Systematic review of mixing technology for recycling waste tailings as cemented paste backfill in mines in China

Abstract

The development of industry is inseparable from the support of mining. However, mining processes consume a large amount of energy, and increased tailing emissions can have a significant impact on the environment. In the past few decades, the mining industry developed many technologies that are related to mineral energy management, of which cemented paste backfill (CPB) is one of the representative technologies. CPB has been successfully applied to mine ground control and tailings management. In CPB technology, the mixing process is the key to achieving materials with good final quality and controlled properties. However, in the preparation process, the mixed homogeneity of the CPB is difficult to achieve because of fine tailings, high solid volume fraction, and high viscosity. Most research focused on the effect of mixing ingredients on CPB properties rather than on the preparation process of the CPB. Therefore, improving the performance and reducing the production cost of CPB by optimizing the mixing process are important. This review summarizes the current studies on the mixing technology of CPB and its application status in China. Then, it compares the advantages and disadvantages of multiple mixing equipment and discusses the latest results and research hotspots in paste preparation. Finally, it concludes the challenges and development trends of mixing technology on the basis of the relevant application cases in China to promoting cement-based material mixing technology development.

Keywords

cemented paste backfill / mixed homogeneity / mixing technology / cement-based material

References

[1] T. Kasap, E. Yilmaz, and M. Sari, Physico-chemical and micro-structural behavior of cemented mine backfill: Effect of pH in dam tailings, J. Environ. Manage., 314(2022), art. No. 115034.

[2] Jiao HZ, Chen WL, Wu AX, et al. Flocculated unclassified tailings settling efficiency improvement by particle collision optimization in the feedwell. Int. J. Miner. Metall. Mater., 2022, 29(12): 2126.

[3] Chen QS, Zhang QL, Qi CC, Fourie A, Xiao CC. Recycling phosphogypsum and construction demolition waste for cemented paste backfill and its environmental impact. J. Cleaner Prod., 2018, 186, 418.

[4] H.Z. Jiao, Y.C. Wu, H. Wang, et al., Micro-scale mechanism of sealed water seepage and thickening from tailings bed in rake shearing thickener, Miner. Eng., 173(2021), art. No. 107043.

[5] Y.X. Wei, Heavyweight of Environmental Protection: Looking at the Layout Direction of Environmental Protection Stocks from the Large-scale Industrial Sewage Seepage Pit in North China!, Xueqiu, 2017 [2022-05-10]. https://xueqiu.com/7995134966/84274862?from=groupmessage

[6] de Paiva CA, Santiago ADF, Filho JFDP. Content analysis of dam break studies for tailings dams with high damage potential in the Quadrilâtero Ferrifero, Minas Gerais: Technical weaknesses and proposals for improvements. Nat. Hazards, 2020, 104(2): 1141.

[7] Chen X, Shi XZ, Zhou J, Du XH, Chen QS, Qiu XY. Effect of overflow tailings properties on cemented paste backfill. J. Environ. Manage., 2019, 235, 133.

[8] Boger DV. Rheology and the resource industries. Chem. Eng. Sci., 2009, 64(22): 4525.

[9] Guo QF, Xi X, Yang ST, Cai MF. Technology strategies to achieve carbon peak and carbon neutrality for China’s metal mines. Int. J. Miner. Metall. Mater., 2022, 29(4): 626.

[10] Xie HP, Ju Y, Ren SH, Gao F, Liu JZ, Zhu Y. Theoretical and technological exploration of deep in situ fluidized coal mining. Front. Energy, 2019, 13(4): 603.

[11] L. Liu, S.S. Ruan, C.C. Qi, et al., Co-disposal of magnesium slag and high-calcium fly ash as cementitious materials in backfill, J. Cleaner Prod, 279(2021), art. No. 123684.

[12] Wu AX, Li H, Chen HY, Wang YM, Liao CP, Ruan ZE. Status and prospects of research on rheology of paste backfill using unclassified-tailings (Part 2): Rheological measurement and prospects. Chin. J. Eng., 2021, 43(4): 451.

[13] Wu D, Zhao RK, Xie CW, Liu S. Effect of curing humidity on performance of cemented paste backfill. Int. J. Miner. Metall. Mater., 2020, 27(8): 1046.

[14] Tuylu S. Effect of different particle size distribution of zeolite on the strength of cemented paste backfill. Int. J. Environ. Sci. Technol., 2022, 19(1): 131.

[15] Jafari M, Shahsavari M, Grabinsky M. Cemented paste backfill 1-D consolidation results interpreted in the context of ground reaction curves. Rock Mech. Rock Eng., 2020, 53(9): 4299.

[16] S.H. Yin, Y.J. Shao, A.X. Wu, H.J. Wang, X.H. Liu, and Y. Wang, A systematic review of paste technology in metal mines for cleaner production in China, J. Cleaner Prod., 247(2020), art. No. 119590.

[17] Grima-Olmedo C, Antonio JBM, Ramirez-Gomez A, Galindo DGL. Review of teams settling for sterile of mine: The conventional thickener to the deep cone for the production of pasta. DYNA, 2015, 90(4): 359.

[18] H.J. Wang, A.X. Wu, W.G. Xiao, P.H. Zeng, X.W. Ji, and Q.W. Yan, The progresses of coarse paste fill technology and its existing problem, Met. Mine, 2009, No. 11, p. 1.

[19] Y.L. Zhao, J.P. Qiu, S.Y. Zhang, et al., Low carbon binder modified by calcined quarry dust for cemented paste backfill and the associated environmental assessments, J. Environ. Manage., 300(2021), art. No. 113760.

[20] Liu Q, Zhang XW. Overview of the research progress of the paste backfill technology in China. Mod. Min., 2016, 32(5): 1.

[21] Wang Y, Wang HJ, Wu AX. Mathematical model of deep cone thickener underflow concentration based on the height to diameter ratio. J. Wuhan Univ. Technol., 2011, 33(8): 113.

[22] Ao SF, Cui MJ, Shi ZL, et al. The industrial practice and application of resources comprehensive utilization technologies in Huize Lead-zinc mine. China. Min. Mag., 2016, 25(11): 102.

[23] Zhou B, Zhou XW, Chen Y, Chen Z. The application of paste tailing technology in high latitude cold area. Adv. Mater. Res., 2014, 937, 386.

[24] Liu KF, Feng CR, Qi XP, et al. Geological characteristics and prospecting indicator of Wuheshalu sandstone copper deposit in Wuqia County, Xinjiang. Northwest. Geol., 2020, 53(3): 113.

[25] L. Chen, Q.H. Gu, R. Wang, Z.D. Feng, and C. Zhang, Comprehensive utilization of mineral resources: Optimal blending of polymetallic ore using an improved NSGA-III algorithm, Sustainability, 14(2022), No. 17, art. No. 10766.

[26] S. Song, J.L. Chu, and H. Zhang, Study on environmental risk assessment and control countermeasures of tailings pond in a mountainous area of North China, IOP Conf. Ser.: Earth Environ. Sci., 585(2020), No. 1, art. No. 012095.

[27] Cheng HY, Wu SC, Zhang XQ, Wu AX. Effect of particle gradation characteristics on yield stress of cemented paste backfill. Int. J. Miner. Metall. Mater., 2020, 27(1): 10.

[28] Kumar D, Mohanta DK, Reddy MJB. Intelligent optimization of renewable resource mixes incorporating the effect of fuel risk, fuel cost and CO₂ emission. Front. Energy, 2015, 9(1): 91.

[29] M.C. Valigi, S. Logozzo, L. Landi, C. Braccesi, and L. Galletti, Twin-shaft mixers’ mechanical behavior numerical simulations of the mix and phases, Machines, 7(2019), No. 2, art. No. 39.

[30] Kumar A, Sekhar C. Demand response based congestion management in a mix of pool and bilateral electricity market model. Front. Energy, 2012, 6(2): 164.

[31] Belem T, Benzaazoua M. Design and application of underground mine paste backfill technology. Geotech. Geol. Eng., 2008, 26(2): 147.

[32] Sun W, Wang HJ, Hou KP. Control of waste rock-tailings paste backfill for active mining subsidence areas. J. Cleaner Prod., 2018, 171, 567.

[33] Li ZT, Folmer H. Air pollution and perception-based averting behaviour in the Jinchuan mining area, China. Ann. Reg. Sci., 2023, 70(2): 477.

[34] Yim HJ, Kim JH. Physical characterization of cementitious materials on casting and placing process. Materials, 2014, 7(4): 3049.

[35] Z.G. Xiu, S.H. Wang, Y.C. Ji, F.L. Wang, and F.Y. Ren, Experimental study on the triaxial mechanical behaviors of the Cemented Paste Backfill: Effect of curing time, drainage conditions and curing temperature, J. Environ. Manage., 301(2022), art. No. 113828.

[36] Zhang Y, Yu GR, Yu L, et al. Computational fluid dynamics study on mixing mode and power consumption in anaerobic mono- and co-digestion. Bioresour. Technol., 2016, 203, 166.

[37] Li JJ, Cao S, Yilmaz E, Liu YP. Compressive fatigue behavior and failure evolution of additive fiber-reinforced cemented tailings composites. Int. J. Miner. Metall. Mater., 2022, 29(2): 345.

[38] L.H. Li, J. Yang, H.Y. Li, and Y.H. Du, Insights into the microstructure evolution of slag, fly ash and condensed silica fume in blended cement paste, Constr. Build. Mater., 309(2021), art. No. 125044.

[39] Wu AX, Ruan ZE, Wang JD. Rheological behavior of paste in metal mines. Int. J. Miner. Metall. Mater., 2022, 29(4): 717.

[40] Wallevik JE. Rheological properties of cement paste: Thixotropic behavior and structural breakdown. Cem. Concr. Res., 2009, 39(1): 14.

[41] Han D, Ferron RD. Effect of mixing method on microstructure and rheology of cement paste. Constr. Build. Mater., 2015, 93, 278.

[42] He ZX, Xie KW, Zhang CQ, Xie CJ. Activating mixing technology and its application in mine backfill. Gold, 2000, 21(9): 18.

[43] Liu SC, Song M, Hao L, Wang PX. Numerical simulation on flow of ice slurry in horizontal straight tube. Front. Energy, 2021, 15(1): 201.

[44] Bao SX, Luo YP, Zhang YM. Fabrication of green one-part geopolymer from silica-rich vanadium tailing via thermal activation and modification. Int. J. Miner. Metall. Mater., 2022, 29(1): 177.

[45] Small N, Sadeghiamirshahidi M, Gammons CH. Inorganic precipitation of calcite in mine tailings using trona. Mine Water Environ., 2022, 41(4): 970.

[46] Power IM, Paulo C, Long H, et al. Carbonation, cementation, and stabilization of ultramafic mine tailings. Environ. Sci. Technol., 2021, 55(14): 10056.

[47] L.H. Yang, H.J. Wang, A.X. Wu, et al, Effect of mixing time on hydration kinetics and mechanical property of cemented paste backfill, Constr. Build. Mater., 247(2020), art. No. 118516.

[48] Goldszal A, Bousquet J. Wet agglomeration of powders: From physics toward process optimization. Powder Technol., 2001, 117(3): 221.

[49] Iveson SM, Litster JD, Hapgood K, Ennis BJ. Nucleation, growth and breakage phenomena in agitated wet granulation processes: A review. Powder Technol., 2001, 117(1–2): 3.

[50] Cazacliu B, Legrand J. Characterization of the granular-to-fluid state process during mixing by power evolution in a planetary concrete mixer. Chem. Eng. Sci., 2008, 63(18): 4617.

[51] Wang HJ, Yang LH, Wang Y, Wu AX, Zhou X, Zhang LF. Multi-scale materials’ dispersive mixing technology of unclassified tailings paste. J. Wuhan. Univ. Technol., 2017, 39(12p): 76.

[52] Betz G, Bürgin PJ, Leuenberger H. Power consumption profile analysis and tensile strength measurements during moist agglomeration. Int. J. Pharm., 2003, 252(1–2): 11.

[53] H.N. Geng, Q. Xu, S.B. Duraman, and Q. Li, Effect of rheology of fresh paste on the pore structure and properties of pervious concrete based on the high fluidity alkali-activated slag, Crystals, 11(2021), No. 6, art. No. 593.

[54] Knight PC, Instone T, Pearson JMK, Hounslow MJ. An investigation into the kinetics of liquid distribution and growth in high shear mixer agglomeration. Powder Technol., 1998, 97(3): 246.

[55] Park M, Lee C, Hong J. Critical values in the morphology transition of a liquid bridge. J. Korean Phys. Soc., 2002, 40, 992.

[56] D.Y. Gao, L.J. Zhang, M. Nokken, and J. Zhao, Mixture proportion design method of steel fiber reinforced recycled coarse aggregate concrete, Materials, 12(2019), No. 3, art. No. 375.

[57] Cazacliu B, Roquet N. Concrete mixing kinetics by means of power measurement. Cem. Concr. Res., 2009, 39(3): 182.

[58] Cazacliu B. In-mixer measurements for describing mixture evolution during concrete mixing. Chem. Eng. Res. Des., 2008, 86(12): 1423.

[59] Williams DA, Saak AW, Jennings HM. The influence of mixing on the rheology of fresh cement paste. Cem. Concr. Res., 1999, 29(9): 1491.

[60] Komurlu E, Kesimal A. Sulfide-rich mine tailings usage for short-term support purposes: An experimental study on paste backfill barricades. Geomech. Eng., 2015, 9, 195.

[61] D. Berti, G. Biscontin, and J. Lau, Effect of biochar filler on the hydration products and microstructure in Portland cement-stabilized peat, J. Mater. Civ. Eng., 33(2021), No. 10, art. No. 04021263.

[62] Yan ZP, Yin SH, Yan RF, Zou L, Kou YY, Kou PF. Effect of mixing time on the homogeneity and early strength of coarse aggregate paste. Chin. J. Nonferrous Met., 2022, 32(4): 1164.

[63] Zhou YL, Bin F, Wang YB. Evaluation method of continuous mixing uniformity of full tailings paste filling. Mod. Min., 2021, 37(1): 53.

[64] Turlova OV, Markova SV, Kormina IV. Effect of new-generation plasticizers on the properties of clay pastes. Glass Ceram., 2012, 69(3–4): 92.

[65] Qi CC, Xu XH, Chen QS. Hydration reactivity difference between dicalcium silicate and tricalcium silicate revealed from structural and Bader charge analysis. Int. J. Miner. Metall. Mater., 2022, 29(2): 335.

[66] Liu L, Xin J, Huan C, et al. Effect of curing time on the mesoscopic parameters of cemented paste backfill simulated using the particle flow code technique. Int. J. Miner. Metall. Mater., 2021, 28(4): 590.

[67] Srpak D. Justification of PLC-use for “smaller” applications. Tech. Gaz, 2008, 15(4): 49.

[68] E. Lloret-Fritschi, T. Wangler, L. Gebhard, et al., From Smart Dynamic Casting to a growing family of Digital Casting Systems, Cem. Concr. Res., 134(2020), art. No. 106071.

[69] Zhang L, Hu JH, Wang XZ, Chai XW, Zhao L. Collaborative mining sequence optimization for multiple stopes under intensive mining. Adv. Civ. Eng., 2021, 2021, 1.

[70] E.F. Felix, R. Carrazedo, and E. Possan, Carbonation model for fly ash concrete based on artificial neural network: Development and parametric analysis, Constr. Build. Mater., 266(2021), art. No. 121050.

[71] Phu ND, Hung NN, Ahmadian A, Senu N. A new fuzzy PID control system based on fuzzy PID controller and fuzzy control process. Int. J. Fuzzy Syst., 2020, 22(7): 2163.

[72] Ceravola A, Stein M, Goerick C. Researching and developing a real-time infrastructure for intelligent systems—Evolution of an integrated approach. Rob. Auton. Syst., 2008, 56(1): 14.

[73] Y.N. Su, M.H. Dai, and H.Y. Zhou, Design and application of intelligent management platform based on big data, Secur. Commun. Netw., 2022(2022), art. No. 1790678.

[74] X.D. Chen, J. Wu, Y.J. Ning, and W. Zhang, Experimental study on the effect of wastewater and waste slurry of mixing plant on mechanical properties and microstructure of concrete, J. Build. Eng., 52(2022), art. No. 104307.

[75] A. Ozersky, A. Khomyakov, and K. Peterson, Novel ultra high performance concrete mixing technology with preliminary dry forced packing, Constr. Build. Mater., 267(2021), art. No. 120934.

[76] Collin V, Jézéquel PH. Mixing of concrete or mortars: Distributive aspects. Cem. Concr. Res., 2009, 39(8): 678.

[77] Y. Tian, P.P. Yuan, F. Yang, et al., Research on the principle of a new flexible screw conveyor and its power consumption, Appl. Sci., 8(2018), No. 7, art. No. 1038.

[78] X. Zou, Calculation of power and energy consumption for double horizontal shaft concrete mixer, Constr. Mach., 2020, No. 7, p. 55.

[79] A. Peys, R. Snellings, B. Peeraer, et al., Transformation of mine tailings into cement-bound aggregates for use in concrete by granulation in a high intensity mixer, J. Cleaner Prod., 366(2022), art. No. 132989.

[80] P.X. Lu, Improvement of ϕ2700×4000 wet rod mill, Min. Process. Equip., 2001, No. 1, p. 76.

[81] Hilson G. Pollution prevention and cleaner production in the mining industry: An analysis of current issues. J. Cleaner Prod., 2000, 8(2): 119.

[82] Zhang P, Li HY, Shi SH. Potvin Y, Grice T. Large scale backfill technology and equipment. Mine Fill 2014: Proceedings of the Eleventh International Symposium on Mining with Backfill, 2014, Perth, Australian Centre for Geomechanics, 73.

[83] Yang XB, Yang ZQ, Chen ZJ, Gao Q. Design on large-capacity mixing equipment for high-density rod-milled sand aggregates slurry in Jinchuan. Min. Process. Equip., 2017, 45(8): 66.

[84] X.H. Zhao, C.Y. Liu, L.M. Zuo, et al., Synthesis and characterization of fly ash geopolymer paste for goaf backfill: Reuse of soda residue, J. Cleaner Prod., 260(2020), art. No. 121045.

[85] X. Song, Experimental study and case analysis of super retarded concrete, Ready-Mixed Concr., 2012, No. 3, p. 67.

[86] Agarwal SK. Development of water reducing agent from creosote oil. Constr. Build. Mater., 2003, 17(4): 245.

[87] Li H, Wu AX, Wang HJ, Chen H, Yang LH. Changes in underflow solid fraction and yield stress in paste thickeners by circulation. Int. J. Miner. Metall. Mater., 2021, 28(3): 349.

[88] Zhang LF, Wu AX, Wang HJ. Effects and mechanism of pumping agent on rheological properties of highly muddy paste. Chin. J. Eng., 2018, 40(8): 918.

[89] H. Allam, F. Duplan, S. Amziane, and Y. Burtschell, Assessment of manufacturing process efficiency in the dispersion of carbon fibers in smart concrete by measuring AC impedance, Cem. Concr. Compos., 127(2022), art. No. 104394.

[90] H.Z. Jiao, W.X. Zhang, Y.X. Yang, et al., Static mechanical characteristics and meso-damage evolution characteristics of layered backfill under the condition of inclined interface, Constr. Build. Mater., 366(2023), art. No. 130113.

[91] J. Rosales, S.M. Pérez, M. Cabrera, et al., Treated phosphogypsum as an alternative set regulator and mineral addition in cement production, J. Cleaner Prod., 244(2020), art. No. 118752.

[92] Xue GL, Yilmaz E, Song WD, Yilmaz E. Influence of fiber reinforcement on mechanical behavior and microstructural properties of cemented tailings backfill. Constr. Build. Mater., 2019, 213, 275.

[93] Xu WB, Li QL, Zhang YL. Influence of temperature on compressive strength, microstructure properties and failure pattern of fiber-reinforced cemented tailings backfill. Constr. Build. Mater., 2019, 222, 776.

[94] Y.Y. Wang, Z.Q. Yu, and H.W. Wang, Experimental investigation on some performance of rubber fiber modified cemented paste backfill, Constr. Build. Mater., 271(2021), art. No. 121586.

[95] T. Mashifana and T. Sithole, Clean production of sustainable backfill material from waste gold tailings and slag, J. Cleaner Prod., 308(2021), art. No. 127357.

[96] Zhou Q, Liu JH, Wu AX, Wang HJ. Early-age strength property improvement and stability analysis of unclassified tailing paste backfill materials. Int. J. Miner. Metall. Mater., 2020, 27(9): 1191.

[97] Knapen E, Van Gemert D. Effect of under water storage on bridge formation by water-soluble polymers in cement mortars. Constr. Build. Mater., 2009, 23(11): 3420.

[98] H.Z. Jiao, W.B. Yang, Z.E. Ruan, J.X. Yu, J.H. Liu, and Y.X. Yang, The micro-scale mechanism of tailings thickening processing from metal mines, Int. J. Miner. Metall. Mater., 2022. https://doi.org/10.1007/s12613-022-2587-0

[99] Feng Y, Yang QX, Chen QS, et al. Characterization and evaluation of the pozzolanic activity of granulated copper slag modified with CaO. J. Cleaner Prod., 2019, 232, 1112.

[100] H.Y. Cheng, S.C. Wu, H. Li, and X.Q. Zhang, Influence of time and temperature on rheology and flow performance of cemented paste backfill, Constr. Build. Mater., 231(2020), art. No. 117117.

[101] Q.Y. Wu, Price and scale effects of China’s carbon emission trading system pilots on emission reduction, J. Environ. Manage., 314(2022), art. No. 115054.

[102] Li GC, Wang HJ, Wu AX, Jiao HZ, Wang FZ. Analysis of thickening performance of unclassified tailings in rakeless deep cone thickener. Chin. J. Eng., 2019, 41(1): 60.

[103] Yu GB, Yang P, Chen ZC, Men RY. Study on pipeline self-flowing transportation of cemented tailing fill slurry based on fluent software. Adv. Mater. Res., 2013, 734–737, 833.

[104] Bao YY, Li TC, Wang DF, Cai ZQ, Gao ZM. Discrete element method study of effects of the impeller configuration and operating conditions on particle mixing in a cylindrical mixer. Particuology, 2020, 49, 146.

[105] Qi CC, Fourie A, Chen QS, Zhang QL. A strength prediction model using artificial intelligence for recycling waste tailings as cemented paste backfill. J. Cleaner Prod., 2018, 183, 566.

[106] Łaźniewska-Piekarczyk B. The influence of selected new generation admixtures on the workability, air-voids parameters and frost-resistance of self compacting concrete. Constr. Build Mater., 2012, 31, 310.

[107] Qi CC, Yang XY, Li GC, Chen QS, Sun YT. Research status and perspectives of the application of artificial intelligence in mine backfilling. J. China Coal Soc., 2021, 46(2): 688.

[108] Chang PK, Peng YN. Influence of mixing techniques on properties of high performance concrete. Cem. Concr. Res., 2001, 31(1): 87.

[109] Jordan MI, Mitchell TM. Machine learning: Trends, perspectives, and prospects. Science, 2015, 349(6245): 255.

[110] X.B. Qin, L. Liu, P. Wang, M. Wang, and J. Xin, Microscopic parameter extraction and corresponding strength prediction of cemented paste backfill at different curing times, Adv. Civ. Eng., 2018(2018), art. No. 2837571.

[111] C.C. Qi, Q.S. Chen, and S.S. Kim, Integrated and intelligent design framework for cemented paste backfill: A combination of robust machine learning modelling and multi-objective optimization, Miner. Eng., 155(2020), art. No. 106422.

[112] Huang QH, Jiang ZL, Zhang WP, Gu XL, Dou XJ. Numerical analysis of the effect of coarse aggregate distribution on concrete carbonation. Constr. Build. Mater., 2012, 37, 27.

[113] Wang BJ, Wang W, Qi C, Kuang YW, Xu JW. Simulation of performance of intermediate fluid vaporizer under wide operation conditions. Front. Energy, 2020, 14(3): 452.

[114] Kozić MS, Ristić SS, Linić SL, Hil T, Stetić-Kozić S. Numerical analysis of rotational speed impact on mixing process in a horizontal twin-shaft paddle batch mixer with non-Newtonian fluid. FME Trans., 2016, 44(2): 115.

[115] Gao RG, Zhou KP, Zhou YL, Yang C. Research on the fluid characteristics of cemented backfill pipeline transportation of mineral processing tailings. Alex. Eng. J., 2020, 59(6): 4409.

[116] Ś. Krzeszowski and P. Grajper, Application of dedicated software for balancing water systems of a deep mine, Appl. Water Sci., 12(2022), No. 6, art. No. 139.

[117] Cai MF, Tan WH, Wu XH, Zhang LP. Current situation and development strategy of deep intelligent mining in metal mines. Chin. J. Nonferrous Met., 2021, 31(11): 3409.

[118] H. Agrawal, S. Durucan, W.Z. Cao, A. Korre, and J.Q. Shi, Rockburst and gas outburst forecasting using a probabilistic risk assessment framework in longwall top coal caving faces, Rock Mech. Rock Eng., (2022), p. 1.

[119] Wu AX, Wang HJ, Yin SH, Ruan ZE. Conception of in-situ fluidization mining for deep metal mines. J. Min. Sci. Technol., 2021, 6(3): 255.

[120] M.F. Yuan, Study and application of mobile backfilling system in the underground metal mine, Met. Mine, 2011, No. 9, p. 5.

[121] A. Szczurek, M. Maciejewska, M. PrzybyŁa, and W. Szetelnicki, Improving air quality for operators of mobile machines in underground mines, Atmosphere, 11(2020), No. 12, art. No. 1372.