Edwin Letts Oliver
Edwin Letts Oliver was born in San Francisco in 1878. He graduated from the College of Mining, University of California, in 1900 and in 1945 received an Honorary LL.D from the same University. He had various surveying jobs in several mines until 1903 when he joined North Star Mines Co. Between 1906 and 1910, he worked on the metallurgy of North Star ores, and designed and built two cyanide plants. The problem of treating gold ore slime started Dr. Oliver on research that led from the direct precipitation of gold from cyanide solutions while still mixed in pulp, to the development of the Oliver Continuous Filter for the recovery of gold solutions from cyanide slime in 1908. This filter proved so successful that it soon required his full time and in 1910 he established the Oliver Continuous Filter Company sales and engineering offices in San Francisco. Oliver United Filters, Inc. was formed in 1928. Dr. Oliver was President until Dec. 31, 1954 when the company merged with The Dorr Company to form Dorr-Oliver Inc. J.V.N. Dorr, also a Douglas Medalist, and Dr. Oliver are each a Founder-Chairman of Dorr-Oliver. Since 1910, Dr. Oliver has supplied over 8000 units from his factories and 2000 from licensees. Besides patenting various filtering devices Dr. Oliver has been active in mine development and operation. Dr. Oliver is a Life Member of AIME. In 1939 he served as Chairman of the San Francisco Section. He became a member of the AIME Legion of Honor in 1952, and a Director in 1953, which office he still holds.