Improvements in or connected with the Manufacture or Production of Aluminium.
Year: 1890

page_text: Date of Application, 16th Jan., 1890
Complete Specification Left, 14th Oct., 1890-Accepted. 22nd Nov.. 1890
PROVISIONAL SPECIFICATION.
Improvements in or connected with the Manufacture or Production
of Aluminium.
I WILLIAM WHITE of 2 Church Fields Cheshunt in the County of Hertford
Gentleman do hereby declare the nature of this invention to be as follows:-
My invention has for its object to effect the manufacture or production of
aluminium in a more economical and ready manner than has hitherto been done.
In the manufacture of aluminium cryolite has been used but it has the serious
objection that it is frequently contaminated with iron silica and other impurities.
According to my invention 1 manufacture the aluminium from aluminium fluoride
which I prefer to prepare artificially so as to obtain it in a pure or practically pure
state and I utilize the bye products of the manufacture of the aluminium from the
aluminium fluoride in the production of fresh quantities of aluminium fluoride as
hereinafter described. I may prepare the aluminium fluoride from a solution of
hydrate of aluminium in hydrofluoric acid which is then dried or from aluminium
sulphate roasted with fluor spar and lixiviated and dried or by the igneous fusion of
soda or potash alum with fluor spar when aluminium fluoride is formed and the
sulphate of sodium or of potassium with sulphate of calcium are fused and separated.
The aluminium fluoride is heated with sodium or potassium or a mixture of them
there being some excess of aluminium fluoride to act as a flux when aluminium is
liberated, the excess of aluminium fluoride contributing to form a pure and admirable
flux for the metal. The fluoride of sodium (or of potassium or both) formed when
the aluminium fluoride is reduced is used to give up its fluoride as hydro-fluoric acid
when treated with sulphuric acid which hydro fluoric acid is employed for the solution
of hydrate of aluminium in preparing fresh quantities of aluminium fluoride.
Dated the 16th day of Tonner 1800
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with the Manufacture or Production
of Aluminium.
I HELEN WHITE of 2 Church Fields Cheshunt in the County of Hertford Widow,
Executrix of William White deceased late of 2 Church Fields Cheshunt aforesaid,
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 has for its object to effect the manufacture or production of
aluminium in a more economical and ready manner than has hitherto been done.
In the manufacture of aluminium, cryolite has been used but it has the serious
objection that it is frequently contaminated with iron silica and other impurities.
According to this invention I manufacture the aluminium from aluminium fluoride
which I prefer to prepare artificially so as to obtain it in a pure or practically pure
state and I utilize the bye products of the manufacture of the aluminium from the
aluminium fluoride in the production of fresh quantities of aluminium fluoride as
hereinafter described. I may prepare the aluminium fluoride by evaporating to
dryness a solution of alumina or aluminium hydrate in hydrofluoric acid.
The aluminium fluoride is heated with sodium or potassium or a mixture of them,
aluminium is liberated and fluoride of sodium (or of potassium or of both) is formed.
An excess of aluminium fluoride is preferably used as it helps by combining with the

page_text: fluoride of sodium (or of potassium or both) to form a suitable flux for the metal.
This flux when treated with sulphuric acid. gives up its fluorine as hydrofluoric acid
which is used for dissolving alumina or alumina hydrate in preparing fresh supplies
of aluminium fluoride.
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 use of the fluoride of aluminium obtained by evaporating to dryness a
solution of alumina or aluminium hydrate in bydrofluoric acid.
2. The production of aluminium substantially in the
described.
manner hereinbefore 1
1000
HELEN WHITE.