Surfactants of Span80 and Tween80 were adopted to emulsify diesel in an experiment. Based on the studies on effects of diesel microemulsion on the concentrate recovery rate by graphite flotation and fuel-saving efficiency, the optimal conditions for preparing diesel microemulsion were determined as follows: emulsifier's hydrophilic-lipophilic balance (HLB) value of 9, n-butyl alcohol as a co-emulsifier, and emulsifier and co-emulsifier in a mass ratio of 2∶1. Under these conditions, the diesel microemulsion can be prepared with an average particle size of 78.82 nm and uniformly dispersed, presenting excellent stability. Flotation experiments showed that the usage of diesel microemulsion could save 28.66% of oil. And the mechanism of interaction between diesel microemulsion and graphite reveals that diesel microemulsion can significantly reduce the surface tension of the pulp, thus increasing the contact angle of graphite, leading to a higher flotation recovery rate compared to the adoption of conventional diesel.

Based on the optimization of flotation parameters of a low-grade spodumene ore from Sichuan, processing tests were conducted by adopting four flotation schemes to investigate their advantages and disadvantages. It is found that both the process of flotation with full-size range of ores followed by middling regrinding and the process of desliming followed by flotation and sequential returning of middlings are more advantageous than the conventional flowsheet of flotation with full size-range of ores followed by just sequential returning of middlings. It is shown that Li₂O recoveries by two processes can be increased correspondingly by 1.08 and 1.53 percentage points, and the second processing technique can bring a higher Li₂O recovery at 86.7%. However, the first processing technique can produce a higher quality lithium concentrate with a Li₂O grade of 5.76%.

Aiming at addressing the difficulty in selecting parameters for the support vector machine (SVM) model in predicting slope safety factors, a Newton-Raphson Backtracking Optimization (NRBO) algorithm was optimized to assist the SVM model in rapidly selecting appropriate hyperparameters. The NRBO algorithm was improved by introducing a dynamic opposition-based learning strategy, horizontal and vertical crossover strategies, and a modified adaptive coefficient calculation formula, so as to construct an INRBO-SVM model for predicting slope safety factors. Six factors, including bulk density, cohesion, internal friction angle, slope angle, slope height and pore water pressure ratio, were selected as model inputs, with the safety factor as the output. The trained INRBO-SVM model, NRBO-SVM model, SVM model and RBF model were used to predict the safety factors of nine test samples. The results show that the INRBO-SVM model exhibits the best performance in safety factor prediction, with a correlation coefficient of 0.999 9, higher than those of the other models. Its root-mean-square error and mean absolute error are significantly lower than those of the other models. Engineering application results indicate that the prediction errors of the INRBO-SVM model for safety factors are all less than 10%, with most below 5%, confirming the accuracy and practical application value of the model in predicting safety factors.

The separation process and the on-site equipment used for processing a copper-molybdenum bulk concentrate in Yunnan are systematically introduced. By improving the technical flowsheet and optimizing configuration, the processing capacity of Cu/Mo separation system can be increased from 25.00 t/h to 35.70 t/h, while the Mo grade and recovery are improved by 3.98 and 5.74 percentage points, respectively. Meanwhile, the power consumption can be reduced by 10.21%, and the unit production cost of Mo metal can be reduced by 7.06%, bringing a good economic benefit.

A new type of discontinuous mining system for deep-sea polymetallic nodules was proposed, consisting of collecting seafloor ore, conveying to buffer by flexible hose, and high-speed lifting of buffer. Then, the design and key equipment selection were carried out for the collecting system, flexible hose conveyance system and buffer lifting system for comprehensively lifting 100 t/h of ores at water depth of 5 200 m in the Minmetals' Contract Area. Furthermore, flexible hose configuration and load characteristics, as well as cable load dynamics during buffer lifting were all analyzed by hydrodynamic simulation. It is shown that with the flexible hose equipped with 18 buoyancy blocks, minimum bending radius of 1.6 m and a maximum tension of 4.98 kN, the whole mining system can satisfy requirements for the minimum bending radius and safe load capacity. During high-speed lifting of buffer, the cable can have the safety factor of comprehensive stress up to 5.22-6.03, exceeding the safety factor stated in national standard. These findings validate the reliability of this new type of deep-sea discontinuous mining system.

The influence and reaction mechanism of sodium humate as a depressant on the flotation of apatite, dolomite and calcite in sodium oleate system were investigated by performing single-mineral flotation test, adsorption test, Zeta potential measurement, infrared spectroscopy analysis and X-ray photoelectron spectroscopy analysis. The results show that sodium humate can strongly depress dolomite and calcite at pH of 7, but has less effect on apatite flotation. Sodium humate is weakly adsorbed onto apatite, but it can be adsorbed onto dolomite via chemical bonding, and also adsorbed onto calcite by the combined effect of hydrogen bonding and chemisorption. As a result, the variation in adsorption of sodium humate onto apatite, dolomite and calcite leads to its selective depression of the latter two minerals.

In order to address the poor presplit blasting effect on the final slope of the Yulong Copper Mine in Xizang Autonomous Region, the engineering applicable ranges of parameters such as decoupling coefficient, borehole diameter, linear charge density and hole spacing were calculated in consideration of the combined effects of explosion-generated gases and air shock waves, and the presplit blasting parameters were also optimized by performing orthogonal experiment. The results indicate that with a borehole diameter of 120 mm, a linear charge density of 800-1 000 g/m and a hole spacing of 0.9 m, the half-borehole rate after blasting exceeds 95%, the unevenness between adjacent holes is much less than ±5 cm, and the slope gradient deviation is less than ±2°, forming a continuous and regular presplit surface. This confirms the engineering applicability of the theoretically calculated parameter ranges.

Ultra-fine iron ore tailings were modified through thermal activation, and then together with some waste rock were taken for mixed calcination. With the mass ratio of iron ore tailings to waste rock, calcination temperature and calcination time as variables, and the compressive strength of specimens and the content of chemically bound water as the objectives for optimization, an orthogonal experiment was carried out to analyze the sensitivity and influence trends of each factor on the target values, and the hydration products of the cemented materials were also analyzed. The results indicate that with an increase in the mass of waste rock, the specimen compressive strength initially increases and then decreases. As the calcination temperature rises, the specimen compressive strength monotonically decreases. As calcination time is prolonged, the specimen compressive strength first decreases and then increases. In consideration of both calcination cost and material performance, an optimal calcination scheme is finally determined, including iron ore tailings and waste rock in a mass ratio of 7∶3, a calcination temperature of 800 ℃, and a calcination time of 2 h. Under these conditions, the 3-day, 7-day and 28-day compressive strengths of the specimens can reach 4.18, 6.36 and 9.87 MPa, respectively. The main hydration products of the cemented materials are calcium silicate hydrate gel, rankinite, ettringite and hydrotalcite.

The thermal dissipation performance of a battery pack was optimized by thermal simulation, aiming to enhance safety and service life of batteries. A thermal simulation model of the battery pack was established with ANSYS software, and temperature distribution was analyzed for the battery discharged at 1C rate. It is found that the simulation results deviate from actual measurements by less than 0.5 ℃, confirming the high accuracy of the model. Two optimized thermal dissemination schemes were proposed, including I-shaped heatsink and thermally conductive adhesive filling. Study shows that both schemes can effectively improve the thermal dissipation performance, leading to the maximum temperature of cells reduced by 6.0 ℃ and 5.9 ℃, respectively. The scheme of I-shaped heatsink can not only reduce cell temperatures but also significantly reduce temperature differences, resulting in better thermal uniformity.

The effect of Cr content in mass fraction on the microstructure and mechanical properties of Al-Cu-Mg-Ag alloy with a low Cu/Mg ratio was investigated. Results indicate that after an addition of Cr to the Al-Cu-Mg-Ag alloy with low Cu/Mg ratio, phases of Al-Cr and Al_1.6TiCr_0.4 are generated in the alloy; with Cr content from 0.17% up to 0.22%, the alloy has its tensile strength improved from 463 MPa to 484 MPa (a 4.5% increase), and its yield strength enhanced from 288 MPa to 319 MPa (a 10.8% increase). The enhancement in mechanical properties is attributed to solid solution strengthening by Cr and precipitation strengthening by S′ phases.