Appletons' Cyclopædia of American Biography/Stetefeldt, Carl August
STETEFELDT, Carl August, mining engineer, b. in Holzhausen, near Gotha, Germany, 28 Sept., 1838. He was educated at the gymnasium in Gotha, the University of Göttingen, and at the mining-school in Clausthal, where he was graduated in 1861. Soon afterward he came to this country, and since that time he has been engaged in the practice of his profession as a mining engineer and metallurgist. At present (1888) he devotes himself principally to consultation, and has his office in New York. He is widely known through the mining districts by his invention of the Stetefeldt furnace, which is extensively used in the west for the roasting of silver ores preparatory to the extraction of the metal by either amalgamation or lixiviation. Mr. Stetefeldt has been a member of the American institute of mining engineers since 1881, and was its vice-president in 1885-7. Besides technical papers he has written “The Lixiviation of Silver Ores with Hyposulphite Solutions” (New York, 1888).