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Yang B, Wang X, Gu C, Yang F, Liu H, Jin J, Zhou Y. The Failure Mechanical Properties of Cemented Paste Backfill with Recycled Rubber. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093302. [PMID: 37176184 PMCID: PMC10178953 DOI: 10.3390/ma16093302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023]
Abstract
Understanding the mechanical properties and failure process of cemented paste backfill with recycled rubber (RCPB) is the foundation of backfill design in underground mining. In this study, physical and mechanical tests were conducted on RCPB to obtain its mechanical property parameters, such as its uniaxial compressive strength (UCS), toughness, and peak strain. The influence of the rubber dosage on the mechanical properties of RCPB was also analyzed. In addition, the deformation behavior, fracture development, and failure process of RCPB with different rubber contents were observed using the digital image correlation (DIC) technique. The experimental results suggested that, although the UCS of RCPB is reduced as more rubber is added, its toughness and ability to absorb energy is increased. Moreover, the impact resistance of RCPB is improved by this increased toughness. With the increase in the rubber content, the deformation corresponding to the plastic yield stage of RCPB increased, which resulted in better ductility and improved impact resistance. The failure of the RCPB specimens mainly showed an "X" shape. The results of this study help us to better understand the mechanical behavior of RCPB after backfilling underground.
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Affiliation(s)
- Baogui Yang
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Xiaolong Wang
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Chengjin Gu
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Faguang Yang
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Hao Liu
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Junyu Jin
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
| | - Yibo Zhou
- School of Energy and Mining Engineering, China University of Mining and Technology, Beijing 100083, China
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Chen SM, Yilmaz E, Xiang ZG, Wang YM. Curing conditions effect on pore structure, compressive strength and elastic modulus of cementitious tailings backfills. POWDER TECHNOL 2023. [DOI: 10.1016/j.powtec.2023.118458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
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Zhu C, Zhang J, Taheri A, Zhou N, Li Z, Li M. Control effect of coal mining solid-waste backfill for ground surface movement in slice mining: a case study of the Nantun Coal Mine. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:27270-27288. [PMID: 36380178 DOI: 10.1007/s11356-022-24164-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Management of solid waste and protecting the ecological balance of the region are key challenges that the coal mining industry has to face. This study evaluated the effect of solid waste backfilling mining on the overlying strata movement and surface deformation variation pattern in slice mining. The mechanical characteristics of different cemented paste backfills (CPB) were compared. The CPB specimens were made of coal gangue and cement with or without the addition of fly ash. The experiments showed that the mechanical strength of the CPBs made of coal gangue and cement increased dramatically. A numerical simulation was then performed to analyze the variation patterns of the overlying strata displacement and surrounding rock stress distribution before and after filling the 3lower and 3upper coal seams with CPB. The CPBs reduced the movement of the surface by 95.1% and 95% during the mining of the 3lower and 3upper coal seams, respectively. Finally, we used a mining-induced subsidence prediction and analysis system to predict the influence of the 3lower and 3upper coal seams on the ground surface subsidence. It was found that the ground surface subsidence induced by CPB mining was 1/20 that of the cumulative ground surface subsidence caused by caving mining. CPB mining could effectively control the ground surface subsidence caused by multi-slice mining of the thick coal seam, offering protection for buildings above the ground. Our research provides theoretical and technical support for coal mining under buildings subjected to similar conditions.
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Affiliation(s)
- Cunli Zhu
- School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China.
- State Key Laboratory of Coal Resources and Safe Mining, Xuzhou, 221116, Jiangsu, China.
| | - Jixiong Zhang
- School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China
- State Key Laboratory of Coal Resources and Safe Mining, Xuzhou, 221116, Jiangsu, China
| | - Abbas Taheri
- Robert M Buchan Dept Min, Queens Univ, Kingston, ON, Canada
| | - Nan Zhou
- School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China
- State Key Laboratory of Coal Resources and Safe Mining, Xuzhou, 221116, Jiangsu, China
| | - Zejun Li
- School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China
- State Key Laboratory of Coal Resources and Safe Mining, Xuzhou, 221116, Jiangsu, China
| | - Meng Li
- School of Mines, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China
- State Key Laboratory of Coal Resources and Safe Mining, Xuzhou, 221116, Jiangsu, China
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Jiang H, Ren L, Gu X, Zheng J, Cui L. Synergistic effect of activator nature and curing temperature on time-dependent rheological behavior of cemented paste backfill containing alkali-activated slag. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:12857-12871. [PMID: 36114965 DOI: 10.1007/s11356-022-23053-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
Cemented paste backfill (CPB) that contains alkali-activated slag (AAS) produces more desirable properties and performance (enhanced fluidity, higher strength, lower cost, and limited carbon emission) as compared with CPB made with cement. Significant efforts have been devoted to the study of the effect of the individual factor on the rheology of AAS-CPB. However, the synergistic effect of curing temperature, time, and activator nature is still unclear. Therefore, the current research aims to investigate the time-dependent rheology of AAS-CPB under the combined influence of curing temperature, silica modulus (Ms), and activator concentration (AC). The findings revealed that a higher curing temperature results in a reduction in fluidity and an increase in the thixotropy of CPB. The evolution of rheological parameters of AAS-CPB is more insensitive to the curing temperature as compared to that of OPC-CPB. During the initial 2 h, higher AC can weaken the rheological parameter. However, a more rapid growth rate of rheological properties was observed after 2 h. The rheological parameters of AAS-CPB with higher Ms are always lower than those of AAS-CPB with lower Ms at all temperatures studied. In addition, the discrepancy in the linear correlation between thixotropy and plastic viscosity for OPC-CPBs and AAS-CPBs indicates the different hydration rates of slag and Portland cement. These findings are beneficial in guiding the mix proportion design of AAS-CPB in mines with various underground temperatures.
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Affiliation(s)
- Haiqiang Jiang
- Key Laboratory of Ministry of Education On Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, 110819, China
- Key Laboratory of Deep Coal Resource Mining, Ministry of Education, China University of Mining and Technology, Xuzhou, 221116, China
| | - Lei Ren
- Key Laboratory of Ministry of Education On Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, 110819, China
| | - Xiaozhong Gu
- Key Laboratory of Ministry of Education On Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, 110819, China
| | - Jingru Zheng
- Key Laboratory of Ministry of Education On Safe Mining of Deep Metal Mines, Northeastern University, Shenyang, 110819, China
| | - Liang Cui
- Department of Civil Engineering, Lakehead University, Thunder Bay, ON, P7B5E1, Canada.
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Yue C, Liguo X, Zhiyun Z, Xiangling W. Modification of cemented paste backfill with calcined layered double hydroxides for lead-containing tailings disposal. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.118089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kasap T, Yilmaz E, Sari M. Physico-chemical and micro-structural behavior of cemented mine backfill: Effect of pH in dam tailings. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 314:115034. [PMID: 35417837 DOI: 10.1016/j.jenvman.2022.115034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
The tailings created during ore processing have been a serious problem for mining companies and environment since it is a challenging task to effectively manage these highly voluminous/dangerous tailings. Therefore, several tailings disposal methods like tailings dams are needed for sustainable mining operations. The tailings accumulated in the dams reflect a critical raw material source since they might contain key base/precious metals, such as Au, Ag, Co, Ni, Cu and Zn. This study deals with the use-ability of dam tailings in cemented mine/paste backfill (CMB/CPB), considering the physico-chemical and micro-structural aspects. The backfill mixtures were manufactured at 76 wt% solid and 5 wt% cement contents, exposed to cure for up to 56 days, and tested for determining their strength (UCS), geo-chemical (i.e., pH, redox potential, and conductivity) and microstructure (i.e., XRD, TGA, and SEM) characteristics. Results disclosed that the strength of backfill was improved by the augmented basicity/age while only backfills made with sulfide-rich tailings had a noticeable drop in strength. This can be enlightened by the types of tailings (aged and fresh), and the hydration products shaped owing to the interaction of these tailings mixed with cement. While the values of pH detected by chemical tests were amplified up to 14 days, some decreased up to 56 days due to acid formations and erosions. This is the key function of CPB's deterioration physically, chemically, and microstructurally. Lastly, the outcomes of this study will allow us to further explore/assess the effects of dam tailings' potential usages on quality/performance of backfill mixtures.
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Affiliation(s)
- Tugrul Kasap
- Geotechnical, Waste Management and Backfill Laboratory, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey; Institute of Graduate Studies, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey
| | - Erol Yilmaz
- Geotechnical, Waste Management and Backfill Laboratory, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey; Department of Civil Engineering, Geotechnical Division, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey.
| | - Muhammet Sari
- Geotechnical, Waste Management and Backfill Laboratory, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey; Institute of Graduate Studies, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey; Department of Civil Engineering, Geotechnical Division, Recep Tayyip Erdogan University, Fener, Rize, TR53100, Turkey
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Recent Developments in Steelmaking Industry and Potential Alkali Activated Based Steel Waste: A Comprehensive Review. MATERIALS 2022; 15:ma15051948. [PMID: 35269179 PMCID: PMC8911774 DOI: 10.3390/ma15051948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 02/28/2022] [Accepted: 03/03/2022] [Indexed: 01/14/2023]
Abstract
The steel industry is responsible for one-third of all global industrial CO2 emissions, putting pressure on the industry to shift forward towards more environmentally friendly production methods. The metallurgical industry is under enormous pressure to reduce CO2 emissions as a result of growing environmental concerns about global warming. The reduction in CO2 emissions is normally fulfilled by recycling steel waste into alkali-activated cement. Numerous types of steel waste have been produced via three main production routes, including blast furnace, electric arc furnace, and basic oxygen furnace. To date, all of the steel waste has been incorporated into alkali activation system to enhance the properties. This review focuses on the current developments over the last ten years in the steelmaking industry. This work also summarizes the utilization of steel waste for improving cement properties through an alkali activation system. Finally, this work presents some future research opportunities with regard to the potential of steel waste to be utilized as an alkali-activated material.
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Jiang H, Ren L, Zhang Q, Zheng J, Cui L. Strength and microstructural evolution of alkali-activated slag-based cemented paste backfill: Coupled effects of activator composition and temperature. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117322] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Cavusoglu I, Yilmaz E, Yilmaz AO. Sodium silicate effect on setting properties, strength behavior and microstructure of cemented coal fly ash backfill. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.02.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Editorial for Special Issue: Alkali Activated Materials: Advances, Innovations, Future Trends. MINERALS 2021. [DOI: 10.3390/min11010075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alkali activated materials (AAMs), also named geopolymers or inorganic polymers, are materials that are produced when alkaline solutions react with precursors containing aluminosilicate phases [...]
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Influence of Solid Content, Cement/Tailings Ratio, and Curing Time on Rheology and Strength of Cemented Tailings Backfill. MINERALS 2020. [DOI: 10.3390/min10100922] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Understanding the flow process of cemented tailings backfill (CTB) is important for successful pumping into underground stopes. This study examines the effects of solid content (SC), cement/tailings (c/t) ratio, and curing time (CT) on rheological and mechanical properties of CTB mixes. The slurry concentration of the mixes was 65, 67, and 69 wt. %, with c/t ratios ranging from 1:4 to 1:20. Unconfined compressive strength (UCS) tests were performed on hardened CTB mixes after curing 3, 7, and 28 days. The rheological properties of CTB slurries are mainly related to SC. The yield stress and viscosity of fresh mixes increase with increasing SC, but the pipeline resistance loss (PRL) also increases with increasing SC. According to the analysis of variance, the SC and flow rate are the most significant parameters which greatly affect the PRL performance. The c/t and CT parameters are the most significant parameters for affecting the shrinkage rate. The findings offer a reference for theoretical optimization for mine filling systems of similar type.
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