Dr Terry I. Mudder will be inducted in the Environmental Management category. He has more than 30 years experience in the investigation of the chemistry, analysis, fate, aquatic toxicity, and disposal of mining and cyanide wastes. During that time he has emerged as the leading environmental scientist and engineer in the mining industry internationally related to cyanide issues and has been instrumental in expanding the fundamental information and database of the environmental effects of cyanide and its many related compounds. He along with his colleagues established weak acid dissociable or WAD cyanide as the most “toxicologically significant” and “ecologically important” forms replacing free and total cyanide. He aided in perfecting the analytical procedures for cyanide.
He developed along with Mike Botz a mathematical model to allow the prediction of the fate of total, WAD, and free cyanide in tailings and process solution ponds.
Mudder and his technical associates at Homestake Mining Co conducted many of the first acute and chronic bioassays examining the ecological impacts of process solutions containing metals, cyanide, and its related compounds on fish and other aquatic organisms and in that process produced the first site specific instream criteria and standards for cyanide and protection of these sensitive organisms.
He has been instrumental in the development and application of many chemical, physical, and biological treatment processes for cyanide, metals, and other constituents. He is often considered the first to apply biotechnology in the mining industry. First was the development of the novel combined aerobic attached growth biological treatment process using rotating biological contactors at the Homestake Mine in Lead, South Dakota in the early 1980’s. This was the first of its kind relying on bacteria to remove thiocyanate, cyanide, ammonia, and metals from process solution producing up to 15,000 m3/day of treated wastewater that was discharged into a permanent trout fishery. He aided in restoring a stream system that had been contaminated for nearly a century. This development lead to the biological treatment facility at the Nickel Plate Mine in Canada at which the original CIP/CIL circuit was converted into a two stage combined aerobic-anaerobic treatment facility removing very high levels of thiocyanate, cyanide, ammonia, and nitrate some of which reached hundreds of parts per million. Finally, he lead development of the first large scale in-situ biological treatment process called the Biopass Process to allow treatment of draindown from heap leach pads using an existing process solution pond and converting it into an underground anaerobic passive treatment system for removal of cyanide, metals, sulfate, and nitrate.
He also along with his colleagues was one of the first to pilot test two chemical treatment processes including the copper catalyzed hydrogen peroxide process and ozonation for the destruction of cyanide. Along with these chemical treatment processes he was nearly the first to pilot test the use of ion exchange resins for the removal of cyanide from mine process solutions.
Mudder was involved in the development of use of granular activated carbon columns for the purpose of removing low levels of cyanide and metals from process solutions as a tertiary treatment or effluent polishing process.
Mudder along with Adrian Goldstone developed the first modern cyanide recovery facilities used in New Zealand at the Golden Cross Mine and at the Delamar Silver Mine in the United States. Two other cyanide recovery plants were then built using the patented Cyanisorb Process which not only exhibited environmental but also metallurgical advantages as well.
He started the Closure Strategy Group in an attempt to modernize the process of mine closure with emphasis on long term strategies, sustainability, and passive treatment.
