Improvements in the Manufacture of Aluminium Chloride and in the Extraction of Aluminium therefrom.
Year: 1886

page_text: Date of Application, 8th Nov., 1886.
Complete Left, 3rd Aug., 1887.
Complete Accepted, 20th Sept., 1887.
Improvements in the Manufacture of Aluminium Chloride and in
the Extraction of Aluminium therefrom.
1, ORLANDO MORTON THOWLESS, of Newark, New Jersey, United States of America'
Chemist, do hereby declare the nature of this invention to be as follows:-
My invention has for its chief object the production of metallic aluminium at a much
lower cost than heretofore, and to this end it comprises the improvements hereinafter
described.
In carrying the first part of my said invention into practice I dissolve sodium
aluminate or potassium aluminate in wator, and add sufficient hydrochloric or other
suitable acid to cause a precipitate to fall. This precipitate 1 well wash, and after
drying in any convenient manner, dissolve in hydrochloric acid.
This acid solution is subsequently evaporated, so that crystals are obtained, which,
I term aluminium chloride. This aluminium choride contains a larger percentage of
aluminium and a smaller quantity of chlorine than aluminium chloride prepared in the
ordinary manner, and therefore requires a smaller amount of sodium to effect the
reduction as hereinafter described.
The method heretofore generally employed of extracting aluminium from its chloride
consists essentially in fusing the same with metallic sodium. Owing however, to the
high price of sodium this process is very expensive.
According to the present invention I dispense with the use of metallic sodium and
substitute therefor, substances which, during the reduction of the aluminium chloride,
combine to form sodium.
In carrying this part of my said invention into practice I mix the aluminium chloride
crystals with carbonate of soda or soda-ash, chalk, and slack or small coal or other
suitable carbonaceous substance, in somewhat varying proportions.
I have found the following proportions very suitable.
10 parts by weight of aluminium chloride.
chalk.
""
"
"
"3
10
coal or its substitute

page_text: The inixture above described is placed in a suitable furnace, the temperature of
which should be maintained at say 2000° Fahrenheit more or less, and the mixture
should be covered as much as possible to prevent the escape of the gases.
After the reduction is completed the mixture is removed from the furnace and, when
cold, is ground and washed to remove the carbon and other foreign matter from the
metal. The latter can then be re-melted and formed into ingots or blocks of any suitable
shape or size.
Dated this 8th day of November 1886

page_text: the Extraction of Aluminium therefrom.
I, ORLANDO MORTON THOWLESS, of Newark, New Jersey, United States of America,
Gentleman do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My invention relates to the extraction of aluminiuu: from substances containing
the same, and comprises the improvements hereinafter described.
Prior to my invention, it has been common to produce aluminium by first forming
a chloride of aluminium by the treatment of alumina with a stream of chlorine gas,
and then obtaining aluminium therefrom by the use of metallic sodium as a re-agent.
It has, moreover, been proposed to produce aluminium by placing the chloride of
aluminium and certain sodium-producing materials in separate chambers or retorts and
applying heat thereto, and then bringing the vapor of the sodium into contact with
the chloride or with the vaporized chloride at a certain point in the process.
By my invention, I reduce the cost of producing aluminium, and I also simplify the
process and make the result more certain by placing a mixture of the aluminium
chloride or other suitable aluminium compound and the sodium-producing materials in
the same vessel (preferably a closed vessel or retort) and subjecting them to heat in
the said vessel. In my process, I do not depend upon the action of the sodium vapor, at a
critical point in the operation, upon the chloride, as has been heretofore proposed; all
the ingredients which I use are brought into intimate contact by placing thein in one
vessel or chamber. I thus ensure such chemical reactions in the said vessel or chambor
as are necessary for the successful production of aluminium.
In the process above referred to, wherein the sodium-producing substances and the
chloride of aluminium are placed in separate chambers and subjected to heat,
the success of the operation is said to depend upon the action of the sodium vapor upon
the chloride of aluminium in such a manner as to extract the chlorine therefrom, forming
chloride of sodium and setting metallic aluminium free. This process is uncertain by
reason of the fact that, when chloride of aluminium is heated, chlorine gas is given
off; this gas, it is true, forms with the sodium vapor chloride of sodium; but it is
found, in practice, that, when the chlorine passes away from the chloride of aluminium
it leaves the same not in a metallic state, but in the form of oxide of aluminium, or
other powdered substance upon which, in the continuation of the process, the sodium
vapor apparently has no effect.
In my process, I can employ any suitable chloride of aluminium which is compara-
tively free from iron, or I may use double chloride of aluminium and sodium, or
fluoride of aluminium, or double fluoride of aluminium and sodium, and I regard
these compounds as the equivalents of the chloride of aluminium in carrying on my
"

page_text: I prefer, however, to use a chloride of aluminium made in the following manner,
viz ;-by dissolving freshly prepared alumina in hydrochloric acid and evaporating the
same as hereinafter set forth.
In thus preparing the chloride, I dissolve in water a soluble salt of alumina, and
add thereto sufficient acid or alkali, as the nature of the dissolved salt may require, in
order to cause a precipitate to fall, such precipitate being what is known as aluminium
hydrate. When aluminate of soda, aluminate of potash, or other soluble alkaline salt
of alumina is used, sufficient hydrochloric or other suitable acid is added to the solution
to obtain the precipitate. When sulphate, nitrate or acetate of alumina, or other
soluble acid salt of alumina is used, sufficient alkali is added to the solution to obtain
the precipitate. The precipitate is well washed and, after drying in any suitable
manner, is dissolved as soon thereafter as possible in hydrochloric acid. This acid
solution is subsequently evaporated to obtain the desired aluminium chloride.
In carrying on my process of producing aluminium, I employ substances which,
during the reduction, combine to form the sodium necessary for the reduction of the
aluminium from its chloride. For instance, I mix the aluminium chloride with
carbonate of soda or soda-ash and chalk, and small coal or other carbonaceous
substances, (as for example tar, bitumen, asphaltum, molasses or the like) in proportions
which may be somewhat varied.
I do not, however, confine myself to the materials above mentioned, as any suitable
sodium-producing materials may be mixed with the aluminium chloride.
In forming the mixture, the following proportions are found to work well in practice,
viz ten parts by weight of aluminium chloride, three parts by weight of chalk, ten
parts by weight of coal, or its substitute, and ten parts by weight of carbonate of soda,
or soda-ash. I prefer to add to the above ingredients one part by weight of cryolite
to serve as a flux. The latter may be omitted, however, or be replaced by any other
suitable flux, without materially altering the result.
The mixture above described is placed in a suitable vessel in a furnace, the
temperature being maintained at say 2000 degrees Fahrenheit, more or less; and
the said vessel preferably kept closed to prevent the escape of the gases.
After the reduction is completed, the mixture is removed from the furnace, and,
when cold, may be ground and washed to remove the carbon and other foreign matter
from the aluminium. The latter can then be remelted and formed into ingots of any
suitable size and shape.
Having now particularly described and ascertained the nature of my said invention, and
in what manner the same is to be performed, I wish it understood that I do not claim
the production of aluminium by the mutual reaction of an aluminium compound and
sodium-producing substances when the said compound and the sodium-producing
substances are placed in separate vessels, but I claim :—
The improved process of producing aluminium, consisting in mixing aluminium.
chloride or other suitable aluminium compound with soduim-producing substances and
heating the mixture in a vessel or chamber substantially as described, and then, if
necessary or desirable, grinding and washing the product as above specified.
Dhi and Ja 100M