In order to explore the influence mechanism of structural parameters of vertical spiral stirred mill on grinding performance, the coupling method of discrete element method (DEM) and computational fluid dynamics (CFD) was used to systematically analyze the effects of mill bottom gap, side gap and helical lift angle on grinding performance. Firstly, the numerical model of the vertical spiral stirred mill was constructed, and the dynamic characteristics of the medium in the grinding process were revealed by simulation. Secondly, the grinding test was carried out based on the test bench, and the accuracy of the simulation model was verified by the driving torque of the spiral agitator. The results show that the maximum error is only 3.85%. Finally, through multi-parameter simulation and orthogonal test, the influence degree of each structural parameter on grinding performance was quantified, and a comprehensive evaluation method based on energy utilization rate, torque, average normal force and tangential force was proposed. The results show that the side gap of the mill has the most significant effect on the grinding performance, followed by the bottom gap and the helical lift angle. The optimal parameter combination is the ratio of the bottom gap to the medium sphere diameter A=4.0, the ratio of the side gap to the sphere diameter B=3.0 and the helical lift angle C=0.61. The research can provide a reference for the structural optimization and performance improvement of vertical spiral stirred mill.

In order to explore the effect mechanism of magnetization treatment on the reverse flotation behavior of hematite in dodecylamine-cassava starch system, water, starch, dodecylamine and pulp were magnetized respectively, and the mechanism of magnetization treatment in reverse flotation of hematite was analyzed by detecting the changes of reagent adsorption capacity, contact angle and Zeta potential under different magnetization methods. The results show that under the conditions of pH=9, starch dosage of 800 g/t, dodecylamine concentration of 20 mg/L and flotation machine speed of 2 100 r/min, the flotation recovery rate of hematite can be increased by 2.78, 4.16 and 3.84 percentage points respectively by magnetized water, magnetized starch and magnetized pulp. Magnetized water, magnetized starch and magnetized pulp can increase the capacity of starch adsorbed on the surface of hematite particles and reduce the contact angle of the solution on its surface. At the same time, magnetized water and magnetized starch also make the Zeta potential of hematite particles shift positively, while magnetized dodecylamine makes the Zeta potential shift negatively. Magnetized water and magnetized starch promote the adsorption of starch on the surface of hematite. Magnetized dodecylamine inhibits the adsorption of starch on the surface of hematite. Magnetized pulp promotes the hydrolysis of hematite surface, so that more starch can be adsorbed on the surface of hematite particles, thus improving the recovery rate of hematite.

A new inhibitor PN has been developed for copper sulfur flotation separation to address issues such as pipeline blockage and environmental pollution caused by the use of lime inhibitors. The selective inhibition performance and adsorption mechanism of PN inhibitor in flotation process were studied through systematic tests. The results indicate that PN inhibitor has a good selective inhibitory effect on pyrite, but has almost no effect on chalcopyrite. The results of the artificial mixed ore separation test show that under low alkali conditions (pH=8), the optimal separation effect of pyrite and chalcopyrite can be achieved when the dosage of PN inhibitor is 5 mg/L, and a copper concentrate with a copper grade of 31.3% and a copper recovery rate of 92.9% can be obtained. The contact angle measurement results indicate that PN inhibitor can selectively enhance the hydrophilic properties of pyrite surface. The analysis of the microstructure characteristics and elemental content changes of pyrite before and after PN treatment further confirms that PN inhibitor undergo physical adsorption on the surface of pyrite, which can achieve selective inhibition of pyrite. The research results prove that PN inhibitors has the potential to replace lime in copper sulfur separation.

A certain magnetite ore in Zimbabwe has a TFe grade of 42.01%, with fine particle size and high content of silicate minerals. To achieve effective dissociation of iron minerals and gangue, as well as improve the recovery rate of iron resources, a combined process of weak magnetic-strong magnetic-reverse flotation was adopted for experimental research. Through the grinding fineness test, it was determined that the coarse grinding fineness was −0.074 mm, accounting for 81%. The weak magnetic concentrate was further ground to −0.037 mm, accounting for 90%, and the strong magnetic concentrate was further ground to −0.037 mm, accounting for 85%. The magnetic field strength test results show that magnetic field strengths of four weak magnetic operations are 0.33 T, 0.20 T, 0.15 T and 0.10 T, respectively. When the magnetic field strength of the strong magnetic operation is 1.0 T, weak magnetic concentrate with a Fe grade of 62.26% and a Fe recovery rate of 12.25% and strong magnetic concentrate with a Fe grade of 51.32% and a Fe recovery rate of 64.76% could be obtained. For the strong magnetic concentrate, the optimized reagent system through reverse flotation condition experiments is determined with slurry pH of 11.0, corn starch dosage of 500 g/t, CaO dosage of 800 g/t, and self-developed collector CK-T1 dosage of 300 g/t. The closed-circuit test adopts the process of one coarse, two fine, and two scans, and the final Fe grade of the iron concentrate is increased to 65.95%, with a Fe recovery rate of 81.45%. Research has shown that the combination of fine grinding and weak magnetic-strong magnetic-reverse flotation processes can significantly improve the sorting efficiency of fine-grained magnetite, providing a technical reference for the efficient recovery of similar refractory ores.

In response to the problems of low grade, fine embedded particle size, and difficulty in separating copper and molybdenum in a certain porphyry copper-molybdenum ore in Xinjiang, a principle process flow of “copper-molybdenum mixed flotation, concentrate regrinding and copper-molybdenum separation” was determined. Through single-factor condition tests, the key technical parameters of each flotation operation were optimized, and on this basis, a whole process closed-circuit test was conducted. The results show that the stage grinding and stage separation can effectively control the degree of dissociation of the target minerals and avoid the overgrinding of the easily muddled gangue minerals. The copper concentrate with Cu grade of 23.58%, Mo content of 0.046% and Cu recovery of 82.97%, as well as the molybdenum concentrate with Mo grade of 34.21%, Cu content of 0.96% and Mo recovery of 66.38% are obtained by the whole process closed-circuit test of copper-molybdenum mixed flotation with one roughing, three cleaning and two scavenging and copper-molybdenum separation with one roughing, seven cleaning and one scavenging. Effective separation and recovery of copper and molybdenum have been realized. The research results can provide a technical basis for the efficient development and comprehensive utilization of the copper-molybdenum mineral resources.

In order to improve the separation accuracy of magnetite ore with particle size of 20−50 mm and adapt to the change of ore quality, a magnetite ore classification method based on fuzzy wavelet neural network (IGWO-FWNN) was proposed. Firstly, feature extraction was performed on the data set, and the adaptability of the model was enhanced by fuzzification and quantization. Then, the improved grey wolf algorithm was used to optimize the initial parameters of the model, which ensured the efficiency of model training. In the training process, the fuzzy rule parameters were continuously updated by the gradient descent algorithm to optimize the performance of the network model. Experiment results show that compared with the GWO-FWNN model, the accuracy of the optimized network model reaches 0.966 7, the F₁ value reaches 0.951 2, and the convergence speed of the model is also improved by 24%. The results have verified the effectiveness of the proposed method on the iden tification and classification of magnetite ore, which provides a new thought for the development of magnetic separation technology.

In view of the problems of large dosage of reagents and high cost in the traditional lime-free sodium sulfide flotation process of copper-cobalt sulfide ore and sulfur-oxygen mixed copper ore, a study on the optimization and adjustment of the reagent system was carried out at a processing plant in the Democratic Republic of the Congo. The pH and flotation environment of pulp were adjusted by adding lime to reduce the dosage of Na₂S. As the amount of lime increases, the dosage of Na₂S continues to decrease, and the impact on copper-cobalt recovery is relatively small. However, when the amount of lime increases to a certain value and then increases again, the decrease in Na₂S dosage is relatively small, while the cobalt recovery rate of copper-cobalt sulfide ore decreases more significantly, and the copper recovery rates of both ores also show a downward trend. For copper-cobalt sulfide ores, when the lime dosage is 500−700 g/t, the Na₂S unit consumption is reduced from 637.71 g/t without lime to 312.48 g/t, and the recovery rates of copper and cobalt are 93.38% and 91.82%, respectively. For sulfur-oxygen mixed copper ore, when the lime dosage is less than 350 g/t, the Na₂S unit consumption is decreased from 732.57 g/t without lime to 517.35 g/t, and the copper recovery rate is 86.01%. After the optimization of the reagent system, the cost of flotation reagent for copper-cobalt sulfide ore is reduced from the original USD 1.77 to USD 1.58 per ton, with a decrease of 10.73%. The cost of flotation reagents for sulfur-oxygen mixed copper ore is reduced from the original USD 2.12 to USD 1.74 per ton, with a decrease of 17.92%, all of which have good economic effects.

Under the influence of multiple factors such as slowdown of global economic growth, intensification of geopolitical conflicts and acceleration of energy transformation, the mineral resources market presents complex and changeable characteristics. In order to better grasp the current situation and development trend of mineral resources development and utilization in China, a combination of quantitative and qualitative research methods was adopted, and statistical and comparative analysis methods were comprehensively used to conduct in-depth analysis of domestic and foreign mineral resource market data. By sorting out key indicators such as mineral product output, price, investment, import and export, the operational situation of China's mineral resources market was revealed. By comparing the development and utilization of mineral resources between China and major economies in the world, the status and characteristics of China in the global mineral resources market were clarified. The development and utilization of mineral resources in China was comprehensively analyzed, and the internal and external factors facing its development were grasped. The results show that in 2024, the trend of the global mining market is obviously divided, the price of energy minerals falls, the price of most non-ferrous metals rises, and the price of precious metals such as gold continues to rise sharply. China's mining investment has increased, geological exploration investment and mining fixed asset investment have maintained a high growth trend, and the development of mineral resources has shifted significantly to the west. The proportion of relevant indicators in the western region has continued to rise, the diversified mining development pattern dominated by state-owned holding enterprises has become more reasonable, and the production efficiency of mining enterprises has been continuously improved. The development and utilization of mineral resources generally shows a trend of “quantity increase and price decrease”. The national raw ore production continues to grow, but the price of mineral products generally declines, resulting in a year-on-year decrease in the total output value of the mining industry, the sales income of mineral products and the total annual interest and tax of enterprises. Looking forward to 2025, the slowdown of global economic growth and the increase of supply will lead to the weakening of the international bulk mineral market and the differentiation of the price trend of different mineral products. The global geological exploration investment has fallen back, but the domestic geological exploration investment is expected to continue to increase. The production of China's mining industry is expected to remain stable, but the economic benefits and profits of enterprises have declined. Energy transformation will greatly promote the growth of demand for clean energy technology minerals, and the market value of key minerals is expected to reach $770 billion in 2040. To this end, China needs to give full play to the advantages of a unified domestic market and economic internal circulation, and strengthen the real economy. Scientific and technological innovation should be relied on to promote the transformation and upgrading of energy and mineral resources industry. International cooperation should be strengthened to ensure the effective supply of overseas mineral resources. And sustainable development and utilization of mineral resources should be promoted, so as to provide a solid guarantee for high-quality economic development.

Based on the theory of synergistic mining, the technical challenges such as handling hidden danger in goaf, recycling hidden trouble resources, and ensuring safe and efficient mining of deep ore bodies have been solved for the difficult-to-mine ore bodies in a tungsten mine in southern Jiangxi Province. Four innovative mining designs were proposed, including changing the mining method from the empty-field method to the caving method, taking hidden trouble resources as cover rock layers for deep mining, using the goaf as a free blasting space for cutting grooves and cushion layers, as well as synergistic applying shallow and medium-deep hole blasting technologies. On this basis, the mining design and application of the segmented rock excavation stage caving method were carried out. The results of mining practice show that the segmented rock excavation stage caving method is suitable for dense vein mining. Compared with the original shallow hole shrinkage method, the mining loss rate of this mining method is reduced from 22% to 3%−5%, the daily production capacity of the stope is increased from 65 t to 260 t, the unit consumption of explosives is reduced from 1.18 kg/t to 0.57 kg/t, and the cost per ton of ore is reduced from 65.54 yuan to 33.26 yuan. It is indicated that the theory of synergistic mining has a significant application value in the mining of dense ore bodies in tungsten mines. The research results provide a technical solution that can be used as a reference for dealing with similar problems in mines.

With the gradual reduction of shallow mining resources, mining is moving deeper and deeper. In order to solve the problems of difficult control of the stability of the surrounding rocks and increased support costs in large-section chamber in deep shaft, and to ensure the stable operation of the 941 m mixing plant chambers group, researches on the stability control of the surrounding rocks in large-section chambers was carried out. Multiple technical methods such as laboratory testing, numerical simulation, and field monitoring were adopted. Through comparative analysis, a reasonable construction process and support design were optimized. It is found that when the excavation of the chambers is carried out in the order of batching machine chamber, mixer chamber, and cement silo chamber, the stability of the surrounding pressure is the best. Then, an orthogonal design experiment was used to obtain the optimal support parameters as a spacing of 2 m×2 m among anchor rods, a length of 6 m for anchor cables, and a thickness of 600 mm for concrete lining. A joint support scheme consisting of anchor mesh spraying + grouting anchor rods for initial support and cast-in-place reinforced concrete + anchor cables was proposed. The on-site support results show that the deformation of the surrounding rocks is effectively controlled.