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Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Multipurpose Utilization of Mineral Resources / Kuangchan Zonghe Liyong is the property of Multipurpose Utilization of Mineral Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rock fragmentation is an important phenomenon in mining engineering as its outcome determines the productivity of the entire mining process. Its imperativeness in mining engineering has attracted the attention of various researchers towards its assessments and various methods have been developed for this purpose. Hence, this study chronicle the methods that had been developed for the fragmentation analysis, identify their strengths and weaknesses. The aim is achieved by first harvesting the articles on rock fragmentation from the Scopus database. The mined data are then subjected to bibliometric analysis using the VoSViewer. Thereafter, detailed information about theoretical background of the rock fragmentation and the methods of analysis are provided. The outcome of the study has revealed that different soft computing (SC) methods are available for the assessment of rock fragmentation aside the traditional methods. The performance of the SC methods are better than many existing empirical methods. The practical application of the SC methods is still very unrealistic as they are largely not in the tractable mathematical form. There are some SC methods that are yet to be explored in rock fragmentation assessment. The study has therefore provided the latest and detailed information on the rock fragmentation by blasting. [ABSTRACT FROM AUTHOR]

There is a very thick water-bearing key strata above the coal seam in the Binchang mining area. When the mining scale is large, it easily breaks and leads to rockburst with a surge of water gushing in the panel. Adopting the layout pattern of a small panel and a large coal pillar can improve the stability of the main key strata, but at present, the research on the layout pattern of a small panel and a large coal pillar under extra-thick water-bearing key strata is still not perfect. Therefore, taking the second and third panels of a mine in Binchang as the engineering background, the width of the coal pillar and the mining scale of the panel are optimized by means of theoretical analysis, field measurement, and numerical simulation to prevent rockburst and control water inflow. The results show: (1) through theoretical calculation, it is deduced that the critical width of instability of the isolated coal pillar in the current mining scale is 257 m, and the critical mining scale of breaking and instability of the main key strata in the third panel is 537 m; (2) considering the bearing capacity of the isolated coal pillar and the recovery rate of coal resources, the reasonable width of the isolated coal pillar is 210~270 m, and when the width is 200 m and 250 m, the reasonable mining scale of the third panel is 490~550 m and 640~700 m, respectively; (3) the field practice shows that the actual width of the coal pillar between the second and third panels is less than the reasonable width, and the stress concentration in the isolated coal pillar area is relatively high, so the roof deep hole blasting and large-diameter drilling in coal seam are adopted to relieve pressure. After taking pressure relief measures, the stress concentration in the isolated coal pillar area is effectively reduced, and the pressure relief effect is remarkable. [ABSTRACT FROM AUTHOR]

This is an article in the field of mining engineering. The mineral resources are an important material basis for economic and social development. Figure out the background and development and utilization of mineral resources has a great significance for scientifically formulate strategic planning and policies, and keep the safe baseline mineral resources. The coal and non-metallic building materials are major mineral resources of Ningxia, which have the characteristics of large quantity and high quality. The Metal mineral resources with the characteristics of small scale and poor quality are mainly distributed in Weining Beishan and Xiangshan areas. The advantageous mineral resources of Ningxia include coal, plaster, limestone, quentzite ore, magnesium ore, rock salt, sandstone and soil ore. In recent years, the development and utilization of mineral resources in Ningxia show the characteristics from diversification to simplification, from extensive to intensive, and from large-scale to high-quality. The development and utilization of mineral resources in Ningxia need to start from many aspects, such as coordinate the development and utilization and give full play to the regional advantages of mineral resources, build an industrial chain for the development and utilization of advantageous mineral resources and promote the whole process utilization of various products in the process of mineral resources development, promote the strategic objectives of precise positioning, high-quality and optimal use of mineral resources, system construction, multi-level utilization, consideration of storage and production and long-term utilization. Try to transform mineral resources reserves into momentum of economic and social development in the greatest extent.

This an article in the field of mining engineering. In order to further study the development and utilization prospects of bauxite resources in the southern region of Chongqing, this article adopts methods such as on-site investigation, questionnaire survey, and data collection. By constructing an evaluation index system for the availability of mineral resources, an evaluation model based on Analytic Hierarchy Process and Weighted Superposition Method is used to conduct in-depth research and evaluation of the availability of bauxite resources in the southern region of Chongqing. Firstly, based on the expert scoring results, select the top 12 indicators with average scores as the evaluation indicators for this evaluation. Secondly, use the Analytic Hierarchy Process to determine the weights of the 12 evaluation indicators. Finally, use the weighted superposition method to determine the evaluation indicators for each mining area. The higher the score of the evaluation index, the higher the availability of bauxite resources. Among the 15 bauxite mining areas in the southern region of Chongqing, there are no easy to use mining areas, but there are 4 available mining areas. Recently, there are 7 difficult to use mining areas, and 4 difficult to use mining areas. The evaluation model established using Analytic Hierarchy Process and Enhanced Superposition Method can provide scientific reference for the evaluation of the availability of bauxite resources.

This is an article in the field of mining engineering. Ca2+ and Mg2+ are easily dissolved from fluorapatite and dolomite in the acid medium of reverse flotation, and there is a "cumulative effect" in the process of backwater circulation, which has an adverse effect on the flotation indexes. Taking fluorapatite, dolomite and quartz as the research objects, the effect of different recycle times of backwater on the flotation recovery of three single minerals was studied. The results showed that when pH value was 5, the recovery difference between dolomite and fluorapatite decreased from 72.21% to 64.19%, and the recovery of quartz maintained at about 10%; When the number of cycles reached 5, the recovery difference between dolomite and fluorapatite slightly increased to 69.74%, and the recovery of quartz slightly decreased to 11.22%. In this study, the mechanism of dissolved ions in backwater for three kinds of single minerals was revealed by measuring the number of dissolved ions, zeta potential of mineral surface and ions adsorption capacity of mineral surface under backwater circulation system.

In order to promote the technological development of ultrasonic vibration induced cracking of coal and rock masses, improving the efficiency of coalbed methane production and hard rock excavation in mines, it reviews the development history of ultrasonic technology, summarizing the application status and research progress of ultrasonic vibration in fracturing coal and rock mass, and the key obstructive technology problems and development trends of ultrasonic vibration in the field of coal and rock fracturing are clarified. ① The technical problems of traditional technologies in the fields of coal seam methane production and hard rock excavation in mines is summarized, introducing unique advantages and application fields of ultrasonic technology, besides the development stages and corresponding performances of ultrasonic generator and ultrasonic transducer are described; ② The equipment and process of ultrasonic vibration to promote coalbed methane desorption and permeability increase are induced, analyzing the current situation of promoting permeability increase of coalbed methane by ultrasonic vibration, and the mechanism of pressure reduction, acceleration, potential energy and kinetic energy increase of coalbed methane under ultrasonic cavitation effect, mechanical vibration effect and thermal effect to promote its desorption and permeability increase is expounded; ③ The equipment and process of ultrasonic vibration rock fragmentation are generalized, describing the progress of ultrasonic vibration crushing of hard rock, and it reveals the internal mechanism of hard rock breaking caused by mechanical vibration effect and thermal effect of ultrasonic vibration, such as fatigue damage, subcritical propagation of microcracks, uneven thermal expansion or mineral phase transformation of mineral particles, and deterioration of rock physical and mechanical properties; ④ In view of limitations of ultrasonic generator, transducer and ultrasonic vibration in coal and rock mass fracturing in mines, four suggestions are put forward for the research focus on the efficient application of ultrasonic vibration induced fracturing of coal and rock masses in the field in the future: research and development of high-performance explosion-proof ultrasonic generator and transducer, in-depth analysis of the mechanism of increasing permeability by ultrasonic vibration and design of pipeline technology framework, development and test of multi-function and multi-field coupling indoor ultrasonic vibration cracking coal and rock mass equipment, research and application of anti-interference ultrasonic vibration equipment in underground mines.

This is an essay in the field of mining engineering. In the current new energy development strategy under the new situation, lithium is an indispensable key raw material to support the development of the new energy vehicle industry and promote the new energy revolution. It is positioned as one of China's 24 national strategic mineral resources, and its strategic position is extremely important. The safety of lithium resources and the continuous supply of lithium mineral products are related to the healthy and stable development of many industries and the national economy in China. China is rich in lithium resources. However as the world's largest consumer of lithium resources and producer of lithium batteries, lithium is highly dependent on foreign countries, and there are hidden dangers in the supply system. It is urgent to improve the safety and security of China's lithium resources. Based on the combing and research on the distribution of lithium resources at home and abroad and the supply and demand situation of lithium mineral products, this paper analyzes and elaborates on the main problems and causes faced by China's lithium resources. This paper analyzes the main problems faced by China's lithium resources and their causes, and puts forward opinions and suggestions on the development and utilization, scientific and technological research, industrial structure, institutional mechanism, personnel construction, market regulation, overseas strategy and other aspects in order to increase production of lithium resources and maintain supply and stability, which provides useful reference for ensuring the safety and stability of China's lithium resources and the healthy and orderly development of lithium mining industry.

This is an essay in the field of mining engineering. The main minerals of Heishan iron mine are vanadium titanomagnetite and titanomagnetite. Due to the influence of ore properties, the grade of iron concentrate in this type of deposit is generally low and rich in titanium, silicon, magnesium and other elements, which limits the development benefits of this kind of deposit resources. If the grade of iron concentrate can be further improved in the beneficiation process, it will help to improve the mine benefits and reduce the smelting cost of iron concentrate. This paper systematically studies this type of iron ore by means of optical microscope, mineral dissociation analyzer (MLA) and chemical analysis. This type of iron ore was systematically studied by means of optical microscope, mineral dissociation analyzer (MLA) and chemical analysis.

This is an essay in the field of mining engineering. Recently, the application research of surfactants such as frother agents has become significantly important in mineral flotation, because it provides huge information on the characteristics of the gas-liquid interface before the bubble-particle collision or attachment. Moreover, it proposes important theories for the optimization of the flotation process. This article focuses on the potential measurement, tension test, and adsorption characteristics of the gas-liquid interface. The profile analysis tensiometry (PAT) test method for the adsorption characteristics of the gas-liquid interface is also introduced. Meanwhile, the research work on the characteristics of the gas-liquid interface has prospected.

Rockmass in deep mining is highly susceptible to large-scale collapses under high stress and blast-induced disturbances, leading to casualties and economic losses. To investigate the evolution characteristics of goaf instability and the types of seismic sources that induce instability, an experiment on goaf instability was designed under uniaxial compression conditions based on actual mining operations. The entire experimental process was monitored using digital image correlation analysis and acoustic emission monitoring. By calculating the digital speckle field on the surface of the rock specimen during the experiment, the evolution characteristics of the deformation and strain fields from the beginning of loading to complete failure were analyzed. The study explored the dynamic behavior of cracks from initiation to propagation and eventually inducing large-scale collapse. The results show that the instability process of the goaf begins with the formation of tensile cracks. As stress increases, shear cracks occur in the specimen, leading to macroscopic failure. Furthermore, based on the differences in overall microfracture types measured by RA-AF characteristic parameters during specimen failure, large amplitude acoustic emission events corresponding to the formation of dominant macroscopic cracks were selected, and the focal mechanisms of these events were inverted. The results indicate that shear failure sources are significantly more prevalent than tensile failure sources in acoustic emission events leading to goaf instability. These findings can provide useful guidance for the support design and the prevention and control of rockmass instability disasters.

This is an essay in the field of mining engineering. High-value utilization of rare earths in fly ash can effectively alleviate the environmental pollution caused by fly ash in my country, expand the supply chain of rare earth raw materials, and ensure the strategic safety of rare earths. This article summarizes the research on rare earth element extraction technology reported from fly ash in recent years, and introduces the research progress of acid method, acid-base combined extraction technology and precipitation method and extraction method. The advantages and disadvantages of the three rare earth element extraction and separation processes are compared. It is pointed out that the research on the extraction technology of rare earth from fly ash can be based on the process flowsheet of the existing industrial equipment for extracting aluminum oxide and gallium from fly ash. The exploration of the collaborative extraction and development of aluminum, gallium and rare earth from fly ash can not only speed up the development of the extraction of rare earth from fly ash. The industrialization of the extraction and application of rare earths in coal ash also can further realize the comprehensive utilization of fly ash and increase the added value of fly ash.

This is an essay in the field of mining engineering, which summarized the current situation and characteristics of tungsten tailings resources, and expounds the urgency and necessity of comprehensive utilization of tungsten tailings resources under the requirements of current economic development and environmental protection. The research status of recovery of valuable metal and valuable non-metals in tungsten tailings was comprehensively evaluated. The application and application prospects of tungsten tailings in new building materials were introduced in detail. Combined with the current research focus on tungsten tailings resources in China, the development direction of comprehensive utilization of tungsten tailings is proposed.

This is an essay in the field of mining engineering. The crystal characteristics of spodumene are the endogenous factors that determine the floatability. The collector is an exogenous factor that determines floatability of spodumene. In the flotation process, the common metal ions have an important influence on the performance of spodumene collector. In this essay, the factors affecting the flotation behavior of spodumene are introduced and summarized from the crystal characteristics of spodumene and the effect of external metal ions on the common spodumene collector in industrial production. Firstly, the surface crystal characteristics of spodumene are summarized, and the effect of the active site of spodumene surface crystal on flotation behavior is summarized. Secondly, the effects of common metal ions on the properties of oleic acid, hydroxamic acid, amine and anion-cation complex collectors commonly used in industrial production are summarized. Studies have shown that Ca2+, Fe3+ and Mg2+ can improve the performance of oleic acid collectors. Pb2+ can improve the performance of hydroxamic acid collectors. Ca2+ can improve the performance of amine collectors. The effect of amine collector and spodumene can be inhibited by an iron ball milling medium. This study has theoretical and practical significance for improving the separation efficiency of spodumene and using spodumene collector efficiently.

This is an essay in the field of mining engineering. Copper tailings are mainly concentrated in east China, southwest China and central South China, which are stored in dry dumps or wet discharge in tailings pond. The lack of multi-gradient and multi-direction utilization mode, brings great threat to the environment and safety around the mining area. It is an important measure to ensure the safety of resources and environment in mining area to strengthen the technical research on the utilization of domestic copper mine tailings and realize its large-scale consumption. This paper introduces the general situation and distribution of copper mine tailings resources, summarizes the utilization status of copper mine tailings in valuable element recovery, building materials, filling, reclamation and other aspects, and discusses the existing problems in the utilization of copper mine tailings resources and gives a prospect of reasonable development and utilization, providing a reference for further research and application of copper mine tailings resources.

This is an essay in the field of mining engineering. Evaluation of mineral resources exploitation advantages is of great significance to improving the economic benefits of mineral resources and responding to emergencies. In this essay, taking 7 counties, including Nanning, Guigang and Laibin, Guangxi Zhuang Autonomous Region,as the research area,constructing the evaluation system of bauxite reserve mining advantages in Guangxi based on the analytic hierarchy process (AHP), five elements including transportation and power supply conditions, social economy and resource conditions, topographic conditions, land conditions and technical conditions and geological characteristics of mineral deposits and 14 evaluation factors were designed, using the spatial analysis and mining technology of GIS to calculate and evaluate the mining advantages of bauxite reserves. The evaluation results show that the mining advantage is in the range of 0.3922~4.0328, the mining advantage of Sanshui bauxite in Xiaoyi mining area of Hengxian County is the highest (4.0328), while the mining advantage of Sanli-Daling bauxite in Guigang City is the lowest (0.3922).The evaluation results are generally in good agreement with the actual situation, which proves the effectiveness of the method, and can provide an effective quantitative assessment method for evaluating the same mineral or different mineral deposits in this province or other provinces.

This is an essay in the field of mining engineering. Green mines construction is an important means to promote the green transformation and upgrading of my country's mining industry, and it is also one of the main activities in the practice of ecological civilization in the field of my country's mineral resources. Through combing and analyzing the development history of green mines, the development history of green mine construction in my country is divided into three stages: ideological germination, exploration and development, and full implementation. Economic, social and ecological benefits, etc. The construction effectiveness of the four aspects, focusing on the analysis of the scientific concept and one-sided understanding of the green mine system in the construction of green mines in my country, the existing construction pattern and the characteristics of mineral resources endowment, the demand for the construction of ecological civilization and the mine Create the imbalance between the power and standard system, the evaluation mechanism and the national conditions of mineral resources. Finally, in terms of green mine theory, top-level design, standard system, normalized supervision and management, etc., countermeasures and suggestions for my country's green mine construction are put forward in order to provide a reference for the high-quality development of my country's green mine construction.

This is an essay in the field of mining engineering. Lala Copper Mine is a famous copper-iron polymetallic deposit in Sichuan province. In the past several decades of mine production, a large number of industrial solid wastes have been produced, among which several useful elements such as copper, cobalt and gold are still relatively high in tailings, which has great recovery potential. The tailings of Lala Copper Mine have not gone through systematic beneficiation recovery experiment. Based on the study of Lala copper mine tailings samples, on the basis of process mineralogy study, the process of "copper-sulfur mixed flotation-copper-sulfur separation-iron separation from tailings" was used to recover it, and a copper secondary concentrate with Cu grade of 13.38% and recovery of 21.19% was obtained. Sulfur cobalt concentrate with Co grade of 0.32% and recovery of 17.20%; And iron concentrate with TFe grade of 60.99%. After the recovery of valuable elements, mica and silicate minerals were recovered from the tailings to obtain mica concentrate of better quality, and a mica concentrate with K2O grade of 8.67% and recovery of 35.26% was obtained. The tailings recovered from mica were used to prepare silicon fertilizer, the available silicon content of silicon fertilizer product was 38.75%, and the silicon fertilizer raw material could be consumed 43.59%.

Abstract The gob‐side entry‐retaining by roof cutting and pressure relief (GERRC) method is an advanced no‐pillar mining method that can significantly improve coal recovery and reduce roadway accidents. However, according to case studies, there is relatively little research on the application of the GERRC method in geological conditions of soft rock formations (especially when the roof and floor are both mudstone), and such research is needed. Therefore, based on the typical soft strata of the Xinyi Coal Mine, this paper analyzes the failure mechanism of the roadways and proposes the GERRC method with coal rib and corner strengthened support (CRCSS). The evaluation indexes of the roof convergence rate and cable safety margin are established, and the effects of roof cutting and CRCSS on roadway deformation control are explored by a numerical comparison test. The results show that roof cutting has a limited effect on roadway deformation. The deformation can be reduced by 75.77% by implementing CRCSS on the basis of GERRC. Then, the evolution characteristics of roadway stress and deformation in the process of mining are further discussed through field contrast tests. The field application results show that compared with that of GERRC with conventional support, the surrounding rock deformation of GERRC with CRCSS is reduced by more than 55%, the safety margin of the cable is improved. The overpressure of the hydraulic prop is diminished, and the stability distance of the roadway is reduced by approximately 30%. Finally, this paper discusses the mechanism to control roadway deformation by CRCSS. This research expounds the rationality of CRCSS, and the results can provide a reference for other situations with similar geological conditions.

In order to liberate the shallow quaternary loose aquifer coal pillar resources, taking the 1010-1 working face of the first mining area of Wugou Coal Mine as the test object, the grouting reinforcement test of quaternary loose aquifer and the weathering zone of the bedrock at the bottom was carried out by using the splitting grouting method and the grouting technology combining continuous and intermittent grouting. The results show that: the quaternary loose aquifer control area has complex lithology and weak water content, and mainly receives runoff recharge from the lateral area. The grouting reconstruction project adopts the water displacement and sand fixation scheme of the ground straight hole combined with the directional oblique hole row by row; the strength of the mixed slurry is subject to the ratio of fly ash, and the strength and stone rate of the mixed slurry are higher than those of the cement net slurry. When the fly ash content is 20%, the stone rate is the highest; the diffusion of grout in the quaternary loose aquifer is very uneven, the grouting process needs to control the grout diffusion range by controlling the grouting amount, the influence of grouting on the surface is reflected in the grout diffusion and pressure conduction, and the pressure conduction is the main one; after injection, the true density and water content of the core hole samples slightly increased, while the compressive strength, tensile strength and shear strength slightly increased; with the increase of sampling depth, the compressive strength of the rock layer in the wind-oxidized zone of bedrock increased first, then decreased and then increased, and the compressive strength increased about 2-5 times.

The orientation of deep-seated orebodies was observed shifted from the northwest to north at the Xincheng deposit in the Jiaoxibei gold field during the mining operations. To make informed decisions, understanding the geological factors influencing this directional change is crucial for mining engineers. Prior research suggested that the ore-controlling fault morphology might correlate with the orebody positions and the thickness of alteration zones. Hence, the morphology of fault structures emerges as a key point in this work. First, we constructed a three-dimensional (3D) fault surface model. A large fault framework was interpreted using gravity-magnetic-electrical geophysical datasets, and then, the local details of the fault surfaces were characterized using an interpolation method based on the drillhole fault gouge data. Subsequently, we statistically assessed the spatial association between fault morphology and orebody positioning using the standardized C-values method and demarcated the ore-controlling structures on fault surfaces using quantitative indicators. The indicators of fault dips, fault azimuths, and the second-order trend residuals of fault surfaces represented the fault morphology. The drillhole grade data ^sampling grade*sampling length) were used to describe the scale of mineralization zones, and the cumulative thickness of the pyrite-sericite altered rocks indicated the intensity of alteration zones. Finally, a geostatistical structural analysis was used to depict the mineralization orientation at different locations. Through these methods, we aim to propose a potential pattern of how ore-controlling fault morphology spatially influences the positions and orientations of orebodies. This comprehensive approach offers valuable insights into exploring deep-seated mineralization at the Xincheng deposit, aiding in a better understanding of the deposit's geological dynamics for future mining endeavors. [ABSTRACT FROM AUTHOR]

This article explored, investigated, and aimed to show the impact of a selfless choice of the Mining Engineering career and how it can affect students' performance, including failure and poor performance compared to those who made the right choice. In addition, various factors that can make this a bad experience were taken into account; such as the emotional and psychological impact of studying a career without personal interest, stress, anxiety, and lack of motivation; as well as how this can influence the mental health of students due to family pressure, social expectations or the search for secure employment, from the analysis of the work perspective of graduates, including the difficulty of finding employment, job dissatisfaction and high job turnover. Instruments such as interviews and surveys were used to obtain real statistics about the problem. [ABSTRACT FROM AUTHOR]

It is essential to understand the in situ stresses underground for engineering design and ground stability control in mining, geotechnical and petroleum engineering. Determination of the complete 3D stresses is particularly difficult due to the complex conditions underground. Overcoring and some other methods have been used in the past. They are either very expensive to implement or are based on some pre-assumptions. A recently developed alternative method is based on differential-direction drilling (D3 method). By this method, the complete 3D in situ stresses can be estimated through measurements of diametrical borehole deformation in multiple non-parallel planes. The D3 method has overcome the theoretical hurdle of using 2D data to find a 3D solution to the in situ stresses. It has five mathematical models to fit the anticipated field conditions. This paper, as a follow-up, considers practical applications of the D3 method and analyzes a few key factors which may affect its application. The minimum space angle between measurement planes and the minimum number of measurement directions in each plane (or around a borehole) are determined. The effects of measurement errors and selection of a proper model for a specific site condition are also analyzed. A statistical approach is applied to help detect erroneous measurement data and search for the best-fit solution. Practical drilling patterns in mining and petroleum engineering are also suggested. [ABSTRACT FROM AUTHOR]

Grouting cable is one of the most critical technologies in mine support. However, there are few studies on the effect of post-peak residual strength of cement grout under direct shear testing, which is of great significance for evaluating the bearing capacity of grouting cables in the whole life cycle. Hence, in this study, we carried out a systematic direct shear test to reveal the shear characteristics of cement grout under both constant normal loading (CNL) and constant normal stiffness (CNS) boundary conditions. The test results show that, under the same initial normal stress, the peak shear strength of the cement grout obtained under the CNS boundary conditions is greater than that under the CNL boundary conditions. The high initial normal force reduces the effect of boundary conditions on the post-peak mechanical shear properties of the cement specimens. Moreover, under CNS boundary conditions, the acoustic emission activity of the sample has an obvious signal before the peak shear strength, accompanied by multiple large ringing counts, indicating that the internal damage of the cement grout starts before the peak intensity. This work enhances the understanding of cement grouting fracture characteristics in mining support engineering. [ABSTRACT FROM AUTHOR]

Rotary percussion rock drills have been widely used in mining and civil engineering fields, and their performance needs to be further improved. To deeply understand the mechanisms of the rock drills, this article reviews the previous studies from fundamental theories to state-of-the-art techniques on the rotary percussive rock drilling processes, including stress wave propagation, dynamic bit penetration, and factors affecting drilling efficiency and penetration rates. An enormous variety of research approaches and their findings are provided to related researchers and engineers. In addition, important future issues are presented for discussing the further progress of rotary percussive rock drilling. [ABSTRACT FROM AUTHOR]

Peculiar hierarchical microstructures in creatures inspire modern material design with distinct functionalities. Creatures can effortlessly construct sophisticated yet long‐range ordered microstructure across bio‐membrane through ion secretion and precipitation. However, microstructure biomimicry in current technology generally requires elaborate, point‐by‐point fabrication. Herein, a spontaneous yet controllable strategy is developed to achieve surface microstructure engineering through a natural surface phenomenon similar to ion secretion‐precipitation, that is, coupled dissolution‐precipitation. A series of hierarchical microstructures on mineral surfaces in fluids with tunable morphology, orientation, dimension, and spatial distribution are achieved by simply controlling initial dissolution and fluid chemistry. In seawater, long‐range ordered film of vertically aligned brucite flakes forms through interfacial dissolution, nucleation, and confinement‐induced orientation of flakes with vertically grown {110} plane, on the edge of which, fusiform aragonite epitaxially precipitates. With negligible initial surface dissolution, prismatic aragonite epitaxially grows on a calcite polyhedron‐packed surface. By tuning fluid chemistry, closely packed calcite polyhedron and loosely packed calcite micro‐pillars are engineered through rapid and retarded precipitation, respectively. Surprisingly, the spontaneously grown microstructures resemble those deliberately created by human or found in nature, and tremendously modulate surface functionality. These findings open new possibilities for facile and customizable engineering of microstructural surfaces, hierarchical heterostructures, and biomimetic materials. [ABSTRACT FROM AUTHOR]

Aiming at the technical problems of frequent dynamic pressure disturbance of regenerated roof and roadway stability control in the process of forming large-section support return channel under the delamination mining, taking 1200-2 fully mechanized caving face of Baiyinhua No. 4 Mine as the engineering background, numerical simulation and theoretical analysis were adopted. The overburden structure of the lower stratified caving face and the loading characteristics of the roof after the expansion are analyzed, and the breaking forms and the limiting conditions of the roof are given.The combined support scheme of anchor rod + metal mesh + steel ladder belt + I-beam insertion + suspension beam + anchor cable + single pillar is studied to form a set of safe and efficient construction support technology system. Practice shows that this scheme can effectively reduce the roof subsidence, narrow the scope of plastic failure zone, and ensure the stability of roadway surrounding rock during the support withdrawal period. Successfully complete the efficient withdrawal of hydraulic support. The research results can provide a good reference for the roof management and the smooth output of coal resources under similar conditions. [ABSTRACT FROM AUTHOR]

In the realm of engineering rotary excavation, the rigid and brittle nature of the Polycrystal Diamond Compact (PDC) layer poses challenges to the impact resistance of conical teeth. This hinders their widespread adoption and utilization. In this paper, the Abaqus simulation is used. By optimizing the parameters of the radius of the cone top arc, we analyzed the changing law of the parameters of large-diameter D30 series conical PDC teeth, such as the equivalent force, impact force, and energy absorption of the conical teeth during the impact process, and optimized the best structure of the conical PDC teeth. After being subjected to a high temperature and high pressure, we synthesized the specimen for impact testing and analyzed the PDC layer crack extension and fracture failure. The findings reveal the emergence of a stress ring below the compacted area of the conical tooth. As the radius of the cone top arc increases, so does the area of the stress ring. When R ≥ 10 mm, the maximum stress change is minimal, and at R = 10 mm, the stress change in its top unit is relatively smooth. Optimal impact resistance is achieved, withstanding a total impact work value of 7500 J. Extrusion cracks appear in the combined layer part of PDC layers I and II, but the crack source is easy to produce in the combined layer of PDC layer II and the alloy matrix and extends to both sides, and the right side extends to the surface of the conical tooth in a "dragon-claw". The failure morphology of the conical teeth includes ring shedding at the top of the PDC layer, the lateral spalling of the PDC layer, and the overall cracking of the conical teeth. Through this study, we aim to promote the popularization and application of large-diameter conical PDC teeth in the field of engineering rotary excavation. [ABSTRACT FROM AUTHOR]

This paper proposes a method for dynamically controlling the working slope configuration in seasonal stripping open-pit coal mines. Constructing a bench group working slope model calculates the cyclic advancement time of the stripping working slope. A mathematical optimization model is then established to minimize the transport work of the overburden, and a Sequential Quadratic Programming (SQP) algorithm is employed to solve it. The method is applied to the Shengli West No. 2 open-pit coal mine, and the results show that the number of benches in the bench group is 5. The working bench width is 89 m, and the working slope advancement meets the stripping and mining engineering continuity requirements while minimizing the transport work of the overburden. The maximum advancement speed of the working slope under this configuration is 320 m/year. The paper also analyzes the working slope's maximum advancement speed variation with changes in the bench combination form and cyclic advancement distance. [ABSTRACT FROM AUTHOR]

Tailings dam failures cause catastrophic impact on the environment and surrounding communities. Incidences of failure in the recent past have caused industrialists and researchers to seek innovative ways for proactively managing their safety and disaster mitigation. Given Industry 4.0 technologies now available, researchers are looking to develop digital tools for cost-effective, realtime monitoring of tailings dams. However, published literature indicates that a reliable framework is still lacking. This paper proposes a framework for developing a data-driven system for monitoring tailings dam stability and early warning detection. The framework relies upon digital twin simulation and machine-learning (ML) techniques, and comprises four main components: realtime data collection, digital twin modelling, ML-based early detection and prediction, and intelligence-driven decision-support. Sensors gather real-time geophysical data from monitored structure, and the digital twin uses this data to simulate dam behaviour. ML algorithms analyse the data and simulations to enable early detection of instability and failure prediction. Literature suggests that digital twin and ML-based approaches may have advantages over traditional monitoring techniques and other AI-based methods. The paper concludes with a discussion of the framework's limitations, opportunities for improvement, and potential for application in mining and geotechnical engineering. The paper serves as a basis for model development and future research. [ABSTRACT FROM AUTHOR]

Condition monitoring and predictive maintenance applications receive ongoing scientific attention in production technology. Larger companies, especially machine and component manufacturers, already offer related products. Small and medium-sized enterprises (SMEs) in particular show interest in developing and offering solutions in this market themselves to gain economic advantages, to improve resource utilization of their machines or to be able to offer these advantages to their own customers. In the development process, however, they often encounter problems already in the digitization of the machines. The first hurdle is to obtain an analysis-capable data set. This is due to the fact that common and established general data mining development process models, such as CRISP-DM, do not focus on production technology, causing difficulties for engineers during deployment. A problem with existing process models is the limited practicality in the engineering domain due to restricted adaptability. In a previous paper, a guideline for engineers for data mining suitable digitization of production machines was developed in order to solve these problems. The related results were provided in the context of a project for condition monitoring of mixing machines. In this paper, the proposed method is applied to components of a 5-axis CNC milling machine in three different monitoring use cases. A complete workflow is presented, including effect analysis, sensor selection, formulation of predictive scenarios, data preparation, training of machine learning algorithms and vizualization. Data and documentation are provided alongside this publication. [ABSTRACT FROM AUTHOR]

Rock burst disaster is still one of the most serious dynamic disasters in coal mining, seriously restricting the safety of coal mining. The b value is the main parameter for monitoring rock burst, and by analyzing its changing characteristics, it can effectively predict the dangerous period of rock burst. This article proposes a method based on deep learning that can predict rock burst using data generated from microseismic monitoring in underground mining. The method first calculates the b value from microseismic monitoring data and constructs a time series dataset, and uses the dynamic time warping algorithm (DTW) to reconstruct the established b value time series. A bidirectional short-term and short-term memory network (BiLSTM) loaded with differential evolution algorithm and attention mechanism was used for training, and a prediction model for the dangerous period of rock burst based on differential algorithm optimization was constructed. The study used microseismic monitoring data from the B1+2 fully mechanized mining face and B3+6 working face in the southern mining area of Wudong Coal Mine for engineering case analysis. The commonly used residual sum of squares, mean square error, root mean square error, and correlation coefficient R2 for time series prediction were introduced, which have significant advantages compared to basic LSTM algorithms. This verifies that the prediction method proposed in this article has good prediction results and certain feasibility, and can provide technical support for the prediction and prevention of rock burst in steeply inclined thick coal seams in strong earthquake areas. [ABSTRACT FROM AUTHOR]

This research aims to identify the geological and lithological structures of mine land, determine the slope stability of the land, and determine the sustainability of landslide management in Kutai Kartanegara Regency, East Kalimantan, Indonesia. This present research was conducted in Samboja and Sebulu sub-districts, Kutai Kartanegara Regency, East Kalimantan, Indonesia. Data collection concerning the geological structure, lithology, and sustainability of coal mine landslides was carried out. Rock data, such as its physical and mechanical properties, were taken from complete coring drilled and then analyzed in a geomechanics laboratory. This procedure was carried out in three locations, with the first and second samples collected in the Kampungbaru Formation representing the youngest formation. In addition, the third taken in the Pulubalang Formation represents the oldest coal-bearing formation. The data relating to the avalanche condition were collected through surveys, interviews, and filling out questionnaires using a purposive sampling method. The respondents were 13 mining engineering heads from various mine sites in Kutai Kartanegara Regency, three mining environmental experts, and four academics. The results showed that of the 50-joint data, those with potential positions for landslides were located at N333°E/61° and N110°E/74°. The most dominant lithology in the study area was claystone, followed successively by sandstone, siltstone, and shale, with a specific gravity between 2.55 and 2.66. The dominant claystone indicated a relatively prone area. Meanwhile, the strength of the mechanical properties of the rock (direct shear) cohesion ranged from 17.80 and 174.53 kPa, with shear angles ranging from 10.88° to 42.01°. Based on the design of the slope stability in the three locations, this study demonstrated the maximum slope angle ranging from 29° to 37°, a height of 50.17 to 70.16 meters, a single slope height of 10 meters with an angle ranged from 32° to 44°, and a factor of safety (FOS) ranging from 1.326 to 1.452 with stable conditions. Multi-dimensional scaling (MDS) simulation results of the sustainability status comprised of a total of 49 attributes derived from five dimensions, namely ecological, economic, social, law, institutional and technological, demonstrated a score fell of 50.01. Furthermore, to increase the sustainability score, this study identified some sensitive factors as follows: condition of the slope of the mine slope, MSME business of residents, role of NGOs in mine landslides, concern of pit supervisory personnel for mine landslides, and mastery of mine landslide technology. Hence, the projection sustainability score increased to 82.00, which was achieved in the good category. [ABSTRACT FROM AUTHOR]

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