Preface xiii 1 Optimization of the Mechanical Comminution -- The Crushing Stage 1 Ngonidzashe Chimwani 1.1 Introduction 2 1.2 The Role of Crushers 5 1.3 Conclusion 31 2 Challenges Related to the Flotation Process of Complex Phosphate Ores 41 Nheta Willie and Hlahane Morake D. 2.1 Introduction to the Geology of Complex Phosphate Ores 42 2.2 Phosphate Rock Beneficiation Processes 44 2.3 Froth Flotation of Sedimentary Phosphate Ore 48 2.

4 Challenges Facing Flotation of Phosphate Rock 54 2.5 Future Research Directions 58 2.6 Conclusion 58 3 Increasing Ionic Strength and Oxyhydroxo Species in Process Water on the Floatability of Chalcopyrite and Pentlandite for a Selected Cu--Ni Bearing Ore Flotation 65 Malibongwe S. Manono, Katlego M. Matibidi, Lisa L. October, Catherine K. Thubakgale and Kirsten C. Corin 3.

1 Introduction 66 3.2 Materials and Methods 69 3.3 Results and Discussion 72 3.4 Froth Column Studies from a Two-Froth Column 78 4 Relating the Flotation Response of Pyrrhotite to the Adsorption of Sodium Carboxymethyl Cellulose and Sodium Isobutyl Xanthate on its Surface in Process Water of a Degrading Quality 87 Malibongwe S. Manono, Lisa L. October and Kirsten C. Corin 4.1 Introduction 88 4.

2 Experimental Methods 91 4.3 Results and Discussion 97 4.4 Conclusions 107 5 Simulated Short Cycle Water Recirculation on the Flotation Performance of a UG2 Cu--Ni--PGM Ore 111 Malibongwe S. Manono, Michael S. Ngau and Kirsten C. Corin 5.1 Introduction 112 5.2 Materials and Methods 115 5.

3 Results and Discussion 126 5.4 Conclusions 137 6 Complexity of Chalcopyrite Mineral Affecting Copper Recovery During Leaching 145 Kolela J. Nyembwe, Frans Waanders, Martin Mkandawire, Bhekie Mamba and Elvis Fosso-Kankeu 6.1 Introduction 146 6.2 CuFeS2 Crystal Structure 147 6.3 Application of Dissolution/Leaching of Chalcopyrite 148 6.4 Challenges Associated with Copper Dissolution from the Chalcopyrite Mineral 149 6.5 H2SO4-Fe2(SO4)3-FeSO4-H2O Speciation 153 6.

6 Parameters Affecting Dissolution 155 6.7 Thermodynamic Considerations 160 6.8 CuFeS2 Phases Conversion/Copper Sulfide (Cu-S) Intermediate Phases 161 6.9 Conclusion 172 7 Fe3+-Fe2+ Redox Cycle Peculiarity in the Acid Dissolution of Copper--Cobalt Complex Ores 179 Bienvenu Mbuya, Léon Zeka and Antoine F. Mulaba-Bafubiandi 7.1 Introduction 180 7.2 Conventional Leaching of Copper--Cobalt Minerals 182 7.3 Fe3+--Fe2+ Redox Cycle in the Dissolution of Mixed Oxidized and Sulfide Minerals 202 7.

4 Application of Mineral--Mineral Leaching Process to the Dissolution of Complex Ores 208 7.5 Conclusion 212 8 Rare Earth Elements (REEs) in Complex Ores and Spent Materials: Processing Technologies and Relevance in the Global Energy Transition 217 Theophilus Ile Ojonimi, Tina Phiri Chanda, Ilemona C. Okeme, Ferdinand Asuke and Antoine F. Mulaba-Bafubiandi 8.1 Introduction 218 8.2 The Chemistry of REEs 220 8.3 REE Minerals and Deposit Types 220 8.4 REE Ore Mining and Processing Technologies 223 8.

5 Relevance of REEs in Energy Transition 239 8.6 Conclusion 241 References 241 Index 249.