Mineral Facts and Problems: 1960 Edition

MINERAL FACTS AND PROBLEMS, ANNIVERSARY EDITION

GEOGRAPHIC DISTRIBUTION OF THE
INDUSTRY
The aluminum reduction industry is a major
consumer of electric power and uses approxi-
mately 3 percent of the domestic electric power
generated. In order to maintain its competi-
tive position, large quantities of low cost de-
pendable electrical energy are a necessity for
this industry. Before 1950 plants were built
near sources of low-cost hydroelectric power
such as the Niagara Falls area, the Tennessee
Valley area, and the lower Columbia River
area of the Pacific Northwest. However,
aluminum consuming and other industries
entered these areas, and in some instances the
cost of power from new facilities was in-
creased. Since 1950, in addition to situating
plants in the limited number of places where
new hydropower supplies became available, the
industry has built several large plants where
natural gas, lignite, or bituminous coal for
thermally generated electric power are avail-
able. New plants in the Ohio River Valley are
near the markets and can take advantage of
lower water freight rates (9, 11).
As indicated by figure 1, alumina, the basic
raw material for the primary aluminum
smelters, is produced in the South Central
United States in Arkansas, Texas, Louisiana,
and Alabama. The reduction plants are more
widely dispersed. See table 3.
TABLE 3.-Geographic distribution of aluminum reduction
plants
Number of Annual
Location aluminum capacity, Percent of
reduction thousand total
plants tons
Pacific Northwest--------.------ 8 689 31
New York, Ohio, and West Vir-
ginia.. . ...------------------ ---- 3 335 15
Arkansas and Louisiana rkasas.eas 3 411 19
Alabama, Tennessee, and North
Carolina ---------.------------- 3 394 18
Texas.-- ------------------- ----- 3 365 17
Total ...--------------------. 20 2, 194 100

Completion of new facilities under construc-
tion in 1959 will result in new capacity in
Indiana and increased capacity in New York,
Ohio, Texas, and West Virginia.
DEFINITION OF TERMS, GRADES, AND
SPECIFICATIONS
Pig.-Metal as initially produced by a pri-
mary reduction plant, taken directly from the
reduction cell and cast into a convenient form.
Pig is cast in a wide variety of sizes but the
usual commercial size is 50 pounds, with a 99.5
percent guaranteed minimum aluminum con-
tent.
Ingot.-A cast form suitable for working or
remelting that has been poured from either a
melting or alloy furnace. The common com-
mercial size is 30 pounds and the aluminum
content is 99.5 plus percent.
Potline.-A number of reduction cells or
pots, usually 100 to 150, connected in electrical
series.
Super-purity aluminum.-Contains a mini-
mum of 99.99 percent aluminum.
Aluminum Alloys.-Generally divided into
two major groups: Wrought and casting.
Table 4 gives the chemical composition for two
alloys of each type. Unalloyed metal usually
contains 99.5 percent aluminum and small
quantities of iron and silicon. Even when no
alloying elements have been added, the quan-
tity of impurities present has to be controlled
carefully. Metal with over 99.5 and up to
99.85 percent aluminum is available at costs
up to 3 cents per pound more than standard
commercial metal. It is used where superior
electrical conductivity or corrosion resistance
is required. Purities higher than 99.85 percent
are necessary for certain applications.
There are several acceptable methods of
designating aluminum alloys. However, a 4-
digit code for wrought alloys was adopted by
The Aluminum Association in October 1954.
The first digit indicates the major alloying
ingredient. If the first digit is 1 the alloy has

TABLE 4.-Chemical analysis of some aluminum alloys, in percent 1

Type and number
Wrought 1100 2 3....
Wrought 2024 '_...
Casting 43____------
Casting 108 --------

0. 20
3. 8-4. 9
0. 10
3. 5-4. 5

Fe -Si
1. O0
1.50 0. 50
0.8 4.5-6.0
1.0 2.5-3.5

0. 05
0. 30-0. 9
0. 30
0. 30

I Values are maximum unless shown as a range; aluminum is remainder.
2 Aluminum minimum-99.00 percent.

----------
1. 2-1. 8
0. 05
0. 03

0.10
0. 25
0. 20
0. 20

0. 20
0. 20

0. 10

Other ele-
ments
Each Total

0. 05
0. 05
0. 05

0.15
0. 15
0. 15
0. 30

3 Replaces commercial designation 2S.
4 Replaces commercial designation 248.

1 1 1

30

United States. Bureau of Mines. Mineral Facts and Problems: 1960 Edition. [Washington D.C.]. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc38790/. Accessed September 17, 2014.