Table of Contents

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 Liquid?Liquid 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 Uncertainty 348

12.2 Basic Statistical Terms and Concepts 353

12.3 The Normal Distribution 354

12.4 Probability and Confidence 355

12.5 Linear Regression and Correlation 373

12.6 Selecting Appropriate Statistical Functions 375

12.7 Hypothesis Testing 382

12.8 Analysis of Variance (ANOVA) 384

12.9 Factorial Design and Analysis of Experiments 387

12.10 The Taguchi Method 390

References 396

Problems 397

APPENDIX A ATOMIC WEIGHTS 399

APPENDIX B MISCELLANEOUS CONSTANTS 401

APPENDIX C CONVERSION FACTORS 402

APPENDIX D FREE ENERGY DATA 403

References 410

APPENDIX E LABORATORY CALCULATIONS 412

E.1 Background Information 412

E.2 Solution Preparation Principles 413

E.3 Solution Preparation Calculations 413

Problem 415

APPENDIX F SELECTED IONIC SPECIES DATA 416

APPENDIX G STANDARD HALF-CELL POTENTIALS 418

APPENDIX H GENERAL TERMINOLOGY 420

APPENDIX I COMMON SIEVE SIZES 423

APPENDIX J METALS AND MINERALS 424

INDEX 429

About the Author

MICHAEL L. FREE, PhD, is Professor of MetallurgicalEngineering at the University of Utah. Dr. Free's research shedsnew light on metal processing and interactions in aqueous media. Hehas been the principal investigator for fifty research projectsfunded 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 100publications.