Biomining (eBook)

Douglas E. Rawlings: Professor and Head of Department of Microbiology at the University of Stellenbosch, South Africa. BSc (Hons), PhD Rhodes University, South Africa. Fellow of the University of Cape Town, Royal Society of South Africa (an immediate past President of RSSAf). Editor of previous book on subject Biomining, Theory, Microbes and Industrial Processes, published by Springer and RG Landes (1997). D. Barrie Johnson: Reader in Environmental and Applied Microbiology at the University of Wales, Bangor, U.K. Doctoral and Batchelor degrees from the University of Wales. Fellowships held at the Idaho National Engineering and Environmental Laboratories, (US Department of Energy).

Preface 5
Contents 7
List of Contributors 16
1 The BIOX™ Process for the Treatment of Refractory Gold Concentrates 19
1.1 Introduction 19
1.2 The BIOX™ Process Flow Sheet 20
1.3 Current Status of Operating BIOX™ Plants 23
1.4 The BIOX™ Bacterial Culture 26
1.5 Engineering Design and Process Requirements 27
1.6 BIOX™ Capital and Operating Cost Breakdown 36
1.7 New Developments in the BIOX™ Technology 39
1.8 BIOX™ Liquor Neutralization and Arsenic Disposal 45
1.9 Conclusion 50
References 50
2 Bioleaching of a Cobalt-Containing Pyrite in Stirred Reactors: a Case Study from Laboratory Scale to Industrial Application 52
2.1 Introduction 52
2.2 Feasibility and Pilot-Scale Studies 54
2.3 Full-Scale Operation: the Kasese Plant 63
2.4 Conclusion 70
References 71
3 Commercial Applications of Thermophile Bioleaching 73
3.1 Introduction 73
3.2 Commercial Context of Copper Processing Technologies 73
3.3 Key Factors Influencing Commercial Decisions for Copper Projects 77
3.4 Techno-commercial Niche for Thermophilic Bioleaching 82
3.5 Thermophilic Heap Bioleaching of Marginal Ores 89
3.6 Summary 94
References 94
4 A Review of the Development and Current Status of Copper Bioleaching Operations in Chile: 25 Years of Successful Commercial Implementation 97
4.1 Historical Background and Development of Copper Hydrometallurgy in Chile 97
4.2 Technical Developments in Chile in the Direct Leaching of Ores 99
4.3 Current Status of Chilean Commercial Bioleaching Operations and Projects 102
4.4 Current Advances Applied Research and Development in Bioleaching in Chile 109
4.5 Concluding Remarks 110
References 111
5 The GeoBiotics GEOCOAT® Technology – Progress and Challenges 112
5.1 Introduction 112
5.2 The GEOCOAT® and GEOLEACH™ Technologies 112
5.3 The Agnes Mine GEOCOAT® Project 118
5.4 Developing Technologies 126
References 127
6 Whole-Ore Heap Biooxidation of Sulfidic Gold- Bearing Ores 128
6.1 Introduction 128
6.2 History of BIOPRO™ Development 128
6.3 Commercial BIOPRO™ Process 130
6.4 Commercial BIOPRO™ Operating Performance 135
6.5 Lessons Learned 143
6.6 Final Thoughts 151
References 152
7 Heap Leaching of Black Schist 154
7.1 Introduction 154
7.2 Significance and Potential of Talvivaara Deposit 154
7.3 Biooxidation Potential and Factors Affecting Bioleaching 155
7.4 Leaching of Finely Ground Ore with Different Suspension Regimes 156
7.5 Heap Leaching Simulations 157
7.6 Dynamics of Biocatalyst Populations 163
References 165
8 Modeling and Optimization of Heap Bioleach Processes 167
8.1 Introduction 167
8.2 Physical, Chemical and Biological Processes Underlying Heap Bioleaching 168
8.3 Mathematical Modeling 173
8.4 Application of Mathematical Modeling – from Laboratory to Heap 179
8.5 Case Study I – Chalcocite 182
8.6 Case Study II – Sphalerite and Pyrite 185
8.7 The Route Forward – Chalcopyrite 188
8.8 Conclusions 188
References 189
9 Relevance of Cell Physiology and Genetic Adaptability of Biomining Microorganisms to Industrial Processes 191
9.1 Introduction 191
9.2 Biooxidation of Minerals Is a Marriage Between Chemistry and Biology 191
9.3 General Chemistry of Mineral Biooxidation 192
9.4 Advantages of Mineral Biooxidation Processes Compared with Many Other Microbe- Dependent Processes 193
9.5 Should New Processes Be Inoculated with Established Microbial Consortia? 195
9.6 Types of Organisms 196
9.7 General Physiology of Mineral-Degrading Bacteria 198
9.8 Autotrophy 199
9.9 Nitrogen, Phosphate and Trace Elements 200
9.10 Energy Production 201
9.11 Adaptability of Biomining Microorganisms 205
9.12 Metal Tolerance and Resistance 206
9.13 Conclusions 209
References 209
10 Acidophile Diversity in Mineral Sulfide Oxidation 213
10.1 Introduction 213
10.2 Acidophiles in Mineral Sulfide Oxidation 213
10.3 Dual Energy Sources: Mineral Dissolution by Iron- Oxidizing and by Sulfur- Oxidizing Bacteria 217
10.4 Acidophiles in Mineral Processing 219
10.5 Diversity in Iron Oxidation 222
10.6 Summary 225
References 226
11 The Microbiology of Moderately Thermophilic and Transiently Thermophilic Ore Heaps 231
11.1 Introduction 231
11.2 Heat Generation Within Bioleaching Heaps 232
11.3 Effect of Temperature on Bioleaching Microorganisms 235
11.4 Microbial Populations of Moderately Thermophilic or Transiently Thermophilic Commercial Bioleaching Heaps 240
11.5 Summary 246
References 247
12 Techniques for Detecting and Identifying Acidophilic Mineral- Oxidizing Microorganisms 250
12.1 Biodiversity of Acidophilic Microorganisms That Have Direct and Secondary Roles in Mineral Dissolution 250
12.2 General Techniques for Detecting and Quantifying Microbial Life in Mineral- Oxidizing Environments 251
12.3 Cultivation-Dependent Approaches 254
12.4 Polymerase Chain Reaction (PCR)-Based Microbial Identification and Community Analysis 258
12.5 PCR-Independent Molecular Detection and Identification of Acidophiles 266
12.6 Future Perspectives on Molecular Techniques for Detection and Identification of Acidophiles 268
References 270
13 Bacterial Strategies for Obtaining Chemical Energy by Degrading Sulfide Minerals 275
13.1 Introduction 275
13.2 Pyrite As a Model System for Understanding Bacterial Sulfide Leaching Activities 276
13.3 Electronic Structure and Thermodynamic Properties of Pyrite 276
13.4 The Energy Strategy of Leptospirillum ferrooxidans 281
13.5 The Energy Strategy of Acidothiobacillus ferrooxidans 284
13.6 Surface Chemistry, Colloids and Bacterial Activity 286
13.7 Mechanism of Colloidal Particle Uptake into the Capsule and Exopolymeric Substances 286
13.8 Energy Turnover at the Nanoscale, a Strategic Skill Evolved by Bacteria 289
13.9 Summary 290
References 290
14 Genetic and Bioinformatic Insights into Iron and Sulfur Oxidation Mechanisms of Bioleaching Organisms 293
14.1 Introduction 293
14.2 Relevant Biochemical and Chemical Reactions 294
14.3 Genetics of Bioleaching Microorganisms 294
14.4 Iron and Sulfur Oxidation and Reduction in Acidithiobacillus ferrooxidans 299
14.5 Iron Oxidation in Other Bioleaching Microorganisms 308
14.6 Outstanding Questions and Future Directions 313
References 314
Index 320