IMPROVEMENTS IN THE TREATMENT OF ORES CONTAINING SULPHIDE OF ANTIMONY FOR THE PURPOSE OF OBTAINING THE SAID SULPHIDE IN A CONCENTRATED FORM
Year: 1884

page_text: We EDWARD WILLIAM PARNELL of 28 Canning Street Liverpool in the County
of Lancaster Analytical. Chemist, and JAMES SIMPSON of 8 Rumford Place,
Liverpool in the County of Lancaster, Alkali Manufacturer, do hereby declare tho
nature of our Invention for "IMPROVEMENTS IN THE TREATMENT OF ORES
CONTAINING SULPHIDE OF ANTIMONY FOR THE PURPOSE OF OBTAINING THE
SAID SULPHIDE IN A CONCENTRATED FORM," and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
In the preparation or manufacture of metallic antimony from the natural
sulphide or stibnite there is always a loss and inconvenience in working the ores
containing a small percentage of antimony. This arises partly from the greater
bulk which has to be dealt with and partly from the extra cost of flux and other
articles necessary for bringing the particles of metal together in the molten
condition.
The object of our Invention is to treat ores containing a low percentage of
sulphide of antimony in a cheap and efficient manner so as to separate the gangue
or other impurity from the said sulphide of antimony and obtain the latter in a
more concentrated form.
For this purpose (a) we grind or pulverize the ore till it is in a state of fine
division say till it will pass through a sieve of 40 meshes to the inch or thereabouts
and we add the finely pulverized ore to an aqueous solution of ammonium sulphide
preferably a polysulphide in a closed vessel fitted with any convenient means for
agitation or the solution may be added to the pulverized ore. The sulphide of
antimony passes into solution combining with the sulphide of aminonium while the
gangue and other impurities, remain undissolved and are allowed to settle to the
bottom of the vessel in which the operation is conducted. We find it advantageous
in practice to employ a solution containing about 20 per cent. of ammonium
sulpbide. (b) The said gangue or impurity is removed from the said vessel in any
convenient way or the solution of double sulphide is decanted or run into another
vessel leaving the residue behind. (e) The solution of double sulphide is decomposed
by boiling in a closed vessel, sulphide of ammonium being carried off with the

page_text: steam and recovered for repeated use by means of a condensing apparatus and
sulphide of antimony being precipitated in a dense form in the decomposing vessel
together with any excess of sulphur. (d) As soon as the sulphide of ammonium
has passed over into the condenser the remaining liquor containing sulphide of
antimony mixed with some sulphur is dealt with in any convenient method, such
as by being allowed to drain and evaporated to dryness or passed through a filter
press when it will be in a highly concentrated condition and more suitable for the
production of metallic antimony than it was before its separation from the gangue
or other impurity.
In employing the recovered ammonium sulphide from the condenser for treating
a fresh lot of ore it is advisable to add a small quantity of sulphur to facilitate its
action.
We wish it to be understood that we do not claim dissolving sulphide of
antimony in sulphide of ammonium as it was known that precipitated sulphide of
antimony was soluble in that re-agent.
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 :-
The process herein described consisting (a) in adding finely pulverized sulphide
of antimony ore to a solution of sulphide of ammonium and agitating it with the
latter in a closed vessel till the sulphide of antimony is dissolved a soluble double
sulphide of antimony' and ammonium being formed (b) in separating the gangue or
impurity from the solution of double sulphide, (c) in decomposing the double
sulphide of antimony and ammonium by boiling the solution in a closed vessel and
in recovering the sulphide of ammonium by means of a condenser for repeated use,
and (d) in obtaining the sulphide of antimony produced in the foregoing operations
by separating it from the residual liquor by decantation, evaporation or filtration.
Dated this 20th day of August 1884.