IMPROVEMENTS IN TREATING SOLUTIONS OBTAINED FROM BURNT CUPREOUS PYRITES." IN TREATING SOLUTIONS OBTAINED FROM BURS."
Year: 1871

page_text: LETTERS PATENT to Frederic Claudet, of Nos. 6 and 7, Coleman
Street, in the City of London, for the Invention of "IMPROVEMENTS
IN TREATING SOLUTIONS OBTAINED FROM BURNT CUPREOUS PYRITES."
IN TREATING SOLUTIONS OBTAINED FROM BURNT CUPREOUS PYRITES."
PROVISIONAL SPECIFICATION left by the said Frederic Claudet at the
Office of the Commissioners of Patents, with his Petition, on the
23rd September 1871.
I, FREDERIC CLAUDET, of Nos. 6 and 7, Coleman Street, in the City
of London, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN TREATING SOLUTIONS OBTAINED FROM BURNT CUPREOUS
PYRITES," to be as follows:-
This Invention has for its object improvements in treating solutions
obtained from burnt cupreous pyrites.
In the treatment of Portuguese, Spanish, and other burnt cupreous
pyrites by the wet method after recalcination with salt, the waste
liquors that remain after precipitation of the copper contain as is well
A

page_text: known a large proportion of sodium and iron salts, and some other
metallic salts, among which are cobaltic chloride.
In the Specification of a former Patent granted to me and dated
the 3rd day of November 1866, No. 2858, I proposed employing these
waste solutions for the purpose of making sulphate of sodium and
peroxide of iron. By the process described in this Specification the
oxide of iron is obtained in a crystalline form, and I find that in this
form its mercantile value is less than it is when in the form of rouge.
This crystalline form I find to have resulted from the fusion of the salt,
which also has the further disadvantage of causing the iron to become
peroxidized partly at the expense of the sulphuric acid, and so the
yield of sulphate of sodium was reduced.
"
According to my present Invention I proceed as follows:-The
solutions are either concentrated in the ordinary "salting down pans'
of alkali works, or in iron or other pans constructed and heated on the
same principle as those employed in Cheshire for brines, and the salts
raked out as deposited; or they are evaporated in a reverberatory
furnace and the salts fished therefrom by means of perforated ladles
or shovels. The " yellow salts" thus obtained, consisting of a mixture
of all the alkaline and metallic salts originally in solution, are now
charged into a calcining furnace and subjected to a low heat, taking
care to avoid fusion and to renew the surfaces by repeated and
prolonged stirring. The iron in the salts thus becomes peroxidized,
and the chloride of sodium is more or less completely transformed
into sulphate of sodium with the evolution of hydrochloric acid and
chlorine. These gases are made to pass through a tower of the
description usually employed for the condensation of such gases, and
being thereby condensed serve for the lixiviation of the calcined ores
and for other purposes.
:
The calcined salts after being withdrawn from the furnace in which
the oxidation of the iron has been effected are now treated with boiling
water, by which the soluble salts are dissolved. The iron oxide left
undissolved on the addition of water to the calcined salts is now
separated by filtration or otherwise, and may be dried and employed
as a pigment or otherwise. The oxide of iron thus prepared is
not crystalline, but is in the state of finely divided rouge, and can
be employed as a pigment for the polishing of glass and for other
purposes.

page_text: The liquors obtained, by treating the calcined yellow salts with
water, after separation by filtration or subsidence from the undissolved
rouge, are run into a suitable tank, where the oxide of cobalt together
with traces of nickle; zinc, iron, and manganese are precipitated either
by milk of lime or caustic alkali or by an alkaline carbonate of
sulphide.
As for the precipitate [thus obtained if not 'sufficiently rich in cobalt
it is concentrated by subsequent operations, either by melting with
arsenical pyrites into a speiss, or the cobalt is rendered soluble by
roasting with or without the addition of sulphuric acid and separated
by the wet way.
"
The alkaline salts separated by filtration or otherwise mainly consist
of a mixture of sulphate of sodium and chloride of sodium, and are,
converted into "salt cake" by the addition either of sulphuric
"nitre cake,
acid or
an impure bi-sulphate of sodium, and sub-
sequent ignition.
"
:
In some cases I prefer to add directly to the "yellow salts" obtained
by evaporating the waste liquors, sulphuric acid, or "nitre cake," either
before or during the process of calcination; and when this course is
adopted the solution separated by filtration or otherwise from the oxide
of iron or rouge are treated with milk of lime, as previously described,
and evaporated to dryness and ignited, and thus affords “salt cake" of
good qualtity without any further addition of sulphuric acid either in
the liquid form or as a bi-sulphate.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederic Claudet in the Great Seal Patent
Office on the 23rd March 1872.
i
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
CLAUDET, of Nos. 6 and 7, Coleman Street, in the City of London,
>send greeting.
"
i
"
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of September, in
the year of our Lord One thousand eight hundred and seventy-one, in
i
•

page_text: •
the thirty-fifth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Frederic Claudet, Her
special license that I, the said Frederic Claudet, my executors, adminis-
trators, and assigns, or such others as I, the said Frederic Claudet,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN TREATING SOLUTIONS OBTAINED FROM BURNT CUPREOUS.
PYRITES," upon the condition (amongst others) that I, the said Frederic
Claudet, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
.
NOW KNOW YE, that I, the said Frederic Claudet, do hereby declare
the nature of the said Invention, and in what manner the same is to.
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
This Invention has for its object improvements in treating solutions
obtained from burnt cupreous pyrites.
In the treatment of Portuguese, Spanish, and other burnt cupreous
pyrites by the wet method after reclamation with salt, the waste liquors
that remain after precipitation of the copper, contain as is well known
a large proportion of sodium, and iron salts, and some other metallic
salts, among which are cobaltic chloride.
In the Specification of a former Patent granted to me, and dated the
3rd day of November 1866, No. 2858, I proposed employing these waste
solutions for the purpose of making sulphate of sodium, and peroxide
of iron. By the process described in this Specification the oxide of iron
is obtained in a crystalline form, and I find that in this form its
mercantile value is less than it is when in the form of rouge. This
crystalline form I find to have resulted from the fusion of the salt,
which also has the further disadvantage of causing the iron to become

page_text: peroxidized partly at the expense of the sulphuric acid, and so the
yield of sulphate of sodium was reduced.
"
According to my present Invention I proceed as follows:-The
solutions are either concentrated in the ordinary "salting down pans
of alkali works or in iron or other pans constructed and heated on the
same principle as those employed in Cheshire for brines, and the salts
raked out as deposited; or they are evaporated in a reverberatory
furnace, and the salts' fished therefrom by means of perforated ladles or
shovels. The "yellow salts" thus obtained, consisting of a mixture of
all the alkaline and metallic salts originally in solution, are now
charged into a calcining furnace and subjected to a low heat, taking
care to avoid fusion and to renew the surfaces by repeated and
prolonged stirring. Samples are taken from time to time for the
purpose of being tested, and when but a small quantity of iron remains
in a soluble state, usually under two per cent., the charge is drawn.
The iron in the salts thus becomes peroxidized, and the chloride, of
sodium is more or less completely transformed into sulphate of sodium
with the evolution of hydrochloric acid and chlorine. These gases are
made to pass through a tower of the description usually employed
for the condensation of such gases, and being thereby condensed serve
for the lixiviation of the calcined ores and for other purposes...
着
The calcined salts after being withdrawn from the furnace in which
the oxidation of the iron has been effected are now treated with water,
by which the soluble salts are dissolved. The iron oxide left
undissolved on the addition of water to the calcined salts is now
separated by filtration or otherwise, and may be dried and employed
as a pigment or otherwise. The oxide of iron thus prepared is not
crystalline, but is in the state of finely divided rouge, and can be
employed as a pigment for the polishing of glass and for other
purposes. I operate in the following manner:-The calcined salts are
put into a vat with an agitator, and are then mixed with hot water in
sufficient quantity to dissolve the salts, and the liquor allowed to flow
through a number of settling tanks, where it deposits the rouge in
qualities more or less fine, which are then collected thoroughly washed
with water.
The liquors obtained by treating the calcined yellow salts with water,
after separation by filtration or subsidence from the undissolved rouge,
are run into a suitable tank, where the oxide of cobalt together

page_text: with nickel, zinc, iron, and manganese, are precipitated either by
milk of lime or caustic alkali, or by an alkaline carbonate or sulphide.
I use by preference milk of lime which I add until the liquor is slightly
alkaline.
From the precipitate thus obtained cobalt may be extracted, for
which purpose
if it is not sufficiently rich in cobalt it is con-
centrated by subsequent operations either by melting with arsenical
pyrites into a speiss, or the cobalt is rendered soluble by roasting with
or without the addition of sulphuric acid and separated by the wet
way.
The solution of alkaline salts separated by filtration or otherwise
mainly consists of a mixture of sulphate of sodium and chloride of
sodium, and are evaporated to dryness and converted into "salt cake"
by the addition either of sulphuric acid or "nitre cake," an impure
bi-sulphate of sodium produced in the manufacture of sulphuric acid
and subsequent ignition. I ascertain by analysis the composition of
the alkaline salts, and add sulphuric acid or nitre cake in such
proportion as to convert the whole of the remaining chloride of
sodium into sulphate. I then heat the mixture. in a reverberatory
furnace, using heat sufficient to drive off the hydrochloric acid and
water and form a marketable salt cake.
·
In some cases I prefer to add directly to the "yellow salts" obtained
by evaporating the waste liquors, sulphuric acid, or
"nitre cake,"
either before or during the process of calcination; and when this
course is adopted the solution separated by filtration or otherwise from
the oxide of iron or rouge is treated with milk of lime, as previously
described, and evaporated to dryness and ignited, and thus affords
"salt cake" of good quality without any further addition of sulphuric
acid either in the liquid form or as a bi-sulphate (nitre cake).
In other cases it may be desirable to supply the amount of sulphuric
acid necessary to convert the common salt present into sulphate of
soda by adding sulphuric acid directly to the waste liquors previous to
evaporation, or to dissolve therein with or without the addition of water
a sufficient quantity of nitre cake or copperas (proto-sulphate of iron)
or both of them to effect the decomposition during subsequent
evaporation and calcination of the common salt present. The yellow
salts thus obtained are then calcined at a low temperature and treated

page_text: precisely as before described. By the use of copperas as above described
the yield of rouge is raised.
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I
claim,―
1st. The treatment of salts obtained from the waste liquors from
burnt cupreous pyrites, recalcined with common salt by a process of
roasting without fusion, and separation of the soluble from the
insoluble part of the product, substantially as described.
2nd. The treatment of waste liquors or salts obtained from the waste
liquors from burnt cupreous pyrites recalcined with common salt by
the addition of sulphuric acid or a compound thereof, as nitre cake or
sulphate of iron; and by heating and roasting the mixture and
afterwards separating the soluble from the insoluble part of the product,
substantially as described.
3rd. The method substantially as described of obtaining valuable
commercial products from solution obtained from burnt cupreous
pyrites.
In witness whereof, I, the said Frederic Claudet,. have hereunto
set my hand and seal, this Twentieth day of March, in the
year of our Lord One thousand eight hundred and seventy-two.
FRED. CLAUDET. (L.S.)