Mineral Facts and Problems: 1960 Edition Page: 15
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ALUMINA AND BAUXITE
By R. C. Wilmotl
ALUMINA (A1203), the raw material for producing aluminum, comprises
one-seventh of the earth's crust. Although bauxite is the only commer-
cial ore of alumina, other potential sources of alumina are almost un-
limited.
SUMMARYWorld consumption of alumina in 1958 was
estimated at 8 million tons; nearly 57 percent
was consumed in North America and 38 percent
in Europe. The consumption of alumina in the
United States in 1958 was about 3.2 million
tons, and by 1975 annual consumption may be
12 million tons.
World bauxite production in 1958 was esti-
mated at 20.7 million tons, of which 57 percent
was produced in the Western Hemisphere.
Over 90 percent of the bauxite consumed in the
United States is used in alumina production and
the remainder by abrasive, chemical, refractory,
and other industries. Bauxite consumption in
the United States was 7 million tons in 1.958 and
by 1975 consumption may be 25 million tons.
Although the United States produces es-
sentially all of its alumina requirements and
is the world's largest consumer of bauxite, less
than 20 percent of its bauxite requirement is
produced domestically. The domestic bauxite
reserve, which occurs mainly in Arkansas, is
estimated at 50 million tons averaging about
52 percent A1203. The reserve is too small to
permit production to be expanded significantly.
The total world reserve of bauxite at the end
of 1958 was estimated at 3.2 billion tons, with
the largest deposits in Guinea, Australia, Ja-
maica, Hungary, Ghana, and Surinam.
As a result of improvements in technology
it has been possible to reduce the grade of ore
used in alumina plants. In 1930 ores used in
the United States averaged 60 percent alumina,
but by 1958 ore averaging as little as 50 per-
1 Commodity specialist.cent alumina was being used. The average
grade of ore treated will probably continue to
decrease gradually, and successful application
of processes now being tested would result in
some plants using materials containing less
than 35 percent alumina.
Bauxite, an ore containing hydrated alu-
minum oxide minerals such as gibbsite, boehm-
ite, or diaspore, is formed by weathering proc-
esses acting on alumina-bearing rocks. The
largest deposits occur in tropical or subtropi-
cal climates and are at or near the surface.
Most bauxite is mined by open-pit methods,
but bauxite is also recovered by underground
mining methods in the United States and in
Europe.
Assurance of an adequate and dependable
long-range supply of alumina requires discov-
ery of new sources and the solution of numer-
ous mining and metallurgical problems. A
challenging problem is the development of a
commercial process for producing alumina
from domestic low-grade materials. Problems
of the Bayer process include the need to im-
prove its efficiency and development of meth-
ods for utilizing tailings. There is insufficient
information on quantity, grade, and type of
potential alumina resources, and exploration
is handicapped by lack of a rapid method of
analyzing for alumina. Mechanical beneficia-
tion of low-grade bauxites is hampered by the
high loss of alumina in removing iron and
silica.
15
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United States. Bureau of Mines. Mineral Facts and Problems: 1960 Edition, report, 1960; Washington D.C.. (https://digital.library.unt.edu/ark:/67531/metadc38790/m1/23/?rotate=90: accessed April 23, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.