Hydrometallurgy: Fundamentals and Applications

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 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

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.