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.

Part of the waste residue generated during the development and utilization of rare earth resources belongs to the associated radioactive solid waste. The safe and effective disposal of this type of waste residue is an urgent problem that needs to be solved in the current development of the rare earth industry. By the method of investigation and analysis, based on the types and sources of rare earths, statistics were conducted on the types, yields and radioactive nuclide activity levels of waste generated during the mining and selection process. Combined with the development plan of the rare earth industry, the stock and increment of rare earth waste in typical provinces(autonomous regions) were preliminarily estimated. And the current status and existing problems of the treatment and disposal of rare earth associated radioactive waste residue were sorted out. On this basis, a strategy for regional landfill disposal is proposed: it is recommended to implement a 7+x model nationwide, and to build rare earth waste residue warehouses in major rare earth provinces(autonomous regions), with reference to the model of Baotou in Inner Mongolia, to collect and dispose of rare earth associated radioactive waste residues in the provinces(autonomous regions). Based on the estimated amount and increment of waste residues, suggestions for the scale of rare earth waste residue disposal in each province(autonomous region) are provided.

Clay is a crucial component of the coexisting radioactive waste cover layer. The investigation of its shielding performance is of significant importance. In this study, the effects of clay type, clay moisture content, emulsion type, clay+geomembrane on radon shielding were studied by means of self-designed experimental apparatus. The results show that montmorillonite stands out as a clay type with relatively superior shielding capabilities, montmorillonite with 25% moisture surpassed other moisture levels, montmorillonite combining either polyurethane emulsion or geomembranes can yield favorable shielding effects. This research provides essential data and theoretical guidance for the utilization of clay in radon shielding.

Sandstone-type uranium deposits point has been found in Chepaizi area of the western Junggar Basin, among which the Neogene Shawan Formation uranium mineralization is widely distributed. The uranium metallogenic potential and prospecting direction in this area have been studied, but the uranium metallogenic conditions are not clear. The formation of sandstone-type uranium deposits is the result of water-rock interaction. It is important to study the relationship between hydrogeological conditions and uranium mineralization. According to the paleohydrogeological evolution, the hydrodynamic conditions of uranium mineralization were analyzed. The hydrochemical components were used to analyze the hydrogeochemical characteristics of groundwater. The uranium exploration and oil data were used to analyze the geochemical characteristics of rocks, sand body characteristics, sedimentary facies characteristics, development characteristics of ancient interlayer oxidation zones, and oil-gas transformation. The differences in the hydrogeological conditions of uranium mineralization in the three sand groups of the first member of the Shawan Formation and the favorable areas for uranium mineralization were revealed. The research shows that the 128 group has the most favorable hydrogeological conditions for uranium enrichment where is the intersection of the underwater distributary channel of the fan delta front and the braided river delta front and on both sides of the fault zone. The thickness of the sand body is stable, the connectivity is good, the uranium mineralization lasts for a long time. The uranium metallogenic condition of Tachakou area and 126 group is less. The 3 sand group of Shawan Formation was the best, the 1 sand group was the second, and the 2 sand group was the worst.

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-situ leaching uranium technology is an important means of sandstone type uranium mining in China. In-situ leaching drilling is the only channel connecting the ground to the underground ore layer, which plays an important role in uranium mining. The construction efficiency of in-situ leaching drilling affects the construction and development of the entire uranium mine. Taking a certain uranium mine as the research object, the efficiency and existing problems of in-situ leaching drilling construction from 2019 to 2020 were statistically analyzed. The results show that compared with core drilling machines, water well drilling machines have significant advantages in construction. The configuration of mud pumps, drilling depth, logistics management, and support all have an impact on the efficiency of drilling construction. Improvement suggestions have been proposed for the factors affecting construction efficiency, in order to achieve the goal of reducing costs and increasing efficiency.

The groundwater baseline is an important benchmark for determining the impact degree of in-situ leaching of uranium and determining the restoration target value. Due to the complex hydrogeological conditions and poor comparability of monitoring data, the determination of groundwater baseline still lacks a relatively contractual and unified technical method and standard specification. Therefore, the procedure of determining groundwater baseline is put forward, the monitoring factors, spatial scale, number and density of samples, sampling frequency and sampling depth are discussed and demonstrated by applying mathematical and statistical methods based on the monitoring data from two in-situ leaching of uranium projects in Xinjiang and Inner Mongolia. The research results can provide some guidance for determining groundwater baseline of in-situ leaching of uranium.

There is severe blockage in the surrounding ore bearing layers of the injection well in a certain uranium leaching experimental mining area. The inner diameter of the casing of the injection well is only 80 mm. After the completion of conventional air compressor well washing, a small diameter submersible pump well washing test was carried out in three injection wells. The initial pumping capacity is around 4.5 m³/h, and the minimum pumping capacity during this period is 3.4 m³/h. The sand content of the first turbid flushing water from two wells is analyzed to be 4.36 and 5.19 kg/m³ respectively. Particle size, electron microscopy scanning, and chemical composition analysis show that the mineral debris in the settled dry residue of the well washing water is mainly composed of silt and fine sand debris, with a small amount of clay debris. Chemical precipitation mainly consists of CaCO₃, MgCO₃, and FeCO₃. The submersible pump has operated for about 27.5 h accumulatively without any failure. The test shows that the submersible pump is feasible, with less investment, low cost, high safety and convenient implementation.

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.