Final Report: Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization

EPA Grant Number: R825549C048
Subproject: this is subproject number 048 , established and managed by the Center Director under grant R825549
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (1989) - Great Plains/Rocky Mountain HSRC
Center Director: Erickson, Larry E.
Title: Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization
Investigators: Munshower, Frank F. , Jennings, Stuart R.
Institution: Montana State University - Bozeman
EPA Project Officer: Hahn, Intaek
Project Period: August 13, 1993 through April 7, 1998
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Heavy Metal Contamination of Soil/Water , Land and Waste Management


This project will attempt to demonstrate an alternative, cost-effective, permanent mine tailing reclamation methodology through the marriage of mineral processing and land reclamation techniques. The approach to be used, clean tailing reclamation (CTR), utilizes potentially field-deployable mineral separation technologies to remove dense sulfide minerals from tailing material by gravimetric separation, followed by vegetative stabilization of the cleaned tailing material with native plants. CTR will allow for removal of environmental contaminants and acid-forming materials.

Summary/Accomplishments (Outputs/Outcomes):

Mine waste is a widespread and pervasive problem in EPA Regions VII and VIII. Historical mining activity has contaminated many thousands of acres of soil by uncontrolled waste disposal practices resulting in resource degradation that will cost billions of dollars to remediate. One of the principal problems associated with reclamation of hardrock mine sites is tailing reclamation. Tailing materials cover tens of thousands of acres of land in the region pair. This research specifically compliments research being conducted in Anaconda, Montana, on tailing reclamation and will provide comparisons on the relative strength of this technology through plant performance, geochemical distribution of contaminants, and cost of implementation. Upon completion of this research, the findings will be useful to Superfund managers and Potentially Responsible Party decision-makers, and to operational mines and regulators.

Research will be implemented at Montana State University. Outside expertise will be solicited from other experts in mineral separation in conjunction with the use of experimental equipment housed at Butte, Montana. Contract laboratories will be solicited and appropriate sample analyses will be submitted for analysis. Sample material used in research will be collected from three locations in coordination with regulatory personnel. Representative samples of tailings materials will be collected from each of the three locations and chemically characterized to identify the elemental and mineralogical distribution of the heavy metal and acid-generating contaminants. Subsequent to sample characterization, mineralogical separation of the dense sulfide minerals will be performed using gravimetric techniques. For bench-scale work, mineral separation technologies considered will include technologies developed through the Superfund Innovative Technology Evaluation (SITE) Program. Following tailing material reprocessing activity, subsamples will be chemically characterized to determine the efficacy of the reprocessing/tailing cleaning technologies. Greenhouse studies will be implemented in the cleaned tailing material to compare performance of the cleaned tailing material with conventional reclamation approaches. The native grass species selected for use are Red top (Agrostis alba) and Basin wild rye (Leymus cinereus).

In the Western U.S., environmentally insensitive disposal of mine tailing material has resulted in a legacy of polluted water and degraded terrestrial resources. Technologies for remediation of these sites are few, while tens of thousands of acres of land are covered with tailing materials. Conventionally, when mine tailings are remediated, attempts are made to hydrologically isolate waste by placement in a repository followed by topsoil capping. Despite the apparent simplicity of this approach, the high cost of capping, local shortage of topsoil and site specific engineering challenges undermine the feasibility of reclamation. Alternately, in-situ reclamation through additions of lime, organic matter and other amendments has been demonstrated as a plausible less costly reclamation technique. In-situ methods allow for establishment of vegetation, yet total metal levels are unchanged and may possibly be released to the environment at a later date. Clean Tailing Reclamation (CTR) is a technology for removal of metal sulfides and associated heavy metal constituents from tailings through reprocessing. Treatment results in a metal concentrate suitable to either metal recycling or careful disposal, and a cleaned silicate media suitable for use as a soil substrate. This marriage between metallurgical and agronomic techniques is a potentially less costly and environmentally cleaner reclamation technology for mine tailings than those which are currently implemented.

The goals of this research project parallels the need for alternative tailing reclamation methodologies for acid producing tailing material:

1. Demonstration of an alternative, cost effective' permanent method for tailing reclamation;
2. Reduction of the toxicity. mobility. and bioavailability of metal contaminants in tailings;
3. Reduction of the acid generating potential of tailing material;
4. Establishment of vegetation on reprocessed and amended tailing materials;
5. Recovery and recycling of economically valuable mineral resources.

The approach applied to this research investigation is split into two phases. The first phase of the research was demonstration of CTR in a controlled laboratory and greenhouse setting under HSRC funding. The first phase has been completed. The second, and pending, phase of the research will be a field deployment of CTR technology.

Following field collection of three different tailing materials, separation of sulfides from silicates by conventional metallurgical technique was demonstrated resulting in a metal enriched sulfide (pyrite) concentrate. A corresponding decrease in metal levels was observed in the cleaned tailing substrate. The resultant cleaned tailing material exhibited metal levels similar to the topsoil control.

Laboratory leaching experimentation performed on cleaned tailings (both with and without lime addition), lime amended field tailings (high lime rate), topsoil, and unamended tailings revealed significant differences between the experimental treatments. The unamended tailing materials typically had measured water soluble metal levels orders of magnitude higher than the experimental treatments. The topsoil, conversely, exhibited high levels of water soluble plant nutrients and lower levels of plant inhibitory elements. The cleaned tailings (low lime rate) and lime amended field tailings (high lime rate) exhibited similar low levels of plant nutrients and heavy metals, while the cleaned tailings (without lime addition) revealed an elevated heavy metal signature compared to the cleaned tailings with additional lime. Therefore, reprocessing to remove sulfides and other heavy metals was successful in reducing total metal concentrations and lime rates, while some supplemental lime was required for control of pH and soluble metals. These treatments effects demonstrate the great potential for decreased reclamation cost through decreased lime requirement, and decreased ecological risk through removal of heavy metals.

Greenhouse response to the same experimental treatments was similar to the soluble chemistry evaluation where the best plant growth observed was in the topsoil treatments. Both the lime amended field tailings and cleaned tailings supported the perennial grasses seeded. But production was significantly less than the topsoil as would be expected due to the lower levels of plant macronutrients. The unamended controls supported little or no vegetation. An evaluation of sunflower (Helianthus annus) grown in the harshest of the three tailing materials revealed good plant growth in the cleaned tailings while lime amended tailing treatments resulted in the death of the seeded vegetation. Clean tailing technology, therefore, may support a broader diversity of plant species than in-situ reclamation techniques.

A technology transfer seminar was conducted in September 1996 to present the preliminary findings of the Clean Tailing Reclamation Study to government, industry and private consulting firm participants. The seminar was well attended, and all participants expressed an interest in obtaining the final report upon publication.

Subsequently, discussions have been conducted regarding the applicability of CTR technology to field sites in Montana. Remediation of vast tailing areas near Anaconda, Montana, has been proposed by EPA at a cost of nearly $200 million. Conventional reclamation methods are quite costly, while CTR Technologies could result in significant cost savings at this site alone. Presentation of the technology to project managers responsible for Superfund cleanup in Anaconda was held on March 10, 1998.

Journal Articles on this Report : 2 Displayed | Download in RIS Format

Other subproject views: All 6 publications 2 publications in selected types All 2 journal articles
Other center views: All 904 publications 230 publications in selected types All 182 journal articles
Type Citation Sub Project Document Sources
Journal Article Jennings SR, Dollhopf DJ. Acid-base account effectiveness for determination of mine waste potential acidity. Journal of Hazardous Materials 1995;41(2-3):161-175. R825549C048 (Final)
not available
Journal Article Jennings SR, Dollhopf DJ, Inskeep W. Hydrogen peroxide oxidation of sulfide and sulfate minerals for prediction of mine waste acid generation. Geological Society of America 1995;27(4):16. R825549C048 (Final)
not available

Supplemental Keywords:

vegetation, reclamation, metallic minerals, mining, tailings., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Contaminated Sediments, Environmental Chemistry, Geochemistry, Remediation, Fate & Transport, Analytical Chemistry, Hazardous Waste, Ecology and Ecosystems, Hazardous, fate and transport, hazardous waste treatment, contaminant transport, Superfund sites, acid mine drainage, contaminated sediment, kinetics, biodegradation, contaminated soil, vegetation, reclamation, heavy metal contamination, phytoremediation, heavy metals, metals

Relevant Websites: Exit

Progress and Final Reports:

Original Abstract
  • 1994
  • 1995
  • 1996
  • 1997

  • Main Center Abstract and Reports:

    R825549    HSRC (1989) - Great Plains/Rocky Mountain HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825549C006 Fate of Trichloroethylene (TCE) in Plant/Soil Systems
    R825549C007 Experimental Study of Stabilization/Solidification of Hazardous Wastes
    R825549C008 Modeling Dissolved Oxygen, Nitrate and Pesticide Contamination in the Subsurface Environment
    R825549C009 Vadose Zone Decontamination by Air Venting
    R825549C010 Thermochemical Treatment of Hazardous Wastes
    R825549C011 Development, Characterization and Evaluation of Adsorbent Regeneration Processes for Treament of Hazardous Waste
    R825549C012 Computer Method to Estimate Safe Level Water Quality Concentrations for Organic Chemicals
    R825549C013 Removal of Nitrogenous Pesticides from Rural Well-Water Supplies by Enzymatic Ozonation Process
    R825549C014 The Characterization and Treatment of Hazardous Materials from Metal/Mineral Processing Wastes
    R825549C015 Adsorption of Hazardous Substances onto Soil Constituents
    R825549C016 Reclamation of Metal and Mining Contaminated Superfund Sites using Sewage Sludge/Fly Ash Amendment
    R825549C017 Metal Recovery and Reuse Using an Integrated Vermiculite Ion Exchange - Acid Recovery System
    R825549C018 Removal of Heavy Metals from Hazardous Wastes by Protein Complexation for their Ultimate Recovery and Reuse
    R825549C019 Development of In-situ Biodegradation Technology
    R825549C020 Migration and Biodegradation of Pentachlorophenol in Soil Environment
    R825549C021 Deep-Rooted Poplar Trees as an Innovative Treatment Technology for Pesticide and Toxic Organics Removal from Soil and Groundwater
    R825549C022 In-situ Soil and Aquifer Decontaminaiton using Hydrogen Peroxide and Fenton's Reagent
    R825549C023 Simulation of Three-Dimensional Transport of Hazardous Chemicals in Heterogeneous Soil Cores Using X-ray Computed Tomography
    R825549C024 The Response of Natural Groundwater Bacteria to Groundwater Contamination by Gasoline in a Karst Region
    R825549C025 An Electrochemical Method for Acid Mine Drainage Remediation and Metals Recovery
    R825549C026 Sulfide Size and Morphology Identificaiton for Remediation of Acid Producing Mine Wastes
    R825549C027 Heavy Metals Removal from Dilute Aqueous Solutions using Biopolymers
    R825549C028 Neutron Activation Analysis for Heavy Metal Contaminants in the Environment
    R825549C029 Reducing Heavy Metal Availability to Perennial Grasses and Row-Crops Grown on Contaminated Soils and Mine Spoils
    R825549C030 Alachlor and Atrazine Losses from Runoff and Erosion in the Blue River Basin
    R825549C031 Biodetoxification of Mixed Solid and Hazardous Wastes by Staged Anaerobic Fermentation Conducted at Separate Redox and pH Environments
    R825549C032 Time Dependent Movement of Dioxin and Related Compounds in Soil
    R825549C033 Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas
    R825549C034 Modeling the use of Plants in Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances
    R825549C035 Development of Electrochemical Processes for Improved Treatment of Lead Wastes
    R825549C036 Innovative Treatment and Bank Stabilization of Metals-Contaminated Soils and Tailings along Whitewood Creek, South Dakota
    R825549C037 Formation and Transformation of Pesticide Degradation Products Under Various Electron Acceptor Conditions
    R825549C038 The Effect of Redox Conditions on Transformations of Carbon Tetrachloride
    R825549C039 Remediation of Soil Contaminated with an Organic Phase
    R825549C040 Intelligent Process Design and Control for the Minimization of Waste Production and Treatment of Hazardous Waste
    R825549C041 Heavy Metals Removal from Contaminated Water Solutions
    R825549C042 Metals Soil Pollution and Vegetative Remediation
    R825549C043 Fate and Transport of Munitions Residues in Contaminated Soil
    R825549C044 The Role of Metallic Iron in the Biotransformation of Chlorinated Xenobiotics
    R825549C045 Use of Vegetation to Enhance Bioremediation of Surface Soils Contaminated with Pesticide Wastes
    R825549C046 Fate and Transport of Heavy Metals and Radionuclides in Soil: The Impacts of Vegetation
    R825549C047 Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants
    R825549C048 Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization
    R825549C049 Laboratory and Field Evaluation of Upward Mobilization and Photodegradation of Polychlorinated Dibenzo-P-Dioxins and Furans in Soil
    R825549C050 Evaluation of Biosparging Performance and Process Fundamentals for Site Remediation
    R825549C051 Field Scale Bioremediation: Relationship of Parent Compound Disappearance to Humification, Mineralization, Leaching, Volatilization of Transformaiton Intermediates
    R825549C052 Chelating Extraction of Heavy Metals from Contaminated Soils
    R825549C053 Application of Anaerobic and Multiple-Electron-Acceptor Bioremediation to Chlorinated Aliphatic Subsurface Contamination
    R825549C054 Application of PGNAA Remote Sensing Methods to Real-Time, Non-Intrusive Determination of Contaminant Profiles in Soils
    R825549C055 Design and Development of an Innovative Industrial Scale Process to Economically Treat Waste Zinc Residues
    R825549C056 Remediation of Soils Contaminated with Wood-Treatment Chemicals (PCP and Creosote)
    R825549C057 Effects of Surfactants on the Bioavailability and Biodegradation of Contaminants in Soils
    R825549C058 Contaminant Binding to the Humin Fraction of Soil Organic Matter
    R825549C059 Identifying Ground-Water Threats from Improperly Abandoned Boreholes
    R825549C060 Uptake of BTEX Compounds by Hybrid Poplar Trees in Hazardous Waste Remediation
    R825549C061 Biofilm Barriers for Waste Containment
    R825549C062 Plant Assisted Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances: Experimental and Modeling Studies
    R825549C063 Extension of Laboratory Validated Treatment and Remediation Technologies to Field Problems in Aquifer Soil and Water Contamination by Organic Waste Chemicals