On the Occurrence and Persistence of Coal-Mineral Microagglomerates in Respirable Coal Mine Dust

Details

• Personal Author:
  Gonzalez J ; Keles C ; Sarver E
• Description:
  A previous effort to characterize respirable coal mine dust in 16 US mines turned up a curious finding: particle-based analysis using scanning electron microscopy (SEM) tended to overpredict the abundance of dust sourced from rock strata, and under predict the abundance of coal, when compared to mass-based thermogravimetric analysis (TGA). One possible explanation is the occurrence of coal-mineral microagglomerates (MAGs). Coal particles covered with fine mineral dust could be mostly coal by mass but classified as minerals by SEM due to their surface elemental content. In the current study, a subset of the previously analyzed mine dust samples was re-examined, and SEM images and elemental mapping showed that MAGs are indeed present. Furthermore, dust samples were created and sampled passively in the laboratory, demonstrating that MAG formation can occur due to dust generation processes and the sampling environment, rather than as a mere artifact of respirable dust sampling procedures. Finally, experiments were conducted to evaluate dispersibility of MAGs in liquid suspensions, which might shed some light on their possible fate upon inhalation. Results indicated that sonication in deionized water was effective for MAG dispersion, and a solution that mimics natural lung surfactant also appeared to enhance dispersibility. An understanding of MAG occurrence might be important in terms of exposure assessment. [Description provided by NIOSH]
• Subjects:
  Dust Occupational Health Particulate Matter Respiratory System Safety
• Keywords:
  Author Keywords: Respirable Coal Mine Dust; SEM-EDX; Microagglomerates; Occupational Health Respirable Dust; Coal Dust; Dust Exposure; Particulates; Particle Size Analysis; Scanning Electron Microscopy; Rock Mechanics; Mineral Dusts; Inhalation; Exposure Assessment;
• DOI:
  https://doi.org/10.1007/s42461-022-00555-7
• ISSN:
  2524-3462
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  271-282
• Volume:
  39
• Issue:
  2
• NIOSHTIC Number:
  nn:20064770
• Citation:
  Min Metall Explor 2022 Apr; 39(2):271-282
• Contact Point Address:
  Emily Sarver, Department of Mining and Minerals Engineering, Virginia Polytechnic Institute & State University, Blacksburg, VA
• Email:
  esarver@vt.edu
• Federal Fiscal Year:
  2022
• Performing Organization:
  Virginia Polytechnic Institute & State University
• Peer Reviewed:
  True
• Start Date:
  20190903
• Source Full Name:
  Mining, Metallurgy & Exploration
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:cbd98fbd1530ac8f66f04b87a4ed9973235e4fa0fedd2fb87e7724f7521b35aa3cf05c4737c9161db0d23828eb6b97099122fa447da195d375aa441bc20a9c51
• Download URL:
  https://stacks.cdc.gov/view/cdc/248952/cdc_248952_DS1.pdf
• File Type:
  [PDF - 2.05 MB ]