A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater
Background and Objective Limited by locations, as well as economic and technical levels, most of the coal-based solid waste is still accumulated in the form of open-air landfills without treatment, thus occupying large quantities of land resources and causing secondary pollution to the environment....
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Editorial Office of Coal Geology & Exploration
2025-01-01
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| Series: | Meitian dizhi yu kantan |
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| author | Shuning DONG Shujiang YU Xingling DONG Buqin ZHANG Xiaoming GUO Xiaodong WANG Kai WANG Shibin ZHU Boqiang WU Lei LIU |
| author_facet | Shuning DONG Shujiang YU Xingling DONG Buqin ZHANG Xiaoming GUO Xiaodong WANG Kai WANG Shibin ZHU Boqiang WU Lei LIU |
| author_sort | Shuning DONG |
| collection | DOAJ |
| description | Background and Objective Limited by locations, as well as economic and technical levels, most of the coal-based solid waste is still accumulated in the form of open-air landfills without treatment, thus occupying large quantities of land resources and causing secondary pollution to the environment. The proper treatment and reduction of high-salinity wastewater (e.g., high-salinity mine water and high-salinity water from the coal chemical industry) represent a key link in the achievement of zero liquid discharge. However, existing technologies for high-salinity wastewater treatment are generally confronted with issues such as great initial investment and high operation costs of the treatment engineering. Methods This study developed a technology for the synergistic treatment of coal-based solid waste and high-salinity wastewater (also referred to as solid-liquid synergistic waste backfilling). Specifically, high-salinity water, rather than ordinary water and additives such as early strength agent, and solid waste cementitious materials—used to replacing part of cement, were mixed while stirring to produce filling paste, which was then pumped to the underground goaves of coal mines. To analyze the feasibility of this technology, this study investigated the mechanical properties and potential environmental impacts of filling paste prepared using coal-based solid waste and high-salinity wastewater from a certain coal mine in the Ningdong coal base in Ningxia. The mechanical properties, microstructures, and heavy metal leaching characteristics of the solidified filling paste were analyzed using the uniaxial compressive strength (UCS) test, scanning electron microscopy (SEM), and inductively coupled plasma-mass spectrometry (ICP-MS). Results and Conclusions The results indicate that the strength of all the solidified filling paste increased over time but gradually decreased with an increase in the quantity of mineral powders added and a decrease in the proportion of cementitious materials. Notably, after some time, all filling paste prepared using high-salinity water as mixing water exhibited 3-day strength exceeding 0.5 MPa, meeting the minimum requirements specified in Technical specification for coal mine gangue-based solid waste filling (NB/T 11432—2023). Their 14-day strength reached 3.38‒5.99 MPa, satisfying the requirements of various scenarios in most coal mine filling. The assessment results obtained using Nemerow’s pollution index and extraction toxicity tests indicate that the leachate from the solidified filling paste exhibited a comprehensive pollution index of heavy metals of 0.25, rated as “Safety” according to the grading criteria for comprehensive pollution assessment. The leaching test results of the solidified filling paste indicate that the primary pollutant concentrations in the leachate all fell below the requirements of Class III water standard specified in Identification standards for hazardous wastes-Identification for extraction toxicity (GB 5085.3—2007) and Standard for groundwater quality (GB/T 14848—2017). Therefore, the technology for synergistic treatment of coal-based solid waste and mine high-salinity water can meet the relevant standards in the assessment of mechanical properties and environmental stability. This technology enables the recyclable, low-cost, and full quantitative utilization of coal-based solid waste and high-salinity water, enjoying significant economic and ecological benefits. The results of this study will provide technological support for the construction of waste-free mines, mining cities, and chemical industry. |
| format | Article |
| id | doaj-art-ddf898c488fb425b90f2301f260d91ee |
| institution | Kabale University |
| issn | 1001-1986 |
| language | zho |
| publishDate | 2025-01-01 |
| publisher | Editorial Office of Coal Geology & Exploration |
| record_format | Article |
| series | Meitian dizhi yu kantan |
| spelling | doaj-art-ddf898c488fb425b90f2301f260d91ee2025-02-12T07:20:17ZzhoEditorial Office of Coal Geology & ExplorationMeitian dizhi yu kantan1001-19862025-01-0153116317310.12363/issn.1001-1986.25.01.003225-01-0032dongshuningA key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewaterShuning DONG0Shujiang YU1Xingling DONG2Buqin ZHANG3Xiaoming GUO4Xiaodong WANG5Kai WANG6Shibin ZHU7Boqiang WU8Lei LIU9CCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaBeijing Symgreen Environmental Technology Group Co., Ltd., Beijing 100041, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaFeny Co., Ltd., Changsha 410600, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaBeijing Symgreen Environmental Technology Group Co., Ltd., Beijing 100041, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaCCTEG Xi’an Research Institute (Group) Co., Ltd., Xi’an 710077, ChinaBackground and Objective Limited by locations, as well as economic and technical levels, most of the coal-based solid waste is still accumulated in the form of open-air landfills without treatment, thus occupying large quantities of land resources and causing secondary pollution to the environment. The proper treatment and reduction of high-salinity wastewater (e.g., high-salinity mine water and high-salinity water from the coal chemical industry) represent a key link in the achievement of zero liquid discharge. However, existing technologies for high-salinity wastewater treatment are generally confronted with issues such as great initial investment and high operation costs of the treatment engineering. Methods This study developed a technology for the synergistic treatment of coal-based solid waste and high-salinity wastewater (also referred to as solid-liquid synergistic waste backfilling). Specifically, high-salinity water, rather than ordinary water and additives such as early strength agent, and solid waste cementitious materials—used to replacing part of cement, were mixed while stirring to produce filling paste, which was then pumped to the underground goaves of coal mines. To analyze the feasibility of this technology, this study investigated the mechanical properties and potential environmental impacts of filling paste prepared using coal-based solid waste and high-salinity wastewater from a certain coal mine in the Ningdong coal base in Ningxia. The mechanical properties, microstructures, and heavy metal leaching characteristics of the solidified filling paste were analyzed using the uniaxial compressive strength (UCS) test, scanning electron microscopy (SEM), and inductively coupled plasma-mass spectrometry (ICP-MS). Results and Conclusions The results indicate that the strength of all the solidified filling paste increased over time but gradually decreased with an increase in the quantity of mineral powders added and a decrease in the proportion of cementitious materials. Notably, after some time, all filling paste prepared using high-salinity water as mixing water exhibited 3-day strength exceeding 0.5 MPa, meeting the minimum requirements specified in Technical specification for coal mine gangue-based solid waste filling (NB/T 11432—2023). Their 14-day strength reached 3.38‒5.99 MPa, satisfying the requirements of various scenarios in most coal mine filling. The assessment results obtained using Nemerow’s pollution index and extraction toxicity tests indicate that the leachate from the solidified filling paste exhibited a comprehensive pollution index of heavy metals of 0.25, rated as “Safety” according to the grading criteria for comprehensive pollution assessment. The leaching test results of the solidified filling paste indicate that the primary pollutant concentrations in the leachate all fell below the requirements of Class III water standard specified in Identification standards for hazardous wastes-Identification for extraction toxicity (GB 5085.3—2007) and Standard for groundwater quality (GB/T 14848—2017). Therefore, the technology for synergistic treatment of coal-based solid waste and mine high-salinity water can meet the relevant standards in the assessment of mechanical properties and environmental stability. This technology enables the recyclable, low-cost, and full quantitative utilization of coal-based solid waste and high-salinity water, enjoying significant economic and ecological benefits. The results of this study will provide technological support for the construction of waste-free mines, mining cities, and chemical industry.http://www.mtdzykt.com/article/doi/10.12363/issn.1001-1986.25.01.0032coal-based solid wastehigh-salinity watersolid-liquid synergismdownhole fillinggroundwater |
| spellingShingle | Shuning DONG Shujiang YU Xingling DONG Buqin ZHANG Xiaoming GUO Xiaodong WANG Kai WANG Shibin ZHU Boqiang WU Lei LIU A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater Meitian dizhi yu kantan coal-based solid waste high-salinity water solid-liquid synergism downhole filling groundwater |
| title | A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater |
| title_full | A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater |
| title_fullStr | A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater |
| title_full_unstemmed | A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater |
| title_short | A key technology for synergistic backfilling of coal-based solid waste and high-salinity wastewater |
| title_sort | key technology for synergistic backfilling of coal based solid waste and high salinity wastewater |
| topic | coal-based solid waste high-salinity water solid-liquid synergism downhole filling groundwater |
| url | http://www.mtdzykt.com/article/doi/10.12363/issn.1001-1986.25.01.0032 |
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