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Assessment of the Geoavailability of Trace Elements from Minerals in Mine Wastes: Analytical Techniques and Assessment of Selected Copper Minerals

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Assessment of the Geoavailability of Trace Elements from Minerals in Mine Wastes: Analytical Techniques and Assessment of Selected Copper Minerals Assessment of the Geoavailability of Trace Elements from Minerals in Mine Wastes: Analytical Techniques and Assessment of Selected Copper Minerals By Rhonda Driscoll, Phillip Hageman, William Benzel, Sharon Diehl, David Adams, Suzette Morman, and LaDonna Choate Scientific Investigations Report 2011-5211 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2011 About USGS Products For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS About this Product Publishing support provided by Denver Science Publishing Network For more information concerning this publication, contact: Center Director, USGS Central Mineral and Environmental Resources Science Center Box 25046, Mail stop 973 Denver, CO 80225 (303) 236-1562 or visit the Central Mineral and Environmental Resources Science Center Web site at: http://minerals.cr.usgs.gov Suggested citation: Driscoll, Rhonda, Hageman, Phillip, Benzel, William, Diehl, Sharon, Adams, David, Morman, Suzette, and Choate, LaDonna, 2011, Assessment of the geoavailability of trace elements from minerals in mine wastes: analytical techniques and assessment of selected copper minerals: U.S. Geological Survey Scientific Investigations Report 2011-5211, pamphlet, 68 p. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................2 Sample Preparation .......................................................................................................................................2 Introduction............................................................................................................................................2 Preparation Method .............................................................................................................................2 Mineralogical Analyses ................................................................................................................................3 Introduction............................................................................................................................................3 Methods..................................................................................................................................................3 Results ....................................................................................................................................................5 Carbonate Minerals Azurite and Malachite ............................................................................5 Sulfide Minerals Chalcopyrite and Bornite ...........................................................................10 Summary...............................................................................................................................................24 Bulk, Leachate, and Acid-Base Accounting Geochemical Study of Four Copper-Bearing Minerals ...........................................................................................................................................25 Introduction—Bulk Sample Chemistry.... ........................................................................................25 Bulk Sample Digestion Methods ......................................................................................................25 Bulk Chemistry Summary...................................................................................................................25 Introduction—Leaching Studies ......................................................................................................26 Laboratory Leaching Methods and Sample Analysis ...................................................................28 Leachate Geochemistry .....................................................................................................................28 Leachate pH ................................................................................................................................28 Leachate Specific Conductance (SC) ....................................................................................28 Major Anions by Ion Chromatography ............................................................................................29 Alkalinity ......................................................................................................................................29 Leachable Copper ......................................................................................................................29 Summary of Leaching Studies ...................................................................................................................30 Acid-Base Accounting (ABA) Study .........................................................................................................32 Summary of Acid-Base Accounting Study ..............................................................................................32 Leachate pH as an Indicator of Acid-Base Potential ............................................................................33 In Vitro Bioaccessibility Extractions .........................................................................................................34 Introduction..........................................................................................................................................34 Methods................................................................................................................................................34 Ingestion Pathway .....................................................................................................................34 Inhalation Pathway ....................................................................................................................35 Cell-Carrier Fluid ........................................................................................................................35 Results ..................................................................................................................................................35 Discussion ............................................................................................................................................40 Limitations of Results .........................................................................................................................43 Summary...............................................................................................................................................43 Procedure for Determination of Metal Toxicity Using MetPLATETM ....................................................44 Introduction..........................................................................................................................................44 General Method ..................................................................................................................................44 Summary...............................................................................................................................................45 Conclusion.....................................................................................................................................................49 Selected References ...................................................................................................................................50 iv Figures 1. Photographs of intergrown azurite and malachite .........................................................................6 2. X-ray diffraction scans of azurite .......................................................................................................7 3. Semi-quantitative mineralogy for azurite .........................................................................................9 4. Unit cell model for azurite..................................................................................................................10 5. Thin-section micrographs of malachite ..........................................................................................11 6. X-ray diffraction scan of malachite .................................................................................................12 7. Semi-quantitative mineralogy for malachite ..................................................................................13 8. Unit cell model for malachite ............................................................................................................14 9. Reflected-light micrographs of malachite ......................................................................................15
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