International Journal of Mining Science and Technology最新文献

{"title":"Response properties of geometries of coal penetrating fracture on seepage behavior","authors":"Penghua Han ,&nbsp;Kai Wang ,&nbsp;Jiewen Pang ,&nbsp;Xiaofeng Ji ,&nbsp;Cun Zhang","doi":"10.1016/j.ijmst.2025.01.003","DOIUrl":"10.1016/j.ijmst.2025.01.003","url":null,"abstract":"<div><div>The fracture surfaces of coal-rock masses formed under mining-induced stress generally exhibit complex geometries, and the fracture geometry is one of the primary factors affecting the seepage characteristics of coal-rock penetrating fracture. This paper investigates the seepage characteristics of 5 groups of coal penetrating fracture (CPF) with different joint roughness coefficients (JRCs). Based on 3D morphology scanner tests and hydraulic coupling tests, a characterization method of effective geometric parameters in fracture surfaces under various confining pressures was improved, and a relationship between effective geometric parameters and the confining pressure is established. The results indicate that the nonlinear flow behavior in a CPF primarily includes three types: non-Newtonian fluid seepage under high confining pressure and low JRC, non-Darcy seepage under low confining pressure and high JRC, and the whole process of seepage characteristics between these two conditions. Among them, non-Newtonian fluid seepage is caused by significant fracture expansion, while non-Darcy seepage can be attributed to turbulence effects. During the seepage process, the geometric parameters with different JRC fracture samples all exhibit exponential changes with the increase of confining pressure. In addition, under high confining pressure, the effective contact ratio, effective fracture aperture, and void deviation ratio with high JRC fracture samples under high confining pressure increase by 93.5%, 67.4%, and 24.9%, respectively, compared with those of low JRC fracture samples. According to the variation of geometric parameters in a CPF with external stress, a seepage model considering geometric parameters in a CPF is proposed. By introducing the root mean square error (RMSE) and coefficient of determination (<em>R</em>²) to evaluate the error and goodness of fit between model curves and experimental data, it is found that the theoretical curves of model in this paper have the best matching with the experimental data. The average values of RMSE and <em>R</em>² for model in this paper are 0.002 and 0.70, respectively, which are better than models in the existing literature.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 191-211"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Macro- and micro-mechanical response and damage mechanism of sandstone under high-temperature conditions","authors":"Laiwei Wu ,&nbsp;Yanli Huang ,&nbsp;Junmeng Li ,&nbsp;Guiyuan Wang ,&nbsp;Yingshun Li ,&nbsp;Xiaotong Li ,&nbsp;Junzhi Chen ,&nbsp;Chuning Ji","doi":"10.1016/j.ijmst.2025.01.004","DOIUrl":"10.1016/j.ijmst.2025.01.004","url":null,"abstract":"<div><div>The thermal effects of coal combustion considerably influence the physical and chemical properties, structural characteristics, and stability of rocks, posing a serious threat to the safety of coal mining operations. In this study, the impacts of temperature on the physical and chemical characteristics (i.e., mineral phase, microstructure, and mechanical strength) of sandstone were investigated by employing experimental methods, including microstructural analysis, uniaxial acoustic emission (AE), and nuclear magnetic resonance (NMR). The results indicate that temperature alters the mineral phase and the pore characteristics, and these two factors jointly affect the mechanical properties of sandstone. The influence of temperature on the mechanical strength of sandstone is categorized into low-temperature strengthening and high-temperature damage, with a threshold temperature identified at 600 °C. The low-temperature strengthening effect encompasses both pore strengthening and mineral phase strengthening, while the high-temperature damage effect primarily results from pore damage. As the experimental temperature rises, both the number of AE events and the AE energy transition from a surge in the post-peak failure stage to a stepwise increase during the loading process. This transition implies that the failure mode of the sandstone sample evolves from brittle failure to tensile failure.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 265-274"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of acid fracturing fluid modifying coal microstructure stimulated by ultrasonic","authors":"Shaojie Zuo ,&nbsp;Rui Gan ,&nbsp;Zhijie Wen ,&nbsp;Liang Zhang ,&nbsp;Zhizhong Jiang ,&nbsp;Fuping Zhao ,&nbsp;Chengwei Liu ,&nbsp;Kun Li ,&nbsp;Zhiyuan Xu","doi":"10.1016/j.ijmst.2025.01.005","DOIUrl":"10.1016/j.ijmst.2025.01.005","url":null,"abstract":"<div><div>The combination of ultrasonic and acid fracturing fluid can strengthen the modification effect on the micropore structure of the coal matrix, thereby enhancing the efficiency of the acid fracturing process. In this research, acetic acid was utilized to formulate acid fracturing fluids with varying concentrations, and the evolutionary traits of both the acid fracturing fluids and ultrasonic waves in relation to coal samples were investigated. The functional group structure, mineral composition, micropore structure and surface morphology of coal samples were characterized by FTIR, XRD, N₂ adsorption at low temperature and SEM-EDS. The results showed that aromatics (<em>I</em>) and branching parameters (CH₂/CH₃) were reduced by 81.58% and 88.67%, respectively, after 9% acetic acid treatment. Acetic acid can dissolve carbonates and clay minerals in coal, create new pores, and increase porosity, pore volume and pore fractal dimension. After modification by 7% acetic acid, the pore volume increased by 5.7 times. SEM observation shows that the diameter of coal surface holes increases, EDS scanning shows that the content of mineral elements in coal decreases, the connectivity of coal holes increases, and the holes expand. The findings of this research offer theoretical direction for optimizing ultrasonic-enhanced acid fracturing fluid modification.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 275-293"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic loading of marble: Correlating the attenuation of the electric and acoustic activities and highlighting criticality indices in terms of natural time","authors":"Dimos Triantis ,&nbsp;Ilias Stavrakas ,&nbsp;Ermioni D. Pasiou ,&nbsp;Stavros K. Kourkoulis","doi":"10.1016/j.ijmst.2024.12.015","DOIUrl":"10.1016/j.ijmst.2024.12.015","url":null,"abstract":"<div><div>The attenuation of the acoustic activity in marble specimens under uniaxial compressive loading-unloading loops is quantified in juxtaposition to that of the electric activity. In parallel, the existence of “pre-failure indices” warning about entrance into a critical stage, that of impending fracture, is explored. The acoustic activity is quantified in terms of the normalized number of acoustic hits, their average rate of production and their cumulative energy, and, the cumulative counts and their average rate of change. The electric activity is studied in terms of the pressure stimulated currents and the electric charge released. The analysis revealed that the acoustic and electric activities are linearly correlated to each other, suggesting that they are different manifestations of the same damage mechanisms. In addition, Kaiser’s effect, governing the acoustic activity, is found to govern, also, the electric activity. Moreover, it is concluded that entrance into the critical stage is safely predicted by means of a simple criterion, based on the evolution of the average rate of change of the normalized cumulative counts in the natural time domain. These predictions are almost identical with those of the criterion based on the “variance” and the “entropies” of the time series of acoustic events in this domain.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 159-174"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on failure precursory characteristics and moisture content effect of pre-cracked rocks under graded cyclic loading and unloading","authors":"Wei Zhang ,&nbsp;Dongxiao Zhang ,&nbsp;Weiyao Guo ,&nbsp;Baoliang Zhang","doi":"10.1016/j.ijmst.2024.12.014","DOIUrl":"10.1016/j.ijmst.2024.12.014","url":null,"abstract":"<div><div>It is important to analyze the damage evolution process of surrounding rock under different water content for the stability of engineering rock mass. Based on digital speckle correlation (DSCM), acoustic emission (AE) and electromagnetic radiation (EMR), uniaxial hierarchical cyclic loading and unloading tests were carried out on sandstones with different fracture numbers under dry, natural and saturated water content, to explore the fracture propagation, failure precursor characteristics and damage response mechanism under the influence of water content effect. The results show that with the increase of water content, the peak stress and crack initiation stress decrease gradually, and the decreases are 15.28%–21.11% and 17.64%–23.04%, respectively. The peak strain and crack initiation strain increase gradually, and the increases are 19.85%–44.53% and 19.15%–41.94%, respectively. The precracked rock with different water content is mainly characterized by tensile failure at different loading stages. However, with the increase of water content, the proportion of shear cracks gradually increases, while acoustic emission events gradually decrease, the dissipative energy and energy storage limits of the rock under peak load gradually decrease, and the charge signal increases significantly, which is because the lubrication effect of water reduces the friction coefficient between crack surfaces.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 249-264"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing the recovery of iron and rare earth elements from the solid waste at Bayan Obo","authors":"Na Zhao ,&nbsp;Qiang Zhang ,&nbsp;Hongwei Ma ,&nbsp;Yongsheng Sun ,&nbsp;Peng Gao ,&nbsp;Zhao Cao ,&nbsp;Zhenyue Zhang","doi":"10.1016/j.ijmst.2024.12.006","DOIUrl":"10.1016/j.ijmst.2024.12.006","url":null,"abstract":"<div><div>The storage of solid waste in Bayan Obo has resulted in significant resource wastage and environmental concerns. In this study, an efficient process was developed to recover iron and rare earth elements (REEs) from this waste by processes of hydrogen-based mineral phase transformation (HMPT), magnetic separation, and flotation. Under optimal HMPT conditions (525 °C, 12.5 min, and 30% H₂ concentration), an iron concentrate with a TFe grade of 64.09% and a recovery of 95.33% was obtained. The magnetic properties of the solid waste were greatly enhanced by HMPT, allowing the effective magnetic separation of iron minerals. Further optimization of the flotation process resulted in a REEs concentrate with a rare earth oxide (REO) grade of 65%–70% and a REEs recovery of 60%–65%. Hematite was reduced to magnetite during HMPT, and bastnaesite was decomposed to REEs oxides and fluorides, and the particle structure was significantly destroyed. However, changes in monazite, fluorite, and barite were minimal.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 295-306"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on coal damage and fracture extension law of liquid nitrogen injection pre-cooling and fracturing under true triaxial stress","authors":"Botao Li ,&nbsp;Haifei Lin ,&nbsp;Jianping Wei ,&nbsp;Hongtu Zhang ,&nbsp;Shugang Li ,&nbsp;Zongyong Wei ,&nbsp;Lei Qin ,&nbsp;Pei Wang ,&nbsp;Rongwei Luo ,&nbsp;Zeran Liu","doi":"10.1016/j.ijmst.2024.12.013","DOIUrl":"10.1016/j.ijmst.2024.12.013","url":null,"abstract":"<div><div>To more accurately describe the coal damage and fracture evolution law during liquid nitrogen (LN₂) fracturing under true triaxial stress, a thermal–hydraulic-mechanical-damage (THMD) coupling model for LN₂ fracturing coal was developed, considering the coal heterogeneity and thermophysical parameters of nitrogen. The accuracy and applicability of model were verified by comparing with LN₂ injection pre-cooling and fracturing experimental data. The effects of different pre-cooling times and horizontal stress ratios on coal damage evolution, permeability, temperature distribution, and fracture characteristics were analyzed. The results show that the permeability and damage of the coal increase exponentially, while the temperature decreases exponentially during the fracturing process. As the pre-cooling time increases, the damage range of the coal expands, and the fracture propagation becomes more pronounced. The initiation pressure and rupture pressure decrease and tend to stabilize with longer pre-cooling times. As the horizontal stress ratio increases, fractures preferentially extend along the direction of maximum horizontal principal stress, leading to a significant decrease in both initiation and rupture pressures. At a horizontal stress ratio of 3, the initiation pressure drops by 48.07%, and the rupture pressure decreases by 41.36%. The results provide a theoretical basis for optimizing LN₂ fracturing techniques and improving coal seam modification.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 213-229"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bond length and interface failure mechanism of anchor cable under continuous radial pressure conditions","authors":"Jian Ouyang,&nbsp;Xiuzhi Shi,&nbsp;Xianyang Qiu,&nbsp;Zongguo Zhang,&nbsp;Zeyu Li","doi":"10.1016/j.ijmst.2025.01.001","DOIUrl":"10.1016/j.ijmst.2025.01.001","url":null,"abstract":"<div><div>The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions. Through field pull-out tests, theoretical analysis, numerical simulation, and industrial tests, this study clarifies the relationship between radial pressure and bonding length for the ultimate pull-out force and reveals the microscopic failure process of the resin-rock interface in the anchoring system. The results show that the ultimate load increases with the increase of bonding length in three different stages: rapid, slow, and uniform growth. The new mechanical model developed considering radial pressure describes the inverse relationship between radial pressure and the plastic zone on the bonding section, and quantifies the reinforcing effect of confining pressure on the anchoring force. During the pull-out process of the anchor cable, the generation of failure cracks is in the order of orifice, bottom, and middle of the hole. Radial pressure can effectively enhance the ultimate pull-out force, alleviate the oscillation increase of pull-out force, and inhibit resin cracking, but will produce an external crushing zone. It also reveals the synergistic effect between bonding length and radial pressure, and successfully carries out industrial tests of anchor cable support, which ensures the stability of the stope roof and provides an important reference for the design of anchor cable support in deep high-stress mines.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 2","pages":"Pages 231-247"},"PeriodicalIF":11.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative principles of dynamic interaction between rock support and surrounding rock in rockburst roadways","authors":"Lianpeng Dai ,&nbsp;Dingjie Feng ,&nbsp;Yishan Pan ,&nbsp;Aiwen Wang ,&nbsp;Ying Ma ,&nbsp;Yonghui Xiao ,&nbsp;Jianzhuo Zhang","doi":"10.1016/j.ijmst.2024.12.009","DOIUrl":"10.1016/j.ijmst.2024.12.009","url":null,"abstract":"<div><div>Rockbursts, which mainly affect mining roadways, are dynamic disasters arising from the surrounding rock under high stress. Understanding the interaction between supports and the surrounding rock is necessary for effective rockburst control. In this study, the squeezing behavior of the surrounding rock is analyzed in rockburst roadways, and a mechanical model of rockbursts is established considering the dynamic support stress, thus deriving formulas and providing characteristic curves for describing the interaction between the support and surrounding rock. Design principles and parameters of supports for rockburst control are proposed. The results show that only when the geostress magnitude exceeds a critical value can it drive the formation of rockburst conditions. The main factors influencing the convergence response and rockburst occurrence around roadways are geostress, rock brittleness, uniaxial compressive strength, and roadway excavation size. Roadway support devices can play a role in controlling rockburst by suppressing the squeezing evolution of the surrounding rock towards instability points of rockburst. Further, the higher the strength and the longer the impact stroke of support devices with constant resistance, the more easily multiple balance points can be formed with the surrounding rock to control rockburst occurrence. Supports with long impact stroke allow adaptation to varying geostress levels around the roadway, aiding in rockburst control. The results offer a quantitative method for designing support systems for rockburst-prone roadways. The design criterion of supports is determined by the intersection between the convergence curve of the surrounding rock and the squeezing deformation curve of the support devices.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 1","pages":"Pages 41-55"},"PeriodicalIF":11.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical and experimental study on high-entropy flotation of micro-fine cassiterite","authors":"Shuming Wen,&nbsp;Yongchao Miao,&nbsp;Yanyu Tang,&nbsp;Zhengyong Song,&nbsp;Qicheng Feng","doi":"10.1016/j.ijmst.2024.12.012","DOIUrl":"10.1016/j.ijmst.2024.12.012","url":null,"abstract":"<div><div>Tin is a critical metal for various industries, making its recovery from low-grade cassiterite ores crucial. This study aimed to optimize the flotation recovery of cassiterite using multi-component collector systems. Several collectors were initially selected through micro-flotation tests, leading to the identification of optimal proportions for a four-component collector system (SHA-OHA-SPA-DBIA in a 4:3:2:1 ratio). Molecular dynamics simulations and surface tension tests were used to investigate the micellar behavior of these collectors in aqueous solution. The adsorption characteristics were quantified using microcalorimetry, enabling the determination of collection entropy and changes in Gibbs free energy. The four-component collector system showed the highest entropy change and the most favorable Gibbs free energy, leading to a cassiterite recovery of above 90% at a concentration of 8.0×10⁻⁵ mol/L. Various analytical techniques were employed to systematically characterize the adsorption mechanism. The findings revealed a positive correlation between the adsorption products formed by the multi-component collectors on the cassiterite surface and the entropy changes. Industrial-scale testing of the high-entropy collector system produced a tin concentrate with an Sn grade of 6.17% and an Sn recovery of 82.43%, demonstrating its substantial potential for practical applications in cassiterite flotation.</div></div>","PeriodicalId":48625,"journal":{"name":"International Journal of Mining Science and Technology","volume":"35 1","pages":"Pages 19-39"},"PeriodicalIF":11.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}