draft acid rock drainage technical guide

274 Pages·2013·16.34 MB·English

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DRAFT ACID
ROCK DRAINAGE
TECHNICAL GUIDE
VOLUME 1

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DRAINAGE TECHNICAL GUIDE V
VOLUME 1
BRITISH COLUMBIA ACID MINE DRAINAGE TASK FORCE REPORT
Prepared for the:
British Columbia Acid Mine Drainage Task Force, with funding from Energy, Mines and Resources
Canada and the British Columbia Ministry of Energy, Mines and Petroleum Resources under the
Canada/British Columbia Mineral Development Agreement 0985-90).
Prepared by:
Steffen Robertson and Kirsten (B.C.) Inc.
801 -1030 West Georgia Street
Vancouver, B.C. V6E 2N7
In Association With:
Norecol Environmental Consultants
700 - 1090 West Pender Street
Vancouver, B.C. V6E 2N7
Gormely Process Engineering
612 - 1200 West Pender Street
Vancouver, B.C. V6E 2S9
August 1989
Canadian Cataloguing in Publication Data
Main entry under title:
Draft acid rock drainage technical guide
Loose-leaf for updating
Includes bibliographical references
ISBN 0-7718-8893-7
1. Acid mine drainage - British Columbia. 2. Mines
and mineral resources - British Columbia - Waste
disposal. 3. Sulphides - British Columbia. I.
British Columbia Acid Mine Drainage Task Force. II.
Steffen Robertson and Kirsten (B.C.) Inc. III.
Norecol Environmental Consultants. IV. Gormely
Process Engineering. V. British Columbia. Ministry
of Energy, Mines and Petroleum Resources. VI.
Canada/British Columbia Mineral Development Agree
ment. VII. Title: British Columbia Acid Mine Drain
age Task Force report.
TD899.M5D72 1989 622' .509711 C89-092276-4
DISCLAIMER
The purpose of this guide is to provide the user with an understanding of the
processes of acid generation and metal leaching from sulphide wastes and to provide
guidance and recommendations in the application of currently available technology.
This guide is issued as a draft document with the intention of being updated as
technology progresses. The user of this guide assumes full responsibility for the design
of facilities and for any action taken as a result of the recommendations contained in
this guide. Neither the Province of British Columbia Acid Mine Drainage Task Force
nor the consultants who prepared this document may be held liable for the outcome
of any action taken by the user.
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989
AUTHORS OF THE TECHNICAL GUIDE
This Guide was compiled on behalf, and under the direction of the Province of British
Columbia Acid Mine Drainage Task Force, by Steffen Robertson and Klrsten (B.C.) Inc.,
in Association with Norecol Environmental Consultants and Gormely Process
Engineering. The different chapters and sections of the report were authored as
follows:
Chapter 1: Steffen Robertson and Kirsten
Chapter 2: Norecol Environmental Consultants
Chapter 3: Steffen Robertson and Kirsten
Chapter 4: Norecol Environmental Consultants
Chapter 5: Steffen Robertson and Kirsten
Chapter 6: 6.1 to 6.6 Steffen Robertson and Kirsten
6.7 & 6.8 Norecol Environmental Consultants
6.9, 6.10.1 & 6.10.2 Steffen Robertson and Kirsten
6.10.3 & 6.10.4 Norecol Environmental Consultants
6.11 Steffen Robertson and Kirsten
Chapter 7: Steffen Robertson and Kirsten
Chapter 8: 8.1 & 8.2 Steffen Robertson and Kirsten
8.3 Gormely Process Engineering
8.4 & 8.5 Norecol Environmental Consultants
Chapter 9: Steffen Robertson and Kirsten
Chapter 10: Steffen Robertson and Kirsten
Chapter 11: Norecol Environmental Consultants
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989
1
TABLE OF CONTENTS
VOLUME I - TECHNICAL GUIDE
PART I - INTRODUCTION AND DESCRIPTION OF PROCESSES
CHAPTER 1: INTRODUCTION TO ACID ROCK DRAINAGE TECHNOLOGY
1.1 Objectives of this Technical Guide 1-1
1.2 Description of Acid Rock Drainage 1-1
1.3 Brief History of Acid Rock Drainage 1-2
1.4 Overview of ARD in British Columbia 1-4
1.4.1 History of ARD in British Columbia 1-4
1.4.2 ARD in British Columbia Today 1-6
1.5 Lessons from Other Provinces and Countries 1-8
1.6 Acid Rock Drainage Research in Canada 1-9
1.7 Sources of Acid Rock Drainage 1-10
1.7.1 Underground Mines 1-10
1.7.2 Open Pit Mines 1-10
1.7.3 Waste Rock 1-10
1.7.4 Spoil Piles 1-11
1.7.5 Tailings 1-11
1.7.6 Stockpiles and Spent Heap-leach Piles 1-11
1.8 Objectives of Prediction, Control and Monitoring Technology ... 1-11
CHAPTER 2: THE ACID GENERATION PROCESS
2.1 Introduction 2-1
2.2 Sulphide Minerals 2-2
2.3 Chemical and Biological Reactions Related to Acid Generation . 2-4
2.4 Stages in the Development of Acid Rock Drainage 2-8
CHAPTER 3: METAL LEACHING AND MIGRATION PROCESSES
3.1 Introduction , 3-1
3.2 Physical Controls 3-2
3.3 Chemical Controls 3-2
3.4 Biological Controls 3-3
3.5 Impact on the Environment 3-3
3.6 Application of Theory to Prediction, Control and Monitoring . . .. 3-4
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989
PART II - PREDICTION
CHAPTER 4: PREDICTION OF ACID GENERATION AND ACIDIC DRAINAGE
4.1 Introduction and Approach to Prediction 4-1
4.1.1 Introduction 4-1
4.1.2 Approach to Prediction 4-1
4.2 Geographical, Paleoenvironmental, and Geological Comparisons 4-4
4.2.1 Geographical Comparisons 4-4
4.2.2 Paleoenvironmental and Geologic Models 4-4
4.3 Sampling Methods for Static and Kinetic Tests 4-6
4.3.1 Objectives of Sampling 4-6
4.3.2 Application of Sampling Program 4-8
4.4 Static Predictive Tests 4-9
4.4.1 Introduction 4-9
4.4.2 Procedure for conducting a static test 4-10
4.5 Kinetic Tests 4-14
4.5.1 Introduction 4-14
4.5.2 Procedures for conducting a kinetic test 4-14
4.6 Mathematical Models 4-18
4.7 Summary 4-19
CHAPTER 5: ACID GENERATION AND METAL LEACHING MODELS
5.1 Introduction 5-1
5.2 Mechanisms or Processes Simulated 5-2
5.3 Model Selection and Development 5-3
5.4 Input Data Requirement 5-8
5.5 Model Applications 5-9
5.6 Conclusions 5-11
PART III - CONTROL
CHAPTER 6: CONTROL OF ACID GENERATION
6.1 Introduction 6-1
6.2 Objectives of Acid Generation Control 6-1
6.3 Approach to Acid Generation Control 6-2
6.4 Available Control Measures 6-4
6.5 Conditioning of Tailings/Waste Rock 6-5
6.6 Waste Segregation and Blending 6-6
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989
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6.7 Bactercides 6-7
6.8 Base Additives 6-9
6.9 Covers and Seals to Control Acid Generation 6-12
6.9.1 Soil Covers 6-13
6.9.2 Synthetic Membrane Covers 6-13
6.9.3 Water Cover 6-15
6.9.4 Saturated Soil or Bog 6-15
6.10 Subaqueous Deposition 6-16
6.10.1 Disposal Into Man-Made Impoundments 6-16
6.10.2 Disposal into Flooded Mine Workings 6-17
6.10.3 Lake Disposal 6-18
6.10.4 Marine Disposal 6-20
6.11 Conclusions 6-21
CHAPTER 7: CONTROL OF ARD MIGRATION
7.1 Introduction 7-1
7.2 Diversion of Surface Water 7-1
7.2.1 General 7-1
7.2.2 Underground Mines 7-2
7.2.3 Open Pits 7-2
7.2.4 Waste Rock Dumps and Spoil Piles 7-2
7.2.5 Tailings Deposits 7-3
7.2.6 Stockpiles and Spent Heap-leach Piles 7-3
7.3 Groundwater Interception 7-3
7.3.1 General 7-3
7.3.2 Underground Mines 7-4
7.3.3 Open Pits 7-4
7.3.4 Waste Rock Dumps and Spoil Piles 7-5
7.3.5 Tailings Deposits 7-5
7.3.6 Stockpiles and Spent Heap-leach Piles 7-5
7.4 Covers and Seals to Control Infiltration 7-5
7.4.1 General 7-5
7.4.2 Soil Covers 7-5
7.4.3 Synthetic Covers 7-30
7.4.4 Placement of Covers 7-36
7.5 Waste Rock and Tailings Placement Methods 7-39
7.5.1 Waste Rock Dumps 7-39
7.5.2 Tailings 7-39
7.6 Conclusions 7-40
CHAPTER 8: COLLECTION AND TREATMENT OF ARD
8.1 Introduction 8-1
8.2 Collection Systems 8-1
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989
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r- 8.3 Chemical Treatment 8-1
8.3.1 Process Chemistry 8-1
8.3.1.1 Neutralization 8-2
r- 8.3.1.2 Precipitation 8-4
8.3.1.3 Scale Formation 8-7
8.3.1.4 Ume 8-8
r 8.3.1.5 Sludge Stability and disposal 8-9
I 8.3.2 Alternative Process Configurations 8-11
8.3.2.1 Unit Operations 8-11
r 8.3.2.2 Case Histories 8-17
8.3.3 Process Development and Testwork Procedures 8-23
8.3.3.1 Characterization of Feed 8-24
8.3.3.2 Small Scale Batch Precipitation and
Coagulation Test 8-26
8.3.3.3 Settling tests 8-27
8.3.3.4 Sludge characterization and stability 8-28
8.3.3.5 Batch oxidation testing 8-29
r- 8.3.3.6 Testing for other unit operations 8-30
8.3.4 Design 8-31
8.3.4.1 Design Criteria 8-31
8.3.4.2 Design Procedures 8-33
8.3.5 Process Control and Operation 8-38
8.3.5.1 Reagent dosing system and control 8-38
8.3.5.2 Oxidation Control 8-39
8.3.5.3 Turbidity measurement 8-39
8.3.5.4 Analytical support 8-39
r 8.3.5.5 Operator duties 8-40
[ 8.3.5.6 Maintenance and repair 8-41
8.3.5.7 Troubleshooting 8-41
r 8.3.6 Long Term Outlook 8-41
' 8.3.6.1 Process Reliability 8-41
8.3.6.2 Plant Integrity 8-41
r
; 8.3.6.3 Sludge Stability 8-42
8.3.7 Capital and Operating Costs for Typical Installations . . 8-42
8.3.7.1 Review of available experience . , 8-42
r
8.3.7.2 Cost summary 8-43
8.3.7.3 Development of "rules of thumb" 8-44
r~ 8.3.8 Future Directions for Reseach & Development 8-47
8.4 Wetland Treatment 8-47
8.4.1 Overview 8-47
r 8.4.2 Wetland Treatment Processes 8-48
8.4.3 Advantages of Wetland Treatment Systems 8-49
8.4.4 Disadvantages of Wetland Treatment Systems 8-49
8.4.5 Preliminary Design Considerations 8-50
8.4.6 Reasearch Needs 8-52
8.5 Other Treatments 8-53
BC AMD TASK FORCE, DRAFT TECHNICAL GUIDE, VOL I. AUGUST 1989