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Assessment of Factors Affecting Pyrite Reactivity.

PB92140227

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	Acid mine drainage Pyrite Oxidation Pollution abatement Sampling Chemical reactivity Sulfides Reaction kinetics Chemical properties Physical properties Weathering pH Leaching Chemical composition Geomorphology Sulfur Assessments
Source Agency	Bureau of Mines
NTIS Subject Category	68 - Environmental Pollution & Control 48A - Mineral Industries 48F - Geology & Geophysics 99F - Physical & Theoretical Chemistry
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	J0398006

Assessment of Factors Affecting Pyrite Reactivity.

Assessment of Factors Affecting Pyrite Reactivity.
PB92140227

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	Acid mine drainage Pyrite Oxidation Pollution abatement Sampling Chemical reactivity Sulfides Reaction kinetics Chemical properties Physical properties Weathering pH Leaching Chemical composition Geomorphology Sulfur Assessments
Source Agency	Bureau of Mines
NTIS Subject Category	68 - Environmental Pollution & Control 48A - Mineral Industries 48F - Geology & Geophysics 99F - Physical & Theoretical Chemistry
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	J0398006