Extractive Metallurgy 1: Basic Thermodynamics and Kinetics / Edition 1

by Alain Vignes

Overview

This book is dedicated to the processes of mineral transformation, recycling and reclamation of metals, for the purpose of turning metals and alloys into a liquid state ready for pouring.

Even though "process metallurgy" is one of the oldest technologies implemented by man, technological innovation, with the development of processes that are both focused on product quality and economically and ecologically efficient, continues to be at the heart of these industries.

This book explains the physico-chemical bases of transformations, vital to their understanding and control (optimization of operational conditions), and the foundations in terms of "process engineering" (heat and matter assessment, process coupling: chemical reactions and transport phenomena), vital to the optimal execution and analysis of transformation process operations.

This book is addressed to students in the field of metallurgy and to engineers facing the problem of metal and alloy development (operation of an industrial unit or development of a new process).

Product Details

ISBN-13:	9781848211605
Publisher:	Wiley
Publication date:	04/11/2011
Series:	ISTE Series , #440
Pages:	344
Product dimensions:	6.30(w) x 9.30(h) x 1.00(d)

About the Author

Alain Vignes was Professor of Metallurgical Reaction Engineering at the School of Mines of Nancy in France, then Professor and Director of the Materials Research Center of the School of Mines of Paris. He was then Chief Metallurgist for the French Nuclear Power Company.

Table of Contents

Preface xi

Chapter 1 Metallurgical Thermochemistry 1

1.1 Introduction 1

1.2 Quantities characterizing the state of a system and its evolution 3

1.2.1 The types of operations 3

1.2.2 Stoichiometric description of a chemical system 4

1.2.3 Evolution of a system's state: degree of advancement of a reaction 6

1.2.4 Characteristic quantities of a phase's composition 11

1.3 Thermodynamic fundamentals of reactions 16

1.3.1 Reaction enthalpy 16

1.3.2 Gibbs free energy of a system, affinity of a reaction and chemical potential of a component 18

1.3.3 Expressions of the chemical potential and activities of a component 21

1.3.4 Affinity of a reaction: law of mass action (thermodynamic modeling of a process) 28

1.3.5 Applications 32

1.4 Phase diagrams 36

1.4.1 Binary phase diagrams 36

1.4.2 Ternary phase diagrams 36

1.5 Bibliography 39

Chapter 2 Oxides, Sulfides, Chlorides and Carbides 41

2.1 Introduction 41

2.2 Metal-oxygen/metal-sulfur systems activities in the intermediate phases 42

2.2.1 Phase diagrams 42

2.2.2 Component activities in the intermediate phases 46

2.3 Standard Gibbs free energy: temperature diagrams for oxides - Ellingham-Richardson diagrams 51

2.3.1 Stoichiometric oxides 51

2.3.2 Unstoichiometric compounds 54

2.3.3 Thermodynamic data for the reduction of oxides by a reducing gas 58

2.4 Thermodynamic data for sulfides and chlorides 58

2.4.1 Ellingham-Richardson diagram for sulfides 58

2.4.2 Stability diagrams for the (M-O-S) systems 60

2.4.3 Ellingham-Richardson diagram for chlorides 62

2.4.4 Stability diagrams of M-O₂-Cl₂ systems 62

2.5 Metal-carbon phase diagrams and the Ellingham-Richardson diagram for carbides 63

2.6 Carbon and carbon oxide reactions 67

2.6.1 Oxidation reactions 67

2.6.2 Boudouard's reaction 68

2.6.3 The different types of coal 70

2.7 Bibliography 71

Chapter 3 Metal Solutions, Slags and Mattes 73

3.1 Introduction 73

3.2 Metal solutions 74

3.2.1 Phase diagrams and activities of liquid alloys components 74

3.2.2 Activities and solubilities of metalloids in metal solutions 83

3.2.3 Solubility and precipitation of oxide and sulfide compounds in metals 92

3.3 Mattes 93

3.3.1 Structure and physical properties of sulfide melts (mattes) 93

3.3.2 Thermodynamic data for the binary Fe-S, Ni-S, Cu-S and Pb-S systems 95

3.3.3 Thermodynamic data of ternary mattes 97

3.3.4 Thermodynamic data for M-O-S systems 99

3.4 Slags 106

3.4.1 Structure and physical properties 106

3.4.2 Phase diagrams and activities 110

3.4.3 Phase diagrams and activities of oxide mixtures forming the basis of metallurgical slags CaO-SiO₂-Al₂O₃-MgO 111

3.4.4 Phase diagrams and activities of mixtures of CaO-SiO₂ -Al₂O₃-MgO oxides and reducible (iron, manganese and chrome) oxides 115

3.5 Bibliography 127

Chapter 4 Aqueous Electrolytic Solutions and Salt Melts 131

4.1 Introduction 131

4.2 Thermodynamics of aquec us electrolyte solutions 131

4.2.1 Chemical potentials and activities of the components of electrolyte aqueous solutions 132

4.2.2 Aqueous solutions of acids and bases 138

4.2.3 Aqueous solutions of metallic salts: complexation and speciation 148

4.2.4 Solubility of oxides and hydroxides 156

4.2.5 Solubility of salts 165

4.2.6 Solubility of gases in an aqueous solution 171

4.3 Thermodynamics of salt melts (fluxes) 173

4.3.1 Compositions and physical properties of fluxes 174

4.3.2 Thermodynamic properties 174

4.3.3 Solubility of oxides in halides 177

4.4 Bibliography 179

Chapter 5 Reaction Kinetics 183

5.1 Introduction 183

5.2 Rate of a chemical reaction 184

5.2.1 Definitions 184

5.2.2 Expressions of the rate of a chemical reaction 186

5.3 Homogeneous precipitation 189

5.3.1 Thermodynamics of primary nucleation 190

5.3.2 Nucleation and primary particle formation processes 191

5.3.3 Secondary nucleation 193

5.4 Kinetics and mechanism of heterogeneous reactions 194

5.4.1 Mechanism of heterogeneous chemical reactions 194

5.4.2 Rates of heterogeneous reactions in fluid-solid systems 195

5.4.3 Experimental rates of gasification reactions 197

5.4.4 Experimental rates of oxide and sulfide dissolution by acid-base reactions 202

5.4.5 Rates of heterogeneous chemical reactions in fluid-fluid systems 206

5.4.6 Experimental rates of transfer processes 207

5.4.7 Experimental rates of gas-liquid reactions 209

5.5 Reaction rates for in situ conversion of a solid particle 211

5.5.1 Reduction of an oxide in solid state by carbon monoxide or hydrogen 211

5.5.2 Roasting of a zinc sulfide particle 214

5.6 Heterogeneous precipitation 215

5.6.1 Deposition mechanism 216

5.6.2 Silicon deposition by heterogeneous thermal decomposition of silane 216

5.7 Bibliography 217

Chapter 6 Transport Kinetics 219

6.1 Introduction 219

6.1.1 Identification of the rate-limiting step 222

6.2 Equations of change and relationships between diffusion fluxes and driving forces 223

6.2.1 Equations of change (in terms of the fluxes) 223

6.2.2 Relationships between diffusion fluxes, driving forces and transport properties 225

6.3 Interphase mass or heat transport (mass and heat transfer) 227

6.3.1 Definitions of heat and mass transfer coefficients 227

6.3.2 Kinetics of diffusion-controlled processes 229

6.4 Mass and heat transfer coefficients 236

6.4.1 Mass and heat transfer (across a phase boundary) between two semi-infinite and stagnant phases 237

6.4.2 Heat and mass transfer between a flat wall and a fluid flowing along the flat surface in forced convection: boundary layer theory 239

6.4.3 Heat and mass transfer between particles, drops or bubbles and a continuous fluid phase 243

6.5 Overall kinetics of extraction processes under mixed control 247

6.5.1 Extraction process-type gasification 247

6.5.2 Transfer process-type solvent extraction 249

6.5.3 Note on the rule of addition of resistances acting in series 250

6.6 Bibliography 251

Chapter 7 Particulate Kinetics 253

7.1 Introduction 253

7.2 Gasification/leaching of a particle 254

7.2.1 Non-porous particles 254

7.2.2 Porous particles (pellets) 259

7.3 Heterogeneous precipitation: growth rate of the particles 263

7.4 In situ conversion of a solid particle 264

7.4.1 Non-porous particle: the shrinking unreacted core model 265

7.4.2 In situ conversion of a porous particle: the grain pellet model 269

7.5 Conversion of a particle undergoing strong exo- or endothermic chemical reactions 270

7.5.1 Exothermic chemical reactions 270

7.5.2 Endothermic chemical reactions 275

7.6 Transfer processes between two fluid phases, one phase being dispersed (as drops or bubbles) in the second phase 276

7.6.1 Heat transfer 276

7.6.2 Mass transfer 277

7.6.3 Hydrogen removal from liquid steel bath by injection of inert gas bubbles 278

7.7 Bibliography 280

Chapter 8 Electrochemical Reactions 283

8.1 Overview of electrochemical processes 283

8.2 Equilibrium electric potential of an elementary electrochemical reaction 285

8.2.1 Nernst equation 285

8.2.2 Electrode potentials in aqueous solutions 288

8.2.3 Equilibrium potential metal/ion EM/M^Z+in molten salts 292

8.3 Electrochemical equilibria of metals and metalloids (Pourbaix diagrams) 292

8.3.1 Diagram of electrochemical equilibria of water 293

8.3.2 Pourbaix diagram for metal-water systems 294

8.3.3 Pourbaix diagram for the Fe, Cu and Zn-Cl-H₂O systems 300

8.3.4 Pourbaix diagrams for the M-NH₃-H₂O systems 302

8.3.5 Pourbaix diagrams for the M-HCN-H₂O systems 304

8.3.6 Pourbaix diagrams for the M-S-H₂O systems 305

8.4 Electrochemical kinetics 306

8.4.1 Rate of an elementary electrochemical reaction: Tafel's Law 307

8.4.2 Diffusion-controlled rate of an elementary electrochemical reaction 312

8.4.3 Rate of a redox chemical reaction 313

8.5 Redox electrochemical reactions 314

8.5.1 Cementation or displacement reaction 315

8.5.2 Leaching (dissolution) of metals 319

8.6 Bibliography 322

List of Symbols 325

Index 337

Summaries of Other Volumes 345

Editorial Reviews

"The books are addressed to students in the field ofmetallurgy and to engineers facing the problem of metal and alloydevelopment." (World of Metallurgy, 2011)

 

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