The papers of this volume is organized into seven main aluminium reduction technology themes: 1. Fundamentals, 2. Modelling, 3. Design, 4. Operations, 5. Control, 6. Environmental, 7. Alternative processes The first six themes deal with aspects of conventional Hall-Héroult electrolytic reduction technology, whereas the last theme has papers on nonconventional processes. Papers relating specifically to cathodes and anodes (including inert anode technology) can be found in the Electrode Technology volume (Volume 4 of the Essential Readings in Light Metals collection). To avoid excessive bias toward particular themes, the numbers of papers selected in each theme reflect roughly the distribution found in annual Light Metals volume. For example, approximately 23% of papers in the annual proceedings relate to reduction fundamentals and so that proportion is mirrored in this book.