Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1891-04-16
THE END.
MAKING ALUMINIUM.
The Process of Manufacture at Pittsburg
Works Described.
Washington Post.

During the past year or two much has
been written about the remarkable advices
which have recently been made in the pro-
duction of aluminium, and the consequent
reduction in price that which three or
four years ago placed it among the prec-
ious metals to that point where it could
be purchased by ordinary mortals for the
thousand and one uses to which it can be
so proftably put. But all these discrip-
tons of TIE various discoveries and modes
of manufacture have usually closed with
the announcement thai the fatal point of
the g process was a close y-gaarded secret:
The Post, however. is able to give a de-
scription Of the manufacture of aluminium
as conducted at the works of one of the re-
duction companies in Pittsburg, Pa.
This company imports from Goldschl-
melden near B1esIaa, Germany materia
known as oxide Of aluminium. The
oxide is manufactured from a species Of
clay called beauxite, which is used with
soda and forms an illuminate of soda.
When tie LITTER Is hxlviated in water, a
preci phase is thrown down. This is the
oxide of aluminium as prepared in Ger
many and shipped to Httsburg.
At the works in thelatter place this
DOWOCICu 10 piaOCtt LII d uIy
furnace. and moisture 10 the extent of
driven off. 1t is then taken to the smelt-
ing room, where a numter OF open iron
vessels and pots are PLACED Old the floor.
The pots are of wrought iron, and are
lined with carbon. with a depression or
bon electrode connected With the positive
al Of l,,,n L.
mouth of each pot, and the electric circuit
is completed by conductors from the
negative poles of the dynamos to the iron
pots. When tde current IS 'urned on, and
intense heat is generated between the car
bon lining and the eectrode, simu-
lar, only On a larger scale, 10 that between
the carbon points Of an arc electric lamp.
A quantity of furids salts a1e thrown into
these Uarbon-lined receptaces, which is
soon converted into a molten bath Into
the latter is charged the powdered and
dried oxide Of aluminium, and the process
of reduction commences, every particle of
the powder being subjected to the action
of the bath. The oxygen is absorbed by
the carbon electrodes ana the contents of
the pots are soon reduced to metallic
mall. This does not mix with the furide
bath, as their respective specific GRANTEES
are sufficiently different to prevent any
mechanical mixture.
As the contents of each pot is melted
down, more powdered aIumina is added in
small quantities and when the reduction
becomes complete the metal is ladled out
from each pot, it being easily separated
from the furid bath. The pure metal is
poured into moulds and made into small
pigs and bars. The progress of reduction
is thus direct and continuous one in
which the action of heat other than that
of the electrical current, which is sufhc-
lent to fuse the oath of furide salts and
the alumina, does not enter. The mater
| ial goes into the pot as alumina, a powder,
and comes out converted as pure metal
lie aluminium, worth at the present mar.
ket price So per pound. Five yaars age
this metal cost 500 per pound.
There are abundant derosits of bauxite
in this country, notably In North Carolina
from which alumina could be reduced, but
as yet they have not been successfully
worked. Or at least the manufacturers
find it more advantageous to use the i'm
ported raw material. But they think il
will not be long before they will be able tc
obtain the home product Of sufficient pure
quality to successfully compete with the
| foreign article.