Principles of Metal Refining and Recycling

Thorvald Abel Engh graduated from NTH in 1958. He has worked at IBM's laboratory for process control, Massachusetts Institute of Technology (MIT), at the Metallurgical Research Station in Lulea, and at the Royal Institute of Technology, Stockholm. From 1971 to 1980 he was a lecturer in Metallurgy Engineering, and from 1980-2004 he was a professor of process metallurgy at Norwegian University of Science and Technology. He continued working in the field of refining and recycling metals up to his death in December 2023.


Geoffrey Sigworth has worked extensively in metals production and refining, melt treatment, alloy design and metal casting. Particular areas of his scientific interest have been the thermochemistry of metallic alloys, control of cast microstructures and characterizing quality in net-shaped castings. Dr. Sigworth was formerly technical specialist for foundry products at Alcoa (Aluminum Company of America); and has extensive experience working for other metal producers as a consultant.

Anne Kvithyld earned her PhD in aluminium recycling at Norwegian University of Science and Technology in 2003. She has worked as a visiting scientist at the Colorado School of Mines and now as a senior researcher at SINTEF, in particular in the field of recycling and refining of metals.