Year: 1897

page_text: Date of Application, 1st May, 1897
I, JAMES SWINBURNE, of 66, Victoria Street, Westminster, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention has reference to the treatment of sulphide ores, especially in con-
nection with electrolysis.
According to my invention the sulphide may be heated and treated with chlorine
gas. This converts the sulphide into chloride and gives off either chloride of
sulphur or sulphur. I prefer to have excess of sulphide present, so that there
is only sulphur given off. The action may be incomplete, however.
The chloride of the metal produced is then treated electrolytically, depositing
the metal, and giving off chlorine, which is led to more sulphide, and so on.
Thus for instance if zinc blende is to be treated, a bath of fused zinc chloride is
arranged to begin with. This is electrolysed in the fused state, yielding zinc in
metallic state, and chlorine. The chlorine is led to a suitable furnace, preferable
a sort of sloping hearth, charged with blende at a suitable temperature. The
resulting zinc chloride runs down direct into the electrolytic vat, or is kept till
wanted. This process is continuous, the same chlorine being used over and over
again. This is only true however, if the chlorine gives off pure sulphur, and not
chloride of sulphur. Moreover the vat will eventually become choked with
gangue or impurities. Fresh chloride of zinc will therefore have to be produced
to some extent; but there is no difficulty in making this in well known ways.
If there is any evolution of chloride of sulphur it is turned into hydrochloric and
sulphurous acid, and the hydrochloric acid can be converted into chloride of zinc
by adding it to roasted blende, or zinc carbonate.
In such cases as the treatment of such ores as the well known Broken Hill
sulphides, a mixed chloride is made containing lead, zinc and silver. If the vat
is filled with the mixed chlorides and electrolysed, the silver comes down first and
may be taken out by itself, or mixed with some lead. It may be best to use such
a current density that an alloy of silver and lead is produced, which is very rich
in silver, as there may otherwise be some trouble in working at a temperature
sufficiently high to get the silver in a suitable state for collection. After the silver
the lead will come down, and may be removed. The zinc comes last.
A continuous process will most likely be better, and I propose to carry it out by
running the fused chlorides continuously into a set of vats. In the first the
temperature and current density are arranged for taking out either the silver
alone, or an alloy very rich in silver, which can be easily treated afterwards. The
fused chlorides are then led into the second vat where the lead is taken out. The
chloride of zinc and impurities then run into a vat for taking out the zinc. This
vat will gradually accumulate all the impurities. It may therefore be best to
have several zinc vats with the chloride running through them in succession; a
small flow of very impure chloride coming out of the last. From this it is not
troublesome to recover the zinc chloride, preferably by distillation, to avoid any
wotting

page_text: The silver lead can be refined electrolytically in a fused chloride bath, or by
cupellation in the ordinary way. It may be possible to get the silver out of the
fused chloride by merely passing it over lead without any electrolysis. In this
case the lead is just left till it is sufficiently rich in silver.
The treatment of the ore by the chlorine may be carried out in a suitable oven, or
revolving converter.
Though I have so far described only the electrolysis of fused chlorides, my inven-
tion is also applicable if the chlorides are dissolved in water or brine and
electrolysed in the wet way.
Datad this 20th J
י
1000
I, JAMES SWINBURNE, of 66, Victoria Street, S.W., Engineer, 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 has reference to the treatment of sulphide ores, especially in con-
nection with electrolysis.
According to my invention the sulphide may be heated and treated with chlorine
gas, so as to give off sulphur, and yield chloride which I afterwards treat
electrolytically or otherwise.
The sulphide ore is treated with chlorine at such a temperature and with such
excess of ore that the chlorine replaces the sulphur, forming chloride of the metal
or metals, and liberating sulphur which is condensed. By having a high
temperature, and especially by having excess of sulphide present I avoid the pro-
duction of chloride of sulphur, as it has but a small market and recovery of
chlorine from it involves further expense.
The chloride is run off from the ore in a fused state and electrolysed in that
state, preferably without intermediate cooling. In the case of chlorides of
metals which have a high melting point, such as copper, I prefer to electrolyse
in aqueous solution, as metals generally do not come down from fused chlorides in
a coherent form unless the bath is hot enough to melt them. In some cases,
however, it is a good plan to deposit the infusible metal into a metal that forms a
suitable fusible alloy. Gun metal or brass can thus be made by depositing copper,
or German silver by deposition of nickel. When the ore contains several metals,
the resulting chloride is a mixture of the chlorides of the metals, and it is electro-
lysed fractionally, some of the metals being taken out, when desirable, by exchange
by adding a metal which will take the chlorine from them.
The ore may be poor by reason of presence of undesirable metals such as iron,
or of much gangue. In the case of undesirable metals such as iron being present
I treat the ore with only enough chlorine to decompose the sulphides of the metals
wanted. Thus if the ore contains, say zinc and iron sulphides, I may either con-
vert the whole of the sulphides into chlorides, or I may supply only enough
chlorine to turn all the zinc into chloride, as, if iron, zinc, sulphur, and chlorine
are together at a high temperature, the iron takes the sulphur and the zinc the
chlorine. By that means I get zinc chloride practically free from iron. The
fractional treatment can also be applied to separate lead from iron or zinc, and to
separate the precious metals, enough chlorine being used in the latter case, how-
ever, to attack some of the base sulphides too, so as to free the precious metals.
When the ore is poor owing to gangue, or much undesirable metal a large pro-

page_text: portion of the resulting chloride remains in the interstices of the ore, and cannot
be run off. This must be either distilled off or leached with water. Distillation
can be successfully applied in the case of many chlorides, but in other cases
leaching is preferable. The solution if it is of such a metal as copper may be
treated electrolytically in the wet way, yielding copper and chlorine, but where
the chloride is suitable I prefer to electrolyse it fused. This is especially important
in cases of chlorides which cannot easily be evaporated without decomposition.
Having now given a general outline of the method of working my sulphide
chloride process I will give some specific examples.
According to my invention, if zinc blende is to be treated, a bath of fused
anhydrous normal zinc chloride is taken to begin with. This may be prepared
by adding zinc cautiously to fused lead chloride; or it may be prepared from the
aqueous solution of zinc chloride. This is electrolysed with carbon anodes at a
temperature above the melting point of zinc. The chlorine is led off hot to the
hot zinc sulphide, air being of course excluded. Zinc chloride is thus formed, and
sulphur is given off and condensed. The zinc chloride is run into the vat and
electrolysed and the zinc may be drawn off. The process goes on continuously
until the zinc chloride in the vat is too full of impurities. When this occurs,
the zinc chloride remaining may be recovered by distillation, or by leaching with
water and evaporation. Distillation gives the normal anhydrous zinc chloride
above referred to. If leaching is resorted to, the evaporation of the zinc chloride
solution first gives off water, then at one stage the residue gives off hydrochloric
acid and becomes basic, and then if still further heated, normal anhydrous zinc
chloride distils over, which is the normal zinc chloride above referred to. If the
evaporation of the solution is stopped before the basic chloride is formed, the water
still remaining may be decomposed by adding zinc, while it is at a high tempera-
ture so that the chloride becomes basic, but anhydrous. Electrolysis may also be
employed but I prefer to secure the normal zinc chloride by distillation so as to
avoid the introduction of oxygen into the vat or system.
This recovery of the zinc chloride from the fouled bath is only an incidental
part of the process, one of the main advantages of my process, is that it yields
chlorides such as zinc chloride all ready for electrolysis in the fused state, so that
the electrolysis of the fused chloride, and the treatment of the sulphide with
chlorine go hand in hand.
If the zinc sulphide contains gold silver or other metals such as lead, which will
be replaced by zinc when in the state of fused chlorides, the fused chloride is first
electrolysed to remove them, or zinc is put in to take them out by substitution.
For this purpose an excess of zinc should be used, and the rich alloy removed, and
then the pure zinc deposited.
If the zinc sulphide contains much iron the quantity of chlorine should be kept
so small, that there is not enough to take up such a quantity of iron as would be
objectionable.
Chlorine is
Lead sulphide may also be treated according to my invention.
passed over it at a high temperature to produce lead chloride and sulphur. Silver
and gold go with the lead as chlorides. The fused chloride of lead is then either
partially electrolysed or preferably treated with lead, so as to get out the silver,
gold, etc. The preliminary electrolysis is preferably conducted at a high current
density so as to yield a fusible alloy of the metals to be extracted. Similarly if
lead is used it is put in in sufficient quantity to produce a like result. This alloy
containing the gold and silver is removed, and the electrolysis of the lead chloride
continued to get out the lead, the chlorine being used to treat more ore. Before
running off the lead into pigs it should be left in contact with the bath of lead
chloride a little, to remove any traces of iron or zinc that may have gone down.
The chloride of lead bath may be mixed with another chloride such as chloride of
zinc.
In the case of mixed sulphides such as sulphides of lead and zinc I treat the ore
with enough chlorine to decompose all the lead sulphide, and the lead chloride

page_text: produced contains the precious metals etc., also in the form of chlorides. If it is
desired to extract the lead and zinc, chlorine is supplied to convert both into
chlorides. This is not inconsistent with there always being excess of ore, so that
only sulphur comes off. The silver and gold are then extracted by means of lead,
or preliminary electrolysis. The lead is then electrolysed out, and the electrolysis
is pushed so that all the lead is taken out, a little zine being also deposited, pro-
bably together with a trace of iron, if present in the bath. Before running off
into pigs, this lead is treated with some of the mixed desilverised chlorides. This
removes the zinc and iron and leaves pure lead. The electrolyte, which has had
all its lead removed, is now electrolysed to get out the zinc. The arrangement I
prefer for this treatment is to have four baths 1, 2, 3, and 4 of which 3 and 4 alone
have anodes and cathodes. The mixed chlorides from the ore are run into 1, where
they are treated with lead, which extracts silver, gold, etc. The mixed chlorides
are then run into vat 2, where they are left in contact with lead from vat 3, such
lead containing a little zinc and perhaps iron. The zinc and iron are taken out
by the lead chloride. The refined lead is run off into pigs from vat 2, and the
mixed chlorides run into vat 3 where the lead is extracted. From vat 3 the lead
is taken to vat 2, while the chloride of zinc from which all lead has been thoroughly
removed is run to vat 4, where it is electrolysed for zinc. The gangue etc., collect
in vat 4, and the zinc chloride is recovered when the electrolyte gets too foul, and
the gangue thrown away. At the present market values it may be more profitable
not to extract the zinc, especially if there is much iron in the ore. In this case
only enough chlorine is supplied to the ore to take out the lead, with the silver etc.,
and to make enough zinc chloride to make sure that the lead is all washed out,
in case zinc ore, free from lead, is wanted for smelting. The mixed chlorides are
treated as before but of course less zinc is produced. The ore after treatment by
chlorine is either treated by heat or leaching to recover the zinc chloride with
which it is charged, containing as it does some lead chloride too, and may then be
valuable as a zinc ore if the lead has been properly removed.
Copper sulphide may be taken as another example. Chlorine is passed over the
complex sulphide at a high temperature and the mixed chlorides are obtained and
run into the electrolytic vat. The copper comes down as a fine powder. This is
kept from the anode compartment by a porous partition. The copper may be
deposited into zinc to make brass. If it is preferred to get the copper alone, the
powder is melted together under a flux, the electrolyte having been removed by
distillation or washing out. The copper sulphide should be free from iron; and if
the ore originally contains iron, it should be got out by the ordinary metallurgical
process, before treatment according to my invention.
Enough examples have been given to elucidate my invention. It would be
impossible to describe in detail the treatment of all the various sulphides, as the
sulphide ores are innumerable, sulphides of the various metals occurring in almost
every conceivable association. I will therefore add a few general principles for
guidance in treating these ores.
Most sulphides should be treated at a high temperature as well as with excess
of ore; but some, such as antimony sulphide, are decomposed, not only by chlorine,
but by chloride of sulphur at ordinary temperatures.
When the metal is not easily fusible, or its chloride is very volatile, the elec-
trolysis may be carried on in the wet way, or the infusible metal may be deposited
into a metal which makes a fusible alloy. When the chloride is very volatile, it
may be mixed with other chlorides which raise its boiling point. In such cases
as nickel and cobalt the metal may be sold as a salt without being reduced to the
metallic state.
When the ores contain several metals, they can, except when some give trouble
owing to high melting points, be separated by substitution. For instance a fused
bath containing antimony, lead, and zinc can be treated first, with lead to take out
the antimony, then with zinc to take out the lead, and then the zinc only need be
extracted by electrolysis. On the other hand any fused metal may be freed from

page_text: metals which take chlorine from its chloride, by treatment with the chloride of
the metal to be refined. Thus lead chloride will remove zinc or iron from lead.
I do not recommend this process for extracting iron, manganese, arsenic or
bismuth from their sulphide ores, the metals which I prefer to extract are lead,
copper, zinc, silver and gold when with lead, copper or zinc, cadmium, antimony
and tin.
Having now particularly described & ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. Treating sulphides with chlorine at a high temperature (if necessary) so
that substantially all the chlorine is taken up by the metals and free sulphur
formed, substantially as set forth.
2. Treating sulphides with chlorine at a high temperature (if necessary) so
as to get sulphur and chloride of the metal or metals and electrolysing the chloride
so obtained in the fused state.
3. Treating sulphide ores with chlorine fractionally so as only to convert a
portion of the metallic content into chloride, substantially as described.
4. The herein described cyclic process in which sulphide ore is decomposed with
chlorine evolving sulphur substantially free, and the resulting chloride is elec-
trolysed in the fused state, the evolved chlorine being used for treating more ore,
and so on, substantially as described.
5. In a process substantially as described separating metals in fused chloride
baths by substitution, substantially as described.
6. In a sulphide ore process in which chlorine replaces sulphur purifying the
metals from foreign metals which will take chlorine from the fused chloride of
the metal to be purified, substantially as described.
7. Treating zinc sulphide with chlorine at a high temperature, so as to get off
sulphur, and electrolysing the fused chloride substantially as described.
8. Treating zinc ore with chlorine, extracting the precious and other metals
by substitution, and electrolysing the zinc chloride fused, substantially as
described.
9. Treating zinc ore containing iron with chlorine to extract substantially the
zinc only, substantially as described.
10. Treating lead sulphide with chlorine, so as to get off sulphur, and elec-
trolysing the fused chloride substantially as described.
11. Treating lead ore with chlorine, extracting the precious and other metals
by substitution, and electrolysing the zinc chloride fused, substantially as
described.
12. Treating copper sulphide ores with chlorine so as to get off sulphur, and
electrolysing the chloride &c. produced to extract the copper.
13. Extracting sulphur from sulphide ores by treating them with chlorine,
substantially as and for the purpose set forth.
14. Treating sulphide ores with chlorine, and extracting from the fused chlorides
metals not easily fused in the form of powder.
15. Treating sulphide ores with chlorine, and depositing from the fused chlorides
metals not easily fused into fusible metals with which they alloy.
Dated this 27th day of February 1898.
JAMES SWINBURNE.

page_text: Date of Application, 1st May, 1897
Complete Specification Left 28th Feb. 1898 Accented 1st June 1808
PROVISIONAL SPECIFICATION.
Improvements in Treatment of Sulphide Ores.
I, JAMES SWINBURNE, of 66, Victoria Street, Westminster, Engineer, do hereby
declare the nature of this invention to be as follows:-
-
My invention has reference to the treatment of sulphide ores, in connection
with electrolysis, and is a modification of the invention described in my Pro-
visional Specification No. 10829 of even date.
According to that invention the sulphide may be heated, and treated with
chlorine gas. This converts the sulphide into chloride, and gives off either chloride
of sulphur, or sulphur. I prefer to have excess of sulphide present so that there
is only sulphur given off. The chloride of the metal produced is then treated
electrolytically, depositing the metal and giving off chlorine, which is led to more
sulphide, and so on.
As examples I have, in the said Provisional Specification described the treat-
ment of zinc blende, and such ores as the well known Broken Hill sulphides.
According to this invention the two actions may be carried on together; for
chlorine may be partly soluble in a fused chloride, or the sulphide may be. In
such a case a vat is charged with a mixture of chloride and sulphide and electro-
lysed; sulphur then comes off at the anode, or in its neighbourhood, and the metal
is deposited. Thus for instance, if zinc blende is to be treated, a bath of fused
zinc chloride is arranged to begin with.
This process may also be applied to the treatment of such ores as the well known
Broken Hill sulphides.
Dated the 30th day of April 1897
Improvements in Treatment of Sulphide Ores,
I, JAMES SWINBURNE, of 66, Victoria Street, S.W., Engineer, 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 has reference to the treatment of sulphide ores in connection
with electrolysis, and is a modification of the invention described in my Specifica-
tion No. 10829 of evén date.
According to my invention sulphide ore is run into a bath of suitable fused
chloride, and electrolysed, sulphur coming off at the anode and the metal at the
cathode

page_text: I will give some examples.
Zinc sulphide, which is as free from iron as possible, is run into a vat of fused
zinc chloride. Silver and gold are extracted as completely as possible by metallic
zine. The mixture of chloride and sulphide of zinc is then electrolysed, zinc
coming down at the cathode and sulphur coming off at the anode. The sulphur is
condensed.
Lead sulphide is run into a bath of fused anhydrous lead chloride, or preferably
lead and zinc chlorides, or only zinc chloride. There should be enough zine
chloride to decompose the whole of the lead sulphide, so that it cannot imprison
any such sulphides as silver etc. The whole of the silver and gold can then be
extracted by means of lead. I prefer to use 3 vats, in the 1st the ground galena
is run into zinc chloride, metallic lead being present too. The lead goes up, and
the metals which yield chlorine to lead, go into the lead and make an alloy. The
mixture of lead and zinc chlorides and zinc sulphide, and perhaps traces of iron
and other sulphides are then run off to vat 2, where it is left in contact with lead
from vat 3, so as to extract any traces of zinc and iron. The lead from vat 2 is
run off into pigs, and the mixed chlorides and sulphides are run off into vat 3
which is the only electrolytic vat. Here the lead is taken out, while the zine
sulphide gives off its sulphur. The electrolysis should not in this case be pushed
far enough to deposit iron or zinc in any appreciable quantity, or to use up all
the zinc sulphide, in fact excess of zinc sulphide should be used. The lead from
vat 3 is then taken to vat 2 to be purified, and the electrolyte returned to vat 1
where it receives more ore. When too foul it is treated for the recovery of the
zinc chloride.
In treating complex sulphides such as the lead-zinc sulphide ores the zinc may
or may not be extracted, according to the capital available, and to the nature of
the ore.
If zinc is to be extracted an ore as free from iron as possible is taken.
I prefer to use 4 vats, of which two are electrolytic. The ground ore is run into
the 1st, which contains zinc chloride, and lead. The lead of the ore goes into
chloride, and the metallic lead extracts all the metals which yield their chlorine
to lead. The mixed chlorides and sulphides are run into vat 2 where they meet
the lead from vat 3 and refine it. The lead is then run off into pigs and the sul-
phides and chlorides run into vat 3 where they are electrolysed to extract the lead
completely, a little zinc and perhaps a little iron being taken down too. The
lead from this vat goes to vat 2 to be purified, and the remaining chloride and
sulphide and gangue go to vat 4 where the zinc is taken out. The electrolyte is
then returned to vat 1 where it is treated with more ore. The electrolyte may
be allowed to stand a little between vats 4 and 1 each time, so as to settle out the
gangue. The foulest portion is then put aside each time for treatment for recovery
of zinc chloride. At present prices it will generally pay much better to extract
only the lead and precious metals. In that case vat 4 is dispensed with, and the
zinc chloride is recovered from the zinc sulphide and gangue, and the sulphide may
be sold as lead free zinc ore. If the zinc is not to be extracted electrolytically
no difficulty arises from iron being present in considerable quantity in the ore.
This process is specially applicable to such sulphide ores as those of zinc, lead,
tin, & cadmium. But it may be applied to other ores, for instance nickel and
copper, but in these cases the metal may be deposited into a melted metal which
forms a desirable alloy fusible at a practical temperature, or the finely divided metal
may also be fused together after deposition. A porous partition may be used to
keep the powder from the anode.
This process
specially applicable to ores which contain but little gangue.
When a complex sulphide has been added to the chloride the several metals
can, except when some give trouble owing to high melting points, be separated
by substitution. For instance a fused mass containing antimony, silver, gold,
lead, and zinc can be treated first with lead to take out the antimony, gold and
silver, then with zinc to take out the lead, and then the zinc only need be ex-
tracted by electrolysis. On the other hand any fused metal may be freed from

page_text: metals which take chlorine from its chloride, by treatment with the chloride of
the metal to be refined. Thus lead chloride will remove zinc or iron from lead.
Having now particularly described & ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:-
1. Treating sulphide ores by running them into fused chlorides and electro-
lysing the mixture.
2. Treating sulphide ores with fused chlorides and electrolysing so as to get
off sulphur and metal, substantially as described.
3. Treating zinc sulphide with fused zinc chloride and electrolysing substan-
tially as described.
4. Treating lead sulphide with fused zinc or other suitable chloride and electro-
lysing substantially as described.
5. Treating complex sulphide ores with fused chlorides and electrolysing sub-
stantially as described.
6. Treating copper sulphide ores with fused chlorides and electrolysing
substantially as described.
7. Extracting sulphur from sulphide ores by electrolysing the sulphide treated
with suitable fused chloride substantially as set forth.
8. Treating lead zinc sulphide ores so as to extract the lead and precious metals;
electrolytically setting free the corresponding sulphur and treating the sulphide
of zinc so as to extract the zinc substantially as described.
9. Depositing metals with high melting points into fixed metals with which
they alloy; while sulphur is evolved at the anode.
10. Depositing metals with high melting points in the form of powder, in a
fused chloride bath while sulphur is evolved at the anode.
Dated this 27th day of February 1897.
JAMES SWINBURNE.