Electrochemistry of Flotation of Sulphide Minerals (eBook)

About Authors 5
Preface 7
Table of Contents 9
Chapter 1 General Review of Electrochemistry of Flotation of Sulphide Minerals 14
1.1 Three Periods of Flotation of Sulphide Minerals 14
1.2 Natural Floatability and Collectorless Flotation of Sulphide Minerals 16
1.3 Role of Oxygen and Oxidation of Sulphide Minerals in Flotation 20
1.4 Interactions between Collector and Sulphide Minerals and Mixed Potential Model 21
1.5 Effect of Semiconductor Property of Sulphide Mineral on Its Electrochemical Behavior 25
1.6 Electrochemical Behaviors in Grinding System 27
1.7 The Purpose of This Book 32
Chapter 2 Natural Floatability and Collectorless Flotation of Sulphide Minerals 33
2.1 Crystal Structure and Natural Floatability 33
2.2 Collectorless Flotation 36
2.2.1 Effect of Pulp Potential on Flotation at Certain pH 36
2.2.2 Pulp Potential and pH Dependence of Collectorless Floatability 37
2.3 Electrochemical Equilibriums of the Surface Oxidation and Flotation of Sulphide Minerals 41
2.3.1 The Surface Oxidation of Sulphide Minerals and Nernst Equation 41
2.3.2 Electrochemical Equilibriums in Collectorless Flotation 43
2.3.3 Eh-pH Diagrams of Potential and pH Dependence of Flotation 45
1. Eh-pH Diagram of Chalcopyrite 45
2. Eh-pH Diagram of Galena 47
3. Eh-pH Diagram of Pyrite and Arsenopyrite 48
4. Eh-pH Diagram of Jamesonite 51
2.4 Electrochemical Determination of Surface Oxidation Products of Sulphide Minerals 54
2.5 Surface Analysis of Oxidation of Sulphide Minerals 61
Chapter 3 Collectorless Flotation in the Presence of Sodium Sulphide 66
3.1 Description of Behavior 66
3.2 Nature of Hydrophobic Entity 70
3.3 Surface Analysis and Sulphur-Extract 73
3.4 Comparison between Self-Induced and Sodium Sulphide-Induced Collectorless Flotation 75
Chapter 4 Collector Flotation of Sulphide Minerals 76
4.1 Pulp Potential Dependence of Collector Flotation and Hydrophobic Entity 78
4.1.1 Copper Sulphide Minerals 78
1. Chalcocite 78
2. Chalcopyrite 81
4.1.2 Lead Sulphide Minerals 82
1. Galena 82
2. Jamesonite 89
4.1.3 Zinc Sulphide Minerals 95
1. Sphalerite 95
2. Marmatite 97
4.1.4 Iron Sulphide Minerals 99
1. Pyrite 99
2. Pyrrhotite 101
3. Arsenopyrite 103
4.2 Eh-pH Diagrams for the CoUector/Water/Mineral System 104
4.2.1 Butyl XanthatelWater System 105
4.2.2 Chalcocite-Oxygen-Xanthate System 107
4.3 Surface Analysis 108
4.3.1 UV Analysis of Collector Adsorption on Sulphide Minerals 109
1. Adsorption of Dithiocarbamate on Jamesonite 109
2. Adsorption of Dithiocarbamate and Xanthate on Marmatite 109
4.3.2 FTIR Analysis of Adsorption of Thio-Collectors on Sulphide Minerals 112
1. Adsorption of Ethyl Xanthate on Pyrrhotite 113
2. Adsorption of Ethyl Xanthate on Marmatite 115
3. Adsorption of Ethyl Xanthate on Jamesonite 116
4. Adsorption of Dithiocarbamate on Pyrrhotite 117
5. Adsorption of Diethyl Dithiocarbamate on Jamesonite 119
4.3.3 XPS Analysis of Collector Adsorption on Sulphide Minerals 122
Chapter 5 Roles of Depressants in Flotation of Sulphide Minerals 125
5.1 Electrochemical Depression by Hydroxyl Ion 125
5.1.1 Depression of Galena and Pyrite 126
5.1.2 Depression of Jamesonite and Pyrrhotite 130
5.1.3 Interfacial Structure of Mineral/Solution in Different pH Modifier Solution 131
1. Interfacial Structure of Marmatite/Solution 131
2. Interfacial Structure of Jamesonite/Solution 133
5.2 Depression by Hydrosulphide Ion 135
5.3 Electrochemical Depression by Cyanide 136
5.4 Depression by Hydrogen Peroxide 137
5.5 Depression of Marmatite and Pyrrhotite by Thio-Organic Depressants 138
5.6 Role of Polyhydroxyl and Poly Carboxylic Xanthate in the Flotation of Zinc-Iron Sulphide 142
5.6.1 Flotation Behavior of Zinc-Iron Sulphide with Polyhydroxyl and Polycarboxylic Xanthate as Depressants 142
5.6.2 Effect of Pulp Potential on the Flotation of Zinc-Iron Sulphide in the Presence of the Depressant 144
5.6.3 Adsorption of Polyhydroxyl and Polycarboxylic Xanthate on Zinc-Iron Sulphide 146
5.6.4 Effect of Polyhydroxyl and Polycarboxylic Xanthate on the Zeta Potential of Zinc-Iron Sulphide Minerals 149
5.6.5 Structure-Property Relation of Polyhydroxyl and Polycarboxylic Xanthate 150
Chapter 6 Electrochemistry of Activation Flotation of Sulphide Minerals 155
6.1 Electrochemical Mechanism of Copper Activating Sphalerite 155
6.2 Electrochemical Mechanism of Copper Activating Zinc-Iron Sulphide Minerals 159
6.2.1 Activation Flotation 159
6.2.2 Effect of Pulp Potential on Activation Flotation of Zinc-Iron Sulphide Minerals 160
6.2.3 Electrochemical Mechanism of Copper Activating Marmatite 162
6.2.4 Surface Analysis of Mechanism of Copper Activating Marmatite 163
6.3 Activation of Copper Ion on Flotation of Zinc-Iron Sulphide Minerals in the Presence of Depressants 165
6.3.1 Effect of Depressant on the CUS04 Activating Flotation of Zinc-Iron Sulphide Minerals 165
6.3.2 Influence of Pulp Potential on the Copper Ion Activating Flotation of Zinc-Iron Sulphide Minerals in the Presence of Depressant 168
6.3.3 Zeta Potential of Zinc-Iron Sulphide Minerals in the Presence of Flotation Reagents 170
6.4 Surface Chemistry of Activation of Lime-Depressed Pyrite 172
6.4.1 Activation Flotation of Lime-Depressed Pyrite 172
6.4.2 Solution Chemistry Studies on Activation Flotation of Lime-Depressed Pyrite 174
6.4.3 The Bonding of the Activator Polar Group with Surface Cation 176
6.4.4 Surface Analysis of Lime-Depressed Pyrite in the Presence of Activator 178
Chapter 7 Corrosive Electrochemistry of Oxidation-Reduction of Sulphide Minerals 180
7.1 Corrosive Electrochemistry 180
7.1.1 Concept and Significance of Mixed Potential, Corrosive Potential and Static Potential 181
7.1.2 The Concept of Corrosive Current and Corrosive Speed 182
7.1.3 The Corrosion Inhibitor, Inhibiting Corrosive Efficiency and Its Relationship with Collector Action 183
7.2 Self-Corrosion of Sulphide Minerals 183
7.3 Corrosive Electrochemistry on Surface Redox Reaction of Pyrite under Different Conditions 185
7.3.1 The Oxidation of Pyrite in NaOH Medium 185
7.3.2 Oxidation of Pyrite in Lime Medium 188
7.3.3 Corrosive Electrochemistry Study on Interactions between Collector and Pyrite 191
1. PyritelXanthate Interaction 191
2. PyritelDithiocarbamate Interaction 194
7.3.4 Interaction between Collector and Pyrite in High Alkaline Media 196
7.4 Corrosive Electrochemistry on Surface Redox Reaction of Galena under Different Conditions 199
7.4.1 The Oxidation of Galena in NaOH Solution 199
7.4.2 The Effect of Lime on the Oxidation of Galena 200
7.4.3 Corrosive Electrochemistry Study on Interactions between Collector and Galena 203
1. GalenalXanthate Interaction 203
2. Galena/Dithiocarbamate Interaction 205
7.4.4 Interactions between Collector and Galena at High pH 208
7.5 Corrosive Electrochemistry on Surface Redox Reaction of Sphalerite in Different Media 210
7.5.1 Influence of Different pH Media on Sphalerite Oxidation 210
7.5.2 Inhibiting Corrosive Mechanism of Collector on Sphalerite Electrode 211
Chapter 8 Mechano-Electrochemical Behavior of Flotation of Sulphide Minerals 214
8.1 Experiment Equipment 215
8.2 Mechano-Electrochemical Behavior of Pyrite in Different Grinding Media 216
8.3 Mechano-Electrochemistry Process of Galena in Different Grinding Media 221
8.4 Influence of Mechanical Force on the Electrode Process between Xanthate' and Sulphide Minerals 226
8.5 Surface Change of Sulphide Minerals under Mechanical Force 228
8.5.1 Surface Change of the Pyrite under Mechanical Force 228
8.5.2 Surface Change of Sphalerite in Mechanical Force 230
Chapter 9 Molecular Orbital and Energy Band Theory Approach of Electrochemical Flotation of Sulphide Minerals 232
9.1 Qualitative Molecular Orbital and Band Models 232
9.2 Density Functional Theory Research on Oxygen Adsorption on Pyrite (100) Surface 233
9.2.1 Computation Methods 234
9.2.2 Bulk FeS2 Properties 236
9.2.3 Property of FeSz (100) Surface 238
9.2.4 Oxygen Adsorption 240
9.3 Density Functional Theory Research on Activation of Sphalerite 241
9.3.1 Computational Methods 242
9.3.2 Bulk ZnS Properties 243
9.3.3 Relaxation and Properties of ZnS (110) Surface 245
9.3.4 Relaxation and Properties of ZnS (110) Surface Doped with Cu2+ and Fe2+ 247
9.3.5 Effects of Doped Ions on Mixed Potential 250
9.4 The Molecular Orbital and Energy Band Discussion of Electrochemical Flotation Mechanism of Sulphide Minerals 251
9.4.1 Frontier Orbital of Collector and Oxygen 251
9.4.2 The Molecular Orbit and Energy Band Discussion of Collectorless Flotation of Galena and Pyrite 253
9.4.3 The Molecular Orbit and Energy Band Discussion of Collector Flotation of Galena and Pyrite 254
Chapter 10 Electrochemical Flotation Separation of Sulphide Minerals 257
10.1 Technological Factors Affecting Potential Controlled Flotation Separation of Sulphide Ores 257
10.1.1 Potential Modifiers 257
10.1.2 pH Modifier 259
10.1.3 Frother 261
10.1.4 ConditioningTime 262
10.1.5 Surface Pretreatment 263
10.1.6 Grinding Environment 263
10.2 Flotation Separation of Sulphide Minerals and Ores 266
10.2.1 Copper Sulphide Minerals and Ores 266
1. Chalcopyrite /Galena 266
2. Chalcopyrite / Pyrite 267
3. Chalcopyrite/Arsenopyrite 269
10.2.2 Lead-Zinc-Iron-Sulphide Minerals and Ores 270
10.3 Applications of Potential Control Flotation in Industrial Practice 271
10.3.1 Original Potential in Grinding Process 271
10.3.2 Effect of Lime Dosage on "Original Potential" 272
10.3.3 Coupling with Other Flotation Process Factors 273
10.3.4 Coupling with Reagent Schemes 274
10.3.5 Coupling with Flotation Circuit 275
10.3.6 Applications of OPCF Technology in Several Flotation Concentrators 275
1. Nanjing Lead-Zinc Concentrator 275
2. Xitieshan Lead-Zinc Concentrator 276
3. Fankou Lead-Zinc Concentrator 279
4. Tonglushan Concentrator of CuFeS2-FeS2 Ore Application of Collectorless Flotation 281
References 282
Index of Terms 299
Index of Scholars 308