoring normal operation of the power equipment. This study verifies the reliability of the CFD-DEM model for optimizing the pneumatic conveying system of uranium dioxide particles, offering both theoretical support and practical guidance for achieving efficient and stable transport.

To address the challenges in the design of associated radioactive waste repository and ensure the long-term effectiveness of waste disposal, theoretical and experimental research were conducted on radionuclide migration control technologies for associated radioactive waste disposal sites. A three-dimensional pollution control technology system was established from three dimensions: source, process, and end. Through waste leaching experiments, stabilization agents were screened, and based on this, a new type of stabilization composite material was developed, which effectively resolved the acid rebound issue to a certain extent, achieving source control. Research on seepage process blockage constructed a three-dimensional waterproof intrusion system, blocking external water intrusion from multiple dimensions. For end-of-pipe pollution control technology, soil modification and retardation experiments were conducted using natural clay from a specific region, determining the optimal mixing ratio of modified materials and the thickness of the natural material anti-seepage layer.The practical applications were implemented for a provincial associated radioactive waste repository, and the results show the three-dimensional pollution prevention and control technology plays a critical role in controlling radionuclide migration.

Uranium tailings produced by mining and smelting contain residual radioactivity, and the released radon gas is harmful to human. Covering control is an effective means to inhibit radon. In order to solve the problems of insufficient long-term stability and high cost of traditional covering materials, this study proposed multi-layer covering system based on alkali-activated solidification materials for uranium tailings, and carried out the trial in a tailings pond in the south of China. The selected sodium silicate (with a modulus of 2.0) as the alkali activator, mineral powder as the active material, and river sand as the fine aggregate, determined the optimal mix proportion as mineral powder : solid sodium silicate : uranium tailings (1.25-1.60 mm): river sand : water = 0.8 : 0.2 : 1.4 : 0.6 : 0.5 (mass ratio), with a compressive strength of 10.6 MPa for the solidified body at 28 days. With the alkali-activated solidified body of uranium tailings as the radon shielding layer, the test shows that the radon reduction efficiency of the 5 cm thick alkali-activated solidified body reaches 97.85 %. The multi-layer covering system constructed with the alkali-activated solidified body of tailings as the radon shielding layer consists of a protective layer, a vegetation layer, a radon shielding layer, a drainage layer and a barrier layer, which has functions such as corrosion resistance, seepage prevention, radon reduction, etc., and the radon excretion rate after covering is stable within 0.187-0.419 Bq/(m³·s), which meets the national standard. This system has excellent resistance to wind erosion, rainwater scouring and differential settlement and has good long-term stability. Economic analysis shows that the material cost of this system is only 75% of the same system at home and abroad, and the local of uranium tailings to achieve resource recycling has both environmental benefits and economic advantages, providing an efficient and feasible technical scheme for the decommissioning and treatment of uranium tailings pond.

China's associated radioactive waste residues are wide-ranging in origin, diverse in type, and large in quantity, which has begun to constrain the healthy development of the associated radioactive mineral industry. There is an urgent need to build scientifically standardized repositories for long-term disposal. On the basis of reviewing domestic and international disposal approaches for associated radioactive solid waste, and by analyzing the geological conditions, storage capacity, investment costs, safety assurance, construction conditions, and operation and maintenance of a specific disposal repository as well as the suitability of different disposal methods, then proposing a repository construction scheme with high feasibility.

To solve the problems of large subjectivity, empirical, time-consuming, laborious and low efficiency of manual interaction in the design of open-pit mine slope road, a parametric three-dimensional design method of open-pit mine slope road is proposed. The general idea is: combining with the requirements of open-pit mine slope road design parameters, using parametric slope road design ideas to construct a mathematical model for parametric three-dimensional design of open-pit mine slope road. The research results were developed and realized in the digital mining software platform, and the generated road parametric 3D design model was used for an open-pit mine slope road design. The experimental study shows that the average time for completing the design of a single open-pit mine slope road is 3 h for manual interaction, and 5 min for parametric 3D design method, and the proposed parametric 3D design method of the open-pit mine slope road greatly reduces the workload of the design technicians, and accommodates the rapid automatic updating after the design parameters change. The proposed parameterized 3D design method of open-pit mine slope road greatly reduces the workload of design technicians, adapts to the rapid automatic update after the change of design parameters, and greatly improves the rationality of the design results.

In order to further study the mechanical properties and pore structure evolution of sandstone under the action of liquid nitrogen freezing and thawing cycles, the sandstone in natural water-bearing state and saturated state were taken as the research object. The compressive strength, elastic modulus, pore T₂ map and nuclear magnetic porosity of sandstone after different liquid nitrogen freezing and thawing cycles were measured by nuclear magnetic resonance instrument and rock mechanics test system. The mechanical properties, porosity evolution and pore size distribution of sandstone under the action of liquid nitrogen were analyzed. Based on the SDR permeability model, the permeability change of sandstone after freezing and thawing cycles was calculated. The results show that the uniaxial compressive strength of sandstone decreases significantly after liquid nitrogen freezing treatment, and the decrease of strength increases with the increase of freezing and thawing cycles. When the number of cycles increases from 0 to 5, the decrease of compressive strength in natural state increases from 12.25% to 29.04%, while the maximum decrease of compressive strength of sandstone in saturated state is 55.50%. The results of nuclear magnetic resonance (NMR) test show that the freezing and thawing cycle of liquid nitrogen significantly increases the porosity and permeability of sandstone, especially for sandstone samples in saturated state. After five freezing and thawing cycles of liquid nitrogen, the porosity growth rate is 39.09%; and the permeability growth rate reaches 160%, which is 1.89 times that of natural water-bearing sandstone. The research results can provide a new idea for the efficient leaching of low permeability sandstone-type uranium deposits by liquid nitrogen fracturing technology.

Over the past few decades, China's uranium resource mining and metallurgy technology has undergone a development process from nothing to something, and from weak to strong. It has introduced trackless mining and "three-under" mining technologies, broken through surface heap leaching and underground heap leaching, innovated in-situ blasting leaching and bacterial heap leaching, practiced acid, alkaline and neutral in-situ leaching of uranium mining technologies, explored and improved borehole drilling, underground leaching methods and hydrometallurgical processes, built digital mines in Xinjiang and Inner Mongolia, verified the control of leaching area, the treatment and reuse of waste drilling mud, reverse osmosis treatment of waste liquids, and the groundwater remediation of decommissioned test mines, and implemented the rational mining and metallurgy of uranium-molybdenum and uranium-coal deposits, and explored the technology of extracting uranium from seawater. The new technologies and processes practiced in uranium resource mining and metallurgy have become the driving force for China's natural uranium production. Looking to the future, China's uranium resource mining and metallurgy industry is bound to innovate and create greater breakthroughs.

The development of nuclear energy plays a vital role in the adjustment of national energy structure and environmental sustainability. The stable supply of natural uranium is essential for nuclear energy development. Given China's relatively limited terrestrial uranium reserves, extracting uranium resources from the vast oceanic territories holds significant strategic value. However, the complex and variable marine environment presents considerable challenges for conventional adsorbent materials and technologies to effectively separate uranium at extremely low concentrations, necessitating the urgent development of specialized adsorbent materials for uranium extraction from seawater. In recent years, researchers domestically and internationally have developed numerous uranium separation materials and conducted promising practical trials under seawater conditions. This review comprehensively summarizes the latest research progress in various seawater uranium extraction technologies based on the characteristics of different adsorbent materials, addresses the multifaceted technical challenges encountered in uranium extraction under real seawater conditions, and provides insights into future prospects for the development of uranium extraction technologies from seawater.