Preface xiii 1 Modified Dendrimer Nanoparticles for Effective and Sustainable Recovery of Rare Earth Element from Acid Rock Drainage 1Anyik John Leo, Innocentia Gugulethu Erdogan,  Frans B. Waanders, Martin Mkandawire, Thabo T.I Nkambule, Bhekie B. Mamba and Elvis Fosso-Kankeu 1.1 Introduction 2 1.2 Rare-Earth Element Occurrence in Acid Mine Drainage 10 1.2.1 Acid Mine Drainage Generation and Effects 10 1.2.2 Rare-Earth Elements and Their Importance 15 1.2.3 Classical AMD Remediation and Treatment Methods 16 1.3 Dendrimer as Extraction Agent of Rare Earth Element in AMD 17 1.3.1 Poly(amidoamine) (PAMAM) Dendrimers 19 1.3.2 Principle REE Extraction Using PAMAM 19 1.4 Designed a Recovery System for REE from AMD 21 1.4.1 Process Overview 21 1.4.2 Components and Their Functions 22 1.4.2.1 Reactor 1 – Collection Tank 22 1.4.2.2 Reactor 2 – Mixing Tank 22 1.4.2.3 Reactor 3 – Separation Tank 23 1.4.2.4 Reactor 4 – Recovery of REEs Metals 23 1.5 Challenges and Opportunities for the Future of Metal Mining 24 1.6 Conclusion 25 Acknowledgment 26 References 26 2 Cellulose-Based Nanomaterials for Treatment of Acid Mine Drainage-Contaminated Waters 33 Thato M. Masilompane, Hlanganani Tutu and Anita Etale 2.1 Introduction 34 2.2 Cellulose 36 2.2.1 Structure and Properties of Cellulose 36 2.2.2 Nanocellulose 37 2.3 Synthesis of CNFs and CNCs 39 2.3.1 Synthesis of CNFs 39 2.3.2 Synthesis of CNCs Through Acid Hydrolysis 43 2.3.3 Cationization for Anion Uptake 45 2.3.4 Application of CNF and CNC Nanocomposite in Metal and Anion Removal 46 2.4 Cellulose Composites 50 2.4.1 Cellulose/Chitosan Nanocomposites 50 2.4.2 Cellulose/Metal Oxide Nanoparticles: ZnO, Magnetic Iron Oxide Nanoparticles, Nano Zero-Valent Iron 51 2.5 Valorization of AMD-Contaminated Water and the Possible Uses of Recovered Elements 53 2.5.1 Sludge from AMD 53 2.5.1.1 Removal of Heavy Metals Using Sludge 54 2.5.1.2 Sludge as a Fertilizer 55 2.5.1.3 Sludge Used in Construction Material 55 2.5.2 Resource Recovery 56 2.6 Conclusion 56 References 57 3 Application of Nanomaterials for Remediation of Pollutants from Mine Water Effluents 67 Ephraim Vunain 3.1 Introduction 68 3.1.1 Mine Water Chemistry 69 3.2 Existing Treatment Methods of Mine Water and Their Limitations 70 3.3 Nanoremediation of Mine Water 71 3.4 Application of Nanomaterials for Mine Water Remediation 73 3.5 Conclusions and Future Perspectives 81 References 81 4 Application of Nanofiltration in Mine-Influenced Water Treatment: A Review with a Focus on South Africa 91 Frédéric Jules Doucet, Gloria Dube, Sameera Mohamed, Sisanda Gcasamba, Henk Coetzee and Viswanath Ravi Kumar Vadapalli Abbreviations 92 4.1 Introduction 93 4.1.1 Mine-Influenced Water 93 4.1.1.1 Occurrence and Types of Mine-Influenced Water 93 4.1.1.2 Mine-Influenced Water Treatment 94 4.1.2 Reuse of Mine-Influenced Water 96 4.2 Nanofiltration for Mine-Influenced Water Treatment 97 4.2.1 Introduction—Membrane Separation Technologies 97 4.2.2 Nanofiltration 100 4.2.2.1 Background and Benefits 100 4.2.2.2 Types and Performances of Nanofiltration Membranes 101 4.2.2.3 Limitations and Challenges 124 4.2.2.4 Nanocomposite Membranes and Nanofillers 127 4.2.3 Membrane Distillation 128 4.3 Large-Scale Operations Using Nanofiltration or Reverse Osmosis 128 4.3.1 Integration of Membrane and Conventional Treatment Approaches 128 4.3.2 Pilot-Scale Case Studies 129 4.3.3 Challenges of Scale-Up and Commercialization 133 4.3.3.1 Fouling 133 4.3.3.2 Membrane Selection 133 4.3.3.3 Modeling and Simulation of NF Systems 134 4.3.3.4 Cost Estimates 135 4.3.3.5 Environmental Considerations 135 4.4 Some Perspectives and Research Directions 136 References 137 5 Recovery of Gold from Thiosulfate Leaching Solutions with Magnetic Nanoparticles 153 N.D. Ilankoon and C. Aldrich Abbreviations 153 5.1 Introduction 154 5.2 Recovery of Precious Metals with Magnetic Nanohydrometallurgy 156 5.2.1 Superparamagnetism 157 5.2.2 Iron Oxide Nanoparticles 157 5.2.3 Selective Adsorption 159 5.2.4 Adsorption Mechanisms 162 5.2.5 Recovery of Gold 162 5.2.6 Recovery of Silver 164 5.2.7 Recovery of PGMs 165 5.3 Synthesis and Functionalization of Magnetic Nanoparticles 166 5.4 Characterization of Magnetic Nanoparticles 170 5.5 Recovery of Gold from Thiosulfate Leaching Solutions 175 5.5.1 Preparation of PEI-MNPs 176 5.5.2 Application of PEI-MNPs for Gold Adsorption from Synthetic Leaching Solutions 177 5.5.3 Application of PEI-MNPs for Gold Adsorption from Ore Leachates 180 5.6 Gold Elution and Reuse of the Adsorbent 181 5.7 Industrial Scale-Up and Challenges 182 5.7.1 High Gradient Magnetic Separation 182 5.7.2 Nanoparticle Aggregation and Agglomeration 183 5.7.3 Nanoparticle Dissolution 185 5.7.4 Magnetic Separation from a Solution 185 5.8 Environmental Concerns and Toxicity of MNPs 186 References 186 6 Recovery of Na2CO3 and Nano CaCO3 from Na2SO4  and CaSO4 Wastes 197 Conny P. Mokgohloa, Johannes P. Maree,  David S. van Vuuren, Kwena D. Modibane,  Munyaradzi Mujuru and Malose P. Mokhonoana 6.1 Introduction 198 6.2 Literature Survey 200 6.2.1 Gypsum Reduction 200 6.2.2 Nano CaCO3 202 6.2.2.1 Uses 202 6.2.2.2 Composition and Particle Size 202 6.2.3 Na2CO3 203 6.2.3.1 Introduction 203 6.2.3.2 Uses 203 6.2.3.3 Chemical Properties 204 6.2.3.4 Physical Properties 205 6.2.3.5 Production Methods 206 6.3 Materials and Methods 209 6.3.1 Feedstock, Chemicals and Reagents 209 6.3.2 Equipment 209 6.3.3 Experimental and Procedure 209 6.3.3.1 Thermal Treatment 209 6.3.3.2 OLI Simulations and Beaker Studies 209 6.3.3.3 Na2S Formation 209 6.3.3.4 Ca(HS)2 Formation  209 6.3.3.5 Nano CaCO3 Formation 210 6.3.4 Analysis 210 6.3.5 OLI Software Simulations 210 6.4 Results and Discussion 211 6.4.1 Direct Conversion of Na2SO4 to Na2S 211 6.4.2 CaSO4 Reduction 212 6.4.2.1 CaS Formation 212 6.4.2.2 Ca(HS)2 Formation 213 6.4.3 Na2CO3 Production 213 6.4.3.1 Indirect Conversion of Na2SO4 to Na2S 213 6.4.3.2 NaHCO3 Formation 222 6.4.3.3 NaHCO3 and NaHS Separation 222 6.4.3.4 Na2CO3 Formation 225 6.4.3.5 Up-Concentration of NaHS (Freeze Crystallization) 225 6.4.4 CaCO3 Formation 225 6.4.4.1 Crude and Pure CaCO3 and Ca(HS)2  Formation 225 6.4.4.2 Nano CaCO3 Formation 230 6.5 Conclusions 232 Acknowledgments 232 References 232 7 Recovery of Drinking Water and Nanosized Fe2O3 Pigment from Iron Rich Acid Mine Water 237Tumelo Monty Mogashane, Johannes Philippus Maree, Leny Letjiane, Vhahangwele Masindi, Kwena Desmomd Modibane, Munyaradzi Mujuru and Mabel Mamasegare Mphahlele-Makgwane 7.1 Introduction 238 7.1.1 Formation and Quantities 238 7.1.2 Legal Requirements 238 7.1.3 ROC Process 239 7.1.4 Raw Material Manufacturing 241 7.1.5 Objectives 243 7.2 Literature Review 243 7.2.1 Uses of Nanopigment 243 7.2.2 Production of Nanopigment 244 7.2.3 Market for Nanopigment 246 7.3 Materials and Methods 247 7.3.1 Neutralization 247 7.3.1.1 Feedstock 247 7.3.1.2 Equipment 248 7.3.1.3 Procedure 248 7.3.1.4 Experimental 249 7.3.1.5 Analytical 249 7.3.1.6 Characterization 249 7.3.2 Coagulation 250 7.3.2.1 Feedstock 250 7.3.2.2 Equipment 250 7.3.2.3 Procedure 250 7.3.2.4 Experimental 250 7.3.3 Pigment Formation 250 7.3.3.1 Feedstock 250 7.3.3.2 Equipment 250 7.3.3.3 Procedure 252 7.3.3.4 Experimental 252 7.3.3.5 Characterization of the Sludge 252 7.4 Results and Discussion 253 7.4.1 Neutralization with MgO and Na2CO3 253 7.4.1.1 Solubilities of Alkalis and Products 254 7.4.1.2 Sludge Characteristics 256 7.4.1.3 Flocculant/Coagulant Selection and Dosing 259 7.4.1.4 Centrifugation 260 7.4.2 Concentration of Acid Mine Water 260 7.4.2.1 Freeze Crystallization 261 7.4.2.2 Forward Osmosis 262 7.4.2.3 Feasibility of Forward Osmosis and Freeze Desalination 263 7.4.3 Pigment Formation 263 7.4.3.1 Effect of Temperature 263 7.4.3.2 Elemental Composition of Feed and Product Mineral 264 7.4.3.3 Morphological Characteristics of the Synthesized Pigments 265 7.4.4 Process Configurations 268 7.4.4.1 Iron(III)-Rich Water (Kopseer Dam) (Process Configuration A) 268 7.4.4.2 Iron(II)-Rich Water (Top Dam) (Process Configuration B) 269 7.4.4.3 Tailings and Tailings Leachate 269 7.4.5 Economic Feasibility 272 7.5 Conclusion 283 7.6 Recommendation 284 Acknowledgments 284 References 285 8 Advances of Nanotechnology Applications in Mineral Froth Flotation Technology 289Madzokere Tatenda Crispen, Nheta Willie and Gumbochuma Sheunopa Abbreviations 290 8.1 Introduction to Froth Flotation 290 8.2 Current Developments of Nanotechnology in the Mineral Froth Flotation Process 291 8.2.1 Nanobubbles in Mineral Froth Flotation 291 8.2.1.1 Generation and Conditions of Nanobubble Formation 292 8.2.1.2 Properties and Stability of Nanobubbles 293 8.2.2 General Overview of Applications of Nanobubbles in Mineral Froth Flotation and Recovery of Selected Minerals 294 8.2.2.1 Flotation of Fine and Ultrafine Mineral Particles Using Nanobubbles 295 8.2.2.2 Flotation of Coal Using Nanobubbles 296 8.2.2.3 Flotation of Phosphate Ore Using Nanobubbles 298 8.2.2.4 Interactive Relationship Between Nanobubbles, Collectors and Mineral Particles 299 8.2.3 Nanofrothers in Mineral Froth Flotation 301 8.2.4 Nanocollectors in Mineral Froth Flotation 303 8.2.4.1 Nanopolystyrene Collector 303 8.2.4.2 Cellulose-Based Nanocrystals Collector 307 8.2.4.3 Carbon Black and Talc Nanoparticle Collectors 313 8.2.5 Nanodepressants in Mineral Froth Flotation 315 8.3 Intellectual Property (IP) and Commercialization of Nanotechnology in Mineral Froth Flotation Technology 319 8.4 Current Research Gaps 319 8.5 Conclusion 320 References 320 9 Nanoscale Materials for Mineral Froth Flotation: Synthesis and Implications of Nanoscale Material Design Strategies on Flotation Performance 327n, Gumbochuma Sheunopa, Mudono Stanford and Mamuse Antony 9.1 Introduction 328 9.2 Classification of Minerals 329 9.2.1 Chemical Classification of Minerals 330 9.3 Synthesis and Characterization of Nanoscale Materials 337 9.3.1 Top-Down Synthesis Approach 337 9.3.2 Bottom-Up Synthesis Approach 337 9.3.3 Characterization of Nanomaterials 338 9.3.4 Effect of Nanoparticle Size, Morphology and Structure on Flotation Performance 340 9.4 Nanoflotation Reagents and Mineral Particle Interaction in the Flotation Environment 340 9.4.1 Effect of Mineral Surface Properties on Recovery 343 9.4.1.1 Potential Strategies of Evaluating Surface Properties 344 9.4.1.2 Effect of Mineral Surface Electric Charge and Microstructure on Flotation and Potential Techniques for Tailoring Nanocollector Hydrophobicity 346 9.5 Nanotoxicology 347 9.6 Conclusion 348 References 348 Index 355

Nanotechnology has revolutionized processes in many industries but its application in the mining industry has not been widely discussed. This unique book provides an overview of the successful implementation of nanotechnology in some of the key environmental and beneficiation mining processes. This book explores extensively the potential of nanotechnology to revolutionize the mining industry which has been relying for a very long on processes with limited efficiencies. The nine specialized chapters focus on applying nanoflotation to improve mineral processing, effective extraction of metals from leachates or pregnant solutions using nanoscale supramolecular hosts, and development of nano-adsorbents or nano-based strategies for the remediation or valorization of AMD. The application of nanotechnology in mining has so far received little attention from the industry and researchers and this groundbreaking book features critical issues so far under-reported in the literature: Application of nanotechnology in mineral processing for the enhancement of froth flotationDevelopment of smart nanomaterials and application for the treatment of acid mine drainageRecovery of values from pregnant solutions using nanoadsorbentsValorization of AMD through formation of multipurpose nanoproducts. Audience Industrial interest will be from mining plant operators, environmental managers, water treatment plants managers, and operators. Researchers in nanotechnology, environmental science, mining, and metallurgy engineering will find the book valuable, as will government entities such as regulatory bodies officers and environmentalists.