IMPROVEMENTS IN THE TREATMENT OF SULPHIDES OF ANTIMONY TO OBTAIN CHLORIDES, OXYCHLORIDES AND METALLIC ANTIMONY
Year: 1884

page_text: We JOHN HARGREAVES Albert Road Widnes Lancashire, Chemist, and THOMAS
ROBINSON Hope House Farnworth near Widnes aforesaid, Ironfounder, do hereby
declare the nature of our said invention for "IMPROVEMENTS IN THE TREATMENT
OF SULPHIDES OF ANTIMONY TO OBTAIN CHLORIDES, OXYCHLORIDES AND METALLIC
ANTIMONY," to be as follows:-
The object of this invention is to obtain chlorides of antimony from sulphide of
antimony, suitable for the manufacture of oxychloride of antimony, to make
oxychloride of antimony and to obtain metal therefrom.
Under this invention we avail ourselves of the well known reaction of the
decomposition of chloride of antimony into, oxychloride of antimony and hydro-
chloric acid when the said chloride of antimony is mixed with water.
We find in practice that chloride of antimony obtained in the usual manner by
dissolving ores containing sulphide of antimony in hot strong hydrochloric acid,
contains antimony equal to about 5 lbs to 6 lbs of metallic antimony per cubic foot
of solution, a comparatively small proportion only of the hydrochloric acid being
neutralised, thus leaving a large excess of free hydrochloric acid in solution. When
such a solution of chloride of antimony (hereinafter called acid chloride of antimony)
mixed with water for the purpose of making oxychloride of antimony, a very large
volume of water is required to effect the precipitation of the oxychloride of antimony
and a considerable quantity of antimony is finally retained in solution by the large
amount of free bydrochloric acid present.
To reduce the difficulties of manufacture to a minimum, we employ chlorides of
antimony containing a comparatively small quantity of free acid in solution. This
solution which we hereinafter call concentrated chloride of antimony may be
obtained by evaporation or by neutralisation of the whole or part of free acid
contained in the acid chloride of antimony or by chlorinisation or oxidation of
sulphide of antimony and subsequently dissolving in strong hydrochloric acid or by
other convenient methods.
To obtain oxychloride of antimony we take concentrated chloride of antimony
and slowly mix such chloride of antimony with water in a vessel provided with
suitable means for keeping the mixture in agitation. The small quantity of
chloride of antimony retained in solution may be precipitated by adding alkali
waste, or other convenient source of sulphuretted hydrogen to the solution,
D

page_text: We convert oxychloride of antimony into metallic antimony as follows:-After
the oxychloride of antimony has been washed sufficiently free from hydrochloric
acid, we heat the mass to or near boiling point, and add gradually to it, milk of
lime in sufficient quantity to convert the oxychloride into oxide: during this
operation the mixture is kept at or near the boiling point and constantly agitated
so as to convert the whole of the oxychloride into oxide with as little excess of
lime as possible. The resulting oxide of antimony is run upon a suitable filter,
washed with hot water so as to free the oxide from chloride of calcium, and is
afterwards partially freed from moisture by means of a filter press or centrifugal
machine. The said oxide is afterwards thoroughly dried, mixed with alkali and
carbon and reduced to metal in any convenient manner. With the exception of a
little silica and alumina dissolved by the flux from the sides of the furnace or
crucible together with any excess of lime used in decomposing the oxychloride of
antimony the flux will remain comparatively pure. We re use the flux for
subsequent fusión...
It will be evident that if hydrochloric acid be added to the oxychloride of
antimony, a pure concentrated solution of antimony will be obtained to which the
milk of lime may be added and oxide of antimony obtained, instead of mixing the
milk of lime directly with the oxychloride.

page_text: We JOHN HARGREAVES Albert Road Widnes Lancashire Chemist and THOMAS
ROBINSON Hope House Farnworth near Widnes aforesaid Ironfounder, do hereby
declare the nature of the said invention for IMPROVEMENTS IN THE TREATMENT
OF SULPHIDES OF ANTIMONY TO OBTAIN CHLORIDES; OXYCHLORIDES, AND METALLIC
ANTIMONY" and in what manner the same is to be performed, to be particularly.
described and ascertained in and by the following statement:-
The object of the invention is to obtain chlorides of antimony from sulphide of
antimony suitable for the manufacture of oxychloride of antimony to make
oxychloride of antimony and obtain metallic antimony therefrom.
Under this invention we avail ourselves of the well known reaction of the
decomposition of chloride of antimony into oxychloride of antimony and hydro-
chloric acid when the said chloride of antimony is mixed with water.
1st We find in practice that chloride of antimony obtained in the usual manner;
by dissolving ore containing sulphide of antimony in hot strong hydrochloric acid.
contains antimony equal to about 5lbs to 6lbs of metallic antimony per cubic foot of
solution, a comparatively small proportion only of the hydrochloric acid being.
neutralised thus leaving a large excess of free hydrochloric acid in solution. When.
such a solution of chloride of antimony (hereinafter called acid chloride of
antimony) is mixed with water for the purpose of making oxychloride of antimony,
a very large volume of water is required to effect the precipitation of the
oxychloride and a considerable quantity of antimony is finally retained in solution
by the large amount of hydrochloric acid present.
To reduce the difficulties of manufacture to a minimum, we employ chloride of
antimony containing a comparatively small quantity of free acid in solution. This
solution which we hereinafter call concentrated chloride of antimony may be
obtained by evaporation (by which means the hydrochloric acid could be recovered
for reuse) or by neutralising the whole or part of the free acid contained in the
acid chloride of antimony by means of lime or magnesia or by chlorinisation or
oxidation of sulphide of antimony and subsequently dissolving in strong bydro-
chloric acid, or by other convenient methods.
2nd To obtain oxychloride of antimony we take concentrated chloride of antimony
and slowly mix such chloride of antimony with water contained in a wooden or
stone vessel provided with suitable means for keeping the mixture in agitation.
The precipitated oxychloride of antimony is allowed to settle and the clear liquor.
decanted. The small quantity of antimony, together with any other valuable
metals retained in solution may be recovered in any convenient manner, adding
alkali waste to the solution will usually be found to be the most convenient method
of precipitating the antimony from solution.
When it is desired to reuse the decanted liquor instead of water for the purpose
of precipitating oxychloride of antimony we prefer to neutralize the free acid
contained in it before use.

page_text: 3rd We convert oxychloride of antimony into metallic antimony as follows:-
After the oxychloride of antimony has been washed sufficiently free from hydro-
chloric acid and other soluble impurities, we heat the mass to or near boiling point
and add gradually to it milk of lime in sufficient quantity to convert the oxychloride
into oxide during this operation the mixture is kept at or near the boiling point
and constantly agitated so as to convert the whole of the oxychloride into oxide
with as little excess of lime as possible. The resulting oxide is run upon a suitable
filter washed with hot water so as to free the oxide from chloride of calcium, and
is afterwards partially freed from moisture by means of a filter press or centrifugal
machine. The said oxide is afterwards thoroughly dried, mixed with alkali and
carbon and reduced to metal in any convenient way.
When an open hearth furnace is employed for this purpose we prefer to use a
plus pressure furnace heated by a reducing flame so as to reduce the amount of
antimony lost during the process of melting.
With the exception of a little silica and alumina dissolved by the flux from the
sides of the furnace or crucible together with any excess of lime used in decomposing
the oxychloride of antimony the flux will remain comparatively free. We re use
the flux for subsequent fusion.
It will be evident that if hydrochloric acid be added to the oxychloride of
antimony a pure concentrated solution of antimony will be obtained to which the
milk of lime may be added and oxide of antimony obtained instead of mixing the
milk of lime directly with the oxychloride.
Having now particularly described and ascertained the nature of our said.
invention and in what manner the same is to be performed we declare that what
we claim is
.
First. Obtaining chlorides of antimony from sulphide of antimony, subsequently
converting the acid chlorides into concentrated chlorides and treating such
concentrated chlorides with water for the purpose of producing oxychlorides
substantially as set forth.
Second. Obtaining metallic antimony from oxychlorides of antimony by treating
the latter with lime, mechanical washing and drying and after admixture with a
suitable flux reducing in a furnace or crucible substantially as set forth.
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