Improvements in the Production of Aluminium.
Year: 1889

page_text: Date of Application, 6th Apr., 1889
Complete Specification Left. 20th Dec.. 1889-Accepted. 25th Jan.. 1890
PROVISIONAL SPECIFICATION.
Improvements in the Production of Aluminium.
I, ROBERT ELLIS GREEN, of No. 41 Sandringham Road, Hackney, in the County
of Middlesex, Merchant do hereby declare the nature of this invention to be as
follows:-
1 mix cryolite or similar compounds, that is fluorides of aluminium & sodium or
potassium, with silicate of soda or potash, or with silica and soda or potash ; I then
submit the mixture to the action of a bright red heat in a suitable crucible, under
which action the fluorine & silica combine, liberating the aluminium which is then
collected in the usual way.
ROBT. E. GREEN.
COMPLETE SPECIFICATION.
Improvements in the Production of Aluminium.
I, ROBERT ELLIS GREEN, of 3 St. Johns Terrace, Southall, in the County
of Middlesex, late of 41 Sandringham Road, Hackney, "Merchant," 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
This invention relates to the production of aluminium from the fluorides of
aluminium or double fluorides of aluminium and sodium or potassium, either those
found in nature or produced artificially by the action of silica or compounds of
silicon.
The manner in which the process is to be carried out is as follows:-I provide a
suitable retort, crucible, or furnace, having an inlet at its extreme lowest part to
which inlet a porcelain or other pipe which will resist the heat of the furnace is
attached and fixed, the joints being well luted up with a fire resisting substance, such
as a paste made of plumbago, this pipe is then connected to a supply of coal gas, or
other carburetted hydrogen or hydrogen gas. The size of this pipe for a charge of
material of a quantity up to two hundredweight need not be more than half an inch
diameter. Broken bits of charcoal, coke, or other refractory substance are then placed
at the bottom of the crucible, retort, or furnace so as to cover the opening of the gas
inlet and prevent its being stopped up during the subsequent operations. Upon
this charcoal is placed, fluoride of aluminium, or the double fluoride of aluminium
and sodium or potassium mixed with silica, silicate of soda or potash, or other
compound of silicon and finely powdered charcoal, and upon the top of this mixture
is placed a layer of freshly burnt lime, though this is not absolutely necessary to the
success of the process.
The proportions of these materials may be varied but for a good result the following
are the proportions:-

page_text: quantity of silicon disulphide (Sc S2) would be 86 lbs. instead of the 48 lbs. white
sand; and the quantity of the other silicon compound would be calculated on the
same basis.
These substances having been placed in the retort, crucible, or furnace and this
carefully connected with the gas supply which must be supplied with a shut off cock
or valve, the mouth is closed with the exception of an opening of about one third less
diameter than the gas inlet at the bottom.
The retort, crucible or furnace with its charge is now subjected to a red heat and
maintained thereat for one hour with the gas supply turned on. The decomposition
of the fluoride being completed the gas supply is closed and disconnected from the
retort, crucible or furnace.
The slag being removed the whole is allowed to cool when the greater part of the
aluminium will be found mixed with and absorbed by charcoal, or coke at the bottom
of the retort, crucible, or furnace, and can be separated therefrom by the ordinary
known methods.
There remains also a quantity of aluminium of an inferior quality mixed with the
slag which may be separated by grinding the slag and subjecting it to a second
heating in under the same conditions as above described, that is to say in an atmo-
sphere of carburetted hydrogen gas with a substratum of charcoal or coke, or a similar
porous substance.
It is obvious that the arrangements for carrying out this process may be varied in
many ways either in the forms of retorts and crucibles or the quantities of the different
materials.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First The production of aluminium in the manner substantially as herein
described.
Secondly In the production of aluminium from fluorides of aluminium and
double fluorides of aluminium, and sodium or potassium, and the using of silica or
silicates of soda or potash, or other compounds of silicon, substantially as herein
described.
Dated this 20th day of December 1889.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.