Numerical simulation on thermal accumulation of cemented tailings backfill

Abstract

Based on the collaborative exploitation of deep mineral resources and geothermal resources, the thermal accumulation process of cemented tailings backfill (CTB) was studied by numerical simulation. The effects of thermal accumulation time, slurry proportions and temperature conditions on the thermal accumulation of backfill are analyzed, the influence of the heat conduction between backfill and surrounding rock, the heat convection between backfill and airflow on thermal accumulation were compared simultaneously. The results show that the total thermal accumulation capacity increases by approximately 85% within 10–90 d. The influence of surrounding rock temperature and initial temperature on total thermal accumulation capacity is more significant and it is approximately 2 times of the influence of slurry proportions under the conditions of this study. It is clear that the rise of surrounding rock temperature and the decrease of initial temperature can improve the thermal accumulation capacity more effectively. Moreover, the heat conduction accounts for a considerable proportion in the process of thermal accumulation, the average heat conduction capacity is approximately 25 times of the heat convection capacity. This study can provide the theoretical basis and application reference for the optimization of thermal accumulation process of CTB in the exploitation of geothermal resources.

Keywords

cemented tailings backfill / thermal accumulation / heat conduction / heat convection / total thermal accumulation capacity

References

[1] DudkaA, AdrianoD A. Environmental impacts of metal ore mining and processing: A Review [J]. Jounal of Environmental Quality, 1997, 25: 590-602

[2] RanjithP G, ZhaoJ, JuM H, DeS R V S, RathnaweeraT D, BandaraA K M S. Opportunities and challenges in deep mining: A brief review [J]. Engineering, 2017, 3: 546-551

[3] LuoL-Q, LiK-Y, WengF, LiuC, YangS-Y. Preparation, characteristics and mechanisms of the composite sintered bricks produced from shale, sewage sludge, coal gangue powder and iron ore tailings [J]. Construction and Building Materials, 2020, 232: 117250

[4] CuiL, FallM. An evolutive elasto-plastic model for cemented paste backfill [J]. Computers and Geotechnics, 2016, 7119-29

[5] LiL. A generalized solution for mining backfill design [J]. International Jounal of Geomechanics, 2014, 14(3): 1-11

[6] YinS-H, WuA-X, HuK-J, WangY, ZhangY-K. The effect of solid components on the rheological and mechanical properties of cemented paste backfill [J]. Minerals Engineering, 2012, 35: 61-66

[7] YinS-H, ShaoY-J, WuA-X, WangH-J, LiuX-H, WangY. A systematic review of paste technology in metal mines for cleaner production in China [J]. Jounal of Cleaner Production, 2020, 247: 119590

[8] WangY, FallM, WuA-X. Initial temperature-dependence of strength development and self-desiccation in cemented paste backfill that contains sodium silicate [J]. Cement and Concrete Composites, 2016, 67101-110

[9] ErcikdiB, KesimalA, CihangirF, DeveciH, Alpİ. Cemented paste backfill of sulphide-rich tailings: Importance of binder type and dosage [J]. Cement and Concrete Composites, 2009, 31: 268-274

[10] XieZ-P. Distribution law of high temperature mine’s thermal environment parameters and study of heat damage’s causes [J]. Procedia Engineering, 2012, 43: 588-593

[11] GaoY-G, LiuF-M. The study of thermal pollution disposal on the deep coal mine working face [C]. PACIIA, 2009, 2009: 304-307

[12] LiuL, XinJ, ZhangB, ZhangX-Y, WangM, QiuH-F, ChenL. Basic theories and applied exploration of functional backfill in mines [J]. Jounal of China Coal Society, 2018, 43: 1811-1820

[13] Ghoreishi-MadisehS A, HassaniF, AbbasyF. Numerical and experimental study of geothermal heat extraction from backfilled mine stopes [J]. Applied Thermal Engineering, 2015, 90: 1119-1130

[14] NiuY-S. Research on thermal energy recycling utilization in high temperature mines [J]. Procedia Engineering, 2015, 21: 389-395

[15] GuoP-Y, HeM-C, ZhengL-G, ZhangN. A geothermal recycling system for cooling and heating in deep mines [J]. Applied Thermal Engineering, 2017, 116: 833-839

[16] RodríguezR, DíazM B. Analysis of the utilization of mine galleries as geothermal heat exchangers by means a semi-empirical prediction method [J]. Renewable Energy, 2009, 34: 1716-1725

[17] AhmadS, RizviZ, KhanM A, AhmadJ, WuttkeF. Experimental study of thermal performance of the backfill material around underground power cable under steady and cyclic thermal loading [J]. Materials Today: Proceedings, 2019, 17: 85-95

[18] Al-AmeenY, IanakievA, EvansR. Recycling construction and industrial landfill waste material for backfill in horizontal ground heat exchanger systems [J]. Energy, 2018, 151: 556-568

[19] KayaciN, DemirH. Numerical modelling of transient soil temperature distribution for horizontal ground heat exchanger of ground source heat pump [J]. Geothermics, 2018, 73: 33-47

[20] TongC, LiX-L, DuanmuL, WangZ-S. Research on heat transfer characteristics of soil thermal storage in the non-heating Season [J]. Procedia Engineering, 2017, 205: 3293-3300

[21] WuX, LiuW, LuZ-Y, LiangP-L, JinG. Simulation on temperature variation characteristics of soil around buried pipe in process of heat storage and release [J]. Transactions of CASE, 2017, 33: 204-213

[22] ZhangL, XuP, MaoJ-C, TangX, LiZ-W, ShiJ-G. A low cost seasonal solar soil heat storage system for greenhouse heating: Design and pilot study [J]. Applied Thermal Engineering, 2015, 156: 213-222

[23] BernardesM A D S. On the heat storage in solar updraft tower collectors-Influence of soil thermal properties [J]. Solar Energy, 2013, 98: 49-57

[24] ChenH-B, DingH-W, LiuS-Y, WuW, ZhangL. Comparative study on heat and moisture transfer in soil heat charging at high temperature for various soils [J]. Energy Procedia, 2015, 75: 3148-3153

[25] WangL-H, ZouX-C, TaoH, SongJ, ZhengY. Experimental study on evolution characteristics of the heat storage of surrounding soil in subway tunnels [J]. Procedia Engineering, 2017, 205: 2728-2735

[26] LiW, LiX-G, ZhaoJ, HanM-X. Study on heat storage characteristics of soil and simulation [J]. Acta Energiae Solaris Sinica, 2009, 30: 1491-1495

[27] ZhangX-Y, LiuL, LiuL, LiuL, JiaY-H. Numerical simulation of heat release performance of filling body under condition of heat extracted by fluid flowing in buried tube [J]. Journal of Central South University, 2019, 26: 2160-2174

[28] ZhangX-Y, XuM-Y, LiuL, HuanC, ZhaoY-J, QiC-C, SongK-IL. Experimental study on thermal and mechanical properties of cemented paste backfill with phase change material [J]. Journal of Materials Research Technology, 2019, 9: 2164-2175

[29] ZhangX-Y, ZhaoM, LiuL, HuanC, ZhaoY-J, QiC-C, SongK-IL. Numerical sumulation on heat storage performance of backfill body based on tube-in-tube heat exchanger [J]. Construction and Building Materials, 2020, 265120340

[30] ZHANG Xiao-yan, XU Muyan, LIU Li, LIU Lang, WANG Mei, LI Hai-wei, SONG KI-IL. Numerical sumulation on heat storage performance of backfill body based on tube-in-tube heat exchanger [J]. Energies, 2020, 13. DOI: https://doi.org/10.3390/en13184755.