The SICOMINES copper and cobalt ore in the Democratic Republic of Congo has a Cu content of 2.47% and a Co content of 0.237%, belonging to high oxidation rate and complex mineral composition ores. In response to the high cost of single flotation beneficiation and low recovery rate of copper and cobalt, combined with the properties of the ore, a flotation-magnetic separation combined process was used for beneficiation experimental research. By conducting experiments on the types and dosages of collectors and vulcanizing agents, the optimal process parameters were determined as follows: the dosage of pentyl xanthate collector is 1 185 g/t, and the dosage of combined vulcanizing agent (sodium sulfide : sodium hydrosulfide = 1:1) is 7 000 g/t. When the grinding particle size of the raw ore is –0.074 mm accounting for 70%, the stepwise sulfurization flotation method is firstly used to recover the easily floatable copper sulfide concentrate, copper oxide concentrate, and cobalt concentrate. Then, the flotation tailings are subjected to strong magnetic separation treatment to recover the copper cobalt magnetic minerals. Finally, the total copper recovery rate is 79.83% and the total cobalt recovery rate is 54.79%, achieving the comprehensive and efficient utilization of high oxidation rate copper cobalt ore resources.

Copper-cobalt ore with high oxidation rate in SICOMINES from the Democratic Republic of the Congo contains some copper-bearing minerals which are difficult to be separated, resulting in poor separation indexes. In order to recover copper-bearing minerals in flotation tailings, the mineral composition of flotation tailings was analyzed. The flotation tailings were re-separated by gravity separation, magnetic separation, flotation and combination of various separation methods. Finally, it was determined that the flotation tailings were separated to one roughing and one scavenging strong magnetic separation, the magnetic separation concentrate was separated by one roughing and one scavenging flotation, and the flotation tailings of the magnetic separation concentrate were separated by a section of strong magnetic separation process. The recovery rates of total copper and total cobalt reach 84.74% and 56.88% respectively after adding the re-separation process on flotation tailings, which are 8.96 and 8.28 percentage points higher than those of the original flotation process. Meanwhile, conducting re-separation on the magnetic separation concentrate from magnetic separation of flotation tailings can greatly reduce the leaching acid consumption of magnetic separation concentrate.

In order to realize the efficient utilization of sodium oleate, which is a collector for iron ore flotation, the effect of ethyl oleate on the reverse flotation separation of quartz from fine hematite was investigated by carrying out quartz pure mineral flotation test, binary mixed mineral flotation test and actual mineral flotation closed-circuit test. The promoting effect mechanism of ethyl oleate on the flotation of quartz by sodium oleate was clarified by infrared spectroscopy, surface tension measurement and contact angle measurement. The results show that in the pure mineral flotation test, when the sodium oleate is 160 mg/L and the pulp pH is 11.0, the maximum recovery of quartz increases from 80.34% to 94.85% after adding 40 mg/L ethyl oleate. In the flotation test of binary mixed minerals of quartz and hematite, compared to the dosage of 160 mg/L sodium oleate, when the dosage of sodium oleate is 120 mg/L and the dosage of ethyl oleate is 40 mg/L, the grade of iron concentrate increases from 62.32% to 65.04%, and the recovery of iron concentrate increases from 89.64% to 93.86%. In the actual mineral flotation closed-circuit test, compared with the flotation index under the single sodium oleate system, the grade and recovery of iron concentrate increase by 3.01 percentage points and 3.52 percentage points respectively after adding ethyl oleate. The promotion effect mechanism of ethyl oleate on the flotation of quartz by sodium oleate is that ethyl oleate and sodium oleate are combined by hydrogen bond, which enhances the adsorption strength of sodium oleate on the surface of quartz, strengthens the adsorption stability of the reagent, and improves the hydrophobicity and floatability of the quartz surface.

Taking a copper-silver polymetallic sulfide ore in Inner Mongolia as the research object, the process mineralogy analysis and flotation tests were carried out. The research results of ore properties show that except for a small amount of chalcopyrite, sphalerite and galena in the raw ore, copper and silver mainly exist in the form of silver tetrahedrite. The flotation tests show that, firstly, the copper-silver mixed flotation process is used to realize the separation of copper-silver minerals and sphalerite. Secondly, the mixed flotation concentrate is reground and floated to realize the separation of copper-silver and galena. Finally, the process flow of copper-silver mixed flotation-regrinding of mixed flotation concentrate-copper-silver flotation concentration is determined. The copper-silver concentrate with copper grade of 18.98%, copper recovery rate of 80.98%, silver grade of 10 521.88 g/t and silver recovery rate of 89.81% is obtained by closed-circuit test. By feeding the flotation tailings into the subsequent lead-zinc separation operation, the efficient comprehensive utilization of copper-silver mineral resources has been realized.

In order to efficiently separate copper ore, a stacked step flow separation model was proposed according to Knelson concentrator based on centrifugal gravity separation technology combined with reverse fluidization and step flow principle, and secondary separation was realized on the basis of centrifugal separation. The distribution of pressure, tangential velocity and axial velocity in the separation flow field of the stacked step flow model was analyzed by Fluent software. The effects of rotational speed and reverse flow velocity on the separation characteristics of copper ore were studied. The results show that the pressure distribution of the flow field increases gradually from the center to the wall surface. However, due to the presence of reverse flow force, the maximum pressure does not fully fit the wall surface. The abrupt change of tangential velocity at the step indicates that there is a vortex, which is conducive to the separation of light particles. The axial velocity as a whole presents an upward flow, which is conducive to the discharge of light particles from the upper outlet after separation. The axial volume concentration distribution of Cu particles shows a decreasing trend from bottom to top, and the radial volume concentration is the highest near the wall surface, while the volume concentration of SiO₂ particles is the highest at the top of the axial direction, and the volume concentration is lower at the radial direction. When the feed speed is 0.5 m/s, rotational speed is 50 r/min, and reverse flow velocity is 0.012 m/s, it can be obtained that the recovery of Cu particles is 87.70%, and enrichment ratio is 13.45. The stacked step flow model has the best effect on the separation of SiO₂ particles and Cu particles. The cloud images of particle volume fraction show that Cu particles are enriched in the concave of the inner wall of the step flow, and SiO₂ particles have a low volume fraction in the concave of the wall due to the separation force of vortex and reverse flow, which more directly shows the separation effect of the stacked step flow model. The research results can provide references for the improvement of centrifugal beneficiation equipment.

In order to accurately predict the supply-demand situation and guarantee degrees for important mineral resources in Liaoning Province during the 14th Five Year Plan period, based on the development and utilization of mineral resources during the 13th Five Year Plan period, the method of demand trend analysis was adopted to track the industrial chain, and the development and utilization data of upstream and downstream production links or consumption data of downstream product end markets were collected. The demand and guarantee capacity of iron ore, coal, gold ore, magnesite, flux limestone, and boron ore during the 14th Five Year Plan period were predicted. The accuracy of the prediction results was verified by the actual yield and consumption of each mineral in 2021 and 2022. The results show that the demand for iron ore ranges from 183.75 million to 191.1 million tons per year, coal from 179.92 million to 191.35 million tons per year, gold ore from 8.11 million to 8.92 million tons per year, magnesite from 30.48 million to 33.81 million tons per year, flux limestone from 14.96 million to 15.4 million tons per year, and boron ore from 4.16 million to 5.39 million tons per year in the next 5 years. The guarantee degree of magnesite and flux limestone is relatively high, which can achieve supply-demand balance. Gold ore requires a large amount of imports, and the guarantee degree of iron ore, coal, and boron ore is insufficient. It is necessary to further strengthen the exploration of deep and peripheral mineral resources and improve mining capacity construction.

Safety and stability is the premise of intelligent mine reform. In order to improve the scientific management level of mine enterprises and reduce the accident rate, based on social information processing theory, self-determination theory and affective event theory, a moderated chain mediation model was constructed with taking charge behavior and harmonious safety passion as mediating variables and organizational resilience as moderating variables. A questionnaire survey was conducted to collect data from 400 miners in a coal mine in Shanxi Province in two stages, with a total of 364 valid questionnaires collected. And the hypothesis model was verified by empirical research method. The results are concluded as follows. Firstly, resonant leadership has a positive effect on miners' proactive accountability behavior. Secondly, resonant leadership positively affected miners' proactive accountability behavior through the independent mediating effect of perceived insider status and harmonious safety passion, as well as the chain mediating effect of perceived insider status and harmonious safety passion. Thirdly, organizational resilience can positively regulate the relationship between harmonious safety passion and proactive accountability behavior, and positively regulate the chain mediation relationship between perceived insider status and harmonious safety passion.

To solve the problem of stress-structural failure that may be caused by the excavation of the right tunnel section of deep crushing station, the geological conditions of the tunnel face and the attitude information of the rock mass were collected by UAV, and the three-dimensional rock mass structure numerical calculation model of the right tunnel section of deep crushing station was constructed by combining the display discrete element numerical simulation software 3DEC. The deformation characteristics, failure mechanism and loss mode of deep rock mass under high stress conditions were explored, and the prevention measures were put forward. The results show that the stability of the surrounding rock of the tunnel section is controlled by the contact area of the red-brown granite stratum and the gray-black gray gneiss stratum and the in-situ stress field. The reason for the stress-structural failure of the tunnel section is that the excavation unloading of the crushing station leads to the formation of unfavorable blocks in the JSet #2 and JSet #3 joint groups and the excavation surface. Therefore, for the tunnel section with developed joints, the stress-structural failure disaster is a problem that needs special attention for the stability of surrounding rock after the excavation of the crushing station. It is suggested that the method of “optimizing excavation parameters + combined support form” should be adopted to systematically control the stress-structural damage after excavation unloading of crushing station from three levels of surface, shallow and deep layers.

In order to better reveal the causes of filling pipelines wearing in deep mines, 12 risk influencing factors were summarized and identified based on literature analysis, standard method and expert discussion method. Using DEMATEL (decision-making trial and evaluation laboratory) and ISM (interpretative structural modeling) integrated analysis method, through the processing of index factors data, the influence degrees of index factors and the characteristics of index causal attributes were determined, and each influencing factor was decomposed according to three stages to construct a multi-level hierarchical structure model. The results are drawn as follows. The DEMATEL-ISM method can comprehensively and objectively reflect the correlation of index factors, and the corresponding hierarchical structure can be divided into 4 layers and 3 stages. The inner diameter of the pipeline and the filling times line are the fundamental causes and key influencing factors. The absolute roughness of the pipelines, the proportion of coarse particles, the mass concentration of the slurry, the ratio of slurry flow rate to critical flow rate, and the corrosivity of the filling slurry are the transitional causes. The deflection rate, the weighted average particle size, the pipelines laying quality, the aggregate shape and so on are the direct causes. The research results can provide a theoretical reference for formulating targeted measures to prevent and reduce pipelines wearing and failure.

Daye Iron Ore is in the continuous mining stage of −270 m to −360 m middle section, the remaining ore volume in the −270 m middle section is insufficient, and the stope production capacity will be insufficient in the early stage of −360 m middle section. According to the process characteristics of the upward horizontal layered cut and filling method and sublevel drilling and stage open stoping with subsequent filling, based on the distribution of each stope, the mining process and the current situation of the mining equipment in the −360 m middle section of Daye Iron Mine, the optimization model of stope mining equipment scheduling was established. The genetic algorithm was used to simulate the most compact process arrangement, and the maximum number of simultaneous stopes was solved based on the equipment utilization function. Two schemes of single-section mining and two-section mining were proposed. The results show that when the number of stopes that can be mined simultaneously in the section of −270 m is 3, and the number of stopes that can be mined simultaneously in the section of −360 m is 5, the maximum daily production capacity reaches 4 218 t/d. The scheme of the two-section mining is more efficient, with a more stable ore production and the annual production capacity of 1.437 million tons. The two optimized mining schemes are helpful to solve the problems of insufficient production capacity and unstable production during the two-section continuous mining of Daye Iron Mine.