Coordination Principle of Minerals Flotation

Description

The advent of flotation, with selective interaction of reagents with minerals at its core, has greatly advanced the development of modern mining. Ever since, there has been continuous researched into the mechanism of mineral-reagent interactions, in an effort to design and develop more effective reagents. A unique perspective from coordination is presented to illustrate the principles of reagent molecules interacting with metal ions on mineral surface. For the first time, the influence is unveiled of mineral crystal structures and surrounding atoms on metal ion properties and further on mineral-reagent interactions. The introduction of classical theories for modern chemistry, including orbital structure, electron spin and orbital symmetry matching, into flotation is realized. Researchers, engineers and graduate students among others in the field of mineral processing may gain new insight into flotation and the development of novel reagents. Preface Prologue Contents 1 Theory of Coordination Chemistry 1.1 Introduction 1.2 Valence Bond Theory 1.2.1 Hybridization Types and Spatial Structures of Orbitals 1.2.2 Outer-Orbital Complexes and Inner-Orbital Complexes 1.2.3 Defects of Valence Bond Theory 1.3 Crystal Field Theory 1.3.1 Ideas of Crystal Field Theory 1.3.2 d Orbital Splitting 1.3.3 Electronic Distribution in High Spin and Low Spin States 1.3.4 The Jahn–Teller Effect and Configurational Distortion 1.3.5 Crystal Field Stabilization Energy 1.3.6 Applications of Crystal Field Theory 1.3.7 Improvements of Crystal Field Theory 1.4 Molecular Orbital Theory 1.4.1 Key Ideas of Molecular Orbital Theory 1.4.2 Molecular Orbitals for Regular Octahedral Complexes 1.4.3 Molecular Orbitals for Tetrahedral Complexes 1.4.4 Molecular Orbital Theory and Ligand Field Theory 2 Coordination Characteristics of Mineral Flotation System 2.1 Coordination Characteristics of Mineral Crystals 2.1.1 Coordination Structure of Minerals 2.1.2 Splitting of D Orbitals in Mineral Crystals 2.1.3 Relationship Between the Lattice Energy of Crystals and Crystal Field Stabilization Energy 2.1.4 The Relationship Between the Bond Length of Mineral Crystals and d-Electron Configuration 2.1.5 Effect of CFSE on the Distribution of Metal Ions in Mineral Crystals 2.1.6 Jahn–Teller Effect in Mineral Crystals 2.2 Coordination of Water Molecules as a Flotation Medium 2.3 Coordination Properties of Flotation Reagents 2.3.1 Coordination Power of the Collector 2.3.2 Coordination Power of the Depressant 2.4 Coordination of Reagents with Metal Ions 2.5 π-Backbonding 2.6 HSAB Theory 2.7 Ligand Field Model of the Interaction of Reagents with Minerals References 3 Geometry Principles of Coordination on Mineral Surface 3.1 Spatial Geometry Foundation for Coordination 3.1.1 Configuration of Orbital Hybridization 3.1.2 Close Packing of Crystal Atoms 3.2 Geometric Principle of the Maximum Coordination Number 3.2.1 The 3-Coordinated Close-Packing Structure 3.2.2 The 4-Coordinated Close-Packing Structure 3.2.3 The 6-Coordinated Close-Packing Structure 3.2.4 The 8-Coordinated Close-Packing Structure 3.3 Relationship Between the Coordination Number and the Spatial Structure of Metal Ions 3.4 Spatial Structure of 4-Coordinated Compounds 3.5 Steric Hindrance of Sulfurization on Oxide Surfaces 3.5.1 The 5-Coordinated Iron on Hematite Surface 3.5.2 The 5-Coordinated Zinc on Smithsonite Surface 3.5.3 The 4-Coordinated Copper on Malachite Surface 3.5.4 The 5-Coordinated Lead on Cerussite Surface 3.6 Influence of Space Structure on Metal Ion Valence and Orbital Hybridization 3.7 Steric Hindrance of Interaction of Collectors with 3-Coordinated Metal Ion 3.7.1 Interaction Between Sphalerite Surface and Xanthate 3.7.2 Interaction Between Chalcopyrite Surface and Z-200 Molecule 3.8 Spatial Structure Matching of Reagent Molecules with Mineral Surfaces References 4 Coordination of Flotation Reagents with Metal Ions on Mineral Surfaces 4.1 Influence of Coordination Structure on Orbital Properties 4.2 Influence of Ligand Field Strength on Interaction between Xanthate and Metal Ions on Mineral Surfaces 4.2.1 Differences in Interactions of Xanthate with Pyrite and Hematite: Strong Field Ligand and Weak Field Ligand 4.2.2 Interaction between Xanthate and Oxide Mineral: π Electron Pairs in the Weak Field 4.3 Influence of Ligand Field Structure on Pyrite Floatability 4.4 Influence of Impurities on Sphalerite Floatability 4.4.1 Influence of Impurity Properties 4.4.2 Influence of Iron Content on Sphalerite 4.4.3 Reactivity of d10 Orbitals 4.5 Electronic Structure and Floatability of Copper Sulfide Minerals 4.6 Influence of Transition Metal Ions on Adsorption Performance on Pyrite Surface 4.7 Coordination of Depressants 4.7.1 The Unoccupied π Orbital of Ca(OH)+ 4.7.2 Strong Field Coordination of Cyanides 4.7.3 Delocalized π Bonds in Oxysulfate 4.7.4 Depressive Effect by Sulfate 4.8 Nephelauxetic Effect and Covalent Bond 4.8.1 Nephelauxetic Effect 4.8.2 Influence of Ligand Structure and Ligand Properties on Nephelauxetic Effect 4.8.3 Influence of Spin State on Nephelauxetic Effect References 5 Influence of Crystal Field Stabilization Energy on Interaction of Flotation Reagents 5.1 Crystal Field Stabilization Energy 5.1.1 Effect of Electron Pairing Energy 5.1.2 Influence of Crystal Structure on Crystal Field Stabilization Energy 5.2 Influence of Crystal Field Stabilization Energy on Pyrite Oxidation 5.3 Effect of Crystal Field Stabilization Energy on the Depressive Behavior of Sulfide Minerals 5.3.1 Flotation Critical pH 5.3.2 Depression by Lime on Iron-Sulphide Minerals 5.4 Effect of Collector Adsorption on the Spin State of Metal Ions 5.5 Effect of Crystal Field Stabilization Energy on the Oxidation of Metal Ions 5.5.1 Effect of Crystal Field Stabilization Energy on the Stability of Metal Ions 5.5.2 Effect of Cyanide on Oxidation of Pyrite 5.5.3 Effect of pH Value on Oxidation of Pyrite Surface References 6 Symmetry Matching Between Reagent Molecules and Mineral Surface Orbitals 6.1 Molecular Orbital 6.1.1 Atomic Orbital 6.1.2 Reactivity of Orbital 6.1.3 σ Orbitals and π Orbitals 6.2 Frontier Molecular Orbitals 6.3 Orbital Symmetry Matching and Selectivity of Dithiophosphate 6.4 Orbital Symmetry Matching of Cyanide with Pyrite and Galena 6.5 Selectivity and Frontier Orbital Interactions of Z-200 6.6 Effect of Impurity Atoms on Orbitals of Sphalerite Surface References Appendix