Kaolin is one of Georgia's largest natural resources. According to the U.S. Geological Survey, more than 8 million metric tons of kaolin are mined from Georgia each year, with an estimated value of more than $1 billion. Georgia is by far the leading clay-producing state in America and is recognized as a world leader in the mining, production, processing, and application of kaolin products.
The word kaolin is derived from the name of the Chinese town Kao-Ling (or Gaoling, "high ridge"), located in the Jiangxi Province of southeast China, where the written description of porcelain can be found.
Georgia kaolin deposits occur in Late Cretaceous (about 100 million to 65 million years ago) to Early Paleogene (65 million to 45 million years ago)
Kaolin in Georgia is generally found in a northeast to southwest band of deposits extending from Augusta to Macon to Columbus. This belt parallels the fall line, which marks the boundary between the Piedmont and the Coastal Plain. Deposits are of three types: (1) "soft" kaolin, which breaks easily and is soapy in texture; (2) "hard" kaolin, which is more finely grained, difficult to break, and jagged in texture; and (3) "flint" kaolin, which has no commercial value because its high opaline silica content makes it extremely hard. Kaolin mining activities are restricted to near-surface (less than 150 meters) ore bodies that are 3 to 15 meters thick. Once the ore has been extracted, mine reclamation activities are conducted to restore the landscape to a pristine state.
Kaolin is most commonly used in the paper-coating industry. It is also used as a filler (added to plastics, for example, and rubber compounds),
Kaolin is mined and processed in many countries worldwide. Evaluation of refined kaolin output, however, is a far more meaningful way to estimate the economical state of the industry. The China Clay Producers Association represents the major producers and processors of Georgia kaolin. Members are Engelhard Corporation, Gordon; IMERYS Pigments and Additives Group, Atlanta; J. M. Huber Corporation, Atlanta; and Thiele Kaolin Company, Sandersville. The industry posted an after-tax profit of $33.2 million in 1999, which represents a return of 2.7 percent on its net investment. In 1998 the industry posted a profit of $65.4 million, a return of 5.8 percent. This decline represents rising competition and quality demands. The principal regions of the world that will offer competition to Georgia in the near future include Brazil, China, and Australia.
Vernon J. Hurst and Sam M. Pickering, "Origin and Classification of Coastal-Plain Kaolins, Southeastern USA, and the Role of Groundwater and Microbial Action," Clays and Clay Minerals 45 (April 1997): 274-85.
Haydn H. Murray, Wayne M. Bundy, and Colin C. Harvey, eds., Kaolin Genesis and Utilization: A Collection of Papers Presented at the Keller '90 Kaolin Symposium (Boulder, Colo.: Clay Minerals Society, 1993).
Paul A. Schroeder, University of Georgia
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