John Marsden is a globally recognized leader in mineral processing and extractive metallurgy, with more than four decades of experience developing and implementing innovative metallurgical technologies across the world's major mining regions. A graduate of the Royal School of Mines, London (B.S., Mineral Technology, First-Class Honors, 1982), Marsden began his career with Consolidated Gold Fields, gaining extensive operational experience in both South Africa and the United States before joining Phelps Dodge Corporation in 1990. At Phelps Dodge, Marsden advanced to President of Phelps Dodge Mining Company, overseeing groundbreaking copper development projects in the United States, Chile, Peru, and the Democratic Republic of Congo. His leadership guided the design, construction, and commissioning of several landmark operations, including the Cerro Verde Concentrator in Peru, the Tenke-Fungurume SX-EW plant in the DRC, and multiple major leaching and processing facilities across the Americas. In 2009, he founded Metallurgium, a consulting firm that has since supported more than 150 mining projects in 20 countries-roughly half focused on gold and silver and half on copper, with additional expertise in molybdenum, nickel, cobalt, and zinc. His clients include industry leaders such as Barrick, Rio Tinto, Freeport-McMoRan, Kinross, Hudbay, Vale, and Antofagasta.

Marsden co-authored the acclaimed reference The Chemistry of Gold Extraction (2nd ed., SME, 2006), and he has written or co-edited numerous technical papers and books. He holds seven U.S. patents related to copper extraction. A Fellow and past president of the Society for Mining, Metallurgy & Exploration (SME), Marsden is also a Fellow of the Australasian Institute of Mining & Metallurgy, an Honorary Member of AIME, and a member of the U.S. National Academy of Engineering.

His distinguished honors include the Robert H. Richards Award (2005), Milton E. Wadsworth Award (2007), and two Arthur F. Taggart Awards (2009, 2021). Throughout his career, Marsden has championed technological innovation and sustainable process development to ensure a reliable and efficient global supply of critical minerals essential to the energy transition.