As the first book to compile the fundamentals, applications, reference information and analytical tools on the topic, Hydrometallurgy presents a condensed collection of information that can be used to improve the efficiency and effectiveness with which metals are extracted, recovered, manufactured, and utilized in aqueous media in technically viable and reliable, environmentally responsible, and economically feasible ways. Suitable for students and researchers, this college-level overview addresses Fundamentals of Chemical Metallurgy in Aqueous Media, Speciation and Phase Diagrams, Rate Processes in Aqueous Metal Processing, Aqueous Metal Extraction and Leaching, Fundamentals of Metal Concentration Processes and more.

MICHAEL L. FREE, PhD, is Professor of Metallurgical Engineering at the University of Utah. Dr. Free's research sheds new light on metal processing and interactions in aqueous media. He has been the principal investigator for fifty research projects funded by the Department of Energy, Office of Naval Research, National Science Foundation, and various private corporations. Dr. Free has also authored or coauthored more than 100 publications.

Explores the fundamentals as well as the latest applications in hydrometallurgy

With its unique blend of fundamentals, methods, and applications, this text provides a college-level introduction and overview of hydrometallurgy, the chemical processing of metals in aqueous solutions. The author provides an expertly organized collection of information and analytical tools for effective and efficient extraction, concentration, and recovery of metals from ores, concentrates, and recycled or residual materials. Moreover, readers will discover a broad range of hydrometallurgical methods that are both environmentally responsible and economically feasible.

This text explores several essential topics that are generally not covered extensively in other hydrometallurgy texts, including aqueous electrometallurgy, aqueous corrosion, environmental hydrometallurgy, and metal utilization in aqueous media. In addition, the text covers such topics as:

• Speciation and phase diagrams
• Rate processes in aqueous metal processing
• Aqueous metal extraction and leaching
• Metal concentration processes
• Selective aqueous metal recovery phases
• Process design principles for aqueous processing of metals

Hydrometallurgy also covers environmental regulations as well as remediation technologies. Detailed examples as well as illustrations throughout the chapters help readers fully grasp complex concepts and apply them in practice. At the end of the text, a group of appendices brings together valuable reference materials, including atomic weights, important constants, conversion factors, and laboratory calculations.

Hydrometallurgy is written for students and professional engineers who use, produce, concentrate, or remove metals processed in aqueous media. The text's coverage of the fundamentals is ideal for readers new to the field, while its coverage of advanced topics enables more experienced engineers to take full advantage of the latest applications in hydrometallurgy.

PREFACE xi

1 INTRODUCTION 1

1.1 The Importance of Metals 1

1.2 Mineral Deposition 2

1.3 Importance of Water 10

1.4 Aqueous Processing and Utilization of Metals 12

1.5 Overview of Fundamentals and Applications 17

References 19

Problems 20

2 CHEMICAL FUNDAMENTALS OF HYDROMETALLURGY 21

2.1 General Reactions 21

2.2 Chemical Potential 24

2.3 Free Energy and Standard Conditions 28

2.4 Free Energy and Nonstandard Activities 30

2.5 Equilibrium 31

2.6 Solubility Product 33

2.7 Relationships Amongst K, pK, pKa, and pH 34

2.8 Free Energy and Nonstandard Temperatures 36

2.9 Heat Generation due to Reactions 40

2.10 Free Energy and Nonstandard Pressures 41

2.11 Equilibrium Concentration Determinations 41

2.12 Activities and Activity Coefficients 42

2.13 Practical Equilibrium Problem Solving 47

2.14 Electrochemical Reaction Principles 52

2.15 Equilibrium and Electrochemical Equations 56

References 62

Problems 62

3 SPECIATION AND PHASE DIAGRAMS 65

3.1 Speciation (or Ion Distribution) Diagrams 65

3.2 Metal-Ligand Speciation Diagrams 69

3.3 Phase Stability Diagrams 72

Reference 83

Problems 83

4 RATE PROCESSES 84

4.1 Chemical Reaction Kinetics 84

4.2 Biochemical Reaction Kinetics 92

4.3 Electrochemical Reaction Kinetics 94

4.4 Mass Transport 106

4.5 Combined Mass Transport and Reaction Kinetics 114

4.6 Models for Reactions Involving Particles 117

4.7 Combined Mass Transport and Electrochemical Kinetics 128

4.8 Crystallization Kinetics 130

4.9 Overview of Surface Reaction Kinetics 131

References 134

Problems 135

5 METAL EXTRACTION 137

5.1 General Principles and Terminology 137

5.2 Bioleaching/Biooxidation 159

5.3 Precious Metal Leaching Applications 165

5.4 Extraction from Concentrates 171

References 179

Problems 181

6 SEPARATION OF DISSOLVED METALS 183

6.1 LiquidLiquid or Solvent Extraction 184

6.2 Ion Exchange 200

6.3 Activated Carbon Adsorption 207

6.4 Ultrafiltration or Reverse Osmosis 211

6.5 Precipitation 212

References 214

Problems 215

7 METAL RECOVERY PROCESSES 218

7.1 Electrowinning 218

7.2 Electrorefining 229

7.3 Cementation or Contact Reduction 232

7.4 Recovery Using Dissolved Reducing Reagents 235

References 236

Problems 237

8 METAL UTILIZATION 239

8.1 Introduction 239

8.2 Batteries 240

8.3 Fuel Cells 245

8.4 Electroless Plating 247

8.5 Electrodeposited Coatings 249

8.6 Electroforming 251

8.7 Electrochemical Machining 251

8.8 Corrosion 253

References 262

Problems 263

9 ENVIRONMENTAL ISSUES 264

9.1 Introduction 264

9.2 United States Environmental Policy Issues 266

9.3 Metal Removal and Remediation Issues 268

References 275

Problems 276

10 PROCESS DESIGN PRINCIPLES 277

10.1 Determination of Overall Objectives 278

10.2 Determination of Basic Flow Sheet Segments 278

10.3 Survey of Specific Segment Options 279

10.4 Overall Flow Sheet Synthesis 285

10.5 Procurement of Additional Information 287

10.6 Selected Industrial Flow Sheet Examples 289

References 310

Problem 311

11 GENERAL ENGINEERING ECONOMICS 312

11.1 The Effects of Time and Interest 312

11.2 Return on Investment (ROI) 322

11.3 Cost Estimation 323

11.4 Discounted Cash Flow Economic Analysis 325

11.7 Evaluating Financial Effects of Risk 337

References 344

Problems 345

12 GENERAL ENGINEERING STATISTICS 348

12.1 U…