An Improved Process for Treating Sulphide Ores Containing Zinc and other Metals.
Year: 1895

page_text: Date of Application, 9th Dec.,
4005
Complete Specification Left, 9th Sept., 1896-Accepted, 10th Oct., 1896
Complete Specification Left, 9th Sept., 1896-Accepted, 10th Oct., 1896
PROVISIONAL SPECIFICATION.
An Improved Process for Treating Sulphide Ores Containing Zinc
and other Metals.
We, THOMAS PARKER, of Manor House, Tettenhall, Wolverhampton, in the
County of Staffordshire, Engineer, and JOHN PULLMAN, of 17, Greek Street,
Soho, in the County of Middlesex, Manufacturer, do hereby declare the nature of
this invention to be as follows:-
This invention relates to the treatment of refractory sulphide ores, containing
zinc and other metals, and it has for its object a novel method of treating such
ores, by which method great simplicity, economy, and efficiency, are obtained.
In treating sulphide ores containing zinc and other metals, it has been heretofore
usual to roast the pulverized ores, previous to treating them with sulphuric or other
suitable acid.
By the present invention, we take the pulverized ores in a raw state and we
treat them unroasted with hot concentrated hydrochloric acid, (at a temperature of
about 90° C.) in order to obtain a readily electrolysable solution of chloride
of zinc.
This solution of chloride of zinc is filtered or decanted from the residue, and in
order that it may be made and kept perfectly neutral, which is essential to its
effective treatment in the electrolytic bath we add to it a small quantity of
carbonate of zinc. As there is also a tendency during the electrolysis of zinc
chloride to produce and give off hydrochloric acid we continue the addition from
time to time of carbonate of zinc in small quantities, and in this way the perfect
and economical electrolysis of the zinc chloride results, metallic zinc being
obtained. The chlorine gas evolved in this electrolytic process may be collected
and utilized if desired.
The sulphuretted hydrogen given off during the treatment of the raw sulphide
ores may also be collected and utilized in any of the well-known ways.
The solution of zinc chloride obtained in the manner described will contain also,
whilst hot, lead chloride (if lead be present in the ore), which will be precipitated
when cold, and may be dissolved by hot water or other suitable known solvent and
the lead contained in it recovered.
The zinc chloride may be freed from any iron present by treatment with
carbonate of zinc or zinc oxide, iron oxide being obtained.
The residue from the first treatment with hydrochloric acid as described, may be
again treated with hot hydrochloric acid as before, and filtered' or decanted, the
filtrate containing some lead, zinc, and iron, whilst the residue from it contains any
silver present in the ore.
This silver is recovered in any of the ordinary well-known ways, (for instance by
treatment with hyposulphite of soda, or hot brine).
Dated this 9th day of December 1895.

page_text: An Improved Process for Treating Sulphide Ores Containing Zinc
and other Metals.
We,
THOMAS PARKER, of Manor House, Tettenhall, Wolverhampton, in the
County of Stafford, Engineer, and JOHN PULLMAN, of 17, Greek Street, Soho,
in the County of Middlesex, Manufacturer, 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, that is to say:-
This invention relates to the treatment of what are well known as refractory
sulphide ores, containing zinc and other metals, and it has for its object a novel
process or method of treating such ores, by which method great simplicity, economy,
and efficiency, are obtained.
In treating such sulphide ores containing zinc and other metals, it has been
heretofore usual to roast the pulverized ores, previous to treating them with
sulphuric or other suitable acid."
By the present invention, we take the pulverized ores in a raw state and we treat
them, unroasted, with hot concentrated hydrochloric acid (at a temperature of
about 90° C.), in order to obtain a readily electrolysable solution of chloride
of zinc.
The solution of chloride of zinc thus obtained is filtered or decanted from the
residue, and in order that it may be made and kept perfectly neutral, which is
essential to its effective treatment in the electrolytic bath, we add to it a small
quantity of carbonate of zinc. As there is also a tendency during the electro-
lysis of zinc chloride to produce and give off hydrochloric acid, we continue the
addition from time to time of carbonate of zinc in small quantities, and in this
way a perfect and economical electrolysis of the zinc chloride results, metallic
zinc being obtained. The chlorine gas evolved in this electrolytic process may
be collected, and utilized if desired.
The sulphuretted hydrogen given off during the treatment of the raw sulphide
ores may also be collected and utilized in any of the well-known ways.
The solution of zinc chloride obtained in the manner described, will contain
also, whilst hot, lead chloride (if lead be present in the ores), which will be
precipitated when cold, and may be dissolved by hot water or other suitable
known solvent, and the lead contained in it recovered.
The zinc chloride may be freed from any iron present, by treatment with
carbonate of zinc or zinc oxide, iron oxide being thus obtained.
Or, cold bleach liquor may be added to the hot solution of zinc chloride. This
oxydizes the iron and precipitates an oxychloride of zinc which reacting pre-
cipitates the iron.
The residue from the first treatment with hydrochloric acid as described, may
be again treated with hot hydrochloric acid as before, and filtered or decanted,
the filtrate containing some lead, zinc, and iron, whilst the residue from it
contains any silver present in the ore.
This silver is recovered in any of the ordinary well-known ways, (for instance
by treatment with hyposulphite of soda, or hot brine).
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1. The process for treating sulphide ores to obtain zinc and other metals
contained therein, consisting in treating the pulverized ores, in a raw or unroasted
1

page_text: neutral by the addition of carbonate of zinc, and submitting it to electrolysis
so as to obtain the metallic zinc.
2. In combination with the process claimed in Claim 1, the separation of lead
chloride by precipitation from the solution of chloride of zinc when cold.
3. In combination with the process claimed in Claim 1, the separation of iron
from the solution of zinc chloride by treatment with carbonate of zinc or zinc
oxide, or cold bleach liquor.
4. In combination with the process described in Claim 1, the further treatment
of the residue resulting from the said process, with hot hydrochloric acid, the
solution being filtered or decanted, any lead, zinc, and iron being afterwards
separated from the filtrate, and silver being separated from the residue.
Dated this 9th day of September 1896.
EDWARDS & Co.,
65 and 66, Chancery Lane, London, Agents for the Applicants.