Experiments of erosion corrosion with 3.5% NaCl solution at different flow rates were performed for TP2 copper after different heat treatment (hard and soft states), and the erosion corrosion rates of TP2 copper were tested. The morphology and products after 240 hours of corrosion were characterized, and the mechanism of erosion and corrosion for TP2 copper was also discussed. The results show that flowing medium in corrosion test accelerates the corrosion rate of TP2 copper. The soft TP2 copper presents a higher corrosion rate, compared to hard TP2 copper, after 240 hours of corrosion at the same flow rate. And after 240 hours of erosion corrosion at a higher flow rate, TP2 copper has its surface morphology predominated by gully-like structure and a product of Cu₂O is generated after corrosion.

Based on the relevant patents of layered cathode materials for sodium-ion batteries in China, a review of patent applications (authorization) is presented in terms of annual trend and main applicants. Also, some representative patents on precursors, structure, chemical washing and coating of layered cathode materials for sodium-ion batteries are chosen for analysis, Finally, the industry development trend, as well as technical difficulties and hotspot in this industry are summarized.

Activated carbon derived from coconut shell was prepared as anode material by adopting high temperature pyrolysis and activation. The effects of activation on the structure, morphology and electrochemical properties of coconut shell carbon were investigated by using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the coconut shell carbon after activation process is highly disordered, and also microporous and mesoporous. It delivers an initial discharge specific capacity of 918.22 mAh/g at a current density of 0.1 A/g, and retains a specific capacity of 447 mAh/g after 200 cycles discharge at a current density of 1 A/g.

The advantages and disadvantages of several technologies for recycling spent LiFePO₄ batteries, including pre-treatment, hydrometallurgical process, and direct regeneration and repairing, were presented in terms of recovery efficiency, economic and environmental benefits, and commercial feasibility. The development trend of each technology is also analyzed. All these can serve as reference for optimizing and improving the technologies to recycle spent LiFePO₄ batteries in the future.

For evaluating vibration reliability of Li-ion battery packs used in heavy-duty mining vehicles, ANSYS, finite element software, was adopted to simulate Li-ion battery packs in a heavy-duty mining vehicle and calculate its stochastic vibration. Based on the test performed about random vibration of battery packs, it is found that the first modal frequency of the battery packs is 33.85 Hz, corresponding to the frequency of upper cover of battery packs, which is greater than the external excitation frequency transmitted by frame (30 Hz). thus low-order frequency resonance can be avoided and vibration reliability of the structure can be improved. The calculated stresses in the random vibration of key parts of battery packs, including stiffener, lower box, upper cover and battery brackets, are all lower than the yield strength of the corresponding materials, indicating the structural parts of battery packs meet the requirements for strength reliability. Permanent deformation and damage have not been found in the assembly of battery packs in the random vibration test, verifying the reliability of this simulative computation results.

Based on an analysis of a trend in global patent application and distribution of patented technologies for second life power batteries, as well as a discussion on the global competition situation and hotspots in R & D of technologies in this industry, the relevant patent application situation in China is analyzed. It is found that the number of applications for patents on second life power batteries in various countries is steadily increasing, and there is still room for improvement. The classification, detection, screening, and evaluation of retired power batteries have always been the hotspots in technical R & D and are still in development, for which the patent applications present stable upward trend. China, as a major source of relevant technologies, has been playing an important role in patent portfolio, which is consistent with global development trends. The applications for patents on relevant technologies are still expected to increase in the future. Therefore, it is recommended that relevant enterprises should intensify their efforts in R & D to seize opportunities in the industry, and also improve the patent portfolio.

Based on an introduction of the background and operational effectiveness of the Central Geological Exploration Fund, the important role of the fund in mineral exploration and its profound significance to the market-oriented reform of the geological exploration industry are elaborated. Then, the main problems to be solved urgently are analyzed based on the implementation of the fund project. Some thoughts for promoting reform of the fund are finally put forward in consideration of the current development of the mining sector, actual situation of state finance, as well as the characteristics of the Central Geological Exploration Fund.

The impact of large-diameter pressure-relief borehole arrangement and drilling parameters on roadway stability was studied. It is found that arrangement of boreholes in a two-row pattern, compared to boreholes in a single-row pattern, can benefit stress shift and control of roadway deformation. By adopting the arrangement of boreholes in a single-row pattern and a two-row pattern, the deformation at both sides was reduced by 6.05% and 15.44% respectively, and the original maximum stress was reduced from 39.61 MPa to 33.50 MPa and 32.70 MPa respectively. It is also found that boreholes should be arranged, as much as possible, near the center of two sides, penetrating the plastic zone to the place with the maximum stress. And the spacing between boreholes should be determined based on the horizontal distance of the plastic zone of boreholes, and the burden spacing should be less than the height of stress-relaxed zone.

The west slope of SCM copper cobalt mine in DRC was taken as an example for determining the shear strength parameters of rock mass by a laboratory triaxial compression test, back analysis of landslides, evaluation of rock mass quality and strength conversion with Hoek-Brown criterion, and then the obtained strength parameters were verified. The results show that due to the size effect of the samples, there may be deviation in the cohesion of rock mass shear strength obtained from the laboratory triaxial compression tests. It is found that with the obtained parameters used in slope stability analysis, more accurate evaluation results can be obtained from the slope model with higher sensitivity to friction angle, while lower accuracy from the slope model with higher sensitivity to cohesion. Under the same working condition, the parameters of slope rock mass obtained from the back analysis of shallow landslides can be used for analyzing local or single bench stability, and the parameters of slope rock mass from back analysis of deep-seated landslides or the landslides due to weak structural planes can be used for overall stability analysis. It is found that the shear strength parameters obtained based on Hoek-Brown failure criterion are close to the results from laboratory triaxial compression test, also easy to operate and more accurate, which can have a wide application.

Guizhou Jinfeng Gold Mine was taken as an engineering example for investigating effect of geometric features of rock surface on the performance of shotcrete support in the roadway constructed by drilling and blasting. The rock surface of the roadway was scanned by using a 3D laser scanner, and a 3D geometric model was established for the roadway. The actual shape of cross-sections was created by slicing the geometric model with a 3D software for analyzing the geometric features. With numerical models respectively established for the designed and actual sections, the variation in internal forces of the shotcrete and its supporting effect for the surrounding rock were analyzed. The results show that uneven rock surface of a roadway can lead to significant increase in the shear force and bending moment of shotcrete, but relatively small effect on the axial force. It is found that concave part of surrounding rock in a roadway is subjected to maximum negative bending moment, while convex part is mostly subjected to maximum positive bending moment. Under the interaction of axial force and bending moment, the shotcrete on convex part has an obvious lower safety factor, leading to weakened support to the surrounding rock, thus tensile failure is prone to occur.