Improvement in the Production of Aluminium.
Year: 1891

page_text: Date of Application. 31st Jan., 1891
Complete Specification Left, 14th Aug., 1891-Accepted, 24th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvement in the Production of Aluminium.
I, ENNO MEYER, D. Ph., of No. 34, Tieckstrasse, Berlin N., Prussia, Chemist,
do hereby declare the nature of this invention to be as follows:-
My invention relates to the production of aluminium from alkalic and carth-
alkalic aluminates and to the simultaneous production of hydroxides of the basic
metals contained in the said aluminates.
The process which I employ for the first purpose consists substantially in mixing
the aluminate with a carbonaceous material, such as carbon itself, saw-dust or any
suitable hydro-carburet, and heating the mixture in a reducing flame. Under these
conditions at first the basic metal is driven off in form of vapour together with
carbonic oxide and whatever other gases may be evolved, while an oxide of
aluminium of a low degree of oxidation is formed, from which results aluminium by
the further action of the carbon.
If it is desired to obtain also the basic metal in form of hydroxide, the mixture of
aluminate and carbonaceous material is first subjected to dry distillation, while the
gases and metallic vapors evolved are conducted into water, which absorbs the said
vapors and transforms the substance thereof into hydroxide.
The aluminate is preferably prepared from pure alumina and an alkalic or carth-
alkalic hydroxide by known means. But it may also be made from common aluminic
compounds, such as clay; in this case, however, the aluminium resulting from the
aluminate is impure.
1001
J. H. JOHNSON & Co.,
A conts
COMPLETE SPECIFICATION.
Improvement in the Production of Aluminium.
I, ENNO MEYER, Doctor of Philosophy of No. 34, Ticckstrasse, Berlin N.,
Prussia, Chemist, 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 production of aluminium from alkalic and carth-alkalic
aluminates and to the simultaneous production of hydroxides of the basic metals
contained in the said aluminates.
The process which I employ for the first purpose consists substantially in mixing
the aluminate with a carbonaceous material, such as carbon itself, saw-dust or any
suitable hydrocarburet and heating the mixture in a reducing flame. Under these
conditions at first the basic metal is driven off in form of vapor together with
carbonic oxide and whatever other gases may be evolved, while an oxide of aluminium
of a low degree of oxidation (A10) is formed, from which results aluminium by the
further action of the carbon.
If for instance sodic aluminate of the constitution Al(NaO) is employed
together with carbon the reaction takes place according to the following formula:
Cmen

page_text: aluminate and carbon or other carbonaceous material is first subjected to dry
distillation, while the gases and metallic vapors evolved are conducted into water,
which absorbs the said vapors and transforms the substance thereof into hydroxide.
For practically carrying out my invention the aluminate is preferably prepared
from pure hydrate of alumina, Al(OH)3, by boiling the same with a solution of the
hydroxide of an alkali-metal, for instance with potassic or sodic lye. In case the
latter is employed, the reaction ensues according to the following equation:
Al(OH)3 + 3 NaOH
=
Al(ONa) +3 H2O.
If the hydroxide of an earth-alkali-metal, which is but little soluble, is to be
used, the same is mixed with hydrate of alumina and water, and boiled, or the two
substances are melted together and the product is lixiviated. These processes for
the preparation of aluminates are, however, not new.
The solution of aluminate is mixed with so much finely-powdered coal, or other
dry carbonaceous material, to form a thick pulp therewith which is dried. If
previous to its application, the aluminate is dry, it is mixed in powdered state with
about an equal weight of coal-powder, and, if considered necessary, this mixture is
formed into lumps, either by pressure, or by kneading with water or any other
suitable liquid, dividing and drying. The dry aluminate may also be mixed with a
suitable hydro-carburet, for instance with tar, with or without the addition of other
carbonaceous substances, good proportion being for instance equal parts by
weight of aluminate and tar or 2 parts of aluminate, 1 part of tar and 1 part of
coal powder. The dry or consolidated mass is thereupon distilled in an iron retort,
and the vapors and gases passing over are conducted into water, as already stated,
in view of recuperating the hydroxide of the alkali or earth-alkali-metal for renewed
The residue hereafter remaining in the retort, and which consists in aluminic
oxide of a low degree of oxidation and carbon, is brought into a reverberatory or
a shaft furnace and exposed within the same to a smelting process carried out by
means of a reducing fire. Provided the materials employed are pure, the
aluminium, under those conditions, separates out in pure metallic state.
use.
If any common compound of alumina, such as clay is used as prime material for
the preparation of the aluminate, the operation of boiling the same with the alkalic
or earth-alkalic hydroxide and water will cause a portion of the silica aud any ferrie
oxyhydrate, contained in the clay, &c., to separate out in solid state, so that the
liquid product has to be filtered off, while the remainder of the silica passes into
the solution. The aluminium obtained from this solution is adulterated by silicon
and carbon.
If it is not intended to recuperate the alkalic or earth-alkalic hydroxide
employed in the preparation of the aluminate, the mixture of aluminate and
carbon, &c., may be subjected to the smelting process without previous distillation.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
'
1. The process of producing aluminium, which consists in mixing an alkalic or
earth-alkalic aluminate with a carbonaceous material and smelting the mixture in a
reducing flame, substantially as described.
2. The process of producing aluminium and an alkalic or earth-alkalic hydroxide,
which consists in mixing an alkalic or earth-alkalic aluminate with a carbonaceous
material, distilling the mixture, conducting the volatile products of distillation into
water, and smelting the residue in a reducing flame, substantially as described.
Dated the 14th day of du 1901