Arsenic variation in pyrite in coal

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:349266

Kolker, A; Koeppen, R P ^[1]

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1. Geological Survey, Reston, VA (United States)

Understanding the distribution of As in coal is important in predicting its behavior upon leaching and/or combustion and in devising strategies for its removal. Results show that As-enrichment in pyrite is widespread, and not limited to epigenetic forms. Elemental mapping and quantitative analysis of arsenic distribution in pyrite from 14 coal samples reveals order of magnitude variations in As content within and between individual grains of pyrite. The samples have a wide range in rank and include coals from the Southern Appalachian, Northern Appalachian, Eastern Interior, and Powder River basins of the continental US. In some pyrite grains, As-enrichment is epigenetic, resulting from the post-coalification movement of hydrothermal fluids. Other grains contain high-As micro-domains that formed during diagenesis, early in the coalification process. In rare cases, pyrite shows oscillatory zonation of As. These compositional variations suggest that As can be incorporated into pyrite at various stages of coal formation, and by more than one process. More detailed coal exploration and characterization may help delineate the most As-enriched zones, especially where these are related to movement of hydrothermal fluids through a coal basin.

• DOE Contract Number: AI22-95PC95156; AI22-95PC95145
• OSTI ID: 349266
• Report Number(s): CONF-980985--; ISBN 1-890977-15-2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ARSENIC
COAL
DISTRIBUTION
NATURAL OCCURRENCE
ORIGIN
PYRITE
VARIATIONS