Wendell E. Dunn Jr.

Wendell Earl Dunn Jr. (August 30, 1922 – December 24, 2007) was an American chemical engineer, metallurgist, and inventor. His technologies for high temperature chlorination, gold, tantalum and titanium extraction are still widely used.

Early years
Dunn was the first son of educator Wendell E. Dunn, for many years principal of Forest Park High School in Baltimore, and brother of conductor Thomas Dunn. A graduate of Baltimore City College and Johns Hopkins University, Dunn was also awarded a doctorate in chemical engineering from Johns Hopkins. After completing the Harvard/MIT V-12 program in 1944, he was engaged in aircraft terrain avoidance radar research in both the U.S. and occupied Germany. Dunn served as captain in the U.S. Army Air Corps until 1946.

Chemical research
In 1950 Dunn was a key member of the research and development team at E.I. DuPont de Nemours in Wilmington, Delaware which developed an improved process for the production of high-purity titanium dioxide for use as a paint pigment. He filed his first sole-inventor U.S. patent in 1954. He remained with the firm for 19 years during which time this process grew to become the dominant technology worldwide.

In 1968 Dunn left DuPont to form his own contract research and development firm in Delaware and Sydney, Australia. He worked closely for several years with a major Australian mining house, Peko-Wallsend, to develop a technology to produce a low-cost titanium process feedstock. Thereafter, Dunn returned to South Dakota and for the next three decades made significant contributions to the field of high-temperature chlorination of metal ores.

Between 1975 and 1995 Dunn consulted to international corporations Reynolds Metals, Kerr-McGee and DuPont, among others and performed R&D which formed the bases for several start-up ventures in South Dakota and beyond. He worked with the Lien Brothers and others in the Rapid City area to develop processes for the extraction of ultra-pure niobium from ore, and tantalum metals for use in electronic applications, and for the efficient separation and recovery of gold from low-grade ore and scrap.

From the late-1980s until the late-1990s Dunn joined with European and Asian interests to develop a process for low-cost titanium-based pigments, and worked in India for months at a time. He was an adjunct faculty member in metallurgy at the South Dakota School of Mines and Technology, and was working on a patent application at the time of his death.

Dunn had a whimsical side, and in 1979 penned a political satire, The Sex Tax. Dunn is interred in Green Mount Cemetery in Baltimore. He was the nephew of civil engineer Everett Dunn.

Selected patents
5,004,500 Chlorination process for recovering gold values from gold alloys Filed:  February 13, 1989 4,390,400 Aluminum chloride addition to electrolytic cells  Filed:  May 26, 1981 4,389,391 Process for beneficiating titaniferous ores  Filed:  June 28, 1981 4,378,337 Still heating process for purifying aluminum chloride  Filed:  June 1, 1982 4,363,789 Alumina production via aluminum chloride oxidation  Filed: April 20, 1981 4,355,008 Chlorination process  Filed:  April 20, 1981 4,355,007 Two stage chlorination process for aluminum value containing source  Filed:  April 20, 1981 4,353,740 Chlorine extraction of gold  Filed:  September 11, 1981 4,349,516 Process for treating the gas stream from an aluminum value chlorination process  Filed:  April 20, 1981 4,331,645 Alumina from alkali metal-aluminum chloride complexes  Filed:  April 20, 1981 4,331,637 Process for purifying aluminum chloride  Filed:  April 20, 1981 4,211,755 Process for beneficiating titaniferous ores Filed:  March 3, 1975 4,085,189 Process for recycle beneficiation of titaniferous ores  Filed:  May 21, 1976 4,081,507 Process for removing chemisorbed and interstitial chlorine and   chlorides from a hot titanium dioxide beneficiate-carbon mixture Filed October 3, 1975 3,960,203 Fluidized bed cooler  Filed:  April 9, 1973 3,929,501 Novel titanium dioxide composition  Filed:  June 4, 1973 3,887,694 Production of chlorine  Filed:  December 22, 1972 3,865,920 Process for beneficiating a titaniferous ore and production of chlorine and iron oxide  Filed:  March 14, 1973 3,729,543 Process for preparing alkali-metal tetra-chloroferrate  Filed:  January 21, 1971 3,724,171 Annular flow condenser  Filed:  April 29, 1971 3,713,781 Cross-flow fluid bed reactor  Filed:  October 21, 1970 3,699,206 Process for beneficiation of titaniferous ores  Filed:  March 23, 1970 3,683,590 Dual flue condenser  Filed:  April 29, 1971 3,376,112 Production of chlorine through oxidation of film of ferric chloride salt complex  Filed Aug 3, 1965 3,153,572 Process for the production of niobium pentachloride Filed Jun 1, 1961 3,107,144 Process for converting niobium oxychloride to niobium pentachloride  Filed Nov 4, 1960 3,009,773 Chlorination of niobium oxychloride Filed Mar 31, 1958 2,856,264 Charging fluidizing gas into fluidized bed reactor  Filed Apr 9, 1954