Sustainable Metal Extraction from Waste Streams

K. D. P. Nigam, PhD, is an Emeritus Professor at the Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi, India and Distinguished Professor at Tecnologico de Monterrey, Nuevo León, Monterrey, Mexico. K.K. Pant, PhD, is the Head of the Chemical Engineering Department at the Indian Institute of Technology, Delhi, India. Perminder Jit Kaur, PhD, is a Project Scientist at the Center for Rural Development and Technology at the Indian Institute of Technology, Delhi, India. Garima Chauhan, PhD, is working as a Post-Doctoral Fellow at the Department of Chemical & Materials Engineering at the University of Alberta, Canada.

• Graphical Abstract xiPreface xiii1 Introduction to Sustainability and Green Chemistry 11.1 Introduction 11.2 Defining “Sustainability” 21.3 Dimensions of Sustainability 31.4 New Conceptual Frameworks to Define Sustainability 51.4.1 Five Dimension Framework 51.4.2 Four Force Model 51.4.3 Corporate Sustainable Management 71.5 Green Value Stream Mapping (GVSM) 71.6 “Greening the Waste” 81.7 Green Chemistry Terminology 101.8 Green Ways of Metal Extraction: Core of the Book 11Questions 132 Waste Handling and Pre-treatment 152.1 Introduction 152.2 Waste Categorization 172.2.1 Waste Electrical and Electronic Equipment (WEEE) 172.2.2 Agro-Residue Waste 202.2.3 Industrial Waste 212.3 Legislations and Regulations for Hazardous Wastes 272.4 Handling/Management of Hazardous Waste 282.4.1 Secured Landfilling 292.4.2 Incineration 302.4.3 Recycling of Hazardous Waste 312.5 A Call for Metal Recovery from Waste 312.5.1 Threat to Human Health and Environment 312.5.2 Waste: An Artificial Ore 322.5.3 “Waste” to Wealth 332.6 Pretreatment of Waste 342.6.1 Disassembling the Waste 342.6.2 Size Reduction (Comminution) 342.6.3 Screening/Sieving 352.6.4 Classification 362.6.5 Segregation 362.6.6 Calcination and Chemical Pretreatment 372.7 Summary and Outlook 37Questions 383 Conventional Technologies for Metal Extraction from Waste 393.1 Introduction 393.2 Pyrometallurgical Operations 403.2.1 Pyrometallurgical Treatment of Industrial Waste 403.2.2 Pyrometallurgical Treatment of WEEE 453.2.3 Major Challenges Associated with Pyrometallurgical Operations 493.3 Hydrometallurgical Treatment of Waste 503.3.1 Leaching of Metals in Acidic Medium 503.3.2 Leaching of Metals in Alkali Medium 573.3.3 Leaching with Lixiviants (Cyanide,Thiourea,Thiosulfate) 603.3.4 Halide Leaching 663.4 Summary and Outlook 69Questions 704 Emerging Technology for Metal Extraction from Waste: I. Green Adsorption 714.1 Introduction 714.2 Adsorption 714.2.1 Hydrophilic Compounds 724.2.2 Hydrophobic Compounds 724.2.3 Polymer Matrix 734.3 Green Adsorption 744.4 Parameters Affecting the Adsorption Capacity of Green Adsorbents 754.4.1 Influence of pH 754.4.2 Influence of Temperature 764.4.3 Effect of Initial Concentration 764.4.4 Effect of Adsorbent Dosage 764.4.5 Effect of Co-ions 774.5 Adsorption Kinetic Models 774.6 Mechanism of Metal Uptake 784.7 Green Adsorbents: Relevant Literature 794.7.1 Agricultural Resources 794.7.2 Zeolites 814.7.3 Clay 844.7.4 Industrial Waste 854.7.5 Modified Biopolymers 884.8 Innovative Applications of Adsorption 884.9 Case Study 894.10 Summary and Outlook 90Questions 915 Emerging Technologies for Extraction of Metals from Waste II. Bioleaching 935.1 Introduction 935.2 Bioleaching Process Description 945.3 Factors Affecting the Process Efficiency 955.3.1 Types of Microorganisms 955.3.1.1 Mesophiles 955.3.1.2 Thermophiles 965.3.1.3 Heterotrophic Microbes 975.3.2 Affinity Between Microorganisms and Metal Surfaces 975.3.3 Physicochemical Factors 985.3.3.1 Surface Properties 985.3.3.2 Oxygen and Carbon Dioxide Content 985.3.3.3 pH Value of Solution 995.3.3.4 Temperature 995.3.3.5 Mineral Substrate 995.3.3.6 Surface Chemistry of Metals 995.3.3.7 Surfactant and Organic Extractants 1005.3.4 Reactor Design 1005.4 Mechanism of Bioleaching Process 1015.4.1 Biochemical Reaction (Direct vs. Indirect)Mechanism 1025.4.2 Mechanism of Metal Sulfide Dissolution (Polysulfide Pathway) 1035.5 Engineering Practices in Bioleaching Process 1045.5.1 Batch Process 1055.5.2 Continuous Process 1065.5.3 Hybrid Processes 1105.6 Application of Bioleaching in Extracting Metals from Waste 1105.6.1 Extraction of Metals from WEEE 1115.6.2 Extraction of Metals from Industrial Waste 1155.6.3 Extraction of Metals from Mineral Waste 1185.6.4 Extraction of Metals from Municipal Sewage Sludge 1195.7 Technoeconomic Opportunities and Challenges 1195.8 Summary and Outlook 121Questions 1226 Future Technology for Metal Extraction from Waste: I. Chelation Technology 123Abbreviations 1236.1 Introduction 1236.2 Defining “Chelation” 1246.3 Classification of Ligands 1246.4 Chemistry Associated with Chelation 1276.4.1 Theories Derived for Metal–Ligand Complexation 1276.4.2 Attributes of Metal Ions for Complexation 1296.4.3 Metal–Chelate Complex Formation 1306.4.4 The Chelate Effect 1326.5 Chelation Process for Extraction of Metals 1336.5.1 Framework for Chelating Agent Assisted Metal Extraction from Solid Waste 1336.5.2 Process Parameters Affecting the Metal Extraction Process 1356.5.2.1 Effect of Reaction pH 1356.5.2.2 Effect of Molar Concentration of Chelating Agent 1386.5.2.3 Effect of Reaction Temperature 1406.5.2.4 Presence of Competing Ions in Reaction Zone 1416.5.3 Factors Affecting Stability of Metal–Ligand Complex 1426.6 Novel Applications of Chelating Agents 1436.6.1 Chelating Agents Used for Metal Extraction from Metal-Contaminated Soil 1446.6.1.1 Hydrometallurgical Route of Chelation Process (Direct Use) 1446.6.1.2 Phyto-remediation of Soils in Presence of Chelating Agents 1456.6.2 Chelating Agents Used for Metal Extraction from Industrial Waste 1476.6.3 Chelating Agents Used for Metal Extraction from WEEE 1496.7 Ecotoxicological Concerns and Biodegradability 1516.8 Summary and Outlook 155Questions 1557 Future Technology for Metal Extraction from Waste: II. Ionic Liquids 157Abbreviation 1577.1 Introduction 1587.2 What Are Ionic Liquids? 1587.3 Characteristic Properties of Ionic Liquids 1617.3.1 Melting Point 1627.3.2 Vapor Pressure and Nonflammability 1627.3.3 Thermal Stability 1637.3.4 Density 1647.3.5 Viscosity 1647.3.6 Polarity 1667.3.7 Coordination Ability 1667.3.8 Conductivity 1677.3.9 Solubility 1677.4 Classification of Ionic Liquids 1697.5 Environmental Scrutiny of Ionic Liquids 1717.6 Applications of Ionic Liquids 1737.6.1 Extraction of Metals from Aqueous Media 1737.6.2 Extraction of Metals from Industrial Solid Waste/Ores 1767.6.3 Extraction of Metals from WEEE 1777.7 Summary and Outlook 179Questions 1798 Scale-up Process for Metal Extraction from Solid Waste 181Nomenclature 1818.1 Introduction 1828.2 Process Intensification 1838.3 Intensification of Metal Extraction Processes 1858.3.1 Centrifugation 1858.3.2 Liquid–Liquid Extraction 1858.3.3 Mixing 1868.3.4 Reactors 1888.3.5 Comminution 1888.3.6 Drying 1898.4 Scaling Up from Batch to Continuous Process 1898.4.1 Process Design Fabrication 1908.4.2 Designing of Pilot Plant 1918.4.2.1 Material Balance 1918.4.2.2 Development of Comminution Circuit 1938.4.3 Reactor Sizing and Agitator Selection 1978.4.4 Design of Filtration System 1998.4.5 Design of Heat Exchanger 2018.4.6 Design of Precipitator Unit 2028.4.7 Batch Scheduling 2038.5 Summary and Outlook 204Questions 2059 Process Intensification for Micro-flow Extraction: Batch to Continuous Process 207Jogender Singh, Loveleen Sharma, and Jamal ChaoukiAbbreviations 2079.1 Introduction 2089.2 Miniaturized Extraction Devices 2089.2.1 Intensification in Miniaturized Extraction Devices 2099.2.2 Application of Miniaturized Extraction Devices 2119.3 CFI for Continuous Micro-flow Extraction 2129.3.1 Designing CFI as an Extractor 2169.3.2 Extraction Parameters 2189.3.3 Methodology and Setup for Micro-flow Extraction 2189.3.4 Liquid–Liquid Micro-flow Extraction 2209.3.4.1 Typical Flow Patterns 2209.3.4.2 Extraction Efficiency 2229.3.4.3 Effect of Aqueous Phase Volume Fractions on Extraction Efficiency 2239.3.5 Micro-flow Extraction of Co and Ni 2259.3.5.1 Effect of pH 2259.3.5.2 Effect of Residence Time 2259.3.5.3 Effect of Extractant Concentration 2299.4 Summary and Future Challenges 229Questions 229Bibliography 231Index 273