A numerical model was established by using LS-DYNA software and then used to simulate the influence of pre-split fracture with width of 3 cm and 5 cm, respectively, on blasting effect. It is found that wider pre-split fracture can bring a better effect of blasting vibration attenuation, with the maximum amplitude decay rate of 46%. Based on pre-split blasting tests with different borehole sizes, the on-site vibration monitoring results have verified the correctness of the rule. It is concluded that the parameters of pre-split blasting should be selected based on the actual working conditions in consideration of protection of surrounding buildings.

As for a zinc concentrate collected from mineral processing of a lead-zinc ore, an experimental study was carried out to reduce the carbon content therein. With soluble starch as the carbon depressant, a concentrate with Zn grade of 48.71%, carbon content of 0.86% and Zn recovery of 90.28% was obtained from a closed-circuit test. Compared with the on-site indicators, both the Zn grade and recovery of concentrate are increased by using this new process, while the carbon content therein is reduced to less than 1%, showing a remarkable carbon-reduction effect.

MIL-53(Fe), a metal-organic framework (MOF) material, prepared by using solvothermal synthesis was adopted to adsorb Sb(Ⅲ) in soil. MIL-53(Fe) was used as the adsorbent to adsorb the Sb(Ⅲ) in aqueous solution, and the effects of solution temperature, pH value, adsorbent dosage, initial concentration of Sb(Ⅲ), and humic acid content on adsorption performance were explored. Then, the isotherms and kinetics of adsorption were also analyzed. After 15 d remediation with the adsorbent at an amount of 3%, the TCLP testing shows that the concentration of leachable Sb(Ⅲ) decreases by 94.2%. However, the pH value and humic acid content of the solution have little effect on the adsorption performance. For 25 mL solution with concentration of Sb(Ⅲ) at 10 μg/mL, addition of 20 mg MIL-53(Fe) can bring good adsorption effect. The initial concentration of Sb(Ⅲ) has a significant impact on the adsorption of Sb(Ⅲ) by MIL-53(Fe). At equilibrium, the maximum adsorption capacity of the adsorbent is 102.9 mg/g. The adsorption isotherm of this process fits with the Freundlich model, and its adsorption kinetics can be described using pseudo-second order model.

The ground surface displacement caused by open-pit mining of a large iron mine in Hainan was analyzed by using fuzzy measurement theory. Base on the comparison with the calculated results by using the theory of random media, it has verified that the fuzzy measurement theory is superior and practicable in the analysis of influence of open-pit mining on the surrounding environment.

Alkali leaching of indium from zinc indium ferrite (ZnFe_2-xIn_xO₄) was strengthened by applying a combination of ultrasound and microwave. The results show that there are not a great amount of solid solution of indium in the octahedral lattice of ZnFe_2-xIn_xO₄, and the maximum solid solution approaches 4.0% in a mass fraction (x=0.088). The leaching rate of indium can be enhanced by the external fields in the following descending order: a combined application of ultrasound and microwave, single application of microwave, application of ultrasound followed by microwave or microwave followed by ultrasound, and single application of ultrasound. It is shown that the leaching rate of indium can be up to 56.6% with a combined application of ultrasound and microwave, but only reach 30.2% by singly applying ultrasound. During the alkaline leaching under the external fields, In³⁺ can be released from the lattice, while the octahedral lattice of zinc ferrite will not collapse. With a combined application of ultrasound and microwave, more In³⁺ can be released, leading to lattice constant becoming much smaller. The XRD spectrum shows obvious reduced intensity and rightward movement of diffraction peaks.

The comprehensive recycling ways for tailings after vanadium extraction, including recovery of valuable components, synthesis of new functional materials and preparation of multi-purpose building materials, were explained, which can provide a reference for application of technologies in comprehensive recycling of tailings after vanadium extraction.

Aiming at low intelligence in nickel plate surface defect detection, a detection method based on improved YOLOv5 was proposed. Firstly, the image-enhanced dataset of nickel plate was re-clustered by K-means++ to improve the adaptability of the anchor frame to the dataset. Secondly, the convolutional block attention module (CBAM) was added into the Backbone network to strengthen the feature recognition of interest areas and unclear targets by integration of spatial and channel information. Finally, an efficient IoU (EIoU) loss was introduced to replace the original CIoU loss during bounding box regression to effectively improve the convergence speed of regression, thereby increasing the model detection speed. The experimental results show that with the self-established dataset of nickel plate defect, the improved model, compared to Faster R-CNN, SSD, YOLOv3 and YOLOv5, has higher detection accuracy up to 81.4% on average, with detection speed reaching 61 frames per second. It is concluded that this model can not only improve detection accuracy, but also satisfy the requirements for detection speed.

Effects of electrochemical deposition time on the phase, morphology, bioactivity of hydroxyapatite (HA) coating and the bonding strength with the substrate were investigated adopting alkali-treatment of titanium alloy followed by electrochemical deposition. Results show that the electrochemically deposited coatings prepared on the surface of alkali-treated titanium alloy are composed of flake HA phases, and the electrochemical deposition time has no effect on the phase composition of the coatings, but will bring impact to the coating thickness. After 60 min deposition, the obtained HA coatings is very compacted and has the bonding strength with the substrate up to 17.85 MPa. It is shown that the HA coatings obtained after each deposition time have good bioactivity. In the simulated body fluids (SBF), CO₃^2- substitutes PO₄^3- in the HA into apatite to form steamed bun-shaped carbonated hydroxyapatite（CHA），with the diameter of 7-8 μm. After being immersed in SBF for 3 days，the CHA can be spread all over the surface of HA.

A kind of contaminated paddy soil was taken for pot experiment by adding FeSO₄ to investigate the impact of FeSO₄ on the formation of iron plaques on the root surface and the migration of the Cd from Cd-contaminated paddy soil. Results show that with the addition of FeSO₄ increased from 0 to 320 mg/kg, the pH value of the paddy soil tends to decline, maximally by 0.70. The TCLP-Cd content in the potting soil rises to a certain extent compared to the control group. The addition of FeSO₄ significantly reduces the Cd content in leaves, husks, and brown rice, as well as effectively increases the amount of root iron plaque, thus the absorption of Cd in the soil by rice is moderately controlled. However, the addition of external iron resource can bring impact to the pH of soil and bioavailability of Cd, so it is recommended that in practical operation, FeSO₄ should be added with some alkaline restorative materials such as lime to contaminated paddy fields for enhancing the control.

Based on the process mineralogy study, an experiment was performed on flotation of a phosphogypsum from Hubei Province for its purification. The experiment was run in stronger acid solution with T-609 as the collector, by adopting a process consisting of one roughing, one scavenging, and two cleaning, resulting in the final cleaning concentrate with the content of calcium sulfate dihydrate over 99%, with a whiteness of 75% at 200 ℃. It is shown that this processing flow is characterized by simplicity, high separation rate of phosphogypsum, less addition of agent. The obtained product, with low content of impurities, is up to the special grade in the national standard for gypsum, and can be used for preparation of high-end building materials and gypsum whiskers.