v
Contents
Preface.......................................................................................................................ix
Author .......................................................................................................................xi
Chapter 1 Introduction .......................................................................................... 1
Brief History of Aluminum Recycling .................................................2
Advantages (and Challenges) of Recycling .........................................6
Recommended Reading .......................................................................9
References .......................................................................................... 10
Chapter 2 Ore Body ............................................................................................ 11
Wrought Aluminum Alloy System .................................................. 11
Cast Aluminum Alloy System ..................................................................16
Product Mix ........................................................................................ 21
Recommended Reading .....................................................................26
References ..........................................................................................26
Chapter 3 Scrap Collection .................................................................................29
Materials Life Cycle ...........................................................................29
Scrap Collection Practice ...................................................................32
New Scrap ................................................................................ 32
Old Scrap ................................................................................. 34
Packaging.................................................................................35
Wire and Cable ........................................................................39
Building and Construction .......................................................40
Recommended Reading .....................................................................40
References .......................................................................................... 41
Chapter 4 Aluminum Recycling Economics ...................................................... 45
Scrap Grades.......................................................................................45
Scrap Prices ........................................................................................ 53
Scrap Purchasing ................................................................................ 57
Cost of Processing .............................................................................. 59
Recycling Products and Their Price ...................................................60
Recommended Reading .....................................................................64
References ..........................................................................................64
vi Contents
Chapter 5 Beneciation Technology ................................................................... 67
Comminution ......................................................................................67
Sorting ................................................................................................ 75
Sensor-Based Sorting .........................................................................85
Thermal Processing ............................................................................ 89
Agglomeration ....................................................................................98
Recommended Reading ...................................................................100
References ........................................................................................100
Chapter 6 Beneciation Practice .......................................................................105
New Scrap ........................................................................................ 105
MSW ................................................................................................106
UBCs and Other Packaging ..............................................................108
Automotive Scrap ............................................................................. 110
Electrical and Electronic Scrap ........................................................ 116
Recommended Reading ................................................................... 119
References ........................................................................................ 119
Chapter 7 Melting Furnace Fundamentals ........................................................123
Heat-Transfer Kinetics ..................................................................... 123
Combustion ......................................................................................127
Chemistry of Fluxing .......................................................................129
Refractory Interactions ..................................................................... 132
Recommended Reading ................................................................... 134
References ........................................................................................134
Chapter 8 Melting Furnace Parts and Accessories ........................................... 137
Charging and Preheating ..................................................................137
Burners ............................................................................................. 138
Recuperators ..................................................................................... 143
Refractories ...................................................................................... 143
Stirring .............................................................................................. 146
Road Crucibles ................................................................................. 149
Environmental Equipment ................................................................ 150
Recommended Reading ................................................................... 152
References ........................................................................................ 152
viiContents
Chapter 9 Fossil-Fuel Furnaces ........................................................................ 157
Single-Chamber Designs .................................................................. 157
Multiple-Chamber Furnaces ............................................................. 161
Small-Volume Melters ...................................................................... 164
Rotary Furnaces ................................................................................ 164
Holding and Dosing Furnaces .......................................................... 165
Recommended Reading ................................................................... 166
References ........................................................................................ 166
Chapter 10 Electric Furnace Melting .................................................................. 169
Induction Furnaces ........................................................................... 170
Coreless Furnaces .................................................................. 170
Channel Furnaces .................................................................. 176
Resistance Furnaces ......................................................................... 178
Recommended Reading ................................................................... 181
References ........................................................................................ 181
Chapter 11 Recycling Industry ........................................................................... 183
Who Recycles Aluminum? ............................................................... 183
Inuences on the Aluminum Recycling Industry ............................. 185
Impact of Government ........................................................... 185
Impact of Demand ................................................................. 187
Impact of Cost ....................................................................... 188
Impact of Technology ............................................................ 189
Recycling around the World ............................................................. 189
Recommended Reading ................................................................... 195
References ........................................................................................ 195
Chapter 12 Metal Rening and Purication .......................................................199
Common Impurities in Molten Aluminum .......................................199
Fundamentals of Impurity Removal ................................................. 206
Rening Strategy .............................................................................. 212
Recommended Reading ................................................................... 221
References ........................................................................................ 221
viii Contents
Chapter 13 Dross Processing ..............................................................................227
Types of Dross ..................................................................................227
Processing Options for Dross ........................................................... 229
Hot Processing .......................................................................229
Dross Cooling Options ..........................................................232
Comminution .........................................................................237
Melting Options: Rotary Salt Furnace ...................................238
Salt-Free Processes ................................................................ 240
Salt Cake and Salt Dross Processing .....................................242
Recommended Reading ...................................................................244
References ........................................................................................244
Chapter 14 Safety and Environmental Considerations ....................................... 247
Collection and Beneciation ............................................................247
Thermal Processing and Melting ......................................................250
Responses to Hazards .......................................................................255
Recommended Reading ...................................................................259
References ........................................................................................259

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