Beishan underground research laboratory is the first laboratory in China to study the geological disposal of high-level radioactive waste. A rock crane beam was arranged in the main test level(-560 m) of the underground laboratory. Based on the relevant design standards, the calculation and design steps of rock crane beam were expounded. On this basis, the optimal design scheme of rock crane beam with small crane tonnage was proposed. After adopting this scheme, the material consumption and precious underground space of rock crane beam can be effectively saved, which has practical reference significance for the design of rock crane beam of small tonnage crane in the future.

The method and practice of applying automatic inspection technology in an in-situ leaching uranium mine were studied. The advanced technologies, such as unmanned aerial vehicle(UAV), infrared thermal imaging and laser scanning, were adopted, which can realize automatic inspection and monitoring of mine operation. Mine inspection by advanced UAV replaces traditional manual inspections. In the process of UAV inspection, infrared thermal imaging technology is used to dynamically monitor the orifice and overhead lines, and abnormal conditions can be found in real time. The laser scanning technology is realized by using the load lens, which can accurately scan the physical characteristic structure of the mine surface. The UAV inspection technology not only improves the level and efficiency of mine inspection, but also reduces the human and material costs of mine inspection and supervision, and provides reference for related fields.

Uranium is an important strategic resource as well as a heavy metal element with chemical and radioactive toxicity. Currently, the efficient remediation of uranium in groundwater from uranium mines remains a huge challenge for environmental protection and ecological security. In this study, sodium tripolyphosphate was used to modify nano zero-valent iron (nZVI), successfully preparing STPP-nZVI. The effects of solution pH, STPP-nZVI dosage, temperature, time, U(VI) concentration, and interfering ions on the STPP-nZVI-mediated remediation of U(VI) in groundwater were investigated. FTIR, SEM-Mapping, and XPS were employed to explore the mechanism underlying STPP-nZVI’s remediation of uranium-contaminated groundwater. The results indicate that STPP-nZVI is suitable for treating weakly acidic and alkaline uranium-contaminated groundwater. At a pH of 5.0, the maximum adsorption capacity of STPP-nZVI for U(VI) reached 102.72 mg/g, with U(VI) adsorption occurring as a spontaneous endothermic process. The removal of uranium by STPP-nZVI is primarily attributed to adsorption and reduction. STPP-nZVI materials demonstrate promising application prospects for treating weakly acidic and alkaline uranium-contaminated groundwater.

Since the independent path with so many applications in the ventilation network, it’s significant to search a quick algorithm in the complex network, which can optimize the regulation of ventilation network effect. However, the traditional algorithm of independent path can’t deal with special network search problem, the paths tending to be long, which can’t assure the independence and completeness simultaneously. To solve the problems of traditional independent path search algorithms, the key search theory of independent path was studied systematically and thoroughly. Based on the analysis about the limitation of traditional algorithms, an improved algorithm of independent path was presented. The problem of cut edge and cut vertex in the network were handled to avoid the infinite loop or abortion. The failure cause of the search of independent path completeness was analyzed. And this algorithm can solve the problems of ventilation network that includes unidirectional circuit by modifying the memory search strategy. An adaptive method is proposed according to the improved independent path algorithm, which can get a regulation tree with optimized position and get a set of optimal solutions of the air quantity regulation through increasing resistance.

A method for simultaneous determination of As and Hg in uranium ore by hydride generation atomic fluorescence spectrometer was established, and the effects of digestion temperature, digestion time, medium system, KBH₄ concentration, and uranium content on the detection results were investigated. The results show that the optimal conditions for this method are to dissolve uranium ore with (1+1) aqua regia for 60 minutes at 125 ℃, (5+95)HCl as the medium and 2.0% KBH₄ solution as the reducing agent. The detection limits of this method are 0.006 μg/g (for As) and 0.001 μg/g (for Hg), with relative standard deviations of 2.46% (for As) and 4.22% (for Hg), and recovery rates of 98%~103%(for As) and 97%~106% (for Hg). This method has high accuracy and precision, and can meet the requirements for the determination of As and Hg in uranium ore.

In order to reduce project construction and land acquisition costs, and shorten the project construction cycle, a in-situ leaching mine adopts a quasi-closed circulation system. Compared with traditional in-situ leaching uranium mines, the liquid distribution tank is cancelled and replaced with a liquid collection tank. As the main power source in the quasi-closed circulation system, the liquid distribution pump is prone to tank overflow when it runs unstable, resulting in imbalanced pumping volume in the circulation system and affecting the production progress of the mining area. By adopting measures such as automated real-time monitoring and optimizing the adjustment mode of the mixing pump, the operational stability of the mixing pump in the quasi-closed circulation system of in-situ uranium leaching has been effectively improved.

In the fine filtration production of filter liquor of monazite alkali decomposition, the use of iron plate and frame filter had problems such as poor filtration effect, low automation level, and significant temperature drop after filtration. Improvements were made to the existing fine filtration process, and the applicability of surface filter as fine filtration equipment for filter liquor of monazite alkali decomposition was studied. The results show that the surface filter with PP and PTFE membrane materials has a filtration retention rate of 93% after one hour, which is higher than the retention rate of the iron plate and frame filter. Compared with the iron plate and frame filtration, the surface filter has better filtration efficiency, higher automation level, and better solution insulation effect, which can be well applied in the fine filtration of filter liquor of monazite alkali decomposition.

In response to the problems of high cost and low reuse rate of wired networks, small coverage range and high interference of wireless networks, the in-depth research was conducted on the existing network system in uranium mines, and demand analysis was carried out based on the actual needs. With the goal of full coverage of wireless local area networks for signal wireless transmission, positioning, and remote monitoring of underground personnel and equipment, and on the basis of unified network transmission protocol, the applicability of wireless network transmission technologies such as 5G and Wi-Fi was analyzed. Suitable equipment and working frequency bands were selected, and a network testing platform was built for wireless signal transmission rate and delay experiments to verify the applicability of underground wireless technology applications. The result can guide the construction of underground networks in uranium mines and provide reliable network support for underground production equipment monitoring, environmental monitoring, positioning, communication and important data transmission.

Aiming at the steeply sloping broken thin orebody in the Mianhuakeng mine, the continuous mining method of deep hole blasting without inter-pillar was proposed. According to the technological characteristics of the method, the "inverted step shape" + up and down hole layout continuous mining, "positive step shape" + upward hole layout continuous mining and "positive step shape" + top pillar + upward hole layout continuous mining were proposed. The GRA-AHP and cloud model were combined to evaluate and optimize the three mining schemes, and it was concluded that the scheme of "positive step shape" + top pillar + upward hole layout is relatively safe and efficient, which provides a feasible technical scheme for the mining of broken orebody in Mianhuakeng mine.

Blockage of ore bearing layers is the most common technical problem in in-situ leaching of uranium. A certain experimental mining area has been operating for about 200 days, and the injection pressure of the injection well has increased to 1.65 MPa, and the average injection flow rate has decreased by 51.87%, and serious blockage has occurred in the surrounding ore-bearing layers. The calculation shows that when the natural flow field conditions are transformed into the leaching flow field conditions, the groundwater flow velocity can be rapidly increased by tens to hundreds of times. Hydraulic erosion is the dynamic condition for the migration and precipitation of debris in the ore-bearing layers around the pumping well. The mineral debris and chemical precipitation carried in the leaching solution, which are retained in the tail liquid after surface filtration and resin bed adsorption, are re-deposited and accumulated in the ore bearing layer around the injection well, which is the direct cause of its blockage. During the research period, mechanical blockage was the main factor, accompanied by chemical precipitation blockage. Based on the research results of the maximum pore throat diameter of previous ore bearing layers, combined with underground television observation, the particle size of the leaching solution, well washing water, and the chemical composition analysis of the settling dry residue of the well washing water, it is determined that the mineral debris is mainly clay powder sand particle level debris, and the chemical precipitation is mainly CaCO₃, MgCO₃, Fe(OH)₃, with a small amount of FeCO₃. For this reason, with the goal of “preventing blocking”, a hydrocyclone separator has been added. The surface solid-liquid separation system coupled with “natural sedimentation-hydrocyclone separation-mechanical screening” has achieved obvious results, which is expected to be popularized and applied after further research.