Taking the deposit west of P0 line in Mengqigur, Xinjiang as the research object, aiming at the problems such as large variation coefficient, buried depth, complex occurrence conditions and difficult large-scale development of the ore body, the integrated mode of “exploration and mining combination” was adopted, which combines exploration drilling and production drilling, had made the utilization rate of exploration drilling reach 61%, saved the input cost of drilling and improved the quality of resources. The construction period of the deposit was shortened, the vegetation damage was reduced, and the green and sustainable development of the mine was achieved. The technology has remarkable economic and environmental benefits, and provides a new method for the development of complex sandstone in-situ leaching uranium ore.

Mastering the particle size in the solution throughout the neutral in-situ leaching process has guiding significance for regulating the leaching process, optimizing filters, determining the position of solid removal, alleviating ore bed blockage, restoring the flow rate of injection liquid, and reducing resin bed stratification. For this purpose, the whole process solution of neutral in-situ leaching of uranium from the Nalinggou deposit in Inner Mongolia was taken as the object, and based on laser particle size analyzer test data, the particle size distribution in the solution was obtained. The results show that the frequency distribution curve of particle size in the leaching solution is asymmetric, and the cumulative distribution curve is in an “S” pattern. The particle size distribution range is narrow, and the maximum particle size is less than 100 μm. The resin bed layer has a strong filtering effect on particulate matter, and the accuracy of the tail liquid filter bag should be determined based on the size of the resin ball and system pressure. The addition of O₂ or CO₂ in neutral systems has a weak effect on particle size. The particle size frequency distribution curves of both the qualified solution and the masterbatch solution in the settling tank exhibit a “double peak” pattern, while the lean solution exhibits a normal distribution. The maximum particle size in the mother liquor is about 40 μm. It is recommended to choose a precision of 10~50 μm for the leaching solution bag filter, and simultaneously add a 10~20 μm precision filter between the mother liquor tank and the eluent preparation tank. This study reveals the particle size distribution pattern in the whole process solution of the Nalinggou deposit, enriching the understanding of the particle size of neutral in-situ leaching of uranium, and providing a basis for optimizing surface filtration technology in mines.

In addressing the adsorption issue of low-concentration uranium in nitric acid systems, a chloromethylated styrene-divinylbenzene copolymer was employed as the framework, and phosphorylation was achieved using phosphorus trichloride as the functionalizing reagent. Through Friedel-Crafts alkylation and quenching-hydrolysis/alcoholysis reactions, long-chain hydroxyl and alkyl groups were grafted onto the resin, resulting in uranium adsorbents featuring phosphoric acid and phosphoric ester functional groups, respectively. The resin structural characterization was conducted using infrared spectroscopy, elemental analysis, and thermogravimetric analysis. During the resin preparation, the impact of different process parameters on the phosphorus content and uranium adsorption performance was investigated, leading to the determination of optimal synthesis conditions. Static experiments were performed to assess the influence of pH, equilibrium uranium concentration, and adsorption time on the uranium adsorption properties of the resin. Additionally, a selection of desorption agents and verification of resin reusability were carried out. The results indicate that the prepared phosphoric ester-based uranium adsorbent exhibits excellent adsorption performance for low-concentration uranium (<20 mg/L) in a simulated solution (1 mol/L HNO₃+1 mol/L NaNO₃). The resin saturation adsorption capacity for uranium is 21.9 mg/g dry resin, and the residual uranium concentration in the leachate after adsorption is <0.05 mg/L. Using 0.4 mol/L NaHCO₃ and 0.1 mol/L Na₂CO₃ as composite desorption agents, the desorption efficiency for uranium reaches 98.3%. The synthesized phosphoric ester-based uranium adsorbent proves effective for the adsorption and separation of low-concentration uranium in nitric acid systems.

This paper summarized the sedimentary facies types and characteristics of the Upper Cretaceous Yaojia Formation in Baiquan area, Songliao Basin. It is considered that the Yaojia Formation in Baiquan area can be divided into upper and lower members. The upper member of Yaojia Formation has meander river facies and delta facies, while the lower member has braided river facies and delta facies, and further be divided into 6 subfacies and 10 sedimentary microfacies. The braided river facies sand body of the lower member of Yaojia Formation has large thickness, good uranium anomaly has been found, which has good uranium metallogenic potential, and is a favorable area for uranium prospecting in the future.

Fengcheng paigeite deposit is a large scale multi-metal deposit containing boron, iron and uranium, which is developed by open-pit mining, following by beneficiation (gravity separation, magnetic separation, and flotation) and hydrometallurgical treatment to obtain iron concentrate, sodium borate, and diuranate as products. In this process, several kinds of solid waste are produced such as mining waste rock, beneficiation tailing, and leached uranium tailing. Through detailed investigation of the radioactive characteristics of product and solid waste in the full process, it is indicated that iron concentrate and sodium borate meet their radioactivity quality standard. Mining waste rocks, beneficiation tailing, gravel and coarse sand produced by crushing of ore, and boron mud can be treated and disposed as ordinary solid waste other than radioactive waste. Gravel and coarse sand can be used as building materials. Boron mud is used to produce sub-nanomater silica stone without any limitation related to radioactivity, in case of the boron mud addition not exceeding 50%. Leached uranium tailing should be disposed as extremely low level radioactive waste.

The high rates of submersible pump damage due to pump shaft fracture and pump body corrosion have been studied. By conducting theoretical calculations and ANSYS numerical simulations, the mechanical properties such as strength and stiffness of hexagonal and cylindrical shaft structures were compared. Field comparison tests on the corrosion resistance of 304, 316L, and 904 stainless steel materials were also carried out. The results indicate that under the same load and equivalent diameter conditions, the shear stress on the cross-section of the cylindrical axis is 64.95% of the hexagonal axis, and the torsion angle is only 56.25% of the hexagonal axis torsion angle; the simulation results show that the maximum circumferential deformation of the cylindrical shaft coupling is 68.4% of the maximum circumferential deformation of the hexagonal prism shaft, the cylindrical shaft structure exhibits better torsional performance. While 904 stainless steel has the best corrosion resistance, both 304 and 316L stainless steels demonstrate similar corrosion resistance to acidic media. Considering corrosion resistance margins and manufacturing costs, it is recommended to use a cylindrical pump shaft structure and continue using 316L stainless steel as the main material in the development of submersible pumps for uranium mining.

The well washing process of in-situ leaching uranium mine is an important means to increase the amount of drilling water. However, a large amount of impurities such as sediment in the well washing wastewater cause the bag filter and adsorption tower pressure to rise, which indirectly affects the production progress. Based on the principle of centrifugal force, a sand removal device for well washing wastewater was developed and applied in a certain in-situ leaching uranium mine. The results show that it can reduce the pressure of bag filter and adsorption tower, reduce the frequency of filter bag replacement, increase the adsorption water and increase production capacity. The sand removal device of the well washing wastewater has a certain popularization value in the drilling and well washing technology of in-situ leaching uranium mine.

The environmental risks and hidden dangers of decommissioned uranium mining and metallurgy facilities were elaborated. Based on analyzing the important connotation and role of long-term monitoring of decommissioned uranium mining and metallurgy facilities in China, the overall plan and implementation approach for long-term monitoring were summarized. In response to the current situation and problems in long-term environmental monitoring of decommissioned uranium mining and metallurgy facilities in China, the solutions and methods have been proposed, and the attention has been given to the technical and management measures for subsequent operational monitoring work.

A method for determining uranium content in natural uranium products (U₃O₈) by wavelength dispersive X-ray fluorescence spectrometry was established using solution sample preparation and strontium carbonate as the internal standard. The method determines that the weight of the sample is 1.00 g, and the weight of the internal standard strontium carbonate is 0.600 g. The sample is digested with 15 mL of phosphoric acid and 2 mL of nitric acid to a constant volume of 200 mL. After stirring with magnetic force, the volume of the solution is controlled using a disposable plastic pipette and an electronic scale. Instrument measurement conditions selection feature X-ray line: U-L_α1,Sr-K_α1, channel mask 34 mm, primary collimator 150 μm. The linear correlation coefficient of the working curve of the method is 0.999 8, and the relative standard deviation (RSD) is between 0.031% and 0.050%, indicating good precision; The relative error between the measurement results and the recommended value of the reference material is not less than 0.034%, with good accuracy. Compared with the potentiometric titration method, the absolute deviation of this method is between 0.010% and 0.126%, and the results are accurate and reliable, meeting the requirements for rapid batch analysis of natural uranium products.

Laboratory experiments were conducted on the biostimulation on a mixed system of groundwater and sandstone from a neutral in-situ leaching uranium mine. Based on the biostimulation, the remediation of carbon sources and carbon levels on uranium in groundwater was identified. The results indicate that under ethanol stimulation, the remediation efficiency of target U in neutral groundwater could reach up to 97.48%, this may be related to significant environmental neutral pH and higher reduction Eh values (Pearson’s r>0.7, P<0.01), and the biological metabolism process of ethanol has less disturbance to the water-rock environment, which ensures the relative stability of {\mathrm{HCO}}_3^{-} and {\mathrm{SO}}_4^{2-} plasma environments and made it easier to achieve long-term stability of U in groundwater.