SIC 1459 Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified
SIC 1459
This category covers establishments primarily engaged in mining, milling, or otherwise preparing clay, ceramic, or refractory (heat-resistant) minerals, not elsewhere classified. Establishments producing clay in conjunction with the manufacture of refractory or structural clay and pottery products are classified in manufacturing in the major group for stone, clay, glass, and concrete products.
212325
Clay and Ceramic and Refractory Minerals Mining
Firms in this industry extract raw minerals used in a wide variety of industrial and consumer applications with the most common end use being refractory materials for the manufacture of glass, ceramics, and industrial uses.
Industry firms produced 39.3 million metric tons of common clay and shale in 2003. In 2003, common clay and shale accounted for 58.5 percent of the total output of all clay minerals (including those produced by firms not classified in this industry) sold or used in the United States.
Common clay alone was used to manufacture bricks (56 percent of output), cement (17 percent), and in lightweight aggregate (17 percent). Other uses for common clay alone include such heavy clay products as building brick, flue linings, sewer pipe, drain tile, structural tile, terra cotta, and portland cement clinker (slag). In descending order of output, the leading producers of common clay in 2002 were North Carolina, Texas, Alabama, Georgia, Ohio, Missouri, Oklahoma, California, South Carolina, Kentucky, Arkansas, Virginia, and Pennsylvania.
Shale is one of the most common sedimentary rocks and thus usually has a lower unit price than rarer clays such as kaolin and ball clay. Shale's industrial applications include heavy ceramic ware, portland cement manufacture, and lightweight construction aggregate. The choice of shale as an ingredient in these applications is governed by such factors as its suitability compared with other industrial minerals, the presence of other useful minerals in the market for which it is to be produced (i.e., pumice, sand and gravel, slag, or crushed stone in the lightweight aggregate industry), and its economic viability with respect to other competing minerals such as clay.
The United States was the world leader in the production of bentonite throughout the early 2000s, and the 21 industry companies operating as of 2002 produced an estimated 3.97 million metric tons, valued at $180 million, in 12 states. In 2002, bentonite's specific end uses were as a foundry sand-bonding agent (25.4 percent), as a clumping agent in pet waste litter (22.7 percent), as a drilling mud (20.6 percent), and in iron ore pelletizing (15.1 percent). Bentonite's other uses included the manufacture of decolorizing oils; catalysts for the production of polymers, plastics, and resins in the petrochemical industry; absorbent materials for industrial plants; cattle feeds; and a thickening agent for the production of paints, hand lotions, and pencil lead.
As ingredients in the drilling mud used in the oil-well drilling industry, bentonite-based products aid in the removal of drill cuttings, thicken drilling fluids, stabilize well walls, and reduce friction. Bentonite is also used as an ingredient and preblend in the production of metal casting products for automobiles, kitchen appliances, and other products; as a binding agent in iron ore pelletizing processes in the steel industry; and as a water-absorbing sealant or liner in underground or waterproofed structures.
The United States was the world leader in fuller's earth production throughout the 1990s and early 2000s with 16 companies producing a total of 2.73 million metric tons. Fuller's earth derived its name from the ancient practice of using earth to clean wool—a process known as "fulling." Fuller's earth became a generic name for...
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