A barite ore from Guizhou province is a typical microfine refractory carbon-containing ore with uneven grain size distribution and complex dissemination relationship among barite and gangue minerals. After being milled to a grinding fineness of -0.075 mm 90%, the ore was processed using kerosene and terpenic oil for decarburization, with sodium carbonate as the pH regulator, sodium silicate as the depressant and CY-30 as the collector for barite flotation. A close-circuit flotation test yielded 75.92% barite concentrate grading 93.55% BaSO₄ at 87.85% recovery.

In order to accurately evaluate stability of surrounding rock of roadway with weak intercalation, an improved analytic hierarchy process and criteria importance through inter-criteria correlation (CRITIC) method, were adopted to determine comprehensive weight, and unascertained measure theory (UM) was used to determine unascertained measurement vector. Furthermore, the set pair analysis theory (SPA) was introduced to optimize confidence evaluation process, and then a UM-SPA coupling analysis model was established and used to evaluate the stability of surrounding rock of the roadway with weak intercalation in some gold mine. The results show that in-situ stress, tensile strength and thickness of weak intercalation are the main factors influencing the stability of such kind of roadway. The set pair potentials of sections D4, D5, D6, D7, and D9 belong to micro-reversal potential and tend to be unsafe. The stability of roadway at different levels is in the following descending order: 290^# level > 150^# level > 90^# level. The practical verification has proven that this model has an evaluation result consistent with the actual situation.

Experiments of erosion corrosion with 3.5% NaCl solution at different flow rates were performed for TP2 copper after different heat treatment (hard and soft states), and the erosion corrosion rates of TP2 copper were tested. The morphology and products after 240 hours of corrosion were characterized, and the mechanism of erosion and corrosion for TP2 copper was also discussed. The results show that flowing medium in corrosion test accelerates the corrosion rate of TP2 copper. The soft TP2 copper presents a higher corrosion rate, compared to hard TP2 copper, after 240 hours of corrosion at the same flow rate. And after 240 hours of erosion corrosion at a higher flow rate, TP2 copper has its surface morphology predominated by gully-like structure and a product of Cu₂O is generated after corrosion.

With support vector machine (SVM) optimized by whale optimization algorithm (WOA), a WOA-SVM hybrid model was established for predicting blasting vibration. Then, with root mean squared error and coefficient of determination as evaluation indices of the model, WOA-SVM model, SVM mode, Sadovsky's model and USBM model were compared based on the data of blasting vibration in Sijiaying Iron Mine. A comprehensive evaluation shows that the WOA-SVM model is superior to other models in terms of prediction accuracy.

An efficient defluorination agent (NY-Z02) was used to remove fluoride from high-salt fluoride-containing wastewater generated in the process of recycling spent batteries. The effects of pH value, reaction temperature, reaction time and dosage of defluorination agent on fluoride removal effect were investigated. On this basis, a two-stage fluoride removal process was put forward, with which a pilot test was carried out. Results show that by using a single-stage fluoride removal process, a reaction runs at 20 ℃ for 20 min with pH of 7.0 at the end and by adding defluorination agent at an amount of 1.2%, resulting in the fluoride concentration in the wastewater decreased to 12.5 mg/L. While by using a two-stage fluoride removal process, with addition of defluorination agent at an amount of 1.0%, the fluoride concentration in the wastewater can be decreased to 12.4 mg/L. In the pilot test with the dosage of defluorination agent reduced to 0.768%, the fluoride concentration in the wastewater after fluoride removal process met the requirement of enterprise (F≤20 mg/L). It is found that during the removal process with agent NY-Z02, fluoride ions in wastewater react with the agent and form precipitate of AlF₃, or together with Al (OH)₃ are removed by flocculation and precipitation. It is shown that this process has good fluoride removal effect without bringing in any impurities.

For evaluating vibration reliability of Li-ion battery packs used in heavy-duty mining vehicles, ANSYS, finite element software, was adopted to simulate Li-ion battery packs in a heavy-duty mining vehicle and calculate its stochastic vibration. Based on the test performed about random vibration of battery packs, it is found that the first modal frequency of the battery packs is 33.85 Hz, corresponding to the frequency of upper cover of battery packs, which is greater than the external excitation frequency transmitted by frame (30 Hz). thus low-order frequency resonance can be avoided and vibration reliability of the structure can be improved. The calculated stresses in the random vibration of key parts of battery packs, including stiffener, lower box, upper cover and battery brackets, are all lower than the yield strength of the corresponding materials, indicating the structural parts of battery packs meet the requirements for strength reliability. Permanent deformation and damage have not been found in the assembly of battery packs in the random vibration test, verifying the reliability of this simulative computation results.

Due to high oxidation rate of a lead-zinc sulfide ore, the on-site flotation practice presented poor beneficiation indices. In view of this problem, an optimized closed-circuit process consisting of two stages of roughing, two stages of scavenging, one stage of rough cleaning of combined roughing concentrates, two stages of cleaning and two stages of scavenging for roughing concentrates was proposed. With slime (800 g/t) and CD-2 (300 g/t) as pyrite depressants, CD-1 (600 g/t) and water glass (600 g/t) as gangue depressants, sodium sulfide (500 g/t) as a sulfiding agent, copper sulfate (500 g/t) as an activator, butyl xanthate (200 g/t) as a collector, and terpineol oil (21 g/t) as a foaming agent, a closed-circuit flotation test produced a bulk concentrate grading 16.25% Pb and 27.69% Zn with a lead recovery of 65.05% and a zinc recovery of 92.49%. Compared with the previous on-site flowsheet, the Pb grade and Pb recovery are improved by 2.24 percentage points and 9.36 percentage points, while Zn grade and Zn recovery up by 1.57 percentage points and 5.14 percentage points respectively.

Activated carbon derived from coconut shell was prepared as anode material by adopting high temperature pyrolysis and activation. The effects of activation on the structure, morphology and electrochemical properties of coconut shell carbon were investigated by using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the coconut shell carbon after activation process is highly disordered, and also microporous and mesoporous. It delivers an initial discharge specific capacity of 918.22 mAh/g at a current density of 0.1 A/g, and retains a specific capacity of 447 mAh/g after 200 cycles discharge at a current density of 1 A/g.

Base on the study on homogenization behavior of blast furnace slag (BFS) by dynamic viscosity experiment, a kinetic model was constructed for molten slag conditioning process. The homogenization state of BFS was verified and the final granulation effect was analyzed. It is found that the homogenization time becomes shorten first and then prolonged as the addition of conditioner increases, which is the shortest when an addition of conditioner is at an amount of 15.43%. As for BFS with grain size greater than 1.75 mm, the homogenization time increases obviously. As slag temperature increases, the homogenization time is gradually shortened. Based on the comparison with the composition and mineral phases of fully homogenized BFS, it is verified that homogenization is completed when viscosity value becomes stable. The granulated slag particles with size mainly in the range from 1 mm to 2.5 mm present approximately normal distribution, and the homogenized BFS has amorphous phase content higher than 85%, meeting the requirements in the national standard.

After an in-situ leaching of weathered crust elution-deposited rare earth ores with ammonium sulfate, the obtained tailings were taken to explore the variation of water content, pH value, Zeta potential with sampling depth, and then the total nitrogen content, nitric nitrogen, ammonium nitrogen and the main co-existing ions were also analyzed. The results indicate that the tailings samples were all acidic, and both water content and Zeta potential decreased with increasing of sampling depth. The residual ammonium salt in the ore body mainly exists in the form of water-soluble ammonium (11%-33%), and ion-exchange ammonium (59%-87%) in ammonium nitrogen, presenting the highest content in middle layer and the lowest content in surface layer. XRD analysis reveals that the content of clay minerals in the rare earth tailings positively correlated with the content of residual ammonium. In addition, high content of organic matter in the surface layer of the ore body leads to the highest content of co-existing cations Al³⁺ and RE³⁺ in the surface layer; while as for the ore body at deeper position, the content of co-existing cations Al³⁺ and RE³⁺ decreases obviously, and the co-existing anions SO₄^2- and Cl^- present an opposite variation trend.