An Improved Process for the Manufacture of Aluminium Sulphide.
Year: 1893

page_text: Date of Application, 12th Jan., 1893
Complete Specification Left, 13th Nov., 1893-Accepted, 16th Dec., 1893
PROVISIONAL SPECIFICATION.
An Improved Process for the Manufacture of Aluminium Sulphide.
I, CLAUDE THEODORE JAMES VAUTIN, of 42 Old Broad Street, in the City
of London, Metallurgical Chemist, do hereby declare the nature of my invention
to be as follows:-
My invention relates to the production of aluminium sulphide, and has for its
object to obtain such production in a simple, effective and economical manner.
"My invention consists in the production of aluminium sulphide (Al,S₁) by the
reduction of a metallic sulphide, the base of which is negative to aluminium, and I
find in practice that lead sulphide (PbS) is completely decomposed by metallic
aluminium at the temperature of a bright red heat.
In carrying out the process according to my invention, I place metallic
aluminium slightly in excess of the theoretical quantity necessary to decompose a
given weight of lead sulphide, on the top of a crucible or bed of a furnace (I find
plumbago crucibles answer well).
When a furnace is used it should be preferably gas fired, and lined with a basic
or neutral material.
On the top of the aluminium is placed the lead sulphide, and the temperature
raised to bright red, or that which is sufficient to cause the lead sulphide to become
molten, and also to retain the aluminium sulphide formed in the molten condition.
When the reaction is completed, the contents are cast into a mould, preferably deep
as compared with the breadth; when cold the contents are removed from the
mould, and metallic lead will be found at the bottom of the mass, and aluminium
sulphide forming the material on top. The excess of the aluminium over the
theoretical quantity what was required for the reduction of the lead sulphide will be
found on top of the lead, and non-alloyed with the bulk of the lead and easily
detached.
If natural sulphide of lead (galena) has been used and contained silver or gold
or both, the excess of aluminium will be found alloyed with gold or silver
or both.
The excess of aluminium is added to ensure the complete reduction of the lead
sulphide so that the resulting aluminium sulphide will be free from undecomposed
sulphide of lead. The reaction is explained thus:-
3 PbS + Al, = Al,Sz + 3 P'b.
Any silver or gold or both that may become alloyed with the excess of aluminium
above referred to may be recovered therefrom.
One important value of the sulphide of aluminium so produced is its application
in the reduction of other salts of aluminium in the metallurgy of that metal.
Dated this 12th day of January 1893.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Process for the Manufacture of Aluminium Sulphide.
I, CLAUDE THEODORE JAMES VAUTIN, of 42 Old Broad Street, in the City
of London, Metallurgical 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 consists in the production of aluminium sulphide (Al,S,) from
metallic aluminium, by the re-action of the latter upon, and consequent reduction
of, a metallic sulphide, easily to be obtained at a cheap price, the base of which
must be electro-negative to aluminium, when both are in a molten condition.
I find in practice that lead sulphide (PbS), amongst such sulphides of which
the base is electro-negative to aluminium, at a melting temperature, is completely
decomposed by metallic aluminium at the temperature of a bright red heat.
In carrying out my process, as an example, I place metallic aluminium, slightly
in excess of the theoretical quantity necessary to decompose a given weight of lead
sulphide, in a crucible, or on the bed of a reverberatory furnace.
I find plumbago crucibles answer well, and when a furnace is used it should be
preferably gas-fired, and of a neutral atmosphere, and should be lined with a basic
or neutral material.
On the top of the said metallic aluminium, I place the lead sulphide or galena,
which must be in a finely divided condition not larger than will pass through
a tinch mesh, to prevent explosive disruption with large pieces, and the temperature
is raised to a bright red heat, sufficient to melt the lead sulphide, and aluminium,
and to retain the aluminium sulphide formed in a molten condition.
When the reaction is completed, the contents are poured or tapped into a mould,
preferably deep as compared with its breadth.
When cold, the contents are removed from the mould, and metallic lead will be
found at the bottom of the mass, and aluminium sulphide in a distinct stratum at
the top.
The excess of the aluminium, which was placed in the crucible, over the
theoretical quantity that was required for the reduction of the lead sulphide, will
be found at the top of the lead, and non-alloyed with the bulk of the lead or the
sulphide of aluminium, and therefore easily detached.
This excess of aluminium is added to ensure the complete reduction of the lead
sulphide, so that the resulting aluminium sulphide will be free from undecomposed
sulphide of lead.
If natural sulphide of lead (galena) has been used, and contains silver or gold,
or both, and other impurities, the gold and silver and other basic impurities will be
found to be alloyed with the excess of aluminium, and the valuable parts may be
easily recovered therefrom, or the resulting alloy may have commercial value, or
the aluminium may be recovered for re-use.
The chemical reaction employed in the above process may be expressed thus
The complete reduction of the lead sulphide is ensured by the excess of aluminium,
and by the non-alloying of the lead and aluminium, which also enables the respective
products of lead, aluminium sulphide, and excess aluminium, to be readily and
mechanically detached from one another.
One important commercial value of the sulphide of aluminium, is its application
in the reduction of other salts or oxides of aluminium; and it may be available as
a de-hydrogenizing agent, and a source of sulphuretted hydrogen, and it has not
yet been put on the market in any available quantities or at a moderate price.

page_text: Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The process for the production of aluminium sulphide from metallic
aluminium, by the melting together at a bright red heat, and the consequent
re-action of the latter upon and reduction of another metallic sulphide, the base of
which is electro-negative to metallic aluminium when both are in a molten condition,
substantially as herein described.
2nd. In a process for the production of aluminium sulphide from metallic
aluminium, the melting together at a bright red heat in a crucible or reverberatory
furnace, with neutral atmosphere and basic lining, of metallic aluminium and lead
sulphide for the production of metallic lead and aluminium sulphide, which do not
alloy and may therefore be easily and mechanically separated from one another and
from impurities, substantially as described.
Dated thie 19th dow of October 1893
FELL & WILDING,
1, Queen Victoria Street, London, E.C, Agents for the Applicant.