Aiming at the Mo-Bi-S bulk concentrate from Hunan Shizhuyuan Nonferrous Metals Limited Company, a green, environmentally-friendly and efficient depressant (CYZ-15) and a new cyanide-free processing technique for Mo-Bi-S separation were developed. An experiment with the developed flowsheet produced a molybdenum concentrate grading 40.36% Mo at 92.98% recovery with a yield of 3.02%, and a bismuth concentrate grading 28.14% Bi at 95.64% recovery with a yield of 9.62%. It is shown that cyanide-free and efficient separation of Mo-Bi-S bulk concentrate can be actualized.

A numerical simulation model was established with Fluent software to analyze the disturbance effect of a subsea collector vehicle on seabed sediments, and the generation mechanism of seabed sediment plumes was analyzed. A large-scale tank experiment on diffusion of sediment plume was conducted to investigate the morphological characteristics and concentration variation rule of sediment plume under different initial mass concentrations. The results show that seabed sediment plumes are created mainly by the disturbance due to the movement of a collector vehicle. The overall morphological characteristics of such sediment plume under different discharge concentrations are roughly similar, and the diffusion of sediment plumes can undergo three stages: initial discharge, primary settlement and diffusion, and re-settlement and diffusion. The plume concentration also varies in the following three steps: rapid rise, rapid decline, and slow decline before stabilization.

MXene and cotton-derived biochar were prepared by modified acid etching and high-temperature carbonization, respectively. Based on their characterization with SEM and XRD, a suitable mass ratio of MXene to the cotton-derived biochar for modification purpose was determined. The electrochemical properties of the materials were further explored by performing charge-discharge and cyclic voltammetry tests, and using electrochemical impedance spectroscopy. It is shown that the MXene delivers an initial discharge specific capacity of 434.3 mAh/g at a current density of 0.1 A/g. A composite with MXene and cotton-derived biochar in a mass ratio of 1∶3 can deliver an initial discharge specific capacity of 1 486.60 mAh/g at 0.1 A/g, exhibiting excellent cycling performance, rate capability and electrical conductivity, which can provide a reference for application of MXene in lithium-ion batteries.

To explore the mechanism of phosphogypsum in modification of grouting materials for mines, grouting materials were prepared with different proportion of ingredients. Performance indicators including fluidity, permeability, strength parameters and leaching rates of heavy metals were analyzed, and the microscopic mechanism of phosphogypsum-modified grouting material was also explored with scanning electron microscopy and X-ray diffraction. Results show that an addition of phosphogypsum in grouting materials can not only actualize effective utilization of resource, but also improve fluidity of grouting material. It is shown that by adding 30% of phosphogypsum, the grouting material exhibits better fluidity and impermeability, significantly enhanced compressive and flexural strength, and reduced leaching rates of heavy metals. Furthermore, phosphogypsum can promote secondary hydration reaction, leading to more calcium-silicate-hydrate gel, which thereby can improve structural stability and engineering performance of grouting material.

Three types of carbon-coated silicon monoxide (SiO) materials were synthesized with different carbon sources and coating methods, and then their physicochemical properties and electrochemical performance were analyzed. A uniform and dense carbon film on the surface of material can be obtained by using a gaseous carbon source for vapor-phase coating. While a solid carbon source for liquid-phase coating leads to an uneven and loose film on the surface. With a combination of these two coating methods, the obtained carbon film on the surface can exhibit characteristics of two methods, including inner porous layer and outer dense layer. Electrochemical testing shows that with the combined coating method, the synthesized carbon-coated material delivers a specific capacity of 1 688.45 mAh/g, presenting the first charge-discharge efficiency of 76.13% and the capacity retention rate of 79.6% after 100 charge-discharge cycles.

Based on the unascertained measure theory, ten influencing factors, including hydrological and engineering geological conditions, slope height, slope gradient, foundation pit depth, drainage facilities, adjacent loads, distance from adjacent loads to the pit edge, maximum daily rainfall, support method and construction method, were selected. The weight of each indicator was determined by using the entropy weight method, and an unascertained measure theory model for a certain foundation pit slope was established. Then the slope's stability level was determined by adopting Euclidean distance discriminant method. The results indicate that when there is heavy rainfall and both drainage facilities and support methods are poor, the foundation pit slope is instable. When there is no rainfall and both drainage facilities and support schemes are good, the slope is relatively stable. It is shown that drainage facilities and support schemes have a significant impact on slope stability. Field monitoring data show that the evaluation results are consistent with the actual situation, demonstrating high reliability of the proposed unascertained measure theory and Euclidean distance discriminant method for evaluating foundation pit slope stability.

In order to recycle the waste circuit boards, the acid leachate with a copper content of 34.33 g/L was treated by adopting solvent extraction to recover the copper therein. The effects of extractant type, extraction time, phase ratio, extractant concentration, and extraction temperature on copper extraction efficiency were all investigated. The results show that with AD100 as the copper extractant, phase ratio (V_O/V_A) at 1∶3, and extractant concentration of 60%, an oscillating extraction at room temperature of 25 ℃ for 10 min can result in the copper extraction rate of 96.62%. Then, a back-extraction process is adopted to treat the organic phase with oxalic acid, producing copper oxalate, which can be calcined to obtained copper oxide products.

Based on an introduction of nickel resource and characteristics of lateritic nickel ore, the technical features and application of traditional hydrometallurgical processes (such as high-pressure acid leaching (HPAL), reduction roasting-ammonia leaching) and pyrometallurgical processes (such as rotary kiln electric furnace (RKEF), blast furnace smelting process for ferronickel production, and rotary kiln direct reduction-magnetic separation) are summarized. A new process of suspension roasting pre-reduction electric furnace (SRPEF) is specially introduced. Finally, the prospects for efficient exploitation and clean extraction technologies for lateritic nickel ore are discussed.

The 3104 aluminum alloy treated by hot tandem mills at different finish rolling temperature (FRT) was taken as the samples in the experiment to investigate the effect of FRT on its microstructure and texture evolution during the subsequent cold rolling and intermediate annealing processes. It is found that as the FRT for the 3104 aluminum alloy sample rises, the hot-rolled sheet presents highly recrystallization level, with increased volume fraction of Cube texture and decreased volume fractions of Brass, S and Copper textures. Furthermore, as FRT rises, the average grain size of the intermediate annealed sheet increases, and also the volume fraction of Cube texture in the cold-rolled sheet before intermediate annealing process increases, which is unfavorable for the formation of a strong Cube texture after annealing. As a result, the volume fraction of Cube texture in the final cold-rolled sheet decreases.

An experimental research was conducted on efficient recovery of ilmenite from Panzhihua City by magnetic fluid coupling high-gradient magnetic separation. With MnCl₂ concentration of 40%, magnetic induction intensity of 0.6 T, and pulsation frequency of 400 r/min, the ilmenite was processed by magnetic fluid coupling high-gradient magnetic separation, including one roughing and three cleaning, resulting in a titanium concentrate grading 46.89% TiO₂ at 38.30% recovery. It is shown that the obtained indices are comparable to those obtained from industrial production by adopting magnetic separation combined with flotation process.