Contents Foreword I vii Foreword II ix Preface . xv Abbreviations. xix 1. Introduction to Chemically Bonded Ceramics 1 1.1Ceramics and Hydraulic Cements .. 1 1.2Chemically Bonded Ceramics as Intermediate Products .. 2 1.3Acid-Base Cements CBCs . 3 1.4Solidification by Chemical Bonding in Nature .. 5 1.5General Definition of Chemically Bonded Ceramics 8 1.6Nature of the Chemical Bonding in CBCs . .. 9 1.7Role of Solubility in Chemical Bonding 11 References 12 2. Chemically Bonded Phosphate Ceramics 15 2.1Review on Phosphate-Bonded Ceramics and Cements .. 15 2.2Review on Phosphate-Bonded Dental Cements . 16 2.3Magnesium Phosphate Ceramics .. 19 2.4Generalization of Formation of CBPCs 21 2.5Summary of Literature Survey 22 2.6Applications of CBPCs. .. 23 References 25 3. Raw Materials .. 29 3.1Formation of Phosphoric Acid from Phosphate Rocks .. 30 3.2Acid Phosphates . 31 3.3Major Oxides and Oxide Minerals .. 34 3.4Aggregates .. 37 References 41 4.Phosphate Chemistry 43 4.1Nomenclature .. 43 4.2The Effect of PH . 44 4.3Dissolution Characteristics of Phosphoric Acid . 45 4.4Neutralization of the Acid and Formation of Acid Phosphates 46 4.5Condensed Phosphates .. 48 4.6Dissociation (lonization) Constants of Weak Acids 49 References 50 5.Dissolution Characteristics of Metal Oxides and Kinetics of Ceramic Formation 51 5.1Dissolution Characteristics as the Basis for Forming CBPCs 51 5.2Dissolution of Oxides and Formation of Dissolved Cations . 52 5.3Born Equation .. 55 5.4Kinetics of Formation of CBPCs .. 57 5.5Solubility Product Constant and Its pH Dependence 58 References 62 6. Thermodynamic Basis of CBPC Formation .. 63 6.1Review of Basic Thermodynamic Relations .. 64 6.2Thermodynamics of Solubility Reactions 66 6.3Applications of Thermodynamic Parameters to CBPC Formation .. 67 6.4Temperature Dependence of Solubility Product Constant.. 69 6.5Pressure Dependence of Solubility Product Constants .. 73 References 73 7. Oxidation and Reduction Mechanisms 75 7.1Oxidation and Reduction (Redox) Reactions. .. 76 7.2Redox Potentials . 77 7.3EH-pH Diagrams 80 7.4EH-pH Diagram of Water . 81 7.5Reduction of Iron Oxide and Formation of CBPC 83 References 84 8. Mineralogy of Orthophosphates .. 85 8.1Nature of Interatomic Bonds 85 8.2Rules for Crystal Structure Formation . 87 8.3Major Phosphate Crystal Structures .. 88 8.4Relevance to Minerals Constituting CBPC. .. 94 References 95 9. Magnesium Phosphate Ceramics .. 97 9.1Solubility Characteristics of MgO and Its Reaction with Acid Phosphates. .. 98 9.2Controlling Reaction Rates During Formation of Mg-Phosphate Ceramics98 9.3Fabrication and Properties of Mg-Based Phosphate Ceramics. . . . 103 References . 110 10. Zinc Phosphate Ceramics . 113 10.1Solubility Characteristics of Zinc Oxide .. 114 10.2Formation of Zinc Phosphate Ceramic115 10.3Phase Formation in Zinc Phosphate Cements and their Microstructure . .. 117 10.4Properties of Zinc Phosphate Cements . .. 117 References 118 11. Aluminum Phosphate Ceramics .. 121 11.1Solubility Enhancement with Temperature, and Formation of Berlinite Phase . .. 123 11.2Formation of Berlinite Bonded Alumina Ceramic. .. 128 11.3Consolidation Model of CBPC Formation .. 131 References 133 12. Iron Phosphate Ceramics . 135 12.1Reduction as the Basis for Enhanced Solubility. 136 12.2Ceramic Formation with Iron Oxides. 139 12.3Conclusions . 140 References 141 13. Calcium Phosphate Cements. 143 13.1Chemistry of Calcium Phosphates . 144 13.2Calcium Phosphate Cements from Calcium Silicates and Aluminates 147 13.3Adhesion of Portland Cement and CBPCs .. 151 13.4Calcium Phosphate Cements with Biomedical Applications 152 13.5Conclusions . 154 References 154 14. Chemically Bonded Phosphate Ceramic Matrix Composites 157 14.1Recycling of Benign Waste Streams in CBPC Value-Added Products .. 158 14.2Fiber Reinforcement of CBPC Products .. 169 14.3Niche Applications .. 169 14.4Energy and Environmental Issues Related to Binder Production . . 174 References 175 15. Chemically Bonded Phosphate Ceramic Borehole Sealant 177 15.1Parameters Affecting CBS Slurry Design. .. 178 15.2CBS Engineering Properties in Simulated Downhole Environment. 181 15.3CBS Slurry Designs. 185 15.4Properties of CBS. .. 191 15.5Effect of Individual Components on Slurry Behavior .. 194 15.6Conclusions . 196 References 196 16. Applications of CBPCs to Hazardous Waste Stabilization 197 16.1Test Criterion for Stabilization. .. 199 16.2Chemical Kinetics of Stabilization . 200 16.3General Approach to Phosphate Stabilization. 204 16.4Conclusions . 212 References 212 17.Radioactive Wastes Stabilization. .. 217 17.1Nature of the Radioactive Contaminants .. 219 17.2Mechanisms of Radioactive Waste Immobilization . .. 221 17.3Role of Solubility in Immobilization of Radioactive Elements. . . 221 17.4Waste Acceptance Criteria 226 17.5Case Studies in Stabilization of Radioactive Waste Streams. . . . 229 17.6Macroencapsulation of Large Objects 240 17.7Other Nuclear Applications 241 17.8Conclusions . 241 References 242 18. Dental Cements and Bioceramics .. 245 18.1Bone as a Composite Material. .. 246 18.2Chemically Bonded Phosphate-Based Bioceramics .. 248 18.3Recent Advances in CBPC-Based Biomaterials. 249 18.4Calcium-Based CBPC Biomaterials 251 18.5Conclusions . 252 References 253 Appendices 2S5 A: Thermodynamic Properties of Selected Materials 256 B: Solubility Product Constants 264 C: List of Minerals and Their Formulae . 267 Index 269