Improvements in the Treatment of Ores for Obtaining Metals and other Products therefrom.
Year: 1898

page_text: RAAN DIRIFICATION.
Improvements in the Treatment of Ores for Obtaining Metals and
other Products therefrom.
I, SHERARD OSBORN COWPER-COLES, of 39, Victoria Street, Westminster, in
the County of London, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in the treatment of ores for obtaining
metals, metallic compounds and other products therefrom and has reference more
particularly to the treatment of such ores as are referred to in the Specification
of my prior Application for Patent No. 5943 of 1898.
In carrying out my invention the ore is first crushed screened and if necessary
mixed with zinc blende or other suitable ore as stated in my aforesaid prior
specification for facilitating the subsequent roasting.
3
The ore is then subjected to a preparatory treatment such as that set forth in
my prior specification, i.e. it is subjected to a dead roast for a length of time
sufficient to drive off most of the sulphur it contains and is afterwards crushed and
screened to separate the slimes from the crushed ore. The sulphurous acid gas
produced in this operation is collected and used as hereinafter set forth.
The ore is then placed in suitable vats wherein it is first leached with a weak
solution of sulphuric acid to remove the zinc and copper. The solution thus
produced, containing the zinc and copper, is then passed through a body or bed of
zinc and carbon or zinc and iron to remove the copper. To remove the zinc from
the solution it is then electrolytically treated and the zinc separates out in the
form of either metallic zinc or zinc sponge or dust, and the solution is afterwards
returned to the vats for use over again. After the ore has been leached a
sufficient number of times with the weak sulphuric acid solution to remove the zine
and copper, the said ore is subjected to a solution of strong caustic soda to remove
the lead and form sodium plumbate. The above operations are carried on in a
similar manner to that stated in my said prior specification.
After the treatment with the weak sulphuric acid and before treating the ore
with the caustic soda solution, calcium oxide is mixed with the ore to convert
the sodium silicate into calcium silicate and reconvert into caustic soda any
carbonate of soda that may have been formed.
The gases driven off from the ore during the process of roasting are passed
into water in which chalk or lime is present, the result being that carbon dioxide
(if chalk be used) and sulphurous acid pass away. The carbon dioxide and the
sulphurous acid are then conducted through a solution of sodium plumbate, pro-
duced as above mentioned, with the result that lead sulphite is precipitated. The
Jead sulphite can be used for paint. The carbon dioxide is allowed to pass through
another sodium plumbate solution whereby white lead is precipitated.
The greater part of the sodium plumbate solution is electrolysed and the
lead obtained either as metallic lead or lead sponge which after compression
Be moodil fugod

page_text: The sodium plumbate solution can also be run into an evaporating pan and
subjected to a gentle heat (about 70° C.) to form litharge.
After the ore remaining in the leaching vat has been washed with a weak solution
of caustic soda to remove the remainder of the sodium plumbate solution, it is
leached with a weak solution of cyanide of potassium as explained in my said prior
specification, to remove the silver, the solution being afterwards electrolyzed and
the silver deposited as pure silver.
Dated 3. 9541 1ove of Tuno 1808
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in the Treatment of Ores for Obtaining Metals and
other Products therefrom.
I, SHERARD OSBORN COWPER-COLES, of 39, Victoria Street, Westminster, in
the County of London, 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 relates to improvements in the treatment of ores for obtaining
metals, metallic compounds and other products therefrom and has reference more
particularly to the treatment of such ores as are referred to in the Specification
of my prior Patent No. 5943 of 1898.
In carrying out my invention the ore is first crushed screened and, if necessary,
mixed with zinc blende or other suitable ore, as stated in my aforesaid prior
specification, for facilitating the subsequent roasting.
"
The ore is then subjected to a preparatory treatment such as that set forth in
my prior specification, i.c. it is subjected to a dead roast" for a length of time
sufficient to drive off most of the sulphur it contains and is afterwards crushed and
screened to separate the slimes from the crushed ore; or the said ore is leached,
without screening, in a revolving leaching barrel. The sulphurous acid gas
produced in this operation is collected and used as hereinafter set forth.
The ore is then placed in suitable vats wherein it is first leached with a weak
solution of sulphuric acid to remove the zine and copper. The solution thus
produced, containing the zinc and copper, is then passed through a body or bed of
zine and carbon or zine and iron to remove the copper. To remove the zine from
the solution it is then electrolytically treated and the zine separates out in the
form of either metallic zine or zine sponge or dust, and the solution is afterwards
returned to the vats for use over again. After the ore has been leached a
sufficient number of times with the weak sulphuric acid solution to remove the zine
and copper, the said ore is subjected to a solution of strong caustic soda to remove
the lead and form sodium plumbate. The above operations are carried on in a
similar manner to that stated in my said prior specification.
After the treatment with the weak sulphuric acid and betere treating the ore
with the caustic soda solution, calcium oxide is mixed with the ore to convert
the sodium silicate into calcium silicate and reconvert into caustic soda any
carbonate of soda that may have been formed. The proportion in which the
calcium oxide is used should be about one seventh of the weight of the ore in the
vat. The strength of the caustic soda solution, should be about twenty ozs. of
caustic soda to each gallon of water.
The sulphurous acid gas driven off from the ore during the process of roasting

page_text: is passed into a closed vessel containing water in which chalk is present, the result
being that carbon dioxide and sulphurous acid pass away from such vessel. The
carbon dioxide and the sulphurous acid are then conducted through a solution of
sodium plumbate, obtained as above stated with the result that lead sulphite is
precipitated. The lead sulphite can be used for paint.
The carbon dioxide is allowed to pass through another sodium plumbate solution
whereby white lead is precipitated. The temperature of the solution should be
about 80° C. if the temperature is much lower than this 1 find that the white lead
is precipitated in a crystalline form.
The greater part of the sodium plumbate solution is electrolysed and the
lead obtained either as metallic lead or lead sponge which after compression
can be readily fused.
The sodium plumbate solution can also be run into an evaporating pan and
subjected to gentle heat (about 70° (.) to form litharge.
After the ore remaining in the leaching vat has been washed with a weak solution
of caustic soda to remove the remainder of the sodium plumbate solution, it is
leached with a weak solution of cyanide of potassium as explained in my said prior
specification, to remove the silver, the solution being afterwards electrolyzed
and the silver deposited as pure silver. The strength of the above stated weak
caustic soda solution should be about two or three ozs. of soda to each gallon of
water.
Having now particularly described and 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. In a process of the kind hereinbefore referred to, the method of obtaining
white lead direct from sulphide ore, consisting in employing the sulphurous acid,
driven off from the ore during the roasting operation, to produce carbon dioxide
substantially as described and then passing said carbon dioxide into a sodium
plumbate solution resulting from a subsequent step in the process.
2. In the method of obtaining white lead claimed above, the production of lead
sulphite as a bye product by passing sulphuroua acid and carbon dioxide through
the sodium plumbate solution substantially as described.
3. In a process of the kind hereinbefore referred to, the treatment of the sodium
plumbate solution in an evaporating pan for the production of litharge substantially
as described.
Dotal ibis 1941, low of tu 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.