Robert S. (Bob) Shoemaker was one of the most down-to-earth, operations-savvy engineers of his time. He had a keen eye for detail, an uncanny ability to spot the weak link in a design, a devotion to the practical application of appropriate theory, and just plain old common sense. His intellect was above reproach.
Born and raised in Roseburg, Oregon, Bob earned BS and MS degrees in Inorganic Chemistry from Oregon State College and a second MS in metallurgical engineering from the University of Wisconsin in 1953. In 1975, he was awarded the degree of Metallurgical Engineer honoris causa from Montana College of Mineral Science and Engineering.
Bob’s career began in minerals research and plant operations at several Union Carbide affiliates. In 1962, he joined the Mining and Metals Division of Bechtel Corporation as a supervising engineer, metallurgical engineer, consulting engineer, and eventually, manager of plant design for Bechtel offices in San Francisco, Toronto, and Melbourne. He worked on gold, silver, copper, iron ore, molybdenum, uranium, tungsten, vermiculite, and coal projects around the world. While he had numerous major process designs to his credit, it was precious metal extraction that really distinguished Bob from his peers.
In 1964, Bob was responsible for the Carlin gold plant design for Newmont Mining, the first built in the United States in over thirty years. He pioneered the idea of recycling low-grade gold-bearing solution at the Zortman-Landusky mine in Montana, a concept that quickly became standard practice for heap and dump leaching operations. He ultimately had over eighty heap leaching and forty milling operations to his credit and was a leader in the revolution in gold metallurgy in the late 1970s, 80s, and 90s. The three components to this revolution were: 1) the introduction of heap and dump leaching on a large scale to treat low grade ores; 2) the widespread adoption of carbon adsorption systems for metal recovery from cyanide solution; and 3) the development of methods to effectively process refractory sulfidic ores, including chlorination, roasting, and pressure oxidation. Bob was an innovator and implementer in all of these areas.
Bob was one of the few people in plant design, construction, and operation to commit his experiences to paper. In 1975 and 1981, he co-authored two ground-breaking books with Frank W. McQuiston: Gold and Silver Cyanidation Plant Practice, Volumes I and II. These books contain information on the most important precious metal plants of the time. He also edited several other books and published dozens of technical papers on plant design and practice.
Bob had a huge impact on the industry, but his impact on people is where he is most remembered. Bob once said that his sole reason for working later in life was to help develop young people and the pleasure he got from seeing them advance in their careers. To this end, in 2015, he and his wife, Jean, pledged $1 million for PhD grants in minerals education to the SME Foundation.
Click here to visit Bob's oral history, which is preserved at the Bancroft Library at the University of California, Berkeley.
