The beginnings of the revolutionary froth flotation process are associated with graphite mining

The beginnings of the revolutionary froth flotation process are associated with graphite mining. The E&MJ article on the Dixon Crucible Company includes a sketch of the “floating tanks” used in the age-old method of extracting Graphite. Because Graphite is so light, the mix of Graphite and waste was sent through a final series of water tanks where a cleaner graphite “floated” off, which left destruction to drop out. In an 1877 patent, the two brothers Bessel (Adolph and August) of Dresden, Germany, took this “floating” process a step further and added a small amount of oil to the tanks and boiled the mix – an agitation or frothing action – to collect the Graphite, the first steps toward the future flotation process. Adolph Bessel received the Wohler Medal for the patented process that upgraded the recovery of Graphite to 90% from the German deposit.  In 1885, Hezekiah Bradford of Philadelphia patented a similar process in the United States. Still, it is uncertain if his strategy was used successfully in the nearby graphite deposits of Chester County, Pennsylvania, a major producer by the 1890s. The Bessel process was limited in use, primarily because of the abundant cleaner deposits around the globe, which needed not much more than hand-sorting to gather the pure Graphite. State of the art, ca. 1900, is described in the Canadian Department of Mines report on graphite mines and mining when Canadian deposits became essential producers of Graphite. If you are looking for high quality, high purity and cost-effective Graphite, or if you require the latest price, please email contact mis-asia.