Prof. John A. Herbst: 1942-2025

There was sad news from USA this weekend of the death, on Friday, of Prof. John Herbst, at the age of 83. Prof. Herbst was an Adjunct Professor of Metallurgical Engineering in the Department of Metallurgical Engineering at the University of Utah. 

He gained his PhD from the University of California, Berkeley, under the supervision of Prof. Douglas Fuerstenau and as a graduate student at the University became one of the pioneers in applying population balance models to ball mill comminution.

His main focus was on modelling, simulation, optimisation and control of grinding (comminution) and flotation circuits. He provided a bridge between industry and academia and his focus on process modelling (especially in comminution and flotation) set him apart.

He served as Chair of the Department of Metallurgy and Metallurgical Engineering at the University of Utah from 1977 to 1986 and he founded the USBM Generic Mineral Technology Center for Comminution at Utah in 1982 and served as its director until 1988. 

One of his well-known students, Dr. Osvaldo Bascur, said of his supervisor "John was an outstanding Professor.  His scientific approach to mineral processing using particulate systems was very defined. His class notes were very well organised and his examples very well chosen.  He provided outstanding coaching, mentoring and support for his students at the University of Utah".

Osvaldo Bascur (right) with John Herbst and Prof. & Mrs. Kal Sastry in Cape Town, 2003

John co-founded the company Control International Inc. in 1986 (a joint venture with ARMCO) to apply modelling and control in mineral processing plants. He sold his part of the business in 1996 and formed J.A. Herbst & Associates in Salt Lake City. The overall purpose was to support companies using advanced technology in their processing operations. They developed a dynamic flowsheet simulator, a soft- sensor line for comminution, and an image analysis system for coarse size particles in grinding systems.

From 2000-2016 John was with Metso Minerals, becoming Chief Scientist and Manager of Technology Development before becoming the Robert E. Murray Chair and Professor of Mining Engineering at West Virginia University, and then Adjunct Professor at the University of Utah.

Prof. Herbst received multiple awards from professional societies and he was inducted into the U.S. National Academy of Engineering in 1992 in recognition of his contributions.

In 1995 he was the principal organiser and President of the XIXth IMPC/SME Conference and Exhibition held in San Francisco, at which his former supervisor, Prof. Douglas Fuerstenau became the first person to be awarded the IMPC Lifetime Achievement Award. John was too ill to attend the IMPC in Washington last year, where he was also awarded the Lifetime Achievement Award.

San Francisco 1995 with Doug Fuerstenau and Eric Forssberg

I first met John and his wife Cindy at the IMPC in Sydney in 1993 and in 1998 John and Cindy played very active parts in MEI's Minerals Engineering '98 in Edinburgh.

With John and Cindy and Gordon Agar in Sydney, 1993

John and Cindy with Peter Radziszewski and Barbara Wills, Edinburgh 1998

John and Cindy with conference delegates at the Glenturret whisky distillery, 1998

Since then we caught up at IMPCs in Cape Town and Quebec.

With Doug Fuerstenau and Peter King, Cape Town 2003

Cindy and John with Amanda Wills, Romke Kuyvenhoven and Osvaldo Bascur, Quebec 2016

Prof. John Herbst was a giant in the mineral processing community. He will be sorely missed by his friends around the world and we extend our condolences to his wife Cindy and all his family.