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Xie G, Suo Y, Liu L, Yang P, Qu H, Zhang C. Pore characteristics of sulfate-activated coal gasification slag cement paste backfill for mining. Environ Sci Pollut Res Int 2023; 30:114920-114935. [PMID: 37878178 DOI: 10.1007/s11356-023-30554-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/15/2023] [Indexed: 10/26/2023]
Abstract
With the mass production of coal-based solid waste, coal mine filling can effectively consume it. The coal gasification slag is modified and prepared as coal mine filling material to meet the relevant technical requirements, which can realize the recycling of coal mine → coal chemical industry → coal mine. In this paper, in order to explore the evolution law of the mechanical properties and pore structure characteristics of the modified coal gasification slag-cement cemented paste backfill (MCGS-CPB) prepared by sodium sulfate excitation coal gasification slag, a combined macro-meso-micro testing method is used. MCGS-CPB with different sodium sulfate contents (1~5%) were prepared and tested for uniaxial compressive strength (UCS), mercury intrusion (MIP) and microscopic tests. The results show that sodium sulfate has a significant effect on the UCS and pore structure characteristics of MCGS-CPB. The mechanical properties and pore structure characteristics of MCGS-CPB were best when sodium sulfate was doped at 3%; the mechanical properties and pore structure characteristics of MCGS-CPB were deteriorated when the addition of sodium sulfate is higher than 3%. On the meso-scale, when sodium sulfate was doped with 3%, the more harmful pores of MCGS-CPB gradually changed into harmless, less harmful, and harmful pores, and the macroscopic mechanical properties were gradually improved; when the addition of sodium sulfate is higher than 3%, the harmless, less harmful, and harmful pores of MCGS-CPB gradually changed into more harmful pores, and the macroscopic mechanical properties were deteriorated. On a microscopic scale, sodium sulfate can cause MCGS-CPB to form hydration products with expansion properties. The presence of a reasonable amount of sodium sulfate in the pores of MCGS-CPB is beneficial to the development of mechanical properties. However, excessive presence will lead to the formation of expansion stress, gradual formation of micro-expansion cracks, and deteriorate the macroscopic mechanical properties. Hence, the volcanic ash activity of coal gasification slag excited by external addition of sodium sulfate should not exceed 3%. This study provides a reference value for application ratio of sodium sulfate-stimulated MCGS-CPB used in coal mine filling design.
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Affiliation(s)
- Geng Xie
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China
- State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi'an, 710054, China
| | - Yonglu Suo
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China
- Research Center for Functional Backfill Technology in Mine, Xi'an, 710054, China
| | - Lang Liu
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China.
- Research Center for Functional Backfill Technology in Mine, Xi'an, 710054, China.
- State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi'an, 710054, China.
| | - Pan Yang
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China
- State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi'an, 710054, China
| | - Huisheng Qu
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China
- State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi'an, 710054, China
| | - Caixin Zhang
- Energy School, Xi'an University of Science and Technology, Xi'an, 710054, China
- State Key Laboratory of Green and Low-carbon Development of Tar-rich Coal in Western China, Xi'an, 710054, China
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Du G, Yang R, Yan F, Wei S, Ren D, Li X. Use of Microscopic Characteristics and Multielemental Fingerprinting Analysis to Trace Three Different Cultivation Modes of Medicinal and Edible Dendrobium officinale in China. Biol Trace Elem Res 2023; 201:1006-1018. [PMID: 35507137 DOI: 10.1007/s12011-022-03196-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/07/2022] [Indexed: 01/21/2023]
Abstract
The traceability of different cultivation modes is critical for ensuring the commercial viability of high-value Dendrobium officinale. In this study, by means of polarizing microscopy, SEM-EDX, ICP-MS and ICP-AES, the possibility of combining microscopic characteristics, multielemental analysis and multivariate statistical authenticity analysis was realized to determine the origins of the fresh stem and dried stem powder of D. officinale derived from three different cultivation modes from six provinces of China. The microscopic structure, chemical elements on the surface of the main microstructures and concentrations of Ca, K, Ba, Cs, As and Cu varied among specimens derived from different cultivation modes. The fresh stems of D. officinale derived from different cultivation modes can be effectively and quickly identified by various microscopic characteristics and different contents of Ca on the surface of the parenchyma, phloem and xylem. Meanwhile, linear discriminant analysis showed that 98.1% of the dried stem powder samples were correctly classified, and the accuracy of cross-validation was 95.3%. This study facilitated an effective integrated method for determining the traceability of the fresh stem and dried stem powder of D. officinale derived from three different cultivation modes. This approach offers a potential method for identifying the origins of medicinal plants derived from different cultivation modes.
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Affiliation(s)
- Guangying Du
- Guizhou University of Traditional Chinese Medicine, Dongqing South Road, Huaxi, Guiyang, 550025, GuiZhou, China.
| | - Ruidong Yang
- Guizhou University, Huaxi, Guiyang, 550025, GuiZhou, China
| | - Fulin Yan
- Guizhou University of Traditional Chinese Medicine, Dongqing South Road, Huaxi, Guiyang, 550025, GuiZhou, China
| | - Shenghua Wei
- Guizhou University of Traditional Chinese Medicine, Dongqing South Road, Huaxi, Guiyang, 550025, GuiZhou, China
| | - Deqiang Ren
- Guizhou University of Traditional Chinese Medicine, Dongqing South Road, Huaxi, Guiyang, 550025, GuiZhou, China
| | - Xiangping Li
- Guizhou University of Traditional Chinese Medicine, Dongqing South Road, Huaxi, Guiyang, 550025, GuiZhou, China
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Xin J, Liu L, Xu L, Wang J, Yang P, Qu H. A preliminary study of aeolian sand-cement-modified gasification slag-paste backfill: Fluidity, microstructure, and leaching risks. Sci Total Environ 2022; 830:154766. [PMID: 35337863 DOI: 10.1016/j.scitotenv.2022.154766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/24/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
To realize low-cost green backfill mining, this paper proposes a novel model of aeolian sand-cement-modified gasification slag-paste backfill (ACGPB). This model realizes the safe disposal and resource utilization of hazardous solid wastes. A comprehensive experiment (including slump test, uniaxial compressive strength tests, microscopic test, and leaching toxicity tests) was conducted to explore how the mechanism of ACGPB depends on activator type and dosage. The results showed that fresh ACGPB slurry can be expressed by the Herschel-Bulkley model (R2 ≥ 0.965 in all recipes). With Na2SO4 as activator type, the yield stress, apparent viscosity, thixotropy, and slump of ACGPB slurry increased with increasing activator dosage. With CaO as activator type, the yield stress, apparent viscosity, thixotropy, and slump of ACGPB slurry fluctuated with increasing activator dosage. The mechanical properties of all recipes (not including Control group and C-C1) met the mechanical requirement (3 d ≥ 0.5 MPa and 28 d ≥ 1.0 MPa). In addition, the concentrations of all heavy metals remained within the range specified by the national standard. Specifically, the activator exerted a positive effect on the stabilization/solidification of heavy metal ions (Cu, Cd, Ba, Ni, Cr, Se, and As). Finally, FTIR, TG-DTG, SEM, and hydration heat were used to analyze the microstructure of ACGPB. The research results provide a creative way for the resource utilization of solid waste.
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Affiliation(s)
- Jie Xin
- Energy School, Xi'an University of Science and Technology, Xi'an 710054, China; Research Center for Functional Backfill Technology in Mine, Xi'an 710054, China.
| | - Lang Liu
- Energy School, Xi'an University of Science and Technology, Xi'an 710054, China; Key Laboratory of Western Mines and Hazards Prevention, Ministry of Education of China, Xi'an 710054, China; Research Center for Functional Backfill Technology in Mine, Xi'an 710054, China.
| | - Longhua Xu
- Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education, School of Environment and Resource, Southwest University of Science and Technology, Mianyang 6210102, China
| | - Jianyou Wang
- Yulin Yushen Industrial Area Energy Technology Development Co., Ltd, Yulin 719302, China
| | - Pan Yang
- Energy School, Xi'an University of Science and Technology, Xi'an 710054, China; Research Center for Functional Backfill Technology in Mine, Xi'an 710054, China.
| | - Huisheng Qu
- Energy School, Xi'an University of Science and Technology, Xi'an 710054, China; Research Center for Functional Backfill Technology in Mine, Xi'an 710054, China
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Li M, Wang Q, Yang J, Cui J, Guo X, Zhou W. Experimental study on the permeability of Pb-contaminated silt solidified by CFG. Environ Technol 2022; 43:1294-1306. [PMID: 32941119 DOI: 10.1080/09593330.2020.1825532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
The permeability of soil is a fundamental parameter in hydrological and geotechnical studies, nevertheless, the investigations on the silt especially the heavy mental contaminated silt have rarely been reported. The research introduces the effect of the different factors, including the osmotic pressure, curing time, the content of binders and the concentration of lead, on the permeability and microscopic properties of lead-contaminated silt, which is solidified by a novel curing agent, formed by mixing cement, fly ash and desulphurization gypsum (CFG). According to the tests of the permeability and scanning electron microscope (SEM), the permeability of samples is investigated under different influencing factors. The results demonstrate that the permeability coefficient of the contaminated silt increases with the increasing osmotic pressure and lead ion concentration, while decreases with the increasing CFG content and the curing time, additonally, there are interactions among various factors, which jointly affect the permeability of samples. Moreover, the statistical analysis shows that osmotic pressure has the most significant effect on permeability among various factors. Besides, the influence of lead ion concentration, osmotic pressure and CFG content on the permeability coefficient at the curing time of 14d is more significant than that of 28d, and the influence order of factors was slightly different at different curing time. Furthermore, the SEM test proves the conclusion of the statistical analysis, which also explains the common reasons for the enhancement of the impermeability and unconfined compressive strength (UCS) of the lead-contaminated silt with the increasing curing time.
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Affiliation(s)
- Man Li
- School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, People's Republic of China
| | - Qiang Wang
- School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, People's Republic of China
- Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, People's Republic of China
| | - Jingdong Yang
- School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, People's Republic of China
| | - Jinyang Cui
- School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan, People's Republic of China
| | - Xiaoliang Guo
- School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, People's Republic of China
| | - Wenjun Zhou
- School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, People's Republic of China
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Wu S, Zhang J, Li C, Wang F, Shi L, Tao M, Weng B, Yan B, Guo Y, Chen Y. Characterization of potential cellulose fiber from cattail fiber: A study on micro/nano structure and other properties. Int J Biol Macromol 2021; 193:27-37. [PMID: 34687763 DOI: 10.1016/j.ijbiomac.2021.10.088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 01/15/2023]
Abstract
Exploration of the application prospects of cattail fibers (CFs) in natural composites, and other fields is important for the sustainable development of new, green, light-weight, functional biomass materials. In this study, the physical and chemical properties, micro/nano structure, and mechanical characteristics of CFs were investigated. The CFs have a low density (618.0 kg m-3). The results of transmission electron microscopy and tensile testing data indicated that the cattail trunk fiber (CTF) bundle is composed of parenchyma cells and solid stone cells, demonstrating high specific modulus (10.1 MPa∙m3·kg-1) and high elongation at break (3.9%). In turn, the cattail branch fiber (CBF) bundle is composed of parenchyma cells with specific "half-honeycomb" shape. The inner diaphragms divide these cells into the open cavities. This structural feature endows the CTF bundles with stable structure, good oil absorption and storage capacities. The chemical component and the Fourier transform infrared spectroscopy analyses show that the CFs have higher lignin content (20.6%) and wax content (11.5%), which are conducive to the improvement of corrosion resistance, thermal stability and lipophilic-hydrophobic property of CF. Finally, the thermogravimetric analysis indicates that its final degradation temperature is 404.5 °C, which is beneficial to the increase in processability of CFs-reinforced composites.
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Affiliation(s)
- Shanshan Wu
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Jinlong Zhang
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Chuangye Li
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Fuli Wang
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Lanlan Shi
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Mengxue Tao
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Beibei Weng
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Bin Yan
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China
| | - Yong Guo
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China.
| | - Yuxia Chen
- College of Forest and Garden, Anhui Agricultural University, Hefei 230036, China.
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Zha F, Liu C, Kang B, Yang X, Zhou Y, Yang C. Acid rain leaching behavior of Zn-contaminated soils solidified/stabilized using cement-soda residue. Chemosphere 2021; 281:130916. [PMID: 34029961 DOI: 10.1016/j.chemosphere.2021.130916] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/25/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Cement-soda residue (CSR) has been proven to be an effective binder for treating heavy metal-contaminated soils, and the durability is its most important characteristic. In this study, the effects of acid rain (AR) on the leaching behavior of CSR-solidified/stabilized, zinc-contaminated soils were investigated using flexible-wall soil column leaching tests. After leaching, some parameters were determined such as the unconfined compressive strength (UCS) and permeability coefficient of the samples, the concentrations of Zn2+ and Ca2+ in the filtrate. The test results showed that after AR leaching, the UCS of the solidified soil samples decreased and the permeability coefficient increased, while the zinc concentration in the filtrate always met the third grade of the applicable standard, the Chinese National Environmental Quality Standards (<1 mg⋅L-1). To reveal the binding mechanism, scanning electron microscopy (SEM) and mercury intrusion testing (MIP) were used to observe the microscopic characteristics of the soil samples. At the micro scale, the MIP and SEM results confirmed that the hydration products in the soil samples-hydrated calcium silicate, calcium hydroxide, and calcium zincate hydrate-partially dissolved during AR leaching, resulting in the loss of their internal structure. Consequently, the high alkalinity of the soda residue contributed to H+ neutralization in the AR leaching agent, indicating that soda residue can not only solidify heavy metal zinc ions effectively but can also buffer the erosive effect of AR on soil.
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Affiliation(s)
- Fusheng Zha
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Congmin Liu
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Bo Kang
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Xiuhong Yang
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yang Zhou
- Anhui Urban Construction Engineering Co., Ltd, Hefei, 230002, China
| | - Chengbin Yang
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China
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