(Kinetic Test Procedure for the Prediction of Coal Mine Drainage Quality)
EPA Method 1627

Roger J. Hornberger and Keith B. C. Brady, Editors

Table of Contents  |  List of Figures  |  List of Tables  |  Acknowledgements

Final Report of OSM Cooperative Agreement No. CT-5-30040 with the
Pennsylvania Department of Environmental Protection in cooperation with
the Pennsylvania State University
CSC Dyncorp
US Office of Surface Mining Reclamation and Enforcement
The US Environmental Protection Agency
The US Geological Survey
March 2009

Title Page | List of Figures | List of Tables | Acknowledgements

Chapter 1: Background Information on Kinetic Tests

Chapter 2: First Phase of Weathering Tests (2002)

Chapter 3: Second Phase of Weathering Tests (2003)

Chapter 4: Results of Interlaboratory Study

Chapter 5: Characterization of Rock Samples and Mineralogical Controls on Leachates

Chapter 6: Evaluation of Particle Size and Surface Effects

Chapter 7: Column Leaching Tests: The Underlying Physical Chemistry

Chapter 8: Leaching Behavior of Elements

Chapter 9: Strengths and Weaknesses of Acid-Base Accounting Data

Chapter 10: Summary, Conclusions and Applications

Bibliography

Appendix A: EPA Method 1627: Kinetic Test Method for the Prediction of Mine Drainage Quality

Appendix B: Response to Peer Review Comments on Draft Kinetic Test Procedure

Appendix C: 2002 Data Results from Lab 1 and Lab 2

Appendix D: 2003 Data Results from Lab 1, Lab 2 and Lab 3

Appendix E: 2006 Data Results from Interlaboratory Study

Appendix F: USGS Rock Sample Characterization Data (Appendices 5.1, 5.2 and 5.3 from Chapter 5)

 

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Title Page | Table of Contents | List of Tables | Acknowledgements

Figure 1.1: Solubility curves for calcite as a function of carbon dioxide partial pressure

Figure 2.1a: Humidity Cell

2.1b: Leaching Column
2.1c: Humidified Gas Mixture Schematic

Figure 2.2a: Alkalinity concentrations from shale sample in leaching columns

2.2b: Alkalinity concentrations from sandstone sample in leaching columns

Figure 2.3a: Comparison of humidity cell and leaching column performance on alkalinity production in shale sample using CO2 enhanced mixture

2.3b: Comparison of humidity cell and leaching column performance and alkalinity production in sandstone samples using CO2 enhanced mixture

Figure 2.4a: Conductivity in leachate from shale in humidity cells and leaching columns

2.4b: Sulfate in leachate from shale in humidity cells and leaching columns

Figure 2.5: Boxplots showing the distribution of saturation indices for calcite for leaching apparatuses

Figure 2.6: Alkalinity concentrations of shale, sandstone and limestone samples in leaching columns

Figure 3.1: Revised leaching column design

Figure 3.2: Alkalinity concentrations of two gas mixture scenarios

Figure 3.3: Comparison of PCO2 among laboratories for the leaching columns that had continuous flows of 10% air

Figure 3.4a: Effects of fine particle fractions on sulfate production in shale

3.4b: Effects of fine particle fractions on alkalinity in shale

Figure 3.5a: Sulfate concentrations of Brush Creek Shale using two inch, four inch, and six inch column diameter

3.5b: Alkalinity concentrations of Brush Creek Shale using two inch, four inch, and six inch column diameter

Figure 4.1: Leaching column assembly

Figure 5.1: Sample location and major coal provinces of the eastern United States

Figure 5.2a: Bar chart showing relative proportions of major elements as oxides

5.2b: Bar chart showing concentrations of selected trace elements

Figure 5.3: Houchin Creek Shale – scanned image of polished thin section

Figure 5.4: Houchin Creek Shale – SEM image of rock chip

Figure 5.5: Houchin Creek Shale – EDS spectra for pyrite and muscovite (phengite)

Figure 5.6: Lower Kittanning Shale – scanned image of polished thin section

Figure 5.7: Lower Kittanning Shale – photomicrographs

Figure 5.8: Lower Kittanning Shale – SEM image

Figure 5.9: Lower Kittanning Shale – SEM images of pyrite framboids

Figure 5.10: Lower Kittanning Shale – SEM data showing BSE image of coarse calcite

Figure 5.11: Kanawha Black Flint Shale – scanned image of polished thin section

Figure 5.12: Kanawha Black Flint Shale – photomicrographs

Figure 5.13: Kanawha Black Flint Shale – backscattered-electron SEM images showing pyrite textures

Figure 5.14: Kanawha Black Flint Shale – representative EDS spectra

Figure 5.15: Brush Creek Shale – scanned image of polished thin section

Figure 5.16: Brush Creek Shale – photomicrographs of rock fragment

Figure 5.17: Brush Creek Shale – photomicrographs

Figure 5.18: Brush Creek Shale – SEM image of pyrite framboid

Figure 5.19: Brush Creek Shale – SEM image of a groundmass carbonates

Figure 5.20: Middle Kittanning Sandstone – scanned image of polished thin section

Figure 5.21: Middle Kittanning Sandstone – photomicrographs

Figure 5.22: Middle Kittanning Sandstone – SEM image of pyrite framboids

Figure 5.23: Middle Kittanning Sandstone – SEM image of calcite and siderite

Figure 5.24: Wadesville Sandstone – scanned image of polished thin section

Figure 5.25: Wadesville Sandstone – photomicrographs of rock fragment

Figure 5.26: Wadesville Sandstone – SEM image of zoned carbonate

Figure 5.27: Leechburg Coal Refuse – scanned image of polished thin section

Figure 5.28: Leechburg Coal Refuse – SEM image showing fine-grained texture

Figure 5.29: Trace elements in pyrite-bar chart

Figure 5.30: Trace elements in pyrite-distribution of nine elements

Figure 5.31: Carbonate mineral compositions

Figure 5.32: Leaching column residue

Figure 5.33: Hot acidity concentrations in leachates

Figure 5.34: Concentrations of target analytes in leachates

Figure 5.35: Effluent saturation indices for calcite and gypsium

Figure 5.36: Base-metal concentrations in starting materials and leachates

Figure 5.37: Cadmium and zinc in leach column effluent

Figure 5.38: Trace elements in leachates

Figure 5.39: XRD patterns for shales

Figure 5.40: Bar charts showing relative percentages of different minerals in the crystalline parts of samples

Figure 5.41: Sulfur in leach column effluent as a function of time

Figure 5.42: Cumulative alkalinity in column effluent as a function of time

Figure 6.1: Schematic representation of dissolution as a function of time

Figure 6.2: Effect of SA/V ratio on the release of silicon to leaching solutions for a borosilicate glass

Figure 6.3: Log [Si] vs. Log SA/V for a glassy nuclear waste form

Figure 6.4: Comparison of the normalized release of silicon from a borosilicate glass as a function of surface roughness

Figure 6.5: Box and whisker plot for BET of different rock types used in this program to date

Figure 7.1: Schematic dissolution curve for a congruently dissolving solid of low equilibrium solubility

Figure 7.2: Schematic dissolution curve for a congruently dissolving solid of high solubility and limited mass

Figure 7.3: Schematic dissolution curves for materials dissolving by chemical reaction with the solvent

Figure 7.4: Schematic drawing of expected leaching curves from the experimental columns

Figure 7.5: Range in CO2 content of leach column atmosphere between laboratories

Figure 7.6: Alkalinity vs. carbon dioxide for BCS Shale

Figure 7.7: pH variations of the Houchin Creek Shale leachate

Figure 7.8: Sulfate in effluent from duplicate columns of Houchin Creek Shale

Figure 7.9: Patterns of variation of conductivity of leachate from the Lower Kittanning Shale

Figure 7.10: Patterns of variation of sulfate concentrations from the Lower Kittanning Shale

Figure 7.11: Alkalinity variations in duplicate leaching columns for the Brush Creek Shale

Figure 7.12: Alkalinity concentrations for duplicate Brush Creek Shale columns in Labs 4 and 5

Figure 7.13: Alkalinity concentrations of Lower Kittanning Shale duplicate columns

Figure 7.14: Increase in alkalinity concentrations in duplicate columns at Labs 3, 4 and 5

Figure 7.15: Range of iron concentrations of Houchin Creek Shale

Figure 7.16: Pattern of variation of manganese concentrations for Lower Kittanning Shale

Figure 7.17: Range of manganese concentrations of Houchin Creek Shale

Figure 7.18: Calcium concentrations of Brush Creek Shale duplicate columns

Figure 7.19: Similarity of variations of calcium concentrations in leachate at Labs 4, 5 and 6

Figure 7.20: Sulfate concentrations in effluent from leaching columns of all rock types

Figure 7.21: Differences in alkalinity concentrations of leachate from five rock types

Figure 7.22: Sulfur leaching from BCS3 – PA, the Brush Creek Shale

Figure 7.23: Sulfur leaching from the Kanawha Black Flint Shale

Figure 7.24: Sulfur leaching from the Lower Kittanning Shale

Figure 7.25: Sulfur leaching from the Middle Kittanning Sandstone

Figure 7.26: Sulfur leaching from the Houchin Creek Shale

Figure 7.27: Cumulative carbonate dissolution rate determined using cations and anions for the Brush Creek Shale

Figure 7.28: Same data as in Figure 7.27, but showing only Labs 1 and 4

Figure 7.29: Same data as in Figure 7.27, but showing only Labs 3 and 5

Figure 7.30: Cumulative carbonate dissolution determined using cations and anions for the Lower Kittanning Shale

Figure 7.31: Same data as in Figure 7.30, but showing only Labs 1 and 4

Figure 7.32: Same data as in Figure 7.30, but showing only Labs 3 and 5

Figure 7.33: Relative dissolution rates of minerals

Figure 7.34: Comparison of the “anion” and “cation” methods of determining carbonate dissolution

Figure 7.35: Weathering rates through time for carbonates and sulfur for the Lower Kittanning Shale

Figure 7.36: Weathering rates through time for carbonates and sulfur for the Brush Creek Shale

Figure 7.37: Comparison of weathering rates for pyrite and carbonates for five rock types by four laboratories

Figure 7.38: Plots of week-by-week release and cumulative release of calcium, magnesium and potassium

Figure 7.39: Plots of week-by-week and cumulative release of zinc

Figure 7.40: Plots of week-by-week release and cumulative release of selenium

Figure 7.41: Leach curves for manganese and iron

Figure 8.1: Alkalinity, calcium, magnesium, sodium and potassium concentrations at weeks 1 and 14 for five rocks

Figure 8.2: Sulfate and specific conductance, weeks 1 and 14 for five rocks

Figure 8.3: Selenium and zinc concentration, weeks 1 and 14 for five rocks

Figure 8.4: Iron, manganese and aluminum concentration, weeks 1 and 14 for five rocks

Figure 8.5: Durov (Composition) plot of weeks 1 and 14 leachates

Figure 8.6: Effect of PCO2 on alkalinity, pH and calcium carbonate dissolution

Figure 8.7: Alkalinity concentration, weeks 1 to 14 for five rocks

Figure 8.8: Calcite saturation indices weeks 1 to 14 for five rocks

Figure 8.9: Gypsum saturation indices for five rocks

Figure 8.10: Eh/pH plot of selected iron minerals and week 14 leachates

Figure 8.11: Aluminum solubility as a function of pH for selected sulfate and clay minerals

Figure 8.12: Weekly sulfate flux for Brush Creek Shale

Figure 8.13: Cumulative sulfate leaching for Brush Creek Shale

Figure 8.14a: Calcium flux, Brush Creek Shale with linear trend

8.14b: Calcium flux, Lower Kittanning Shale

Figure 9.1: The “Gray Zone” of NP and MPA

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Table 2.1: Total sulfur and neutralization potential values of rock samples

Table 2.2: Sample Weights

Table 2.3: Partial pressure CO2 as determined from geochemical modeling

Table 2.4: Relative Percent Differences (RPD) of duplicate samples

Table 3.1: Sample characterization

Table 3.2: Particle size distribution of as prepared rock samples

Table 3.3: Particle size distribution of reconstructed samples

Table 3.4: Surface area measurements, sieve analysis, and calculations of effective surface areas before and after weathering tests

Table 3.5: Summary of changes in surface areas after weathering

Table 3.6: Sample weights

Table 4.1: Sample characterization

Table 4.2: Analytes measured and analytical methods used

Table 4.3: Particle size distribution of reconstructed samples

Table 4.4a: Houchin Creek Shale volume differences

4.4b: Kanawha Black Flint Shale volume differences
4.4c: Brush Creek Shale volume differences
4.4d: Lower Kittanning Shale volume differences
4.4e: Middle Kittanning Sandstone volume differences

Table 4.5: Sample types and weights

Table 4.6: Relative Percent Differences (RPD) between analytical QC duplicates

Table 4.7a: Pooled RPDs based on analyte concentrations in duplicate sample pairs

4.7b: Pooled RPDs based on analyte concentrations in duplicate sample pairs
4.7c: Overall RPDs based on analyte

Table 4.8a: Pooled interlaboratory RPDs based on analyte concentrations in replicate samples

4.8b: Overall pooled RPDs based on analyte

Table 4.9: Expected method precision (as RPDs) based on interlaboratory study results

Table 4.10: Overall pooled RPDs based on analyte

Table 5.1: Rock samples

Table 5.2: Geochemical data for rock samples

Table 5.3: Minerals

Table 5.4: Mineralogy determined by XR

Table 5.5: Mineralogy for BCS-3 on replicate splits of raw leach column starting material

Table 5.6: Trace elements in final leach column effluent from one laboratory

Table 6.1: Surface area measurements, sieve analysis and calculation of effective surface areas before and after weathering testing in duplicate for the Kanawha Black Flint Shale

Table 6.2: Surface area measurements, sieve analysis and calculation of effective surface areas before and after weathering testing in duplicate for the Lower Kittanning Shale

Table 6.3: Surface area measurements, sieve analysis and calculation of effective surface areas before and after weathering testing in duplicate for the Houchin Creek Shale

Table 6.4: Surface area measurements, sieve analysis and calculation of effective surface areas before and after weathering testing in duplicate for the Middle Kittanning Sandstone

Table 6.5: Surface area measurements, sieve analysis and calculation of effective surface areas before and after weathering testing in duplicate for the Brush Creek Shale

Table 6.6: Summary of the before and after changes in the observed BET surface areas

Table 7.1: Median monthly temperatures and differences

Table 7.2: Median CO2 content in leaching columns

Table 7.3: Volume of leachate drained out of columns

Table 7.4: Fitting parameters for sulfur release shown in Figures 7.22 – 7.25

Table 7.5: Acid-Base Accounting data for the Brush Creek Shale

Table 7.6: Example table of the computational steps to determine Ca CO3 weathering rate

Table 7.7: Calcium-and magnesium-bearing minerals in rocks used for the leaching study

Table 7.8: Elements and minerals relevant to Ca and Mg concentrations

Table 7.9: Fitting parameters for power law regression of minor element data

Table 8.1: Leachate water type at weeks 1 and 14

Table 8.2: Mean leachate composition for five rocks

Table 8.3: Total elemental content and relative fraction leached

Table 8.4: Total elemental content and absolute amount leached

Table 8.5: Estimated decay constants for calcium, sulfate, alkalinity and selenium concentration, and specific conductance

Table 9.1: Brush Creek Shale summary ABA data

Table 9.2: Houchin Creek Shale summary ABA data

Table 9.3: Kanawha Black Flint Shale summary ABA data

Table 9.4: Lower Kittanning Shale summary ABA data

Table 9.5: Sulfur and NP content of Lower Kittanning Shale field site

Table 9.6: Post-mining spoil water quality from the Lower Kittanning Shale sample site

Table 9.7: Middle Kittanning Sandstone summary ABA data

Table 9.8: Test results for Brush Creek Shale

Table 9.9: Test results for Houchin Creek Shale

Table 9.10: Test results for Kanawha Black Flint Shale

Table 9.11: Test results for Lower Kittanning Shale

Table 9.12: Test results for Middle Kittanning Sandstone

 

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Title Page | Table of Contents | List of Figures | List of Tables

This report represents more than 7 years of work by a team of scientists from various locations to develop and validate this kinetic test method. The project is a cooperative effort between the U.S. Office of Surface Mining Reclamation and Enforcement (OSM), the U.S. Environmental Protection Agency (EPA), the Acid Drainage Technology Initiative (ADTI), the Pennsylvania Department of Environmental Protection (DEP), Pennsylvania State University and CSC Dyncorp. The OSM project coordinator is Eric F. Perry. The EPA project coordinator is Joan E. Cuddeback with CSC Dyncorp. The DEP Principal Investigators for this project are Keith B.C. Brady and Roger J. Hornberger. Dr. Barry E. Scheetz and Dr. William B. White of the Materials Research Institute of the Pennsylvania State University played a key role in the test method development. Jane Hammarstrom and her associates of U.S. Geological Survey (USGS) provided a great amount of detailed information on rock characterization.

This project was jointly funded by OSM and EPA. We thank Vann Weaver, John Craynon, Stephen Parsons and Lois Uranowski from OSM for their assistance in funding all three phases of the project. We thank Mary T. Smith, Bill Telliard and Marion Kelly of EPA for their assistance in funding the interlaboratory validation phase of the project.

We especially thank and are deeply indebted to William A. Telliard of EPA (retired) for his support and guidance throughout this project. His knowledge of the methods development process and his many years experience as Director of Analytical Methods Development for the EPA Office of Water contributed greatly to the successful completion of the project.

The numerous authors of the chapters of this report are given credit at the front of each chapter. These chapters and the appendices of this report document essentially all of the information compiled in this project.

The following persons represent the laboratories participating in the interlaboratory study: Rich McCracken, Duane Wood and Dave Barrett of Mahaffey Laboratories, Timothy W. Bergstresser and Robert Stull of Geochemical Testing, Dr. Charles A. Cravotta, III and Dan Galeone of USGS, Stephanie Olexa of Benchmark Analytical, Vince Conrad of Consol Energy, Susan Hickman and John Sturm of Sturm Environmental Services, Barry E. Scheetz, William B. White and Daniel Shollenberger of Penn State Materials Research Institute, Louis McDonald and Richard Herd of the National Mine Land Reclamation Center at West Virginia University, and Cheryl Daniel at Prochem Analytical.

 

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