Aluminum
Abstract
Aluminum [7429-90-5] is a silver-white metal of group 13 of the periodic table. It is the third most abundant metallic element in the earth's crust but is never found in nature in its elemental state. It occurs mainly as very stable oxides, hydroxides, and silicates. The first commercial aluminum was produced in 1854 by H. Saint-Claire Deville by reaction of sodium metal with molten sodium aluminum chloride. Mass production of aluminum was started by the invention of electrolytic reduction of alumina dissolved in molten cryolite in 1886. It was made independently by C. M. Hall in the USA and P. Héroult in France. All industrial production of aluminum is done in Hall–Héroult cells with prebaked carbon or self-baking Söderberg anodes. Aluminum has many desirable physical properties. It is malleable and lightweight. Pure aluminum is relatively soft and weak, but it forms many strong alloys. It has high thermal and electrical conductivity. Aluminum's adherent surface oxide film makes it corrosion resistant. It resists attack by most acids but alkaline solutions dissolve the oxide film and cause rapid corrosion. It is recyclable, which is very important, because decarbonization and CO2 emission reduction are commitments of the global aluminum industry.
The article contains sections titled:
| 1 | Introduction |
| 2 | Properties of Pure Aluminum |
| 2.1 | Mechanical Properties |
| 2.2 | Physical Properties |
| 3 | Chemical Properties |
| 3.1 | Oxidation of Aluminum |
| 3.2 | Reactions with Aqueous Solutions |
| 3.3 | Reactions at High Temperatures |
| 3.4 | Corrosion |
| 3.5 | Gases and Aluminum |
| 4 | Production |
| 4.1 | History of the Electrolytic Reduction of Alumina |
| 4.2 | Raw Materials |
| 4.2.1 | Carbon |
| 4.2.2 | Aluminum Oxide |
| 4.2.3 | Electrolyte Materials |
| 4.2.4 | Aluminum Fluoride |
| 4.3 | Electrolytic Cell for Aluminum Production |
| 4.3.1 | Electrolyte |
| 4.3.2 | Electrode Reactions |
| 4.3.3 | Net Anode Carbon Consumption |
| 4.3.4 | Anode Effect |
| 4.3.5 | Low-Voltage Anode Effects |
| 4.3.6 | Current Efficiency |
| 4.3.7 | Cell Voltage |
| 4.3.8 | Energy Consumption |
| 4.3.9 | Heat Balance |
| 4.3.10 | Magnetohydrodynamics |
| 4.3.11 | Thermodynamic Considerations |
| 4.4 | Aluminum Production in China |
| 4.5 | Alternative Processes |
| 4.6 | Inert Electrodes |
| 4.6.1 | Inert Anodes |
| 4.6.2 | Inert Cathodes |
| 4.6.3 | Present Status of Inert Anode Cells |
| 4.6.4 | Conclusion |
| 4.7 | Greenhouse Gas Emissions and Decarbonization |
| 4.8 | Digitalization in Aluminum Production |
| 5 | Production of High-Purity Aluminum |
| 6 | Environmental Protection |
| 6.1 | Air Emission |
| 6.2 | Wastewater Discharge |
| 6.3 | Solid Waste |
| 6.3.1 | Spent Potlining |
| 6.3.2 | Red Mud |
| 7 | Economic Aspects |
| 8 | Toxicology and Occupational Health |
| List of Abbreviations | |
| References |
