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Sun X, Zhao Y, Sun Y, Ma Z, Qiu J, Xing J. Stabilization of Pb/Zn mine tailings by modified fly ash: characterization, performance, and mechanism. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34513-1. [PMID: 39190247 DOI: 10.1007/s11356-024-34513-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 07/23/2024] [Indexed: 08/28/2024]
Abstract
The presence of heavy metals in mine tailings poses a serious threat to the surrounding environment. In this study, we aimed to stabilize Pb/Zn-containing mine tailings using modified fly ash (FA) with various alkali solutions. Notably, the modification of FA with Na2SiO3 (NaSi-FA) resulted in the most significant structure changes. To understand the adsorption mechanism of Pb and Zn by modified FA, batch adsorption experiments were conducted. Doubling the adsorption capacity for both Pb and Zn was observed in the modified FA samples compared to unmodified samples. These results could be attributed to the enhanced surface area and porous structure, providing more anchor sites for the heavy metal ions. Additionally, the adsorption of Pb and Zn was found to follow the Langmuir isotherm and pseudo-second order kinetic. Molecular dynamics simulations further supported the notion that Pb and Zn ions could effectively exchange with Na ions within the N-A-S-H gel network, ultimately solidifying them in its structure. Stabilizing Pb/Zn tailings with NaSi-FA resulted in a significant decrease in the leaching of Pb and Zn. Specifically, the leading amount decreased by 55.2% for Pb and 35.3% for Zn, showcasing the superior performance of this stabilization method. This reduction in leaching indicates effective compliance with environmental regulations regarding the containment of Pb and Zn.
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Affiliation(s)
- Xiaogang Sun
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Yingliang Zhao
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China.
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
| | - Yong Sun
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Zhengyu Ma
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Jingping Qiu
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Jun Xing
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
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Yang S, Wang H, Ruan Z, Liu H. Dynamic response and deformation failure microscopic characteristics of cyclic impact-cemented tailing backfill. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:42857-42874. [PMID: 38878246 DOI: 10.1007/s11356-024-33829-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/22/2024] [Indexed: 07/04/2024]
Abstract
Frequent blasting disruptions can lead to cumulative damage within the cemented tailing backfill (CTB), increasing the risks associated with mining operations and reducing the recovery rate of the pillar. To address this issue, the Split Hopkinson Pressure Bar (SHPB) was utilized to conduct cyclic impact tests on CTB containing various cement tailing ratios (CTR) at different curing ages. The tests analyzed the stress-strain curve law, dynamic compressive strength (DCS), dynamic strength increase factor (DIF), absorption energy, and deformation failure characteristics of CTB under different impact velocities. Additionally, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) were employed to investigate the internal pore structural properties of CTB. The research findings indicate that (1) Average strain rate exhibits a linear relationship with the DCS and impact velocity. A lower number of impacts occurred at higher impact velocities and shorter curing age. The number of impacts was drastically reduced when the impact velocity surpassed 3 m/s. As the CTR increased, the number of impacts also increased. When the number of impacts increased, the elastic modulus, dynamic impact strength, and peak strain initially increased before ultimately decreasing. (2) Under the cyclic impact load, the shear failure and axial splitting failure were the main failure modes of CTB. Increasing the CTR may be a more effective strategy for reducing the degree of CTB fragmentation compared to prolonging the curing age. When the impact velocity is lower than 3 m/s, CTB can withstand multiple impacts and maintain high levels of integrity. When the DIF of the first shock is below 1.5, the CTB demonstrates a capability to withstand more than four shocks. If the DIF exceeds 2, the CTB can only endure a single shock. (3) NMR and SEM observations revealed that CTB itself contains more pores. A dense network structure will grow inside CTB as the curing age and CTR are increased, reducing the porosity. The pore size observed in the samples also support that increasing CTR may be a more effective strategy. Our findings contribute to a better understanding of the kinetic response of CTB in deep mines under frequent blasting disruption and offer a valuable reference point for future research in this area.
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Affiliation(s)
- Shixing Yang
- School of Civil and Resources Engineering, University of Science and Technology Beijing, No.30 Xueyuan Road, Haidian District, Beijing, 100083, People's Republic of China.
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China.
| | - Hongjiang Wang
- School of Civil and Resources Engineering, University of Science and Technology Beijing, No.30 Xueyuan Road, Haidian District, Beijing, 100083, People's Republic of China
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Zhuen Ruan
- School of Civil and Resources Engineering, University of Science and Technology Beijing, No.30 Xueyuan Road, Haidian District, Beijing, 100083, People's Republic of China
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing, 100083, People's Republic of China
| | - Hongbin Liu
- Department of Civil Engineering, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada
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Zhang S, Zhang X, Bai H, Wang K. Resource utilization of stone waste and loess to prepare grouting materials. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120452. [PMID: 38401503 DOI: 10.1016/j.jenvman.2024.120452] [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: 10/09/2023] [Revised: 01/12/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Loess, a terrestrial clastic sediment, is formed essentially by the accumulation of wind-blown dust, while stone waste (SW) is an industrial waste produced during stone machining. Utilising loess and SW to prepare environmentally-friendly supplementary cementitious materials can not only address environmental issues caused by solid waste landfills but also meet the demand of reinforcement of coal-seam floor aquifer for grouting materials. In this paper, the effects of the loess/SW mass ratio and calcination temperature on the transformation of calcined products are investigated and their pozzolanic activities are evaluated. The workability, environmental impact and cost of grouting materials based on cement and calcined products are also assessed. Experimental results reveal that higher temperatures favour the formation of free lime and periclase, which tend to be involved in solid-state reactions. Higher temperature and loess/SW mass ratio strengthens the diffraction peaks of dodecalcium hepta-aluminate (C12A7), dicalcium ferrite (C2F) and dicalcium silicate (C2S). The clay minerals in loess become completely dehydroxylated before 825 °C, generating amorphous SiO2 and Al2O3. Covalent Si-O bonds are interrupted and that disordered silicate networks are generated in the calcined products, which is confirmed by the increased strength of the Si29 resonance region at -60 ppm to -80 ppm. Although co-calcined loess and SW contain the most four-fold aluminium at 950 °C, recrystallisation depresses the pozzolanic activity. Hence, the loess/SW sample designated LS2-825 exhibits the better hydration activity. Additionally, grouting materials composed of cement and LS2-825 exhibit good setting times, fluidity, strength and a low carbon footprint in practical engineering applications, and they also provide the additional benefit of being cost effective.
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Affiliation(s)
- Shiyu Zhang
- School of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Xiaoqiang Zhang
- School of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
| | - Hao Bai
- School of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Kai Wang
- School of Mining Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
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Ju Y, Nie X, Zhu Y, Wang K, Zhou H, Ge S. Stress distribution and roof subsidence of surrounding strata considering in situ coal conversion and CO 2 mineralization backfilling: Photoelastic experiments using 3D-printed models of mining faces and goafs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169368. [PMID: 38104844 DOI: 10.1016/j.scitotenv.2023.169368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 12/04/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Coal, a reliable and economical fuel, is expected to remain the primary energy source for power generation for the foreseeable future. However, conventional mining and utilization of coal has caused environmental degradation and infrastructure damage. An in situ coal conversion method has been proposed to mitigate environmental problems and reduce CO2 emissions resulting from coal extraction and utilization. This method involves the in situ conversion and utilization of coal, backfilling of waste rock, and CO2 mineralization to backfill the goaf. In this study, the impact of mining and conversion activities on the surrounding strata was evaluated to ascertain the effectiveness and advantages of the in situ coal conversion method. Transparent stope models were created using three-dimensional printing technology. The stress distribution and deformation characteristics of the surrounding strata were examined using photoelasticity and digital image correlation methods. The results were compared with those obtained using the traditional backfill mining method. The comparison revealed that the disturbance to the surrounding strata was 14.4 times less in the in situ conversion method than in the traditional backfill mining method. Additionally, the disturbance height at the roof and the disturbance depth at the floor were 4.2 and 2.1 times lower, respectively. The roof subsidence in the in situ conversion method was 1.97 times less than that in the traditional backfill mining method. These results confirm the advantages of minimizing the disturbance to surrounding rocks and controlling the subsidence of roof strata.
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Affiliation(s)
- Yang Ju
- State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China; School of Energy and Mining Engineering, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China; School of Mechanics and Civil Engineering, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China.
| | - Xiaodong Nie
- School of Mechanics and Civil Engineering, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China
| | - Yan Zhu
- China Academy of Safety Science and Technology, 32 Beiyuan Road, Beijing 100012, China
| | - Kai Wang
- School of Emergency Management and Safety Engineering, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China
| | - Hongwei Zhou
- School of Energy and Mining Engineering, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China
| | - Shirong Ge
- School of Artificial Intelligence, China University of Mining & Technology, D11 Xueyuan Road, Beijing 100083, China
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Zhao L. Immobilization of Cr(VI)-containing tailings by using slag-cementing materials for cemented paste backfill: influence of sulfate and limestone addition. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:91984-91996. [PMID: 37479941 DOI: 10.1007/s11356-023-28605-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/01/2023] [Indexed: 07/23/2023]
Abstract
Heavy metals in mine tailings lead to serious environmental problems. Cemented paste backfill (CPB) is widely used for treating the mine tailing. The high cost of ordinary Portland cement (OPC) reduces the profit of mine production. The work investigates the treatment of Cr(VI)-containing tailings by using slag-based cementitious materials for CPB. Flue gas desulfurization gypsum (FGDG) and limestone were used to modify the properties of samples. Results showed that the coupling addition of 6 wt% FGDG and 3 wt% limestone (A6L3) led to the highest compressive strength of CPB samples, which also presented satisfactory immobilization effects for Cr(VI). The compressive strength of CPB samples using A6L3 as a binder was comparable to the OPC-based sample, reaching about 5.53 MPa; the immobilization efficiency for Cr(VI) was about 99.5%. The effects of FGDG and limestone were twofold: the addition of FGDG favored the formation of ettringite and then contributed to a more compact structure; besides, incorporating limestone increased the packing density of the CPB system by decreasing the loosening and wedge effect.
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Affiliation(s)
- Liding Zhao
- Department of Mining Engineering, Luliang University, Lvliang, 033000, China.
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Song X, Dong Z, Hao Y, Wang S, Li J, Yuan Q. Study on mechanical properties and damage characteristics of rice straw fiber-reinforced cemented tailings backfill based on energy evolution. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:45295-45314. [PMID: 36705829 DOI: 10.1007/s11356-023-25515-6] [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: 09/07/2022] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Low-cost and underutilized plant fibers can affect the mechanical behavior of cementitious materials such as cemented tailings backfill (CTB). This paper attempts to explore the mechanical properties and damage evolution characteristics of rice straw fiber (RFS)-reinforced CTB (RSFCTB) from the perspective of energy. A series of mechanical and microscopic tests were carried out on CTB and RSFCTB samples. On this basis, the energy evolution law and of the filling body under different stress paths were analyzed. Meanwhile, a damage variable based on dissipation energy was established, and the damage evolution process of the filling body was discussed. The results show that uniaxial compressive strength (UCS) of filling body first grew and then dropped with the enhancement of RSF content, and indirect tensile strength (ITS) was positively correlated with RSF content. Scanning electron microscope showed that RSF was encapsulated by hydration products, which promoted the bridging effect of RSF. The bridging effect of RSF improved the integrity of RSFCTB after compression failure and resulted in bending and asymmetric tensile cracks after tensile failure. The energy storage limit and dissipation energy of the filling body under different stress paths were enhanced due to the incorporation of RSF. The damage curve based on dissipation energy showed three stages of slow, steady, and fast damage under compressive loading. The damage curve of RSFCTB was located below CTB depending on the crack arresting effect of RSF. Moreover, the damage curve under tensile load shows three stages: slow, stable damage, and sudden increase in damage. The damage value of RSFCTB at the mutation point was increased, and the ability of RSFCTB to resist tensile damage was enhanced. The energy evolution and acoustic emission parameters were combined, and their development trends were similar, which proved that it was reasonable to characterize the damage of filling body based on the dissipated energy.
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Affiliation(s)
- Xuepeng Song
- School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
| | - Zilin Dong
- School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Yuxin Hao
- School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Shi Wang
- School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, China
| | - Junbiao Li
- School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Quan Yuan
- School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
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7
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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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8
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Zhang H, Kou J, Sun C, Wang P, Lin J, Li J, Jiang Y. Optimization of cemented paste backfill with carbon nanotubes as a sustainable treatment for lead-containing tailings. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.118152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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9
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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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Zhao Y, Gu X, Qiu J, Zhang S, Guo Z, Sun X. Recycling of arsenic-containing biohydrometallurgy waste to produce a binder for cemented paste backfill: Co-treatment with oil shale residue. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115621. [PMID: 35849925 DOI: 10.1016/j.jenvman.2022.115621] [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: 12/14/2021] [Revised: 06/10/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The high cost of ordinary Portland cement (OPC) limits the broad usage of cemented paste backfill (CPB). Additionally, improper disposal of arsenic-containing biohydrometallurgy waste (BW) can cause tremendous pollution to the environment. Consequently, BW is used to prepare an alternative cementitious material for CPB in this study. The effect of calcined oil shale residue (COSR) on the binder's characteristics was studied. The reaction kinetics of the binder in the presence of COSR were studied via the isothermal calorimeter test and the Krstulovic-Dabic model; mechanical strength and hydration product modifications due to the addition of COSR were also investigated. The leaching of hazardous elements from the binder was also investigated. The results showed that adding COSR reduced the flowability of fresh slurry and early-age compressive strength; however, adding 20 wt% COSR resulted in the highest later age compressive strength, thereby reaching ∼43.65 MPa after 60 days. The compressive strength of the CPB sample using the COSR20 as a binder may reach ∼87% of the OPC-based CPB sample. Furthermore, the presence of COSR had no significant effect on the phase assembles but changed the amount of ettringite (AFt) and calcium silicate aluminate hydrate (C-A-S-H). The results of this study show that the prepared binder could be used as an alternative to OPC in CPB.
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Affiliation(s)
- Yingliang Zhao
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
| | - Xiaowei Gu
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China.
| | - Jingping Qiu
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China.
| | - Shiyu Zhang
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; College of Mining Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Zhenbang Guo
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
| | - Xiaogang Sun
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China; Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
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Sun Y, Zhao Y, Qiu J, Zhang S, Sun X, Gu X. Preparation and characterization of a new alkali-activated binder for superfine-tailings mine backfill. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:73115-73130. [PMID: 35622277 DOI: 10.1007/s11356-022-20746-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Recently, the increasing of ultrafine-tailings increases the amount of ordinary Portland cement (OPC) in cemented paste backfill (CPB), which leads to the rise of CPB cost and carbon emission. As a result, it is necessary to develop alternative binders. The present work focuses on the preparation of a new binder, which is activated by a mixture of calcined quarry dust (CQD) and NaOH at a mass ratio of 1:1. The results indicated that CQD/NaOH was more effective than using NaOH or CQD alone in activating blast furnace slag (BFS) and also showed better performance than OPC. The compressive strength of the CPB samples using 10% CQD/NaOH was around 3.78 MPa after curing for 90 days, around 42% higher than the OPC-based CPB samples. The reaction products of CQD/NaOH-activated BFS consisted mainly of C-(A)-S-H, hydrotalcite like phases (Ht), and M-S-H. The generation of Ht phases lowered the Al incorporation into the structure of C-S-H, resulting in lower average Al/Si ratio and mean chain length.
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Affiliation(s)
- Yong Sun
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
- Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
| | - Yingliang Zhao
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China.
- Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China.
| | - Jingping Qiu
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
- Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
| | - Shiyu Zhang
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
- College of Mining Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Xiaogang Sun
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
- Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
| | - Xiaowei Gu
- College of Resources and Civil Engineering, Northeastern University, Shenyang, China
- Science and Technology Innovation Center of Smart Water and Resource Environment, Northeastern University, Shenyang, China
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Synthesis of a Magnetic Carnation-like Hydroxyapatite/Basic Calcium Carbonate Nanocomposite and Its Adsorption Behaviors for Lead Ions in Water. Molecules 2022; 27:molecules27175565. [PMID: 36080330 PMCID: PMC9457816 DOI: 10.3390/molecules27175565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/17/2022] Open
Abstract
Calcium-enriched compounds have great potential in the treatment of heavy-metal contaminated wastewater. Preparing stable basic calcium carbonate (BCC), which is a calcium-enriched compound, and applying it in practice is a great challenge. This work investigated the formation process of hierarchical hydroxyapatite (HAP)/BCC nanocomposites and their adsorption behaviors regarding lead ions (Pb2+). The morphology of the HAP/BCC nanocomposite was controlled by the addition of monododecyl phosphate (MDP). The carnation-like HAP/BCC nanocomposite was achieved with the addition of 30 g of MDP. The carnation-like HAP/BCC nanocomposite had a high Pb2+ adsorption capacity of 860 mg g−1. The pseudo-second-order and Freundlich model simulation results indicated that the adsorptions of Pb2+ on the nanocomposites belonged to the chemisorption and multilayer adsorption processes. The main effective adsorption components for the nanocomposites were calcium-enriched HAP and BCC. Through the Ca2+ ions exchanging with Pb2+, the HAP and BCC phases were converted to hydroxyl-pyromorphite (Pb-HAP) and hydrocerussite (Pb3(CO3)2(OH)2), respectively. The carnation-like HAP/BCC nanocomposite has great potential in the treatment of heavy metal ions. This facile method provides a new method for preparing a stable HAP/BCC nanocomposite and applying it in practice.
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Shi X, Wang X, Wang X. Dual waste utilization in cemented paste backfill using steel slag and mine tailings and the heavy metals immobilization effects. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117413] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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14
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Li Y, Ni W, Gao W, Zhang S, Fu P, Li Y. Study on Solidification and Stabilization of Antimony-Containing Tailings with Metallurgical Slag-Based Binders. MATERIALS 2022; 15:ma15051780. [PMID: 35269012 PMCID: PMC8911367 DOI: 10.3390/ma15051780] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 02/01/2023]
Abstract
Blast furnace slag (BFS), steel slag (SS), and flue gas desulfurized gypsum (FGDG) were used to prepare metallurgical slag-based binder (MSB), which was afterwards mixed with high-antimony-containing mine tailings to form green mining fill samples (MBTs) for Sb solidification/stabilization (S/S). Results showed that all MBT samples met the requirement for mining backfills. In particular, the unconfined compressive strength of MBTs increased with the curing time, exceeding that of ordinary Portland cement (OPC). Moreover, MBTs exhibited the better antimony solidifying properties, and their immobilization efficiency could reach 99%, as compared to that of OPC. KSb(OH)6 was used to prepare pure MSB paste for solidifying mechanism analysis. Characteristics of metallurgical slag-based binder (MSB) solidified/stabilized antimony (Sb) were investigated via X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). According to the results, the main hydration products of MSB were C-S-H gel and ettringite. Among them, C-S-H gel had an obvious adsorption and physical sealing effect on Sb, and the incorporation of Sb would reduce the degree of C-S-H gel polymerization. Besides, ettringite was found to exert little impact on the solidification and stabilization of Sb. However, due to the complex composition of MSB, it was hard to conclude whether Sb entered the ettringite lattice.
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Affiliation(s)
- Yunyun Li
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China; (Y.L.); (S.Z.); (P.F.); (Y.L.)
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
| | - Wen Ni
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China; (Y.L.); (S.Z.); (P.F.); (Y.L.)
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
- Correspondence:
| | - Wei Gao
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Siqi Zhang
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China; (Y.L.); (S.Z.); (P.F.); (Y.L.)
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
| | - Pingfeng Fu
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China; (Y.L.); (S.Z.); (P.F.); (Y.L.)
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
| | - Yue Li
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China; (Y.L.); (S.Z.); (P.F.); (Y.L.)
- Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 10083, China;
- Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, University of Science and Technology Beijing, Beijing 10083, China
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A Joint Experiment and Discussion for Strength Characteristics of Cemented Paste Backfill Considering Curing Conditions. MINERALS 2022. [DOI: 10.3390/min12020211] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As lots of underground mines have been exploited in the past decades, many stope instability and surface subsidence problems are appeared in the underground mines, while the cemented paste backfill (CPB) technology has been applied for more than 40 years, and it can solve these problems. As it is shown that the effect of backfilling is mainly affected by the mechanical properties of the CPB, and there are lots of factors which can influence the strength of the CPB, but the coupled effects of curing conditions has not been reported. In this research, the coupled effects of curing conditions are importantly considered, and the uniaxial compressive strength (UCS) is adopted as the important evaluation index of CPB, then the evolution law of the UCS for CPB are analyzed, also the mathematical strength model of CPB is established. The findings suggest that the relationship between the UCS of CPB and curing stress develops the function of quadratic polynomial with one variable, while the UCS of the CPB shows the power function as the curing temperature increases. Moreover, the established mathematical strength model is verified on the basis of laboratory experiments, the error between the measured UCS and the prediction UCS is less than 15%. It shows that the established strength model of the CPB by considering the curing conditions can predict the UCS very well, it has great significance for the safety design of CPB.
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