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Bureau of Mines / Minerals yearbook metals, minerals, and fuels 1972
Year 1972, Volume 1 (1972)

Ampian, Sarkis G.
Clays,   pp. 301-327 ff. PDF (2.9 MB)


Page 301

  301Clays 
By Sarkis C. Ampian 
 Clays in one or more of the classification categories (kaolin, ball clay,
fire clay, bentonite, fuller's earth, or common clay and shale) were produced
in 47 States and Puerto Rico. Clay production was not reported in Alaska,
the District of Columbia, Rhode Island, or Vermont. The States leading isa
output were Georgia, 6.2 million -tons; Texas, 5.2 million tons; and Ohio,
4.1 million tons; followed in order by North Carolina, Alabama, and California.
Georgia also led in total value of clay output with $132.3 million; Wyoming
was second with $18.5 million. Compared with 
1971 figures, clay production increased in 
31 States and value increased in 29 States. Total quantity of clays sold
or used by domestic producers in 1972 was approximately 5% higher than in
1971, and total value was approximately 10% higher. Both the total tonnage
and value of clays produced were alltime highs. Modest increases in value
per ton were reported -for all clays except fuller's earth and kaolin, which
declined slightly in value. 
 Kaolin in 1972 accounted for only 9% of the total clay production but for
45% of the domestic clay and shale value. 
Table 1.—Salient clay and clay products statistics in the United States
1 
(Thousand short tons and thousand dollars) 
1968 
1969 
1970 
1971 
1972 
Domestic clays sold or used by producers       Value                    
Exports                                  Value                          
Imports for consumption                    Value                        
Clay refractories, shipments (value)            Clay construction products,
shipments (value) - - - - 
57,348 
$246,938 
1,519 
$44,134 
97 
$1,951 
$229,660 
$590,776 
58,694 
$264,415 
1,574 
$45,767 
82 
$1,750 
$257,507 
$608,982 
54,853 
$267,912 
2,076 
$66,116 
87 
$1,802 
$256,384 
$554,431 
56,666 
$274,431 
1,973 
$65,329 
64 
$1,501 
$236,563 
$641,567 
59,456 
$303,022 
1,847 
$66,216 
67 
$1,309 
$274,679 
$722,236 
Excludes Puerto Rico. 
DOMESTIC PRODUCTION, PRICES, AND FOREIGN TRADE, 
BY TYPE OF CLAY 
KAOLIN 
 Domestic production of kaolin in 1972 and its reported total value increased
9%. The average unit value for all grades of kaolin in 1972 was $25.75 per
ton, $0.04 lower than in 1971. Kaolin was produced in mines in 17 States.
Two States, Georgia (74.6%) and South Carolina (12.8%), accounted for 87.4%
of the total U.S. production in 1972. Arkansas ranked third, Alabama fourth,
and Texas fifth. Output in 1972 declined in Arizona, Arkansas, Idaho, Ohio,
Oregon, and Utah. Increased production was noted in California, Flor 
ida, Georgia, Missouri, Nevada, North Carolina, Pennsylvania, South Carolina,
and Texas. A new producing State in 1972 was Minnesota. 
 Kaolin is defined as a white claylike material approximating the mineral
kaolinite. It has a specific gravity of 2.6 and a fusion point of 1,785°
C. The other kaolin-group minerals, such as halloysite and dickite, are encompassed.
 During 1972 Burgess Pigment Co. added an additional flash calciner at its
Sandersville, Ga., facility, and Engelhard Minerals & 
 ' Physical scientist, Division of Nonmetallic Minerals—Mineral Supply.


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