A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics
Respirable crystalline silica is now considered to be a major culprit of resurgent lung disease among US coal miners—especially in central Appalachia—though questions remain regarding the specific circumstances around exposure to it. As part of a larger investigation of dust in 15 US coal mines, a r...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/12/12/1555 |
| _version_ | 1797456154916290560 |
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| author | Cigdem Keles Emily Sarver |
| author_facet | Cigdem Keles Emily Sarver |
| author_sort | Cigdem Keles |
| collection | DOAJ |
| description | Respirable crystalline silica is now considered to be a major culprit of resurgent lung disease among US coal miners—especially in central Appalachia—though questions remain regarding the specific circumstances around exposure to it. As part of a larger investigation of dust in 15 US coal mines, a recent study examined the silica content in both the respirable mine dust samples and the samples of respirable dust generated in the laboratory from primary source materials (i.e., coal and rock strata and rock dusting products). It concluded the rock strata that is being drilled for roof bolting or is being cut along with the coal is the most significant source of respirable silica in many mines, which is consistent with the expectations based on other scattered datasets. However, little information is available on the characteristics of respirable silica particles which might be important for understanding the exposure risks better. In the current study, which represents another part of the aforementioned investigation in 15 mines, scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM–EDX) were used to analyze the size and surface condition (i.e., degree of surface-associated clay) of 1685 silica particles identified in 58 respirable mine dust samples. The results indicated that silica is typically finer in locations nearby to drilling and cutting activities than it is in other locations within a mine, but the silica in the Central Appalachian mines is not necessarily finer than it is in the mines in other regions. An analysis of the particle surfaces revealed that respirable silica in coal mines often does not occur as “free”, high-purity particles. Rather, there can be a range of occurrences including silica particles having a thin “occlusion” layer of clay, silica within agglomerates that can also contain other particle types including clays, or even silica ingrained within other particles such as coal. |
| first_indexed | 2024-03-09T16:04:15Z |
| format | Article |
| id | doaj.art-7354d663973c4d23ba78c8ff522ac267 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-09T16:04:15Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-7354d663973c4d23ba78c8ff522ac2672023-11-24T16:51:46ZengMDPI AGMinerals2075-163X2022-12-011212155510.3390/min12121555A Study of Respirable Silica in Underground Coal Mines: Particle CharacteristicsCigdem Keles0Emily Sarver1Mining & Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USAMining & Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USARespirable crystalline silica is now considered to be a major culprit of resurgent lung disease among US coal miners—especially in central Appalachia—though questions remain regarding the specific circumstances around exposure to it. As part of a larger investigation of dust in 15 US coal mines, a recent study examined the silica content in both the respirable mine dust samples and the samples of respirable dust generated in the laboratory from primary source materials (i.e., coal and rock strata and rock dusting products). It concluded the rock strata that is being drilled for roof bolting or is being cut along with the coal is the most significant source of respirable silica in many mines, which is consistent with the expectations based on other scattered datasets. However, little information is available on the characteristics of respirable silica particles which might be important for understanding the exposure risks better. In the current study, which represents another part of the aforementioned investigation in 15 mines, scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM–EDX) were used to analyze the size and surface condition (i.e., degree of surface-associated clay) of 1685 silica particles identified in 58 respirable mine dust samples. The results indicated that silica is typically finer in locations nearby to drilling and cutting activities than it is in other locations within a mine, but the silica in the Central Appalachian mines is not necessarily finer than it is in the mines in other regions. An analysis of the particle surfaces revealed that respirable silica in coal mines often does not occur as “free”, high-purity particles. Rather, there can be a range of occurrences including silica particles having a thin “occlusion” layer of clay, silica within agglomerates that can also contain other particle types including clays, or even silica ingrained within other particles such as coal.https://www.mdpi.com/2075-163X/12/12/1555respirable crystalline silica (RCS)respirable coal mine dust (RCMD)scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM–EDX)particle sizeparticle surfaces |
| spellingShingle | Cigdem Keles Emily Sarver A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics Minerals respirable crystalline silica (RCS) respirable coal mine dust (RCMD) scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM–EDX) particle size particle surfaces |
| title | A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics |
| title_full | A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics |
| title_fullStr | A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics |
| title_full_unstemmed | A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics |
| title_short | A Study of Respirable Silica in Underground Coal Mines: Particle Characteristics |
| title_sort | study of respirable silica in underground coal mines particle characteristics |
| topic | respirable crystalline silica (RCS) respirable coal mine dust (RCMD) scanning electron microcopy with energy dispersive X-ray spectroscopy (SEM–EDX) particle size particle surfaces |
| url | https://www.mdpi.com/2075-163X/12/12/1555 |
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