In order to solve the problem that the minimum buried depth of the phreatic surface in a uranium tailings dam is less than the code limit due to complex depositional structures and insufficient drainage facilities in the tailings dam, the numerical analysis on seepage and stability of the tailings dam were conducted by GeoStudio. The variation patterns of phreatic surface and factor of safety under normal, design, special water levels, with/without drainage consolidation measures, were systematically investigated. The results show that before the drainage consolidation measures were taken, the minimum buried depth of the phreatic surface is 1.74 m, 0.93 m, and 0 m under normal, design, and special water levels, respectively. Especially under the special water level, the phreatic surface emerged from the embankment above the 140.9 m platform. The factor of safety was 1.329, 1.321, 1.291 respectively before the drainage consolidation measures were taken. After setting up the horizontal drainage pipe as drainage consolidation measures, the phreatic surface burial depth increased by 3.48~4.59 m, while factor of safety at normal, design, special water levels rose to 1.431, 1.425, 1.402 respectively, with an increase of 7.68%~8.59%. The drainage consolidation measures can effectively optimize seepage conditions of the embankment, significantly reduce the phreatic surface elevation, and enhance dam stability, confirming satisfactory seepage control effectiveness. The results provide strong technical support for the design of drainage consolidation measures in tailings dams and offer valuable references for ensuring long-term safe operation of tailings ponds.

Usually, uranium mines discharge the waste water generated during the adsorption process into an evaporation pond, and eliminate radioactive waste water by natural evaporation.. The active acceleration technology for the evaporation capacity of domestic evaporation ponds, such as atomization devices, heating devices, wind blowing devices, etc., mostly has high energy consumption losses, high operating costs, and is difficult to put into large-scale use. Passive acceleration devices generally have limited improvement in evaporation capacity. A new type of evaporation tower with a frame structure and multiple horizontal evaporation surfaces was proposed. The evaporation towers are uniformly arranged in a matrix form in the evaporation pool, and each tower is connected in series by a wastewater pipeline fixed at the top of the tower to form a collaborative three-dimensional evaporation surface structure, greatly improving the utilization level of evaporation space and generating a multiplier effect on the evaporation capacity of the original evaporation pool. By conducting small-scale simulation experiments, the empirical calculation formula for the evaporation capacity of the evaporation tower matrix system can be used to achieve refined and quantitative design of the three-dimensional evaporation system. This method has the advantages of environmental protection, high efficiency, and no energy consumption, and is suitable for dry and low wind areas. It can effectively save land resources and engineering investment.

In order to solve many problems that have existed in the operation of the mineral resource reserves database over the years, such as data registration errors, data inconsistency, data missing, data duplication, data redundancy, and omission of registration, Henan Province has carried out a cleaning operation on the provincial reserves database. It has explored technical methods of cleaning from aspects such as basic database information, report information, resource reserves data, verification of coordinates and coordinate systems, and mineral deposits, combined with the national survey of mineral resources and annual reserves statistics. Eventually, a list of problems in the reserves database has been formed. The research results have laid a solid foundation for future updates to the reserves database and providing strong support for better mineral resource management.

Acidic wastewater generated by in-situ leaching uranium poses a serious threat to the groundwater environment. Aiming at the problems of long microbial remediation cycle, low survival rate and insufficient stability of electrokinetic remediation, a remediation method of microelectric field-coupled sulfate-reducing bacteria (SRB) was proposed. Through simulated wastewater remediation experiments, a three-chamber electrochemical device was constructed to explore the remediation mechanism and optimize the key parameters by combining the electromigration effect with the reduction function of SRB. The results show that the coupled remediation system significantly enhanced the uranium (VI) removal rate (more than 98%), and effectively reduced the concentrations of Ca, Mg, Al, Fe and other metal ions (removal rate>80%) and sulfate content (removal rate > 90%). Under the influence of an electric field, uranyl ions migrate to the cathode region, where they are predominantly reduced by S^2- generated through the metabolic activity of sulfate-reducing bacteria (SRB) and subsequently co-precipitated. A minor fraction is reduced to U(IV) via electrode reactions. Experiments show that the different potential gradients can lead to different pH in the cathode chamber, which affects the remediation effect, with H⁺ leading to the escape of S^2- under acidic conditions (pH<4) and the formation of soluble uranium complexes easily under alkaline conditions (pH>9); with a potential gradient of 0.2~0.4 V/cm, the balancing remediation efficiency, microbial activity and energy economy. This study provides a theoretical basis and technical support for the green and efficient remediation of acidic wastewater from uranium extraction by in-situ leaching technology.

Low-permeability sandstone uranium mine, with its poor permeability and high injection difficulty, has brought great challenges to the traditional in-situ leaching mining technology. In view of the current low permeability uranium mining problems, this paper discussed the innovative application of high-pressure liquid injection technology in the field of in-situ leaching mining and its effectiveness. Comparative tests were conducted to verify the effectiveness of high-pressure liquid injection technology, pumping liquid volume test and tracer test were carried out under atmospheric pressure and high-pressure conditions respectively. The test results show that compared with the atmospheric pressure condition, the high-pressure liquid injection technology increases the injection flow by 6.4 times, the pumping flow by 1.05 times and the seepage velocity by 33 times. High-pressure liquid injection technology can effectively solve the leachants injection problem in low-permeability sandstone uranium mine, and the technology is convenient to implement in the mine site.

The ore subjected to radioactive sorting treatment is crushed ore, with random shapes, which directly affects the accuracy of ore grade detection. To enhance the accuracy of radioactive separation detection, standard samples of uranium ore were prepared to conduct an influence test on how the shape of uranium ore affects detection efficiency. The relationship between the ore shape factor and the variation coefficient of detection efficiency was examined, leading to the establishment of a detection efficiency correction algorithm based on ore shape. Additionally, a quantification method for ore shape suitable for uranium ore radioactivity detection was proposed. The validity of the proposed detection efficiency correction algorithm has been verified through practical ore sorting tests. After implementing this algorithm, the error in uranium ore grade detection was reduced to less than 5% in over 70% of the test groups. This significantly mitigates the impact of ore shape on detection efficiency and enhances the accuracy of uranium ore grade detection.

With the development of uranium mining, uranium mining technology has rapidly advanced, but various challenges have emerged. In the process of in-situ leaching of uranium, there is often a phenomenon of decreased pumping and injection volume, which seriously affects the efficiency of uranium leaching. In response to the problem of decreased pumping and injection volume, physical, chemical, and combined well cleaning techniques have been carried out. The washing technology can solve the blockage around the wells, but its washing effect lasts for a short time and has a small impact radius, which cannot fundamentally solve the problem of decreased flow rate. The liquid flow cavitation technology is widely used in petroleum extraction, which can effectively increase the production of pumping wells and reduce the pressure of injection wells. However, it has not been involved in the in-situ of uranium process. In this paper, by comparing the difference between uranium leaching technology and petroleum technology, the cavitation device is optimized, and the drilling wellhead device is improved in the ground test, and then the liquid flow cavitation test is carried out. During the test, the operation displacement reached 2 m³/min and the pressure was about 21 MPa, which verified the feasibility of liquid flow cavitation technology in in-situ of uranium, and provided a new idea for improving the permeability of uranium mine.

Due to the change in ore properties of a certain hard rock uranium mine with the increase of mining depth, the heap leaching process of the ore encountered the problem of heap scaling. In order to solve the problem, the effects of leaching agent acidity, spray intensity, column height and particle size on heap scaling were studied. The results show that when the acidity of the leaching agent is 50.0 g/L, the spray intensity is 40.0 L/(m²·h), and the leaching period is 30 days, there is no scaling in the column leaching test, and the uranium leaching rate of -10 mm ore reaches 83.40%. The results of the 800 t ore pilot test confirms that there is no scaling in the heap with high acidity and large spray intensity, and the uranium leaching rate reaches 86.57%.

The kinetics of thorium extraction from hydrochloric acid medium by a binary mixed system of di(2-ethylhexyl) (2-ethylhexyl)aminomethylphosphonate (Cextrant 230) and trialkylphosphine oxide (Cyanex 923) was investigated using the laminar flow constant interfacial cell method. For comparison, the kinetics of thorium extraction by the Cextrant 230 single system was also studied. Systematic investigations were conducted on the effects of stirring rate, temperature, specific interfacial area, extractant concentration, acidity, and chloride ion concentration on the extraction rate.The results show that the extraction regime is deduced to be chemical reaction-controlled for the sole Cextrant 230 system and diffusion-controlled for the mixture system, respectively, and the extraction reaction occurring at the bulk phase would be the rate-determining step. The thorium extraction rate is barely affected with temperature variations in the sole Cextrant 230 system, but increased in the mixture system, with an activation energy of 14.74 kJ/mol. The concentration of chloride and extractants linearly related to the extraction rate indicates that the extraction of Th⁴⁺ both in the sole Cextrant 230 system and mixture system is a pseudo first-order reversible reaction.

Taking the stone coal vanadium ore in Danfeng country, Shangluo city, Shannxi province as the research object, the vanadium leaching characteristics were studied using direct acid leaching and sulphuric acid-curing leaching process, respectively. The results indicate that the optimum vanadium leaching rate is 86.7% when using direct acid leaching process under conditions of sample fineness of 45%, H₂SO₄ concentration of 14%, leaching period of 6 h, leaching temperature of 80 ℃, Ca(ClO)₂ dosages of 3%, CaF₂ dosages of 2%, and the solid-liquid ratio of 1∶2. While the vanadium leaching rate can reach to 93.5% at ambient temperature by using sulphuric acid-curing leaching process under the conditions of sample fineness of 80%, H₂SO₄ dosages of 20%, wetting water dosages of 7.5%, curing temperature of 110 ℃, interval time of 10 h,water leaching period of 120 min, solid-liquid ratio of 1∶2. The results for sulphuric acid-curing leaching process is better than that for direct acid leaching process, and the conclusion can provide technical support for vanadium extraction from stone coal in Shannan region.