Extractive Metallurgy of Copper This page intentionally left blank Extractive Metallurgy of Copper Mark E. Schlesinger Matthew J. King Kathryn C. Sole William G. Davenport AMSTERDAM l BOSTON l HEIDELBERG l LONDON NEW YORK l OXFORD l PARIS l SAN DIEGO SAN FRANCISCO l SINGAPORE l SYDNEY l TOKYO Elsevier The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands First edition 1976 Second edition 1980 Third edition 1994 Fourth edition 2002 Fifth Edition 2011 Copyright Ó 2011 Elsevier Ltd. All rights reserved. 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(Courtesy of Palabora Mining Company. ÓRio Tinto.) Contents Preface xv Preface to the Fourth Edition xvii Preface to the Third Edition xix Preface to the Second Edition xxi Preface to the First Edition xxiii 1. Overview 1 1.1. Introduction 1 1.2. Extracting Copper from CoppereIroneSulfide Ores 2 1.2.1. Concentration by Froth Flotation 4 1.2.2. Matte Smelting 4 1.2.3. Converting 5 1.2.4. Direct-to-Copper Smelting 7 1.2.5. Fire Refining and Electrorefining of Blister Copper 7 1.3. Hydrometallurgical Extraction of Copper 8 1.3.1. Solvent Extraction 8 1.3.2. Electrowinning 9 1.4. Melting and Casting Cathode Copper 10 1.4.1. Types of Copper Product 10 1.5. Recycle of Copper and Copper-Alloy Scrap 11 1.6. Summary 12 Reference 12 Suggested Reading 12 2. Production and Use 13 2.1. Copper Minerals and Cut-off Grades 14 2.2. Location of Extraction Plants 17 2.3. Price of Copper 29 2.4. Summary 29 References 29 3. Production of High Copper Concentrates e Introduction and Comminution 31 3.1. Concentration Flowsheet 31 3.2. The Comminution Process 31 3.3. Blasting 32 3.3.1. Ore-size Determination 34 3.3.2. Automated Ore-toughness Measurements 34 3.4. Crushing 35 3.5. Grinding 35 3.5.1. Grind Size and Liberation of Copper Minerals 35 v vi Contents 3.5.2. Grinding Equipment 36 3.5.3. Particle-Size Control of Flotation Feed 36 3.5.4. Instrumentation and Control 43 3.6. Recent Developments in Comminution 46 3.6.1. High Pressure Roll Crushing 46 3.6.2. Automated Mineralogical Analysis 47 3.7. Summary 47 References 48 Suggested reading 48 4. Production of Cu Concentrate from Finely Ground Cu Ore 51 4.1. Froth Flotation 51 4.2. Flotation Chemicals 52 4.2.1. Collectors 52 4.2.2. Selectivity in Flotation 53 4.2.3. Differential Flotation e Modifiers 54 4.2.4. Frothers 55 4.3. Specific Flotation Procedures for Cu Ores 55 4.4. Flotation Cells 56 4.4.1. Column Cells 56 4.5. Sensors, Operation, and Control 64 4.5.1. Continuous Chemical Analysis of Process Streams 65 4.5.2. Machine Vision Systems 67 4.6. The Flotation Products 67 4.6.1. Thickening and Dewatering 67 4.6.2. Tailings 68 4.7. Other Flotation Separations 68 4.7.1. Gold Flotation 68 4.8. Summary 69 References 69 Suggested Reading 70 5. Matte Smelting Fundamentals 73 5.1. Why Smelting? 73 5.2. Matte and Slag 74 5.2.1. Slag 74 5.2.2. Calcium Ferrite and Olivine Slags 79 5.2.3. Matte 81 5.3. Reactions During Matte Smelting 82 5.4. The Smelting Process: General Considerations 83 5.5. Smelting Products: Matte, Slag and Offgas 84 5.5.1. Matte 84 5.5.2. Slag 84 5.5.3. Offgas 86 5.6. Summary 86 References 86 Suggested Reading 88 6. Flash Smelting 89 6.1. Outotec Flash Furnace 89 6.1.1. Construction Details 90 Contents vii 6.1.2. Cooling Jackets 94 6.1.3. Concentrate Burner 95 6.1.4. Supplementary Hydrocarbon Fuel Burners 95 6.1.5. Matte and Slag Tapholes 96 6.2. Peripheral Equipment 96 6.2.1. Concentrate Blending System 96 6.2.2. Solids Feed Dryer 97 6.2.3. Bin and Feed System 97 6.2.4. Oxygen Plant 98 6.2.5. Blast Heater (optional) 98 6.2.6. Heat Recovery Boiler 98 6.2.7. Dust Recovery and Recycle System 98 6.3. Flash Furnace Operation 99 6.3.1. Startup and Shutdown 99 6.3.2. Steady-state Operation 99 6.4. Control 100 6.4.1. Concentrate Throughput Rate and Matte Grade Controls 100 6.4.2. Slag Composition Control 101 6.4.3. Temperature Control 101 6.4.4. Reaction Shaft and Hearth Control 101 6.5. Impurity Behavior 102 6.5.1. Non-recycle of Impurities in Dust 102 6.5.2. Other Industrial Methods of Controlling Impurities 103 6.6. Outotec Flash Smelting Recent Developments and Future Trends 103 6.7. Inco Flash Smelting 103 6.7.1. Furnace Details 104 6.7.2. Concentrate Burner 104 6.7.3. Water Cooling 104 6.7.4. Matte and Slag Tapholes 105 6.7.5. Gas Uptake 105 6.7.6. Auxiliary Equipment 105 6.7.7. Solids Feed Dryer 106 6.7.8. Concentrate Burner Feed System 106 6.7.9. Offgas Cooling and Dust Recovery Systems 106 6.8. Inco Flash Furnace Summary 106 6.9. Inco vs. Outotec Flash Smelting 107 6.10. Summary 107 References 107 Suggested Reading 110 7. Submerged Tuyere Smelting: Noranda, Teniente, and Vanyukov 111 7.1. Noranda Process 111 7.2. Reaction Mechanisms 114 7.2.1. Separation of Matte and Slag 114 7.2.2. Choice of Matte Grade 115 7.2.3. Impurity Behavior 115 7.2.4. Scrap and Residue Smelting 115 7.3. Operation and Control 116 7.3.1. Control 116 7.4. Production Rate Enhancement 117 7.5. Teniente Smelting 117 7.5.1. Seed Matte 117 viii Contents 7.6. Process Description 118 7.7. Operation 118 7.8. Control 120 7.8.1. Temperature Control 120 7.8.2. Slag and Matte Composition Control 120 7.8.3. Matte and Slag Depth Control 120 7.9. Impurity Distribution 120 7.10. Discussion 121 7.10.1. Super-high Matte Grade and SO2 Capture Efficiency 121 7.10.2. Campaign Life and Hot Tuyere Repairing 121 7.10.3. Furnace Cooling 121 7.10.4. Offgas Heat Recovery 122 7.11. Vanyukov Submerged Tuyere Smelting 122 7.12. Summary 123 References 124 Suggested Reading 125 8. Converting of Copper Matte 127 8.1. Chemistry 127 8.1.1. Coppermaking Reactions 129 8.1.2. Elimination of Impurities During Converting 134 8.2. Industrial PeirceeSmith Converting Operations 134 8.2.1. Tuyeres and Offgas Collection 136 8.2.2. Temperature Control 137 8.2.3. Choice of Temperature 138 8.2.4. Temperature Measurement 138 8.2.5. Slag and Flux Control 139 8.2.6. Slag Formation Rate 139 8.2.7. End Point Determinations 139 8.3. Oxygen Enrichment of PeirceeSmith Converter Blast 140 8.4. Maximizing Converter Productivity 140 8.4.1. Maximizing Solids Melting 141 8.4.2. Smelting Concentrates in the Converter 142 8.4.3. Maximizing Campaign Life 142 8.5. Recent Improvements in PeirceeSmith Converting 142 8.5.1. Shrouded Blast Injection 142 8.5.2. Scrap Injection 143 8.5.3. Converter Shell Design 143 8.6. Alternatives to PeirceeSmith Converting 143 8.6.1. Hoboken Converter 144 8.6.2. Flash Converting 144 8.6.3. Submerged-Tuyere Noranda Continuous Converting 147 8.6.4. Recent Developments in PeirceeSmith Converting Alternatives 150 8.7. Summary 150 References 151 Suggested Reading 153 9. Bath Matte Smelting: Ausmelt/Isasmelt and Mitsubishi 155 9.1. Basic Operations 155 9.2. Feed Materials 156 9.3. The TSL Furnace and Lances 156 9.4. Smelting Mechanisms 163 9.4.1. Impurity Elimination 163 Contents ix 9.5. Startup and Shutdown 163 9.6. Current Installations 164 9.7. Copper Converting Using TSL Technology 164 9.8. The Mitsubishi Process 165 9.8.1. Introduction 165 9.8.2. The Mitsubishi Process 165 9.8.3. Smelting Furnace Details 166 9.8.4. Electric Slag-Cleaning Furnace Details 167 9.8.5. Converting Furnace Details 168 9.8.6. Optimum Matte Grade 169 9.8.7. Process Control in Mitsubishi Smelting/Converting 169 9.9. The Mitsubishi Process in the 2000s 174 9.10.