Publication Date |
1991 |
Personal Author |
Schuman, G.; Caruccio, F. T.; Bradham, W. S. |
Page Count |
88 |
Abstract |
It has been suggested that the single most important factor affecting the occurrence of acid mine drainage is the quantity of calcareous material associated with pyrite-enriched strata. Factors affecting pyrite oxidation and observed variations in pyrite reactivity were studied. Pyrite was extracted from nine pulverized rock, coal, and coal refuse samples using heavy liquid separations. Simulated weathering tests were used to determine the degree of reactivity of the extracted pyritic material. The pyritic samples were analyzed for pyritic sulfur and neutralization potential, for elemental composition, and by x-ray diffractometry. Reflected light microscopy was used to ascertain pyrite morphology distributions. The leaching tests were conducted under abiotic conditions. The simulated weathering tests permitted the partitioning of the samples into two groups based on positive or negative neutralization potential (NP) values. There was no statistically significant relationship between degree of reactivity and elemental composition. Samples with negative NPs, pyrite morphology, expressed as the proportion of framboidal pyrite + mossy pitted pyrite was a major factor influencing the degree of reactivity. Samples with positive NPs, although producing acidity, did so an order of magnitude less than the NP deficient samples, indicating the role that NP plays in controlling pyrite reactivity. For the nine samples grouped together, a linear regression model between cumulative sulfate production and NP (both negative and positive) was established between log of sulfate and NP. |
Keywords |
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Source Agency |
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NTIS Subject Category |
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Corporate Authors |
South Carolina Univ., Columbia. Dept. of Geological Sciences.; Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center. |
Supplemental Notes |
Sponsored by Bureau of Mines, Pittsburgh, PA. Pittsburgh Research Center. |
Document Type |
Technical Report |
Title Note |
Final research rept. May 89-Sep 91. |
NTIS Issue Number |
199210 |
Contract Number |
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