A technique combining mechanical force and heating effect was adopted to selectively disassociate cathode material from spent lithium-ion batteries and roll the aluminum foil by adjusting processing parameters. The results show that a better disassociation effect can be obtained with the frequency of electric motor, air circulation fan and dissociation device at 40 Hz, 40 Hz and 50 Hz, respectively. The aluminum foil with particle size of -1.7+0.075 mm is rolled to be spherical, and the cathode materials with particle size of -0.075+0.048 mm and -0.048 mm are rough on the surface and wrapped by organic binder. The final dissociation rate of cathode sheet can be up to 96.35%, and the cathode material can be recovered at a rate of 94.95% by single operation, with the content of Al impurity less than 0.15%. It is shown that this selective dissociation technique based on a combination of mechanic force and heating effect can actualize an efficient separation and sorting of cathode sheet, not only shortening the battery disposal process flow but also achieving efficient metal enrichment.

By using CFD-DEM coupling approach and Archard wear model, a slurry pump with small flow was numerically simulated under the conditions including different flow rates and particle sizes. Based on the analysis of the movement law of particles in the pump, the distribution of particles in different regions of pump and the collision between particles and wetted parts of the pump, the wear characteristics of wetted parts in the slurry pump, especially the volute were studied. The results show that there is some blockage in the volute approaching the tongue region due to a slow flow rate of particles. It is found that wear of the volute is mainly concentrated on the upper part and near the tongue region. With the increase in the flow rate and velocity of particles, the kinetic energy of the particles collide with the pump wall increases, resulting in serious wear on the body of slurry pump. And the wear will become more serious by the particles with small grain size.

Experiments were performed in a tube furnace for reduction roasting of high-iron manganese oxide ore, respectively with gas-based (CO) and pulverized coal as reducing agents. The effects of roasting temperature and roasting time on the simultaneous reduction of manganese and iron oxides therein were investigated. The results show that during the gas-based reduction roasting, the reduction process of Mn₂O₃ is controlled by chemical reaction, with apparent activation energy of 42.64 kJ/mol. However, the magnetization process of Fe₂O₃ is controlled by internal diffusion, with apparent activation energy of 21.30 kJ/mol. Compared to coal-based roasting process, Mn₂O₃ and Fe₂O₃ are easier to be reduced during the process of gas-based reduction roasting, and the manganese oxides can be directly reduced from Mn₂O₃ to MnO without the step of being reduced to intermediate product Mn₃O₄.

A process consisting of pre-discarding with heavy medium separation and ambient-temperature flotation was adopted for a scheelite ore sampled from the middle-layer mining zone of a tungsten mine in Hunan Province. A heavy medium separation test with the ore size of -15+0.5 mm as the feeding show that in the heavy medium with the density of 2.37 g/cm³, 31.37% of yielded tailings can be discarded, while the obtained heavy product has WO₃ grade and recovery increased to 0.34% and 96.62% respectively. A test by using a process of desulfurization flotation plus ambient temperature flotation for scheelite demonstrates that the process of pre-discarding with heavy medium has little effect on the operation loss rate of WO₃ in sulfur-containing products. However, the raw ore is directly taken into the flotation without a pre-discarding will lead to more tungsten minerals left in the middlings. The closed-circuit test shows that after a pre-discarding by heavy medium separation, the tungsten concentrate from ambient-temperature flotation has its WO₃ grade and recovery reaching 5.50% and 84.15% respectively. It is concluded that pre-discarding by using heavy medium cyclone is conducive to improvement of tungsten product index and comprehensive utilization of tailings.

An experiment on flotation of calcite in pulp with pH of 8.0 and the dosages for sodium silicate and sodium oleate respectively at 300 mg/L and 1.5 × 10^-4 mol/L was performed by using ultrasonic wave with the frequency at 40 kHz, for investigating the influence of ultrasonic power and sonication duration on the flotation behavior. The variation of sodium oleate content on the surface of calcite was analyzed by adsorption measurement, the chemical status of elements on the calcite surface was analyzed by XPS, and the variation of adsorbed reagents was also analyzed by zeta potential measurement. After 15 min-ultrasonication (40 kHz, 150 W), the flotation recovery of calcite can be increased from 8.5% to 82.7%. It is found that ultrasonication can bring in an increase in the adsorbed amount of sodium oleate on calcite, a decrease in the intensity of Si2p on calcite, and also an increase in the content of C1s. Meanwhile, the deconvolution of O1s spectrum shows reduction in the peak area of sodium silicate, but an increase in that of sodium oleate, and the surface zeta potential of calcite almost unchanged. The results indicate that the ultrasonication can induce a desorption of sodium silicate from the depressed calcite in the pulp containing both sodium silicate and sodium oleate, thus the freshly vacancy can be adsorbed by sodium oleate, leading to the significant improvement in floatability of calcite.

After 6061-T4 aluminum alloy sheet for automobile was welded by laser welding, the microstructure, microhardness, strength and plasticity of welded joint, as well as fracture surface morphology of tensile specimen were studied by using metallographic microscope, transmission electron microscope, scanning electron microscope, Vickers hardness test and tensile test. The results show that the laser welded joint of 6061-T4 aluminum alloy has a coarse strip of grain structure in its base metal area, the weld seam has a structure of very fine as-cast dendrite in the center, acicular β″ precipitates segregate at grain boundary, and dislocation density decreases. It is found that both the strength (hardness) and plasticity of laser welded joint are lower than those of base metal.

Qingdao Metro Line 8 was taken as an example for studying the surrounding rock stability of underground tunnel in mud-containing sandstone stratum with pore water. Based on the analysis of deformation and stress evolution law of surrounding rock by simulating three different pore water conditions, the maximum values of vertical displacement (roof subsidence), horizontal displacement (side walls moving closer), vertical stress, horizontal stress and shear stress of the tunnel were finally obtained. The numerical simulation results of tunnel with three kinds of pore water content were applied to the tunnel construction for Qingdao Metro Line 8, and the on-site monitoring results show the deformation of surrounding rock of tunnel roof and side wall is all controlled within the safety range. It is shown that such numerical simulation results provide good reference for the construction of Qingdao Metro Line 8.

A study on the separation of a copper-lead-zinc sulfide ore from Yunnan was presented by adopting a Cu-Pb-Zn full selective flotation process. The mineral liberation degree was enhanced by adopting fine grinding of raw ore and selective regrinding of lead roughing concentrate. A combined usage of depressants sodium sulfite and zinc sulfate benefited the synergistic effect and selectivity in depressing, and collectors Z-200, ethionitrogen and BK906 exhibited high selectivity. Under optimized parameters, a copper concentrate with Cu grade of 22.78%, Cu recovery of 83.28%, Pb content of 3.01% and Zn content of 4.23%, a lead concentrate with Pb grade of 75.86%, Pb recovery of 82.75%, Cu content of 0.17% and Zn content of 1.64%, and a zinc concentrate with Zn grade of 51.87%, Zn recovery of 93.16%, Cu content of 0.24% and Pb content of 0.31%, were obtained.

Rhodococcus opacus (R opacus) was taken as a microbe collector in a flotation experiment to investigate the recoveries of cassiterite, calcite and quartz pure minerals. The results show that, with pulp pH as 4 and R opacus dosage as 1.24 g/L, the recoveries of these three minerals were correspondingly 82.07%, 45.42% and 13.66%. The interaction mechanism between R opacus and cassiterite was investigated by measuring zeta potential and surface tension. Finally, an open-circuit flotation experiment of tin ore was carried out with R opacus as the collector and sodium silicate as the depressant, showing that the grade of tin concentrate was improved from 3.98% to 23.83%.

As for pipes with different lengths, with heave compensation device replaced by elastic constraint, a vibration equation was established by using energy integration approach, and the dynamic response of lifting pump installed at different positions of pipes was analyzed by finite element method. Results show that the harmonic response of stress excited by the following single loads was in an ascending order: torque, wave in longitudinal direction, and a combination of wave and current in horizontal direction. Under excitation by all these three loads with the same phase, the harmonic response of the system increased significantly. When the installed lifting pump was changed from a high position to a low position, the maximum equivalent stress of pipeline increased after an initial falling down. The installation position of lifting pump on the pipe corresponding to the minimum of the maximum equivalent stress was the suboptimal installation position. Based on the suboptimal installation position for the lifting pump on the pipeline with specific length, an empirical formula was established for the suboptimal installation position, which can provide reference for the quantitative design of lifting system.