Year: 1898

page_text: all the bismuth is extracted from the ore in the form of bismuth trichloride.
A similar equation, and result, can be obtained in the case of antimony.
The liquor then consists of ferrous chloride and bismuth chloride."
oxychloride of bismuth is not formed in the presence of ferrous chloride, if ferric
chloride of sufficiently high specific gravity is used in the first place.
The
The tailings consist of sulphur, and residue of the ore. The sulphur can be
separated from the tailings by any convenient method, such as elutriation.
Also the gold present (if any) may be extracted from the tailings by any suitable
method.
The liquor resulting from the treatment of the ore with the solvent liquor, is
separated from the tailings, by siphoning, or the like, (and while still at a high
temperature), and is treated with iron (obtained in a manner to be afterwards
stated), when ferrous chloride alone is left in solution, the metal (bismuth, or
the like) being precipitated chemically pure.
The ferrous chloride is then oxidised to ferric chloride by the following
method:-
--
When ferrous chloride is subjected to the influence of an electric current pass-
ing through it, in double cell, that is, two compartments, or resevoirs, separated
by some porous diaphragm, the anode being in the one, the cathode being in the
other, ferric chloride is rapidly formed at the anode, and iron is deposited at
the cathode. By the equation;-3 FeCl₂ 2 FeCl + Fe it is seen that for every
two parts of ferric chloride produced, one part of iron is deposited, or for six
parts of ferric chloride, three parts of iron are deposited. In the previous
equation, six parts of ferric chloride produced two parts of bismuth trichloride,
and to replace this bismuth by iron, in order that ferrous chloride may alone
result, three parts of iron are necessary.
My method then, is to electrolyse the ferrous chloride, using the iron deposited
on the cathode to throw down the metal (bismuth or the like). As shewn above,
the amount deposited is that required. The process is then continuous, the same
solvent being used repeatedly. The metal on being melted, and run into moulds,
or the like, assumes the crystalline state.

page_text: What I claim is:-
(1) The treatment of sulphide of bismuth (or like metals) with ferric chloride
solution at boiling temperature.
(2) The method of precipitating the metal by means of iron, produced in the
electrolytic oxidation of the ferrous chloride:
The advantages of this process are, no antimony is lost, sulphur and gold can
be saved, less heating material is necessary, saving in time and labour, and low
grade ores can be worked.
A Humid Process for the Extraction of the Metals Bismuth or
Antimony from their Sulphide Ores.
I, JOHN RANALD, of 62, Streatham Hill, in the County of London, Gentleman,
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 follow-
ing statement:-
The objects of my invention are to provide a new and improved process by which
bismuth or antimony can be extracted from their sulphide ores without loss of
the metal and whereby sulphur and also any gold present can be saved less heat-
ing agent being required and the process effecting a saving in time and labour
(as against smelting) and enabling low grade ores to be successfully treated.
I will presume for example that it is bismuth that is to be extracted, antimony
being extracted in the same manner.
The ore having been crushed, is passed through a sieve, preferably one of
30 meshes to the square inch.
It is then, in calculated amount, thrown into vats, containing the solvent
liquor, viz. ferric chloride solution (Fe Cl, Aq) of moderate density such for
example as a density of 1240 (as against water at 1000) and at a temperature at
or near boiling point.
No parts of the vat or apparatus which come in contact with the heated ferric
chloride solution should present a surface of iron to the solution.
The heating of the solution may be effected in any convenient way; for
example, by means of a jet of coal gas, or the like, and air issuing into the charge
through a nozzle within a hood dipping into the charge.
In accordance with the following equation;-
Bi, S, +6 Fe Cl₂ = 6 Fe Cl, +2 Bi Cl, + S
all the bismuth is extracted from the ore in the form of bismuth trichloride.
The
The liquor then consists of ferrous chloride and bismuth chloride.
oxychloride of bismuth is not formed in the presence of ferrous chloride, if ferric
chloride of sufficiently high specific gravity be used in the first place.
The liquor resulting from the treatment of the ore with the solvent liquor,
is separated from the tailings, (which can be done by siphoning, or the like)
and, whilst still at a high temperature, is treated with iron, (which is recovered
and reused as hereinafter described), when ferrous chloride alone is left in solu-
tion, the bismuth being precipitated chemically pure.
The ferrous chloride is then oxidised to ferric chloride which can be done as
follows.
The ferrous chloride is subjected to the action of an electric current passing

page_text: through it, in a double cell, that is, two compartments or reservoirs, separated
by a porous diaphragm, the anode being in the one compartment or reservoir
and the cathode being in the other. Ferric chloride is rapidly formed at the anode,
and iron is deposited at the cathode. By the equation:- Fe C₁₂ = 2 FeCl + Fe
it is seen that, for every two parts of ferric chloride produced, one part of iron is
deposited, or for six parts of ferric chloride three parts of iron are deposited. In
the previous equation, six parts of ferric chloride produced two parts of bismuth
trichloride, and to replace this bismuth by iron, in order that ferrous chloride
may alone result, three parts of iron are necessary. The iron deposited on the
cathode, as aforesaid, is therefore the amount required to throw down the bismuth
from another charge of crushed sulphide ore, and so the process is continuous, the
same solvent being used repeatedly. The metal on being melted, and run into
moulds, or the like, assumes the crystalline state.
The tailings consist of sulphur, and the residue of the ore. The sulphur can
be separated from the residue by any usual, or convenient, means; such, for
example, as elutriation. If any gold be present it can be extracted from the
tailings by any usual, or suitable means.
As before mentioned my invention can be applied in a like manner, to the
recovery of antimony, from sulphide ores thereof.
'
Having now particularly described and ascertained the nature of this
invention, and in what manner the same is to be performed, I declare that what
I claim is;-
-
In the extraction of bismuth, or antimony from their sulphide ores, subjecting
the crushed ores to the action of a solution of ferric chloride at or about boiling
temperature, and then precipitating the metal by means of iron, and recovering
the iron for re-use in the process and the same solvent (ferric chloride) being
used repeatedly substantially as hereinbefore explained.
Dated this 29th day of April 1899
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.