Improvements in the Treatment of Sulphide Ores Containing Zino⚫ in Association with other Metal or Metals, for the Separation and Obtainment of Metals Contained therein.
Year: 1894

page_text: Date of Application, 21st Dec.,
1884
Complete Specification Left, 23rd Sept., 1895-Accepted, 21st Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Sulphide Ores Containing Zino⚫
in Association with other Metal or Metals, for the Separation
and Obtainment of Metals Contained therein.
I, THOMAS PARKER, of Manor House, Tettenhall near Wolverhampton in the
County of Stafford, Engineer, do hereby declare the nature of this invention to be
as follows:-
.
This invention has for its object improvements in the treatment of sulphide ores
containing zinc in association with other metal or metals, for the separation and
obtainment of metals contained therein.
The ore from which metals are to be separated and obtained by means of this
invention is first roasted in the usual or any convenient manner. It is then treated,
for the extraction of zinc, with dilute sulphuric acid, and the resulting sulphate of
zinc solution is circulated through electrolytic cells having lead plates or electrodes
at the surface of which sulphuric acid will be liberated, and zinc plates or electrodes
on the surfaces of which the zinc will be deposited. The electrolytic action is
continued until, by the separation of the zinc therefrom, the solution is of suitable
acid strength, though not exhansted of zinc, to be advantageously utilized in taking
up zine from a further supply of roasted ore. The solution is then used to treat a
further supply of ore, and the uncombined sulphuric acid having thus formed with
the oxide of zinc of the roasted ore sulphate of zinc, the solution is again submitted
to electrolysis as before and further zinc obtained thereby, and sulphuric acid
liberated. The process above described may be repeated over and over again, the
acid solution or mother liquor being strengthened from time to time to make good
any waste of sulphuric acid.
It may sometimes be found, in consequence for instance of the state of the
market, preferable to use hydrochloric acid instead of sulphuric in the process
above described. When this is done, a diaphragm, either complete or partial, is
used and the chlorine is liberated at the surface of the carbon electrodes, or other
suitable electric conductors which will stand the action, such electrodes being
substituted for the lead plates aforesaid, and the chlorine is utilized for any purpose
for which it may be required.
Any silver or lead contained in the ore is left behind after the treatment above
described for the removal of the zinc, and may be dealt with by the ordinary
metallurgical methods for their extraction. Hot hydrochloric acid may be used to
dissolve the chlorides of silver and lead and separate them from silica and other
gangue.
Dated this 20th day of December 1001
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Treatment of Sulphide Ores Containing Zinc:
in Association with other Metal or Metals, for the Separation.
and Obtainment of Metals Contained therein
1, THOMAS PARKER, of Manor House, Tettenhall near Wolverhampton in the
County of Stafford, 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 :—
This invention has for its object improvements in the treatment of ores containing
zinc in association with other metal or metals, for the separation and obtainment of
metals contained therein.
The ore from which metals are to be separated and obtained by means of this
invention is first roasted in the usual or any convenient manner.
It is then treated,
for the extraction of zinc, with dilute sulphuric acid, and the resulting sulphate of
zinc solution is circulated through electrolytic cells having lead plates or electrodes
at the surface of which sulphuric acid will be liberated, and zinc, carbon, or other
suitable plates or electrodes on the surface of which zinc will be deposited. The
liberated sulphuric acid remains in the liquid of the cells. The electrolytic action
is continued until, by the separation of the zinc therefrom, and the consequent
setting free of sulphuric acid, the solution becomes of suitable acid strength, though
not exhausted of zinc, to be advantageously utilized in taking up zinc from a
further supply of roasted ore. The solution is then used to treat a further supply
of ore, and the uncombined sulphuric acid having thus formed with the oxide of
zinc of the roasted ore further sulphate of zinc, the solution is again submitted to
electrolysis as before, and further zinc obtained thereby, and sulphuric acid
liberated. The process above described may be repeated over and over again, the
acid solution or mother liquor being strengthened from time to time to make good
any waste of sulphuric acid. The liberated zinc is collected and smelted in the
usual manner.
Hydrochloric acid, instead of sulphuric, may be used in the process above
described. When this is done, the chlorine is liberated at the surfaces of carbon
electrodes or other suitable electric conductors which will stand the action, such
electrodes being substituted for the lead plates aforesaid, and the chlorine is
collected and utilized for any purpose for which it may be required. When the
hydrochloric acid process is adopted, a diaphragm is employed with each electro-
lytic cell, to separate the chlorine gas liberated at the one pole from the metal
liberated at the other pole, and to facilitate the collection of the gas; and as the
electrolyte is the same on both sides of the diaphragm, the latter may be of any
character which will prevent the liberated chlorine gas from passing through, and
is not necessarily of the usual character of porous diaphragms which are used to
prevent the passage therethrough of liquid. A convenient form of diaphragm for
the purpose may be such as that of which a short length is shewn in sectional plan
on the drawing berewith, consisting of a number of vertical bars a, which may be
of wood or other suitable material, connected at top and bottom with rails or sills
of wood or other suitable material, and filled in between with porous material b,
such as glass wool, which while allowing of the ready flow of the liquid through the
diaphragm will prevent liberated gas from passing through.
The electrolytic cells used in the hydrochloric acid process should be maintained
at a temperature of about 80° Centigrade to prevent the liberated chlorine from
passing into solution in the liquor, and for the purpose also of reducing the electro-
motive force required. As the liquor becomes exhausted of chloride of zinc it is
necessary to evaporate it from time to time in order to maintain, approximately,

page_text: the density necessary for the best electrolytic results. In the hydrochloric acid-
process, the liquor cannot, as will be obvious, be used over and over again as in the
case of the sulphuric acid process.
Any silver and lead contained in the ore are left, after the treatment by either-
process above described for the removal of the zinc, as salts insoluble in cold
water. These may be dissolved in hot water or hot dilute hydrochloric acid, and
thus divided from the insoluble gangue, and be treated chemically for the separation.
of the metals; or the salts of lead and silver may be dealt with by ordinary
metallurgical methods, yielding a lead-silver alloy.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
alaim is :-
1. In the treatment of sulphide ores containing zinc in association with other
metal or metals, the use of sulphuric or hydrochloric acid whereby sulphate or
chloride of zinc is formed, and the submission of such sulphate or chloride to
electrolysis to cause the deposition of zinc and the liberation of sulphuric acid or
chlorine gas, substantially as described, for the purpose set forth.
2. In the treatment of sulphide ores containing zinc in association with other
metal or metals, the use of sulphuric acid whereby sulphate of zinc is formed, and
the submission of such sulphate to electrolysis to cause the deposition of zinc and.
the liberation of sulphuric acid, and the continually repeated use, for the purpose
of taking up further zinc from the ore, of the liquor (strengthened from time to
time with further acid as may be required) which contains the liberated sulphuric
acid, substantially as described.
3. In the treatment of sulphide ores containing zinc in association with lead or
silver, or both of such metals, subjecting them to a process whereby the zinc is
separated therefrom, and then separating such lead or silver, or both of such.
metals, from the insoluble gangue, by treatment with hot water or hot hydrochloric
acid, substantially as described.
4. In the treatment of sulphide ores containing zinc in association with lead or
silver, or both of such metals, subjecting them to the process or either process
described or referred to in Claims 1 and 2, and separating such lead or silver, or
both of such metals, from the insoluble gangue, by treatment with hot water or hot-
hydrochloric acid, substantially as described.
Dated this 16th day of September 1905.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicant..