A large uranium deposit has large resources and thin ore bodies, it faces many technical problems in mining and is located in the ecologically fragile area of northern China. The emergence of virtual simulation technology provides a new means for the verification of mineral deposit mining technology. By constructing a three-dimensional spatio-temporal model of the mineral deposit, and combining with the mining time series of the deposit, the dynamic simulation of the whole life period of the mining process can be realized, and the dynamic display of the mine production links and construction procedures can provide a basis for the decision-making of mineral deposit development. Through the development of the virtual simulation system of the whole life cycle, a unique virtual environment is provided for the data synthesis and interpretation encountered in the planning and design of the large-scale uranium deposit mining engineering, the scene of the future development of the deposit is shown, the rationality and feasibility of the overall mining scheme of the deposit is verified, and the foundation is laid for the development of the deposit.

In the geological exploration of in-situ leachable sandstone type uranium deposits, the original equilibrium state of radium and radon in the ore body is disrupted, resulting in the low uranium content in the ore layer obtained from γ logging interpretation, which affects the accuracy of uranium resource estimation. By constructing geophysical parameter holes, the uranium content interpreted by γ logging is corrected for the radium radon equilibrium coefficient. Taking the observation data of geophysical parameter holes during the reconnaissance phase of the Manglai uranium deposit in the Erlian Basin as an example, multiple γ logging observations were conducted on the disrupted ore sections in the parameter holes, and corresponding radium and radon observation curves were drawn. The results of radium radon balance coefficients calculated using the average method and fitting method were compared and analyzed. The results show that the relative errors of the calculated values obtained by the two calculation methods are within ±3%, and the results calculated using the fitting method are smaller than those calculated using the average method. Using the fitting method is beneficial for reducing the possibility of estimating leakage. By establishing an appropriate mathematical nonlinear regression model and running programming language based on MATLAB software, curve fitting of observed data is achieved, and a mathematical fitting formula that can calculate the limit is obtained. The curve obtained by the fitting method is more consistent with the recovery situation after the destruction of the radium radon balance in theory, and the radon saturation observation value obtained is unique and determined, effectively avoiding the uncontrollable error caused by the fluctuation of the observation data. The calculated radium radon balance coefficient is more scientific and accurate. The research results provide an objective and reliable correction coefficient for the accurate estimation of the uranium resource reserves of the deposit, and also provide guidance for predicting the production capacity of uranium mines.

A certain deposit encountered a certain degree of water inflow during the mining process. In order to solve the water inflow problem and provide a basis for water prevention and control plan, the deposit was taken as the research object, the hydrogeological conditions of the deposit were generalized by analyzing the hydrogeological conditions, types and characteristics of aquifers, groundwater recharge and discharge conditions, geological structural characteristics, hydrogeological parameters, hydrogeological test data, and mining design data. The hydrogeological units of the study area were delineated, and a three-dimensional groundwater flow numerical model was established using GMS software, the predicted water inflow of the mining pit in the middle section below -200 m was obtained.

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.

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.

In order to solve the problem that the standard analysis method of molybdenum concentrate has complicated steps and can only measure one element at a time, an analysis method was developed that has fast analysis speed, simple sample dissolution method and was suitable for the simultaneous determination of multiple elements in molybdenum concentrate. Inductively coupled plasma emission spectrometry (ICP-OES) was used to determine various elements in molybdenum concentrate by matrix separation. The research mainly dissolves molybdenum concentrate in a strong oxidation system of hydrogen peroxide-hydrochloric acid-nitric acid-perchloric acid to remove substances such as carbon and flotation agents from the mineral. Then, effectively eliminated matrix interference by separating molybdenum trioxide precipitation from rhenium in the sample solution. Under the conditions of transmitting power of 1.2 kW, auxiliary gas flow rate of 1.0 L/min, atomizing gas flow rate of 0.7 L/min, and peristaltic pump speed of 12 r/min, the interference of solution acidity, matrix and coexisting elements were studied. The results show that the linear correlation coefficients of the working curve are greater than 0.999, the detection limits are 0.000 3~0.02 μg/mL, and the relative standard deviations are 0.82%~4.96%. The analysis results of GBW(E)070212 and GBW(E)070213 for molybdenum concentrate are basically consistent with those of the standard analysis method.

Several materials such as CaO, Mg(OH)₂, Ca₃(PO₄)₂, sepiolite, CaCO₃ were used to stabilize radioactive monazite waste residue. Different dosing ratios and long-term leaching experiments were carried out, the changes in U, Th, and pH were monitored, and the stabilization mechanism of U and Th was revealed by means of XRD, SEM-EDS, and variation of the distribution and forms. The results show that under the condition of 5.0% and 7.5% dosage ratio, the leaching solution of all experimental groups meet the standard requirements of pH=6~9. In subsequent long-term leaching experiments, only Ca₃(PO₄)₂ has the long-term stability ability for U and Th nuclides. In the short term, the increase in pH of waste residue has a stabilizing effect on U, and the activation and redissolution of U after stabilization is a long-term process unrelated to acid reflux. The stability of Th is mainly affected by pH, pH>6 can achieve long-term stability of Th. During the stabilization process, the surface of the waste residue become rough due to the formation of precipitation, and the precipitated U and Th secondary phases are mostly amorphous. The stabilization of U and Th nuclides is mainly related to promoting the transition of exchangeable state and carbonate complex state to iron-manganese oxidation state and residual state.

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.

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.

In view of the leachate from uranium tailings pond containing uranium, manganese, ammonia nitrogen and other pollutants, the comprehensive recovery treatment was carried out by ion exchange to recovery uranium, electroflocculation to remove the heavy metal ions and gas membrane to recover ammonia nitrogen. The effect of ion exchange method on uranium recovery was verified. The removal effect of electroflocculation on uranium, manganese and other heavy metal ions was investigated under different pH of raw water, aeration time and electroflocculation time. And the separation effect of gas membrane on ammonia nitrogen in wastewater under different ammonia nitrogen concentration was studied. The results show that the first stage removal rate of uranium by resin can reach 95.7%. The electroflocculation effect is the best when the pH of raw water (pH=7.5) is not adjusted and no aeration is performed, the concentration of uranium and manganese in the effluent can be reduce to 99.79 μg/L and 0.06 mg/L, respectively, after 5 min electroflocculation. When the ammonia nitrogen concentration in raw water is lower than 297.00 mg/L, the removal rate of ammonia nitrogen in effluent after one treatment is greater than 99%, and the ammonia nitrogen concentration is reduce to 1.91 mg/L. This process can realize the recovery of uranium and ammonia nitrogen, and the concentration of other kinds of pollutants is lower than the national standard.

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.

The static and dynamic adsorption behavior of porous silica gel on uranium in high fluoride solution was studied, the feasibility of the application of silica gel adsorption and uranium removal technology in the treatment of high fluoride radioactive wastewater was explored, and the influence of various adsorption conditions was verified. When ρ(F^-) in the solution reaches 100 g/L, the static adsorption capacity of porous silica gel for uranium is 31~33 mg/g, indicating that the high fluoride environment has a small impact on the adsorption of uranium by porous silica gel and has a high selectivity for {\mathrm{UO}}_2^{2+} and F^-. The static adsorption test shows that the best adsorption effect for uranium is achieved when the radioactive wastewater pH=8~9. The dynamic adsorption test shows that when the pH of radioactive wastewater is 9, the working capacity of the porous silica gel adsorption column is about 20 times the column volume. Most of the uranium in the adsorbed silica gel column can be desorbed by 1 mol/L HNO₃, with a capacity of about 10 times the column volume. The porous silica gel column was desorbed with 1 mol/L HNO₃ eluent and reused 5~6 times, with the basically same penetration curve position for uranium.

The standardization construction of safety production is of great significance for the safety production management of units. In order to explore the influencing factors of safety production standardization construction in a certain geological exploration group, the entropy weight method was used to analyze the safety production standardization evaluation results of its four subordinate units. The results indicate that emergency management, continuous improvement, inspection and maintenance, production site and process, occupational health, and safety warning signs are the key influencing factors that need to be focused on in the construction of safety production standardization in the geological exploration group. Improvement suggestions are proposed to address these influencing factors.

The electromagnetic radiation environment of 750 kV single cycle parallel transmission line was calculated and predicted by adopting the calculation model recommended by Appendix C and D of Technical Guidelines for Environmental Impact Assessment of Electric power Transmission and Distribution (HJ 24—2020). The results show that when the minimum height to ground of the conductor passing through farmland, garden land, pasture land, livestock and poultry breeding land, roads and other places is 15.5 m, the maximum value of the power frequency electric field intensity under the single cycle parallel line is more than 10 kV/m, the minimum height to ground of the conductor needs to be elevated to 16.5 m to satisfy the limit requirement of 4 kV/m. The power frequency magnetic field generated by the 750 kV single cycle parallel transmission line is less than the public exposure control limit(100 μT), which generally will not be an environmental constraint for the construction of the line, however, the power frequency electric field generated by the line is the main factor of the electromagnetic environmental impact, and the control limit of the power frequency electric field strength(4 kV/m) is an environmental constraint for the construction of the line, and it is also a key control factor for the electromagnetic environment of the transmission and transformation power. The field measurement results and the theoretical prediction results are in good conformity, indicating that the prediction model used has good applicability, and the results of the study can provide technical support for the construction and environmental supervision of 750 kV single cycle parallel transmission lines.