taining sulphur for the Extraction of Metals and other Constituents.
Year: 1885

page_text: taining sulphur for the Extraction of Metals and other
Constituents.
We ROBERT OXLAND of 32 Portland Square Plymouth in the County of Devon
Consulting Chemist and CHARLES OXLAND of Greystoke Crystal Palace Park Road
Sydenham in the County of Surrey Mining Engineer do hereby declare the nature
of our invention for "IMPROVEMENTS IN THE TREATMENT OF ORES AND MATERIALS
CONTAINING SULPHUR FOR THE EXTRACTION OF METALS AND OTHER CONSTITUENTS
to be as follows:-
»
For this purpose we take ores containing sulphur such as the Spanish ores which
contain sulphur iron copper silver and gold, after being ground to fine powder we
digest the same in strong sulphuric acid for a sufficient length of time, with heat
in suitable vessels of cast iron or of lead or of fire brick or stone ware until all the
copper is taken into solution which may be ascertained from time to time by
examination and testing of the ore under operation. The charge is then removed
from the digester to a tank whether the whole of the soluble matter is separated
from the remainder of the ore. If the operation be properly conducted the whole
of the copper may be in this manner separated without acting on more than 1
or 2% of the iron pyrites but if considered desirable as it may be in certain cases
the whole of the pyrites may be rendered soluable but in so doing a large quantity
of the sulphur is volatilized which is condensed in a chamber through which the
sulphurous and sulphuric acids are passed on their way to the acid chambers where
they are collected and converted into sulphuric acid in a form suitable for
successive operations. The solution obtained after being filtered or allowed to
settle until bright and clear must then be treated with a soluble iodide so as to
cause the precipitation of the silver and the gold. After these metals are separated
by filtration or settlement the solution is then removed to another tank where the
copper may be precipitated by boiling on metallic iron or by any other suitable
process and after the separation of the copper silver and gold the remaining
sulphate of iron may be concentrated to the crystallizing point and the saturated
solution thus obtained may be employed either for the manufacture of sulphate
of iron copperas or green vitriol or may be used with the addition of sufficient
fresh acid for the treatment of ores instead of with sulphuric acid alone as above

page_text: described. The sulphur obtained in the condensing chamber may be washed
melted and rendered fit for market or the sulphate of iron (proto or persulph) may
be used for the manufacture of Nordhausen acid or for reuse.
The final residue of iron pyrites free from copper is obtained in a form suitable
for use by the sulphuric acid manufacturers.
Sulphuretes containing gold obtained in the usual way by the concentration, of
the residuary matters of the treatment of gold quartz may be digested with
sulphuric acid until the whole or nearly the whole of the pyrites is rendered soluble.
.Nearly the whole of the gold is found in the undissolved residue which will consist
principally of silica. Any gold remaining in solution may be precipitated by
digesting with metallic iron. The precipitate collected on a filter and well washed
may then be mixed with the first residue and may finally be treated either by
fusion with suitable fluxes or amalgamated with mercury and further treated so as
to obtain the gold in the form of ingot or bullion-If the ore thus operated on
contain silver it will be found in solution with the sulphate of iron from which it
may be separated as before" described by: precipitation with soluble iodides or
other ways. If for any reason such as the formation of per-sulphate of iron-by the
action of the SOH on the per oxide of iron it be thought desirable to calcine the
gold sulphuretes as above described more of the gold will be found in solution but.
it may be precipitated by digestion with metallic iron as already indicated.
. F
This process is also applicable for the separation of copper from calcined ores such
as purple ore or burnt ore from acid manufacture.
-Rich copper ores containing sulphur may be treated in the same manner as poor
copper ores.
་
In place of employing sulphuric acid in the uncombined state we can employ an
acid salt such as per sulphate of iron or bi-sulphate of soda.
1
5 3
r :
注
A
J
CARPMAEL & Co.,
Agents for the Applicants.

page_text: Constituents.
We ROBERT OXLAND of 32 Portland Square Plymouth in the County of Devon
Consulting Engineer and CHARLES OXLAND of Greystoke Crystal Palace Park
Road Sydenham in the County of Surrey Mining 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:-
For this purpose we take ores containing sulphur such as the Spanish ores
which contain sulphur iron copper silver and gold after being ground to fine
powder we digest the same in strong sulphuric acid for a sufficient length of time.
with heat in suitable vessels of cast iron or of lead or of fire: brick or stone ware
until all the copper is taken into solution which may be ascertained from time to
time by examination and testing of the ore under operation.
We employ by preference sulphuric acid of a specific gravity of 1.84 weaker acid
may be used but then the process will be delayed and the concentration of the acid
will take place during the process. We employ such a quantity of acid or of
acid mixed with sulphate of iron as hereinafter described as is necessary to
reduce the mass of finely powdered ore to the consistency of treacle or of a
fluid paste.
The vessels in which the process is carried on (cast iron vessels serve the purpose
well) should be closed and connected with a sulphuric acid chamber preferably a
chamber in which the manufacture of acid is also carried on in the usual manner,
the vapours of sulphurous and sulphuric acid generated in the process pass into the
chamber and are utilized. The heat should be raised to about 600° Fahrenheit In
about half an hour the operation will usually be complete.
The charge is then whilst still semi fluid removed from the digester to a tank
where the whole of the soluble matter is separated from the remainder of the ore
by treatment with water preferably in the manner known to chemists as methodical
washing and a solution of high specific gravity is obtained whilst at the same time
a complete or practically complete separation of the soluble from the insoluble
matter is effected. If the operation be properly conducted the whole of the copper
may in this manner be separated without acting on more than 1 or 2 per cent of
the iron pyrites.-The solution obtained after being filtered or allowed to settle
until bright and clear must then be treated with a soluble iodide so as to cause the
precipitation of the silver and the gold.
Iodide of sodium may conveniently be employed. It should be added in quantity
very slightly in excess of the equivalent of the gold and silver present.
After these metals are separated by filtration or settlement the solution is then
removed to another tank where the copper is precipitated by boiling on metallic

page_text: non or by any other suitable process as for example precipitation by sulphido of
sodium. After the separation of the copper silver and gold the remaining sulphate
of iron may be concentrated to the crystallizing point and the saturated solution
thus employed may be employed either for the manufacture of sulphate of iron
copperas or green vitriol or may be used with the addition, of sufficient fresh
acid for the treatment of ores instead of with sulphuric acid alone as above
described.
The final residue of iron pyrites free from copper is obtained in a form suitable
for use by the sulphuric acid manufacturers.
In the treatment of a fresh charge of ore the sulphate of iron from a previous
charge may as above stated be employed and this we prefer. We in this case take
the quantity of sulphuric acid required for the charge say three times the weight
of the copper in the ore and we add to it sulphate of iron in saturated solution in
quantity such that when the mixture with the ore is inade the mass shall have
the requisite semifluid consistency we then proceed in the manner already
described.
Another way in which we in some cases work is as follows: we employ a larger
quantity of sulphuric acid-proportioning it both to the copper and the iron in the
ore in place of to the copper only and we continue the treatment with heat for a
considerably longer time, in this way nearly the whole of the iron pyrites may be
brought into solution. A larger quantity of sulphur than in the previous case is
also volatilized and to arrest this. before reaching the sulphuric acid chamber we
provide an intermediate chamber in which it condenses. The charge on removal
from the digester is treated with water and the rest of the process is as already
described.
The sulphur obtained in the condensing chamber may be washed melted and
rendered fit for market.
The sulphate of iron (proto or persulphate) may be used for the manufacture of
Nordhausen acid or for reuse or sale.
Sulphurets containing gold obtained in the usual way by the concentration of
the residuary inatters of the treatment of gold quartz may be digested with
sulphuric acid until the whole or nearly the whole of the pyrites is rendered
soluble. The operation is conducted in the manner already described the acid
being employed in quantity sufficient to reduce the finely powdered material to a
semifluid consistency. After heating for some time nearly the whole of the gold
is found in the undissolved residue which will consist principally of silica.
Any gold remaining in solution may be precipitated by digesting with metallic
iron. The precipitate collected on a filter and well washed may then be mixed
with the first residue and may finally be treated either by fusion with suitable
fluxes or amalgamated with mercury and further treated so as to obtain the gold
in the form of ingot or bullion.
If the ore thus operated on contain silver it will be found in solution with the
sulphate of iron from which it may be separated as before described by precipitation
with soluble iodides or other ways.
If for any reason such as the formation of persulphate of iron by the action of
the sulphuric acid (SO* H) on the peroxide of iron or to remove arsenic it be
thought desirable to calcine the gold sulphurets before treatment as above
described and thereby to remove a portion of the sulphur more of the gold will be
found in solution but it may be precipitated by digestion with metallic iron as
already indicated.
This process is applicable for the separation of copper from calcined ores
containing sulphur such as purple ore or burnt ore from acid manufacture.
Rich copper ores containing sulphur may be treated in the same manner as poor
copper ores.
In place of employing sulphuric acid in the uncombined state we can employ an
acid salt such as persulphate of iron or bisulphate of soda.

page_text: 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
1. The process substantially as described for the treatment of ores and materials
consisting in mixing the same in a finely powdered state with strong sulphuric
acid or an acid sulphate to a semi fluid consistency and exposing the same to a
high heat thereby separating sulphur and sulphurous acid and rendering the
metallic constituents or some of them soluble in water.
2. The treatment of copper ores containing sulphur and iron pyrites as herein
described first by heating the ore with strong sulphuric acid or an acid sulphate
and then dissolving out the resulting copper salt with water thereby separating the
copper from the iron pyrites which remains with the residue.
3. The treatment of copper ores containing sulphur and iron pyrites by the aid
of strong sulphuric acid or an acid sulphate and heat as herein described the said
treatment being conducted in a closed vessel connected with a chamber in which
the resulting acid vapours are condensed whereby sulphuric acid is obtained and
the copper in the ore and more or less of the iron present in it is rendered soluble
in water.
4. The treatment of sulphuret ores or materials containing gold such as the
residuary matters from the treatment of gold quartz as herein described first by
heating the ore or material with strong sulphuric acid or an acid sulphate and then
dissolving out the resulting salts with water.
5. The treatment of ores or materials containing sulphur by heating the same
with strong sulphuric acid or an acid sulphate then dissolving out the resulting
salts in water and afterwards successively precipitating the several metals which
the solution contains substantially as described.