With aluminum hydroxide powder as raw material, aluminum hydroxide was roasted into α-Al₂O₃, and the phase transformation and microstructure change during the process were investigated. Then, the kinetics of the calcination process was calculated by simulation with multiple scanning method. It is found that the optimum conditions for aluminum hydroxide calcinated into α-Al₂O₃ are as follows: calcination temperature of 1200 ℃, time of 2 h, heating rate of 5 ℃/min. Three endothermic peaks can be observed during the calcination process of aluminum hydroxide, corresponding to three weightlessness stages. In the first stage of reaction, the function of mechanism is G (α)=[(1-α)^-1/3-1]², the average activation energy is 91.16 kJ/mol and the pre-exponential factor is between 17.00×10⁹ and 44.03×10⁹ min^-1. In the second stage of reaction, the function of mechanism is G (α)=α², the average activation energy is 106.2 kJ/mol and the pre-exponential factor is between 7.70×10⁹ min^-1 and 18.60×10⁹ min^-1. In the third stage of reaction, the function of mechanism is G (α)=α^1/4, the average activation energy is 235.42 kJ/mol, and the pre-exponential factor is between 39.94×10⁹ and 50.79×10⁹ min^-1.

Methylene blue was degraded by adopting a heterogeneous Fenton system composed of manganese residue and H₂O₂, and the effects of initial pH value, H₂O₂ concentration, dosage of manganese residue and reaction temperature on the degradation performance were studied. The reusability of manganese residue was investigated, and the removal mechanism of methylene blue in the manganese residue/H₂O₂ system was also discussed. The results show that the removal rate of methylene blue can exceed 98.1% after 120 min reaction at temperature of 25 ℃, with methylene blue concentration of 20 mg/L, H₂O₂ concentration of 10 mmol/L, manganese residue dosage of 2 g/L, and initial pH value of 2.5. After the manganese residue is recycled for 5 times, the removal rate of methylene blue can be still up to 95.5% by 300 min reaction. In the manganese residue/H₂O₂ heterogeneous Fenton system, ·OH plays a leading role in the degradation of methylene blue.

Mg-1%Al alloy plates were rolled at different strain rates, and the effects of rolling strain rate on microstructure, mechanical properties and damping properties of Mg-1%Al alloy were investigated. As rolling strain rate increases, the average grain size and recrystallization volume fraction of Mg-1%Al alloy increase, while the tensile strength, yield strength and texture strength decrease. As the rolling strain rate increases, the elongation decreases after an initial increase, reaching the highest (25.33%) at a strain rate of 20 s^-1, and the damping performance at room temperature is also improved. The damping value is 0.061 with the strain amplitude of 0.1% at a strain rate of 30 s^-1, which is 1.5 times of that at a strain rate of 15 s^-1. At a certain strain rate, the damping performance decreases as strain frequency increases.

Aluminum sulfate, sodium hydroxide, and high-aluminum pickling sludge were used as raw materials to prepare pseudo-boehmite by adopting a dual aluminum source method. The effects of pH value, reaction temperature, and urea addition on the formation and structure of pseudo-boehmite, as well as the effects of synthesis conditions on the phase and structural properties of pseudo-boehmite were investigated. The results show that as the reaction temperature increases, the specific surface area and pore volume of pseudo-boehmite increase, and the crystallinity also increases. With pH value between 6.5 and 9.5, a clear pseudo-boehmite phase can be obtained; with pH value up to 10.5, a trihydrate alumina phase will be formed. The addition of urea can significantly increase the specific surface area and pore size of pseudo-boehmite.

To solve the problem of structural instability of cathode material (LiNi_0.8Co_0.1Mn_0.1O₂)(NCM)) during cycling, a strategy of co-doping of Rb⁺ and Cl^- was proposed for NCM materials. The synergistic effect of co-doping of Rb⁺ and Cl^- in the NCM lattice can increase the diffusion rate of Li⁺ and relieve the internal strain, thus hindering the mixing of Li⁺/Ni²⁺ during high cut-off voltage cycling. Electrochemical test results show that Li_0.99Rb_0.01(Ni_0.8Co_0.1Mn_0.1) O_1.99Cl_0.01 (RbCl-NCM) has a discharge capacity up to 176.9 mAh/g at a current density of 10C. The initial discharge capacity at 1C is 203.5 mAh/g. After 200 cycles, its capacity retention ratio is as high as 87.8%, showing an excellent cycling performance, while the capacity retention ratio of NCM material is only 57.3%.

Based on the in-depth investigation of the geological characteristics of the phosphate mines in western Hubei, including Sujiapo Phosphate Mine, Maping Phosphate Mine and Taoyuxi Phosphate Mine, rock burst phenomena were analyzed in terms of influencing factors of occurrence position, buried depth and lithology. The appropriate control measures are proposed for rock burst in those phosphate mines in western Hubei. In-situ stress of underground phosphate rock in western Hubei was tested. Based on the obtained results, the mining sequence was optimized to avoid mining operation in the stress concentration area as much as possible, and pressure relief and support measures were taken in local areas to ensure safe underground mining.

To solve the problem of unstable slurry, low density of sintered body, and high carbon residue, the effect of different resin monomer on additive manufacturing of 5052 aluminum alloy with light curing strategy was explored. It is found that different type of monomer can bring great impact to the process of additive manufacturing with light curing strategy and the properties of the following sintered product. When the aluminum slurry prepared with TMPTA or PEG400DA has viscosity higher than 30 Pa·s and settling time is more than 120 h, the formed aluminum alloy substrate has a complete structure with more pores on the surface. When the aluminum slurry prepared with PEG200DA or HDDA has viscosity less than 30 Pa·s and the settling time is less than 16 h, the formed aluminum alloy substrate has no pores on the surface, but is prone to have incomplete structure. When the aluminum slurry prepared with PS-PCL has viscosity less than 30 Pa·s, and is stable and not prone to settling, the formed substrate has a complete structure with no pores on the surface. When the aluminum slurry with solid content around 55% was prepared with PS-PCL, after additive manufacturing process and sintering, the obtained sintered product has the relative density higher than 95%, relativly lower carbon residue (0.259 17%) and relatively higher hardness (29.94HV), with obvious necking growth on the fracture.

Theoretical calculation was made for the flow field in the hydraulic transportation with deep-sea polymetallic nodule collector, and the relationship between particle size of polymetallic nodules and minimum conveying speed was obtained. The distribution of flow pattern in the conveying channel was simulated with the jet velocity of nozzle at 15 m/s, 20 m/s and 25 m/s respectively, and rate of the flow at 30 mm away from the lower surface of the channel was measured. A laboratory test was conducted for nodules pick-up by using a collector with different jet velocities of nozzles, and it is found that the obtained results are consistent with the theoretical calculation and simulation results.

With micron silicon powder as matrix, phosphorus-doped silicon-carbon composite material (Si-P@C) was synthesized by solid-state thermal diffusion and high-temperature pyrolysis, and then used as anode material of lithium-ion batteries. The results show that Si-P@C anode material demonstrates an initial discharge specific capacity up to 2164 mAh/g at a current density of 0.2 A/g. Compared with pure silicon, Si-P@C anode material presents greatly improved cycling performance. After 50 cycles at a current density of 0.5 A/g, it demonstrates a high reversible specific capacity of 1 176 mAh/g, with the capacity retention ratio of 73.5%. It is concluded that phosphorus-doping and carbon coating can effectively improve the electron transfer ability and reaction kinetics of silicon anode.

In response to the problems of high molybdenum loss and difficulty in molybdenum/talc separation existing in the desliming process of a high talc-type molybdenite ore from Henan, ZN-J1, a molybdenum depressant, was introduced in the desliming section to minimize efficiently the molybdenum loss. The feed ore with Mo grade of 0.116%, molybdenum sulfide percentage of 83.53% and talc content of 14.0% was processed by adopting a flowsheet, consisting of desliming, pre-flotation of molybdenum, regrinding, and molybdenum/talc separation, with a combination of sodium silicate and ZN-P1 as depressant. A closed-circuit test with the whole process produced a molybdenum concentrate with Mo grade of 47.68% and Mo recovery of 75.41%, respectively.