Sustainable Mining and Metallurgy

Abstract:The planning of mineral resources is very important to realize the scientific exploration, progression and protection of mineral resources, and is the key of mineral resources management. Yunnan is a major province of mineral resources and is in a critical period of accelerated transformation of mining industry. This paper summarized and analyzed the main contents, implementation progress and achievements of the Yunnan Mineral Resources Master Plan (2021-2025), identified the main problems and risks and challenges in the implementation of the plan, and combined the situation and mineral conditions of Yunnan Province. From the aspects of strengthening policy coordination, promoting exploration and reserve increase, carrying out scientific and technological research, carrying out green mine construction, and expanding open cooperation, this paper put forward countermeasures and suggestions for further promoting the optimization and adjustment of planning implementation. At the same time, it gives a outlook for the next round of mineral resources planning, and provides a reference for ensuring the safety of energy resources and building a beautiful Yunnan.

Abstract:In order to improve the recovery rate of waste power batteries and solve the problem of unknown flow direction of spent power batteries, taking the reward and punishment mechanism as the core, the evolutionary game and prospect theory were coupled to construct a tripartite evolutionary game model of power battery manufacturers, informal recyclers and the government. The influence of key parameters on the game subject was discussed, and the corresponding practical application scenarios were reflected. By change the initial supervision probability of government, the game subject of negative cooperation was judged; By adjusting the distribution proportion of subsidies or fines, the reward and punishment mechanism were optimized. The results show that the governments willingness to improve the initial supervision can accelerate the information exchange between power battery manufacturers and informal recyclers; the power battery manufacturers are passive cooperative enterprises, and the government should focus on supervising them; in the long run, it will be more conducive to the active transformation and upgrading of informal recyclers to focus the distribution proportion of subsidies on power battery manufacturers and the distribution proportion of fines on informal recyclers; increasing the risk attitude coefficient and loss aversion coefficient can speed up cooperative recovery.

Abstract:The traditional solid waste is directly sent to the process cycle, and the zinc in the lime mud is directly introduced into the blast furnace, which not only affects the operation of the furnace, but also leads to the damage of the equipment and the decrease of the comprehensive production efficiency. Therefore, it is of great significance to explore effective zinc extraction process and reduce the enrichment of zinc in blast furnace for improving the economy and environmental protection of iron and steel production. Based on the chemical reaction, kinetics and thermodynamic characteristics of zinc extraction from iron and steel metallurgical lime mud, this paper systematically analyzed the characteristics and applicability of main zinc extraction processes including rotary kiln method, rotary hearth furnace method and multistage leaching method. Although the existing traditional process has certain technical advantages, there are still some problems in practical application, such as high energy consumption, complex operation and great environmental impact. Therefore, the improvement measures of optimizing reactor design, introducing pretreatment technology and intelligent control system and multiprocess integration were put forward to improve the comprehensive efficiency. In the future, the technology of zinc extraction from metallurgical lime mud will develop in a more efficient, environmentally friendly and intelligent direction, and promote the sustainable development of the steel industry.

Abstract:Aiming at the prominent problems of high energy consumption and low efficiency in the disposal of hazardous waste aluminum ash in the aluminum industry, through process and technological innovation, based on thermodynamic analysis, new disposal technologies such as grinding, microwave field and inert large particle assisted strengthening were proposed. Chlorine, silicon chloride and chlorinesilicon chloride were used as chlorinating agents, respectively. Five new processes for efficient chlorination of aluminum ash were developed ( a method for efficient utilization of aluminum ash with chlorine as chlorinating agent, a method for highvalue utilization of secondary aluminum ash with chlorine as chlorinating agent, a method for efficient preparation of aluminum nitride with aluminum ash with chlorine as chlorinating agent, a method for efficient preparation of aluminum fluoride with aluminum ash with silicon chloride as chlorinating agent, a method for preparation of aluminum fluoride with aluminum ash with chlorinesilicon chloride as chlorinating agent ). These five processes can effectively improve the resource utilization rate and disposal efficiency of aluminum ash, and realize the deep highvalue utilization of aluminum ash ( preparation of aluminum nitride and aluminum fluoride ), which has significant economic and social benefits.

Abstract:Copper matte converter blowing is the process of converting copper matte into crude copper in copper smelting process. The blowing process is divided into copper making period and slag making period. The judgment criteria and methods of each stage are different. The quality of crude copper is related to the accuracy of endpoint judgment. Especially with the increasing complexity of raw material composition, the difficulty of judging and controlling the endpoint of blowing is greatly increased. Based on the current research status of endpoint judgment methods for copper smelting converter blowing at home and abroad, this paper expounded the research progress of four kinds of blowing endpoint judgment methods, such as artificial experience method, instrument measurement method, material balance method and neural network method, and looked forward to the development direction of endpoint judgment methods for copper smelting blowing. With the development of detection instruments, the improvement of blowing air supply and material measurement accuracy, coupled with the improvement of converter blowing automation and the development of artificial intelligence, the end point control of copper matte converter blowing is developing towards automatic and accurate judgment and intelligent control.

Abstract:Taking the design of lithium extraction project from lepidolite with an annual output of 10000 tons of batterygrade lithium carbonate as an example, the material balance and heat balance of the roasting process of lepidolite sulfate rotary kiln were calculated by METCAL software, and the main energy consumption was analyzed. The simulation results were compared with the actual operation data of a similar project. The results show that the simulation results are basically consistent with the actual data. The heat loss of the roasting system is mainly the exhaust heat loss of the drying kiln and the heat loss of the rotary kiln, which account for 48.3% of the total heat and should be paid attention to. In the energysaving design, equipment insulation, clinker waste heat utilization and kiln tail gas waste heat utilization should be strengthened to reduce the energy consumption and cost of production.

Abstract:With the rapid development of copper smelting technology, multilance topblown continuous converting approach is applied and gradually extended. Numerical simulation of gascopper slagblister copper threephase mixing characteristics in the furnace was carried out by means of computational fluid dynamics. The influence of the furnace shape, as well as the number, position, diameter and spacing of the multilance, on the mixing intensity and stirring dead zone in the furnace were investigated. The results demonstrate that stirring dead zone and relative static region of the bath in furnace with an elliptical crosssection are reduced by 17.1% and 27.8%, respectively, compared to a furnace with a circular crosssection. The stirring dead zone in the furnace is reduced from 90.6% to 63.7% as the lance number is increased from 6 to 8. The dead zone is reduced from 63.7% to 34.7% when the lance position is reduced from 0.3m to 0.2m. The case with lance diameter of 76mm and lance spacing of 600mm have high stirring capacity of jet and low splashing intensity of molten. If lance diameter and spacing are too large, the slag splashing intensity is enhanced, which is not favorable to industrial production.

Abstract:Glass flakes were prepared by melting method. Under the condition of small number of standard samples and incomplete element content, Xray fluorescence spectrometry for simultaneous determination of 12 elements such as Al, Si, Fe, Ca, Mg, P, Ti, Mn, V, Cr, Zr and Nb in rutile was established by using standard samples to artificially prepare synthetic standard samples and adding various standard samples. The lithium tetraboratelithium metaborate mixed flux (67∶33) was used as the melting sample system. The effects of flux selection, melting temperature, dilution ratio and the amount of release agent on the melting effect were discussed. The standard curve was calibrated by the variation theory α coefficient and the spectral line overlap correction, and the relative standard deviation was 0.21%-4.20% (n=10). The results of melting sample preparationXray fluorescence spectrometry were compared with those of volumetric method and inductively coupled plasma atomic emission spectrometry. The results were satisfactory, indicating that this method can be applied to the rapid analysis of major, minor and trace components in rutile.

Abstract:The paper is aimed at the problem of impact dynamic disasters caused by stress concentration ahead of the working face in mining. The universal axial and vertical stress distribution patterns in the mining space were studied through numerical simulations. The plastic damage mechanism of surrounding rock due to the action of nonuniform stress field was theoretically analyzed. The extension characteristics of the plastic zone of the surrounding rock under sustained stress field evolution were obtained. The mechanism of the butterflydegradation trend of the plastic zone of the surrounding rock ahead of the working face under the effect of largediameter unloading boreholes was explained. The results show that when the advancing length is greater than two square, the stress around the goaf tends to be stable, and the minimum principal stress P₃ along the goaf is affected by stress unloading, and there is an inflection point at the boundary of the goaf. The maximum principal stress P₁ increases sharply within 30m in the vertical goaf, and the significant influence distance can reach 90m. The confining pressure ratio changes obviously within 10m in the goaf, the axial lateral pressure coefficient changes more stably, and the vertical lateral coefficient fluctuates greatly near the goaf. The surrounding rock of the hole shows RPP expansion characteristics in the nonisostatic stress field, that is, when the confining pressure ratio continues to increase, the plastic zone of the surrounding rock of the hole will appear the evolution law of circularellipticalbutterfly shape, and its sensitivity is more and more intense and finally shows plastic deterioration, surrounding rock instability, energy release, which explains the pressure relief mechanism of large diameter borehole in front of the working face.Based on the above research, the layout parameters of largediameter boreholes ahead of the working face in a certain mine were designed with a borehole diameter of 600mm and a spacing of 7.5m. After onsite application, monitoring points were respectively set up in the working face and roadway for electromagnetic monitoring. The monitoring results showed a weaker pressure ahead of the working face and a significant effect of the unloading boreholes.

Abstract:The effects of ryegrass growth on the leaching and migration of Mn and Cd in the soil around the manganese slag yard and its remediation were discussed by collecting the soil with different pollution levels around the manganese slag yard and using ryegrass as the test plant for pot-leaching test. The results showed that the migration of Mn and Cd to water was significantly reduced after planting ryegrass, and the dissolution of Mn and Cd in soil with different pollution levels was generally expressed as the aboveground part of ryegrass group. From the enrichment ability of ryegrass to heavy metals, the enrichment coefficients of Cd in roots were 0.788,0.739,0.547,0.691 and 0.316, respectively, which were higher than those of Mn in roots, indicating that ryegrass had better remediation effect on Cd. After planting ryegrass, the content of available Mn and available Cd in soil increased significantly compared with the control group, but the total Mn content and total Cd content were lower than the control group. The total Mn content decreased by 206.55-897.41mg/kg, and the total Cd content decreased by 0.02-0.40mg/kg.The growth of ryegrass can promote the activation of heavy metals and increase their effectiveness, and then fix heavy metals in the body through plant absorption, thereby reducing the content of heavy metals in the external environment. The growth of ryegrass can reduce the migration of heavy metals to the external environment, reduce the impact of heavy metals on the surrounding environment, and play a certain role in repairing the contaminated soil around the manganese slag yard.

Abstract:The mining geological environment issues induced by the exploitation and utilization of mineral resources in the hilly regions of Southwest China are considered a threat to the production safety of mining enterprises, a cause of declining quality of life for local populations, and a factor that negatively impacts the region‘s green, sustainable, and highquality economic development. In this paper, typical mining geological environment issues in the hilly regions of Southwest China was introduced. The present situation and existing problems of mining geological environment monitoring in the southwestern hilly areas were analyzed from the perspectives of monitoring objects and methods, policy, institutional framework, and technological approaches, and the overall goals and framework for constructing a mining geological environment monitoring system were established. Additionally, implementation pathways for monitoring system construction were proposed. The mining geological environment monitoring system can provide technical support for the systematic monitoring and dynamic management of mine safety production for mining enterprises in these regions.

Abstract:Taking the historical abandoned mine in Maoming as the research object, this paper analyzed the current situation and existing ecological problems of the mining area, put forward the technical route of mine ecological restoration, and introduced the restoration and treatment measures in detail. The abandoned mines left over from history in Maoming mainly have problems such as geological safety hazards, soil function degradation, poor ecological diversity, and serious soil erosion. Therefore, the corresponding mine restoration and management measures mainly include geological disaster prevention and control, terrain remodeling, bare land nearnatural forest construction, lowefficiency forest quality and efficiency improvement, wetland reconstruction, soil reclamation and utilization, etc., and the construction of mine restoration digital twin application platform was suggested, relying on digital twin technology innovation and application, it explores the intelligent management means of mine ecological restoration, and provide reference for similar mine ecological restoration and management.

Abstract:In this paper, the mining and ore dressing expansion project of a mining area was taken as the research object. On the basis of introducing the construction scale, mining and ore dressing process, water supply and drainage scheme of the expansion project in detail, the engineering geological conditions, hydrogeological conditions and groundwater storage within the scope of the project construction were analyzed by means of preliminary geological exploration, topographic and geomorphological investigation and indoor test. At the same time, this paper used the prediction model generalization method to predict the impact of the expansion project construction on groundwater quality and groundwater level, and put forward groundwater environmental protection measures and countermeasures such as source control, zoning prevention and control, and strengthening monitoring.

Abstract:In order to standardize the construction of green mines from the source, it is of great practical significance to integrate the green concept into the whole process of mine construction and explore the technical points of green mine design. There are some problems in the content of green mine, such as the design scope is not specific, the design work is not standard, and the design points are not clear. This paper put forward the basic principles and general requirements of green mine design, and summarized the design points from six aspects: resource development and utilization, energy saving and consumption reduction, waste management, noise control, dust control and ecological environment protection. At the same time, in order to ensure the effective implementation of mine design, safeguard measures are put forward from the aspects of policy guarantee, talent guarantee and supervision.

Abstract:Taking a hexavalent chromium contaminated site in Hunan Province as an example, this paper introduced the technical route of groundwater remediation. On the basis of introducing the general situation of site pollution, groundwater risk control is implemented for the whole site. After technical comparison and selection, for the highpollution area, the source reduction extraction treatment technology was adopted, and the groundwater was purified by ferrous sulfate heptahydrate after extraction, which effectively reduces the total amount of pollutants in groundwater. For lowpolluted areas, insitu injection remediation technology was used to reduce and stabilize hexavalent chromium by calcium polysulfide agent, and reduce the mobility of hexavalent chromium in groundwater, so as to achieve the purpose of reducing pollutant concentration and pollution plume range. Finally, by monitoring the natural attenuation technology, the natural degradation of pollutants in groundwater in the site is monitored and the degradation ability of groundwater was evaluated, which provided theoretical support for the subsequent site restoration. The combined technology of source reduction extractiontreatment in highpolluted areas, insitu injection remediation in lowpolluted areas and monitoring natural attenuation control technology can provide reference for the engineering design and implementation of similar groundwater remediation projects.

Abstract:This paper discussed the application of intelligent power supply and distribution system in coal preparation plant, introduce the technology of automatic inspection tracking system, remote control system of equipment, online approval system of power outage and transmission, and introduced the composition, function and working principle of each system in detail. The system significantly improves the energy utilization efficiency and intelligent management level of the coal preparation plant, reduces the time waste and operation complexity under the traditional power supply and distribution mode, strengthens the safety and reliability of the power supply and distribution operation, helps to reduce energy consumption and production emissions, and promotes the transformation of the coal preparation plant to the direction of energy saving, environmental protection and green development. The reliability of the power supply and distribution system is realized through the threelayer locking protection mechanism, and the paperless and online mobile operation is realized in the whole business process, which greatly improves the work efficiency and production safety.