The traditional trough-type intermittent dissolution method for uranium concentrate is difficult to meet the intelligent development needs of uranium purification. The development of continuous intelligent dissolution technology is imminent. The intelligent dissolution technology requires precise control based on the dissolution reaction mechanism of uranium concentrate and suitable dissolution conditions. Given the above situation, the study first investigated the main chemical reactions during the nitric acid dissolution of U₃O₈ by means of experimental measurements and theoretical calculations. The chemical reaction process during dissolution was determined, and the variation trend of the dissolution reaction was elucidated. Furthermore, through experimental comparisons, the effects of key factors such as nitric acid concentration, temperature, and stirring intensity on the dissolution efficiency of U₃O₈ were investigated. The suitable conditions for nitric acid dissolution of U₃O₈ were determined, and the dissolution kinetics curve was measured. Finally, by comparing the dissolution performance of U₃O₈ from different sources, the reliability of the dissolution parameters was verified. Under the conditions of an initial nitric acid concentration of 6 mol/L, temperature of 60 ℃, stirring speed of 200 r/min, and dissolution time of 60 min, the dissolution rate of U₃O₈ reaches over 98%. The dissolution rules and parameters obtained from the study can serve as a basis for continuous dissolution of uranium oxides such as uranate, uranium peroxide, uranium trioxide, and uranium dioxide.

The leaching toxicity of lead in rare earth smelting slag is significantly high. Taking rare earth smelting slags (S1, S2, S3) from three Sichuan-based rare earth enterprises as research objects, this study conducted laboratory leaching experiments to investigate the immobilization effects of phosphorus-based materials and alkaline substances, both individually and in combination on lead in rare earth smelting slag, while screening and optimizing the dosage and ratio of phosphorus-based materials to alkaline substances. The results demonstrate that the sole addition of phosphorus-based materials can significantly reduce the leaching concentration of lead. For instance, adding 5% calcium superphosphate (by slag mass) can decrease the lead leaching concentration in S1 from 485 mg/L to 70.2 mg/L. However, this approach will cause pH reduction in slag, potentially inducing secondary pollution. While sole application of alkaline substances also notably reduce lead leaching concentration, excessive dosing risked excessively high pH levels. The combined use of phosphorus-based materials and alkaline substances can synergistically regulate slag pH to 9~10 while effectively reducing lead leaching concentration, achieving significantly superior outcomes compared to single treatments. The phosphorus-alkaline combined approach not only mitigate lead migration risks but also minimize environmental hazards caused by chemical overdosing. These findings provide theoretical basis and technical references for the remediation of multi-metal composite pollution in rare earth smelting slags.

In the in-situ leaching uranium mining process, the cyclone suffers from pressure drop and energy consumption limitation, which restricts its wide application. Based on the similarity modeling method, the structural parameters, operational parameters and physical property parameters that affect the pressure drop of the hydro-cyclone in in-situ leaching uranium mining were comprehensively analyzed. The error between the calculated values of this model and the experimental values is within 15%, making it suitable for predicting the pressure drop of hydrocyclones in uranium leaching processes. Additionally, to further analyze the mechanism of pressure drop generation, the internal flow field of the cyclone was simulated by Fluent, which provides a theoretical basis for the optimization of hydrocyclone structure and working condition for in-situ leaching uranium mining.

This paper discusses the impact effect of hydroblasting shot hole on casing of different materials and the application prospect of FRP casing in in-situ leaching uranium. Taking UPVC material casing and FRP material casing as the research objects, under the condition of the same arrangement of spray gun and nozzle, the reliability test was carried out by using abrasive suspension with sand ratio of 10%~15%. By changing the spray pressure and time, the shot-through condition and inner wall deformation of the casing were analyzed. The results show that the FRP casing can be shot through and form shot holes to meet the water volume requirements under a certain pressure; compared with UPVC material, the FRP casing has better high-pressure resistance performance, which can satisfy the demand of hydraulic fracturing technology for casing pressure resistance, and it has a better application prospect in the field of in-situ leaching uranium.

The evaluation of the purchasability of mining equipment is a critical issue in the decision-making process for equipment selection in mining enterprises. To address the limitations of traditional evaluation methods, such as the simplicity and lack of systematicity, a comprehensive evaluation method based on the GRA-AHP-Cloud Model was proposed. Firstly, an evaluation index system was constructed, encompassing four dimensions: production platform, adaptability, functionality, and cost. Secondly, the analytic hierarchy process (AHP) was utilized to determine the weights of each evaluation index, and the grey relational analysis (GRA) was employed to calculate the comprehensive correlation degree between each index of the equipment and the ideal value. Finally, a mathematical model for evaluating equipment purchasability was established through the cloud model, enabling the fuzzy quantitative expression of evaluation results. The method is validated through a case study of mining trolley selection in a mine, demonstrating its effectiveness in assessing the comprehensive performance of equipment.

As the primary industry in the nuclear fuel cycle, uranium mining and metallurgy plays a critical role in ensuring nuclear energy safety, making research on its radiation protection technologies highly significant. This paper systematically reviews the current status and progress in radiation protection technologies for uranium mining and metallurgy in China, while analyzing existing challenges and future development directions. The radiation risks in China's uranium mining and metallurgy industry are characterized by multi-source complexity and intertwined pathways, primarily stemming from internal exposure to radon and its progeny as well as external exposure to gamma radiation. In recent years, China has made progress in digital monitoring technologies, optimized protection designs, and innovative waste management solutions. However, the challenges remain, including limitations in radon ventilation protection technology, incomplete health risk assessment methods, insufficient coverage of monitoring networks, and inadequate performance of protective materials and equipment. Moving forward, China's uranium mining and metallurgy radiation protection efforts should focus on building an intelligent safety management platform, developing interdisciplinary radon migration models, and refining standard systems. By strengthening protection awareness, optimizing technologies and monitoring networks, the industry can achieve a transition from "risk control" to " risk prevention, " providing global uranium resource development with safety technology support and contributing to the sustainable development of nuclear energy.

Oxalate modification represents an eco-efficient strategy to address nanoparticle aggregation in nano zero-valent iron (nZVI) systems while synergistically enhancing U (VI) removal through coupled adsorption-reduction mechanisms. This study synthesized sodium oxalate-modified nZVI (OA-nZVI) via liquid-phase reduction. The oxalate coating effectively suppressed particle agglomeration induced by magnetic interactions and van der Waals forces. Systematic investigations were conducted to elucidate the morphological evolution of nZVI post-modification and its mechanistic behavior in uranium-contaminated groundwater remediation. Characterization revealed that OA-nZVI exhibited a transformation from irregular spherical particles to well-defined spherical geometries, accompanied by an increased Fe⁰ content in the mineral phase. Under optimized conditions (pH=5, 25 ℃, dosage=0.5 g/L), OA-nZVI demonstrated exceptional U (VI) removal efficiency. The enhanced performance originates from synergistic interactions: Carboxyl groups on oxalate ligands facilitated uranyl adsorption via surface complexation, and the Fe⁰ core mediated electron transfer for U (VI) reduction to U (IV). Subsequent oxidation generated goethite (α-FeOOH), which further immobilized uranium through hydroxyl coordination. The removal kinetics adhered to a pseudo-second-order model, while equilibrium data fitted the Langmuir isotherm, yielding a maximum theoretical adsorption capacity of 196.31 mg/g. Notably, competitive ions (Al³⁺and ) exhibited significant inhibitory effects, necessitating consideration in field applications.This work provides critical insights for developing advanced uranium remediation materials. Future research directions should prioritize: Evaluating material stability under complex hydrogeochemical conditions (e.g., high salinity with coexisting /), pH=3~10, and humic acid presence), and validating performance through dynamic column experiments simulating groundwater flow regimes and ion exchange processes. These investigations will bridge the gap between laboratory-scale achievements and practical engineering applications.

Due to the sudden change in load capacity of open-pit mine dump trucks, the sliding mode variable structure will cause the hydraulic braking system to produce chattering characteristics, making it difficult to accurately determine whether there is overlap between the dump truck and the collision detection object's enclosure box, resulting in a longer response time for collision detection. To address this, a collision prevention technology for open-pit mine dump trucks based on LiDAR and improved AI algorithm was proposed. Using a single laser point cloud spatial neighborhood joint segmentation method to distinguish obstacles and ground points around dump trucks on a grid map, and calibrating the position of the laser radar and mining truck through a coordinate transformation matrix. Using the bounding box algorithm in AI algorithms to perform collision detection between dump trucks and obstacles in a grid map. Through an improved hybrid hierarchical bounding box algorithm, it is determined whether the bounding boxes of dump trucks and collision detection objects overlap for collision detection, quickly eliminating detection objects that are unlikely to collide. If there is a possibility of collision, the cascading braking parking strategy is used to actively stop the dump truck and achieve collision avoidance operation. The experimental results show that using this technology, dump trucks can effectively avoid surrounding obstacles and reach the target point in a short period of time, and the collision detection response time is reduced to 35.4 ms, effectively reducing the collision risk of open-pit mine dump trucks.

With the changes in mining conditions and the adjustment of production processes, the original ore distribution system and truck dispatching system have exposed problems such as single function and lack of coordination in terms of ore grade control and transportation safety. In order to optimize the production dispatching process of Nannihu molybdenum mine, a set of intelligent dispatching system upgrade solutions was proposed, which covered the switching of mining dispatching modes, ore loading and unloading control, excavator authority management and secondary ore distribution scheduling algorithm based on ore grade control. By constructing a two-layer framework of "static ore distribution before shift+secondary ore distribution correction", a secondary ore distribution method based on the target excavator influence coefficient model is designed to achieve the coordinated optimization of grade balance and transportation efficiency, and compress the daily grade fluctuation range to±0.003%. In addition, a multi-system collaborative linkage mechanism was proposed, which effectively solved the problems of illegal operation and traffic conflicts of outbound vehicles through RFID positioning, authority configuration and data feedback. The application results show that the system has stabilized the average daily output of the Nannihu molybdenum mine at 15 000 t (±1 000 t), and the ore grade meets the needs of the concentrator, providing a technical solution of dynamic response and multi-target coordination for the intelligent upgrade of mines under complex scenarios.

This study reviews the current status of anti-seepage structures in evaporation ponds at in-situ leaching uranium mines in China, highlighting critical issues such as insufficient redundancy in anti-seepage measures, single-function leak detection systems with limited anti-interference capabilities, and excessive thickness of protective layers leading to increased decommissioning waste. By analyzing domestic and international design standards and engineering practices for anti-seepage structures in evaporation ponds across various industries, the advantages and disadvantages of different technologies were systematically evaluated. Combining the unique characteristics of in-situ leaching uranium mine evaporation ponds, a tripartite optimization framework—redundant anti-seepage, intelligent leak detection, and waste reduction—was proposed. This integrated approach aims to standardize the design of anti-seepage structures for such evaporation ponds, thereby enhancing environmental risk control and promoting sustainable development in the uranium mining industry.