EPA 530-R-94-031 NTIS PB94-200979 TECHNICAL RESOURCE DOCUMENT EXTRACTION AND BENEFICIATION OF ORES AND MINERALS VOLUME 4 COPPER August 1994 U.S. Environmental Protection Agency Office of Solid Waste Special Waste Branch 401 M Street, SW Washington, DC 20460 Technical Resource Document: Copper DISCLAIMER AND ACKNOWLEDGEMENTS This document was prepared by the U.S. Environmental Protection Agency (EPA). The mention of company or product names is not to be considered an endorsement by the U.S. Government or by the EPA. This Technical Resource Document consists of four sections. The first is EPA's Profile of the copper industry; the remaining sections are Reports from several site visits conducted by EPA. The Profile Section was distributed for review to the U.S. Department of the Interior's (DOI's) Bureau of Mines and Bureau of Land Management; the States of Arizona, New Mexico, and Utah; the American Mining Congress (AMC), and environmental organizations. Summaries of the comments and EPA's responses are presented as Appendix 1-A to the Profile Section. The Site Visit Reports were reviewed by individual company, State, and Federal representatives who participated in the site visit. Comments and EPA responses are included as appendices to the specific Site Visit Section. EPA is grateful to all individuals who took the time to review sections of this Technical Resource Document. The use of the terms "extraction," "beneficiation," and "mineral processing" in the Profile section of this document is not intended to classify any waste streams for the purposes of regulatory interpretation or application. Rather, these terms are used in the context of common industry terminology. i Technical Resource Document: Copper TABLE OF CONTENTS Page DISCLAIMER AND ACKNOWLEDGEMENTS .............................................. i 1.0 MINING INDUSTRY PROFILE: COPPER ................................................ 1-1 1.1 INTRODUCTION ............................................................ 1-1 1.2 ECONOMIC CHARACTERIZATION OF THE INDUSTRY ......................... 1-3 1.3 ORE CHARACTERIZATION .................................................. 1-8 1.3.1 Porphyry Copper and Associated Deposits ................................ 1-8 1.3.2 Sedimentary and Metasedimentary Deposits ............................... 1-8 1.3.3 Volcanogenic Massive Sulfide Deposits .................................. 1-9 1.3.4 Veins and Replacement Deposits ........................................ 1-9 1.3.5 Ultrabasic and Carbonatite Deposits ..................................... 1-9 1.3.6 Mineral Assemblages ................................................. 1-9 1.4 COPPER EXTRACTION AND BENEFICIATION PRACTICES ..................... 1-11 1.4.1 Extraction Operations ............................................... 1-11 1.4.1.1 Typical Mining Operations ................................... 1-11 1.4.1.2 Surface Mining Methods ..................................... 1-11 1.4.1.3 Underground Mining Methods ................................ 1-14 1.4.2 Beneficiation Operations ............................................. 1-20 1.4.2.1 Conventional Milling/Flotation ................................ 1-20 1.4.2.2 Leach Operations (In Situ, Dump, Heap, and Vat) ................ 1-42 1.5 WASTES AND OTHER MATERIALS ASSOCIATED WITH COPPER EXTRACTION AND BENEFICIATION ...................................................... 1-73 1.5.1 Extraction and Beneficiation Wastes and Materials ........................ 1-76 1.5.1.1 RCRA Wastes ............................................. 1-77 1.5.1.2 Materials ................................................. 1-78 1.5.2 Waste and Materials Management ...................................... 1-81 1.5.2.1 RCRA Units .............................................. 1-81 1.5.2.2 Non-RCRA Units .......................................... 1-85 1.6 ENVIRONMENTAL EFFECTS ............................................... 1-88 1.6.1 Potential Sources of Contamination ..................................... 1-88 1.6.1.1 Mine Dewatering ........................................... 1-88 1.6.1.2 Releases from Active Leach Units ............................. 1-88 1.6.1.3 Releases from Leach Units During and After Closure .............. 1-89 1.6.1.4 Releases from Tailings Impoundments .......................... 1-89 1.6.1.5 Acid Drainage ............................................. 1-90 1.6.1.6 Beneficiation Reagents ...................................... 1-92 1.6.2 Factors Affecting the Potential for Contamination ......................... 1-92 1.6.3 Affected Media ..................................................... 1-92 1.6.3.1 Ground Water/Surface Water ................................. 1-92 1.6.3.2 Soil ...................................................... 1-93 1.6.3.3 Air ...................................................... 1-93 1.6.4 Damage Cases ..................................................... 1-94 1.6.4.1 National Priorities List ...................................... 1-94 1.6.4.2 304(l) Sites ............................................... 1-94 1.7 CURRENT REGULATORY AND STATUTORY FRAMEWORK ................... 1-95 1.7.1 Environmental Protection Agency Regulations ............................ 1-95 1.7.1.1 Resource Conservation and Recovery Act ....................... 1-95 1.7.1.2 Clean Water Act ........................................... 1-96 1.7.1.3 Clean Air Act ............................................. 1-100 1.7.2 Department of the Interior ............................................ 1-101 1.7.2.1 Bureau of Land Management ................................. 1-101 1.7.2.2 National Park Service and Fish and Wildlife Service ............... 1-103 ii Technical Resource Document: Copper 1.7.3 Department of Agriculture ............................................ 1-103 1.7.3.1 Forest Service ............................................. 1-103 1.7.4 Army Corps of Engineers ............................................. 1-104 1.7.5 State Programs ..................................................... 1-105 1.7.5.1 Arizona .................................................. 1-105 1.8 REFERENCES ............................................................. 1-110 2.0 MINE SITE VISIT: ASARCO/TROY MINE ............................................. 2-1 2.1 INTRODUCTION ............................................................ 2-1 2.1.1 Background ........................................................ 2-1 2.1.2 General Facility Description ........................................... 2-2 2.1.3 Environmental Setting ................................................ 2-7 2.1.3.1 Surface Water .............................................. 2-7 2.1.3.2 Geology ................................................... 2-8 2.1.3.3 Hydrogeology .............................................. 2-8 2.2 FACILITY OPERATIONS .................................................... 2-11 2.2.1 Mining Operations .................................................. 2-13 2.2.2 Milling Operations .................................................. 2-15 2.3 WASTE MANAGEMENT .................................................... 2-18 2.3.1 Types of Waste ..................................................... 2-18 2.3.2 Solid Waste Management Units ........................................ 2-18 2.3.2.1 Tailings Thickener .......................................... 2-18 2.3.2.2 Tailings Pipeline ........................................... 2-19 2.3.2.3 Tailings Impoundment ...................................... 2-19 2.3.2.4 Waste Rock ............................................... 2-24 2.3.2.5 Waste Oil Storage Tanks .................................... 2-24 2.3.2.6 Burn Pit .................................................. 2-24 2.3.3 Waste Water Management Units ....................................... 2-24 2.3.3.1 Mine Water ............................................... 2-24 2.3.3.2 Sanitary Sewage ........................................... 2-25 2.3.3.3 Assay Laboratory Wastes .................................... 2-25 2.3.4 Hazardous Waste Management Unit .................................... 2-25 2.3.4.1 Waste Solvent Tanks ........................................ 2-25 2.4 MONITORING ............................................................. 2-26 2.4.1 Surface Water ...................................................... 2-26 2.4.2 Ground Water ...................................................... 2-29 2.4.3 Air ............................................................... 2-29 2.5 REGULATORY REQUIREMENTS AND COMPLIANCE ......................... 2-30 2.5.1 Operating Permit ................................................... 2-30 2.5.2 Solid Waste ....................................................... 2-30 2.5.3 Surface Water ...................................................... 2-31 2.5.4 Ground Water ...................................................... 2-31 2.5.5 Air ............................................................... 2-31 2.5.6 Hazardous Waste ................................................... 2-32 2.6 REFERENCES ............................................................. 2-33 3.0 MINE SITE VISIT: SAN MANUEL FACILITY MAGMA COPPER COMPANY .................... 3-1 3.1 INTRODUCTION ............................................................ 3-1 3.1.1 Background ........................................................ 3-1 3.1.2 General Description .................................................. 3-2 3.1.3 Environmental Setting ...............................................