Processes of Obtaining Pure Aluminum
The first step in the process is to abstract the pure aluminum from the mixed
form in which it occurs. The clay used is bauxite, which is found in both the
United States and Europe. It was first discovered in Baux, France. Bauxite does
not contain aluminum mixed with other substances, but alumina, which is the
chemical combination of aluminum and oxygen. This alumina is separated from
its impurities by chemical means, and then dried. It is now a pure white powder,
resembling white sand. This part of the process is quite costly.
The next step is to secure the pure aluminum from this combination of aluminum
and oxygen. This is done by electrolysis, a process which consists of decomposing
a compound by passing an electric current through it. As it requires a large
amount of electricity to produce aluminum, the manufacture is
usually located where water power is cheap. For this reason plants are located
at Niagara Falls and Mas-sena (on the St. Lawrence), in New York State.
The aluminum is turned out in the form of ingots or "pigs" a term taken
from iron manufacturing. From one ton of aluminum ore only
one-half ton or less of alumina is obtained, and from this alumina one-fourth
ton or less of "pig" aluminum.