Characteristics of pores in coals exposed to acid mine drainage

Acid mine drainage commonly occupies some pore space after underground coal mining, and this severely depreciates coal pillars, thereby posing a significant risk to mine stability. Considering that such depreciation is reflected in the microstructures of these pillars, in the present study, we propo...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Hao Tang, Jin-zhi Luo, Li-wei Zheng, Chi-yang Liu, Hua-hua Li, Guan-nan Wu, Meng-li Zeng, Xue-song Bai
Formato:	article
Lenguaje:	EN
Publicado:	Elsevier 2021
Materias:	Acid mine drainage Chemical erosion Immersion test Pore orientation Pore size Electrical engineering. Electronics. Nuclear engineering TK1-9971
Acceso en línea:	https://doaj.org/article/237ebd3acf60478384a388c61307d2ab
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:237ebd3acf60478384a388c61307d2ab
record_format	dspace
spelling	oai:doaj.org-article:237ebd3acf60478384a388c61307d2ab2021-11-28T04:34:27ZCharacteristics of pores in coals exposed to acid mine drainage2352-484710.1016/j.egyr.2021.11.055https://doaj.org/article/237ebd3acf60478384a388c61307d2ab2021-11-01T00:00:00Zhttp://www.sciencedirect.com/science/article/pii/S2352484721012002https://doaj.org/toc/2352-4847Acid mine drainage commonly occupies some pore space after underground coal mining, and this severely depreciates coal pillars, thereby posing a significant risk to mine stability. Considering that such depreciation is reflected in the microstructures of these pillars, in the present study, we propose a static immersion method suitable for coal seam samples immersion in the laboratory. We immersed the No. 2–2 coal seam samples from the Ningtiao Tower Coal Mine in Yulin, Shaanxi Province, in different acid mine drainage solutions and monitored the pH, oxidation–reduction potential (ORP), electrical conductivity (EC), total dissolved solids (TDS) among other water quality parameters for 300 h. After the immersion tests, samples were examined using scanning electron microscopy (SEM). The pH, ORP, EC, and TDS of the prepared acid mine drainage solutions increased significantly as the immersion time increased. Changes in water quality parameters are attributed to the absorption of hydrogen ions by insoluble clay minerals in the coal, which reduced the acidity, increased the pH value, and enhanced the electrical conductivity of the acid mine drainage solutions. SEM analysis reveals differences in the pore characteristics of (pore throat size and orientation) of the coal samples, and these are caused by erosive effects of the acid mine drainage solutions. Pores with throat sizes greater than 10μmincreased by 95% as the pH of the acid mine drainage solutions decreased, while the dominant pore orientation (60–90°) decreased to the 0–30° or increased to the 150–180° range, thereby increasing their randomness.Hao TangJin-zhi LuoLi-wei ZhengChi-yang LiuHua-hua LiGuan-nan WuMeng-li ZengXue-song BaiElsevierarticleAcid mine drainageChemical erosionImmersion testPore orientationPore sizeElectrical engineering. Electronics. Nuclear engineeringTK1-9971ENEnergy Reports, Vol 7, Iss , Pp 8772-8783 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Acid mine drainage Chemical erosion Immersion test Pore orientation Pore size Electrical engineering. Electronics. Nuclear engineering TK1-9971
spellingShingle	Acid mine drainage Chemical erosion Immersion test Pore orientation Pore size Electrical engineering. Electronics. Nuclear engineering TK1-9971 Hao Tang Jin-zhi Luo Li-wei Zheng Chi-yang Liu Hua-hua Li Guan-nan Wu Meng-li Zeng Xue-song Bai Characteristics of pores in coals exposed to acid mine drainage
description	Acid mine drainage commonly occupies some pore space after underground coal mining, and this severely depreciates coal pillars, thereby posing a significant risk to mine stability. Considering that such depreciation is reflected in the microstructures of these pillars, in the present study, we propose a static immersion method suitable for coal seam samples immersion in the laboratory. We immersed the No. 2–2 coal seam samples from the Ningtiao Tower Coal Mine in Yulin, Shaanxi Province, in different acid mine drainage solutions and monitored the pH, oxidation–reduction potential (ORP), electrical conductivity (EC), total dissolved solids (TDS) among other water quality parameters for 300 h. After the immersion tests, samples were examined using scanning electron microscopy (SEM). The pH, ORP, EC, and TDS of the prepared acid mine drainage solutions increased significantly as the immersion time increased. Changes in water quality parameters are attributed to the absorption of hydrogen ions by insoluble clay minerals in the coal, which reduced the acidity, increased the pH value, and enhanced the electrical conductivity of the acid mine drainage solutions. SEM analysis reveals differences in the pore characteristics of (pore throat size and orientation) of the coal samples, and these are caused by erosive effects of the acid mine drainage solutions. Pores with throat sizes greater than 10μmincreased by 95% as the pH of the acid mine drainage solutions decreased, while the dominant pore orientation (60–90°) decreased to the 0–30° or increased to the 150–180° range, thereby increasing their randomness.
format	article
author	Hao Tang Jin-zhi Luo Li-wei Zheng Chi-yang Liu Hua-hua Li Guan-nan Wu Meng-li Zeng Xue-song Bai
author_facet	Hao Tang Jin-zhi Luo Li-wei Zheng Chi-yang Liu Hua-hua Li Guan-nan Wu Meng-li Zeng Xue-song Bai
author_sort	Hao Tang
title	Characteristics of pores in coals exposed to acid mine drainage
title_short	Characteristics of pores in coals exposed to acid mine drainage
title_full	Characteristics of pores in coals exposed to acid mine drainage
title_fullStr	Characteristics of pores in coals exposed to acid mine drainage
title_full_unstemmed	Characteristics of pores in coals exposed to acid mine drainage
title_sort	characteristics of pores in coals exposed to acid mine drainage
publisher	Elsevier
publishDate	2021
url	https://doaj.org/article/237ebd3acf60478384a388c61307d2ab
work_keys_str_mv	AT haotang characteristicsofporesincoalsexposedtoacidminedrainage AT jinzhiluo characteristicsofporesincoalsexposedtoacidminedrainage AT liweizheng characteristicsofporesincoalsexposedtoacidminedrainage AT chiyangliu characteristicsofporesincoalsexposedtoacidminedrainage AT huahuali characteristicsofporesincoalsexposedtoacidminedrainage AT guannanwu characteristicsofporesincoalsexposedtoacidminedrainage AT menglizeng characteristicsofporesincoalsexposedtoacidminedrainage AT xuesongbai characteristicsofporesincoalsexposedtoacidminedrainage
_version_	1718408305711251456

Characteristics of pores in coals exposed to acid mine drainage

Ejemplares similares