SIC 1455 Kaolin and Ball Clay

SIC 1455

This category covers establishments primarily engaged in mining, milling, or otherwise preparing kaolin or ball clay, including china clay, paper clay, and slip clay. Establishments primarily engaged in grinding, pulverizing, or otherwise treating clay, ceramic, and refractory minerals not in conjunction with mining or quarrying operations are classified in SIC 3295: Minerals and Earths, Ground or Otherwise Treated.

NAICS CODE(S)

212324

Kaolin and Ball Clay Mining

INDUSTRY SNAPSHOT

In the early 2000s, a total of 28 U.S. firms operating 124 mines produced 9.13 million metric tons of kaolin and ball clay. Of the total U.S. production of clay and shale in 2003, which reached 39.3 million metric tons with a value of $1.6 billion, kaolin accounted for about 20 percent. Ten states, led by Georgia, produced kaolin in the early 2000s. Kaolin's primary uses are for paper coating and filling (54 percent), refractories (17 percent), and other uses (29 percent).

The ball clay segment of the industry was rather small and consisted of four companies in four states in 2002. Tennessee was the leading supplier of ball clay, producing 59 percent of total U.S. output. Following Tennessee were Texas, Kentucky, and Mississippi. U.S. production of ball clay in 2002 reached 1.12 million metric tons with an approximate value of $47 million. The major ball clay markets in the United States were floor and wall tile (41 percent), sanitary ware (25 percent), and other uses (34 percent).

ORGANIZATION AND STRUCTURE

Clays are classified according to their relative plasticity or malleability, their strength when moist (green strength), their strength after drying (dry strength), their air shrinkage properties, and their vitrification range. Vitrification refers to the process by which clay molecules begin to fuse when exposed to heat. A clay's vitrification range therefore describes the temperature levels between which the clay begins to fuse and when it achieves its final fusion or hardness.

Clays are often mixed or blended to achieve the desired properties dictated by their end use. Thus, whiteware ceramic consists of kaolin, ball clay, feldspar, and ground silica. Kaolin, or china clay, derived its name from the hill where it was first extracted in Kao-Ling, China. Historically, more than half the annual U.S. production of kaolin was used as filler and coating material in high-quality paper. Along with wood pulp, kaolin traditionally constituted a large percentage of the paper's...

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