Improvements in or relating to the Manufacture of Copperas and of Ferric Sulphate or Sesqui-persulphate of Iron, Commonly Called Nitrate of Iron.
Year: 1887

page_text: Date of Application, 20th July, 1887
Complete Left, 19th Apr., 1888
Complete Accepted, 15th June, 1888
18881
Improvements in or relating to the Manufacture of Copperas and
of Ferric Sulphate or Sesqui-persulphate of Iron, Commonly
Called Nitrate of Iron.
.
We SAMUEL HALLSWORTH and RICHARD BAILES of The Copperas Works, Armley,
Leeds in the County of York, Manufacturing Chemists, do hereby declare the nature
of this invention to be as follows:-
Hitherto it has been customary to make copperas (sulphate of iron) from liquor
obtained from the beds or heaps of iron pyrites and to neutralize the surplus or free
sulphuric acid contained therein with light scrap iron, and when neutralized and
evaporated to the proper density for yielding crystals, the liquor is then run into
coolers to crystallize. After the process of crystallization is completed the "mother
liquor" is run off into a receptacle for further use; and the copperas after being
removed from the cooler and allowed to drain is ready for use or sale. The said
"mother liquor" which contains a large percentage of sulphate of alumina together
with about an equal quantity of sulphate of iron, both in solution, is then returned to
the evaporating and neutralizing liquor tank or boiler. Fresh liquor from the pyrites
bed in about the same proportion or more if required to make up the quantity, is
then added to the "mother liquor" and the process of evaporation and neutralization
is proceeded with as before described. For the sake of economy the "mother
liquor" is in this way worked up from time to time, and by following this process
is more or less contaminated with sulphate of alumina and in some cases with alum.
Now this has been considered a serious defect for some commercial purposes, and the
object of the first part of this invention is to produce a copperas that is free or nearly
so from these defects, and at the same time to reduce the cost, and expedite the
process of manufacture by dispensing with the neutralizing operation.
In carrying our invention into practice we take, say five thousand gallons of the
liquor that is produced from beds or heaps of Iron pyrites at copperas works, and
elevate the same into an evaporating pan or liquor boiler of the same construction that
is usually employed in the manufacture of copperas. The liquor is then evaporated
to a density of from seventy to seventy-five degrees Twaddle, at a heat of from one

page_text: hundred and eighty to two hundred degree Fahrenheit. The liquor is then run into
coolers, and when cooled and allowed to remain a sufficient time, most of the sulphate
of iron will have crystallized and the "mother liquor" that remains will then contain
free sulphuric acid, a little sulphate of Iron, and some sulphate of alumina. The
"mother liquor" is then withdrawn from the crystallized copperas, and the copperas
is removed from the cooler and allowed to drain in the usual way when it is ready for
sale or use.
Second. Our invention further relates to the manufacture of ferric sulphate or
sesqui-persulphate of iron, commonly called nitrate of iron from the "mother liquor "
that remains after the crystallization of copperas as herein before described.
Hitherto it has been customary in the manufacture of ferric sulphate or sesqui-
persulphate of Iron to employ nitric acid as the oxidizing agent, but in our invention
we employ in place thereof per oxide of manganese preferably in fine powder.
In carrying this portion of our invention into practice we take say two thousand
gallons of the liquor that remains after the above named process, and elevate the same
into an evaporating pan or liquor boiler, and reduce the same by the addition of water
to a density of about forty degrees Twaddle. The reduced liquor is then kept heated
to nearly boiling point, and at the same time we gradually add the fine or dry powder
portion of what is known as "borings waste or refuse," which is a bye product
produced at Aniline Works-or such other suitable materials which contains a large
percentage of hydrated sesqui-oxide of Iron. The process of evaporation and adding
the above named material to the liquor under treatment is continued until the free
sulphuric acid contained therein is neutralized, and when it has attained a density of
about seventy degrees Twaddle at nearly boiling point the liquor is then run off
into a mixing cistern, and whilst still hot per-oxide of manganese in fine powder is
gradually added and well stirred by any suitable means until the remaining proto-
sulphate of Iron is changed to sesqui-persulphate, and the sulphate of alumina is
decomposed, and the alumina precipitated from the liquor.
The completion of the process may be known by the liquor becoming rather muddy
when this occurs no more per-oxide of manganese should be added. A few drops of
the liquor are then put into a shallow plate or dish and placed in a cool place for a
short time. If no crystals of copperas (sulphate of iron) appear the process is
complete ; but if the contrary the process must be continued and a little more
per-oxide of manganese added, and the same test again applied until the desired result
is obtained.
We would here remark that similar results may be obtained by the use of copperas
instead of the herein before mentioned liquor, but we do not prefer to employ it as it
increases the cost of production. When, however copperas is employed, it requires
to be dissolved in water to say about forty degrees Twaddle and then combined with
half the sulphuric acid as is already in combination with the iron in solution. The
remainder of the, operation being continued by adding per-oxide of manganese as
above described.
SAMUEL HALLSWORTH.
RICHARD BAILES.
By W. Fairburn Hart,
Agent for the Applicants.

page_text: We, SAMUEL HALLSWORTH, and RICHARD BAILES, of the Iron Liquor Works,
Armley, Leeds, in the County of York, Manufacturing Chemists, 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 :-
Hitherto in the manufacture of ferric sulphate or sesqui-sulphate of iron the
general custom in the trade has been to employ copperas and sulphuric acid with
nitric acid, as the oxidizing agent, but this invention consists in using first, the
liquor that runs from beds of Iron pyrites at Copperas Works, extracting a
portion of the copperas therefrom, partially neutralizing the remaining liquor with
the fine floury portion of "Iron Borings' waste or hydrated sesqui-oxide of iron,
whether natural or artificial, in fine dry powder, and oxidizing the liquor with peroxide
of manganese, all as hereafter described. Second. In the dissolving of copperas in
water, adding sulphuric acid and mixing it with hydrated sesqui-oxide of iron,
whether natural or artificial, and its subsequent oxidization with peroxide of man-
ganese.
In carrying our invention into practice we take say about five thousand gallons of
the liquor that runs from or is produced from a bed of Iron pyrites when the same
is placed on a heap as is generally done in the manufacture of copperas (sulphate of
iron).
The composition of this liquor has been found by analysis to contain at fifty
degres (cold) Twaddel's Hydrometer, Water about Twenty One per cent., Sulphate
of Iron about Thirty-two per cent., Sulphate of Alumina about Twenty-two per cent.,
Free Sulphuric Acid about Twenty-four per cent., and Alkaline Sulphates about
One per cent. This liquor is placed in what is called an evaporating tank or boiler
similar in construction to that usually employed for the evaporation of the same
liquor in the manufacture of copperas. The liquor is then heated (by similar means as is
employed in the evaporation of the same liquor in the manufacture of copperas) to
about One hundred and ninety degrees Fahrenheit until it is evaporated to a density
(hot) of say about from fifty five to sixty degrees Twaddel. This variation in the density
is required to be made according to the seasons of the year, thus, for the hottest
months of the year about sixty degrees will be found a suitable density, whilst for the
coldest months about fifty five degrees is more suitable. Further, we have found in
practice that the liquor contains rather too much copperas to be economically and
efficiently treated by this process, but when the density is varied as above described
the requisite amount of copperas may be extracted therefrom. The liquor is then run

page_text: into coolers, and when cooled, and allowed to remain say about eight or ten days
the necessary quantity of sulphate of iron (copperas) will have crystallized, and tho
liquor that remains will then contain free sulphuric acid, sulphate of Iron, and sulphate
of Alumina.
The remaining liquor is then withdrawn from the crystallized copperas, and the
copperas allowed to drain in the usual way when it is ready for sale or use.
We now take say about three thousand gallons of the liquor that remains after
the portion of the copperas has been extracted and elevate the same into an evaporating
pan or liquor boiler and reduce the same by the addition of water to a density of
about 45 degrees (cold) Twaddel. The reduced liquor is then heated and kept at
nearly boiling point, and at the same time we gradually add, in a fine dry powder,
about twelve and a half hundredweights of "Iron Borings' Waste or refuse" (which is a
bye product produced at Aniline Works), or an equal weight of hydrated sesqui-
oxide of iron, whether natural or artificial, for neutralizing about one half of the free
sulphuric acid present in the liquor. In practice we have found that the finer or
more floury portions of the above named "Iron Borings' Waste" are the most
suitable for this purpose, as the coarser portions contain a great per centage of metallic
iron.
The process of evaporating and adding one of the above named materials to the
liquor under treatment is continued until the requisite portion of the free sulphuric
acid contained in the liquor is neutralized, and when it has attained a density say
from about sixty five to seventy degrees (Twaddel's Hydrometer) at nearly boiling
point the liquor is then run into a mixing cistern (similar in construction to the
"coolers" employed in the crystallization of copperas) and whilst still hot per-oxide
of manganese in very fine dry powder is gradually added (in the proportion of say
about nine and a half hundredweights to two thousand gallons) and well stirred by
any suitable means until the photo-sulphate of iron is changed to ferric sulphate or
sesqui-sulphate, and the sulphate of alumina present in the liquor is decomposed or
nearly so and precipitated.
Although we have found the above named weights and quantities to give good
results, yet we would have it distinctly understood that they require to be varied in
accordance with the quality of the materials used, or of the liquor under treatment.
We would here remark that the above operation may be performed by using
the liquor without extracting a portion of the copperas contained therein,
and by dispensing with the use of "Iron Borings' Waste," or hydrated sesqui-oxide
of iron, but we prefer to extract such portion of copperas, and to use the partial
neutralizing Agent, as the extraction of a portion of the copperas, and the use of the
fine floury portions of "Iron Borings' waste" (which contains a large percentage
of hydrated sesqui-oxide of iron and some metallic iron) or hydrated sesqui-oxide
of iron in fine dry powder, cheapens the costs of inanufacture by requiring
much less per-oxide of manganese to be used for the oxidizing purpose,
and at the same time a better product or commercial article is obtained containing
more oxidized iron and less free sulphuric acid. However it is absolutely necessary
that a certain quantity of sulphuric acid-either in the free state in the liquor under
treatment, or in combination with the alumina as sulphate of alumina in the
liquor should be present in order to facilitate the process of combination and working
action.
Towards the completion of the operation of adding per-oxide of manganese, the
liquor will become muddy or "cracked" and the Alumina of the sulphate of alumina
more or less precipitated. When this occurs a small quantity of the liquor should
be put into a shallow plate or dish and placed in a cool place for a short time. If
little or no crystals of copperas (sulphate of iron) appear the process is completed, but
if there be much crystallization of copperas the process must be continued, and a
little more per-oxide of manganese added, and the same test applied until the desired
result is obtained.
When the operation of oxidizing the iron in the liquor is nearly completed it is
absolutely necessary that great care should be taken in the further addition of per-

page_text: oxide of manganese, so as to avoid taking up too much of the sulphuric acid,
and thereby neutralizing and oxidizing the solution to too great an extent. If
the process be carried too far the liquor will become thick and gummy which must
be avoided.
We would further remark that ferric sulphate or sesqui-sulphate of iron may be
made by the use of copperas instead of the hereinbefore mentioned liquor, but we do
not prefer to employ it as it increases the cost of production. When however copperas
(sulphate of iron) is employed it requires to be dissolved in water to say about a
density of forty degrees (cold) Twaddel's Hydrometer, and then combined with about
double the quantity of sulphuric acid as is already in combination with the iron in
solution. The remainder of the operation is continued by adding hydrated
sesqui oxide of iron, natural or artificial and per-oxide of manganese as herein
described until the proto-sulphate of iron is changed to ferric sulphate or sesqui-
sulphate. The same care and caution is required to be exercised as in the previous
process.
Ferric sulphate or sesqui-sulphate of iron made by the herein described processos
is applicable for dyeing purposes.
In conclusion we would distinctly have it understood that we are aware that the
herein before described liquor froin the beds of Iron pyrites has been used in the
manufacture of ferric sulphate or sesqui-sulphate of iron by partially neutralizing it
with the coarse portion of "Iron Borings' Waste" (a bye product produced at
Aniline Works), we therefore lay no claim to the exclusive use of such liquor, either
before or after its partial neutralization by the coarse portion of "Iron Borings'
Waste," or to the use of the said coarse portion for partially neutralizing the said liquor,
as it does not contain sufficient hydrated sesqui-oxide of iron for the object we have
in view, neither do we claim the use of per-oxide of manganese for oxidizing the
said liquor, except when used in combination with the herein described processes.
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 or method of manufacturing ferric sulphate or sesqui-sulphate of
iron from the liquor obtained from beds of Iron pyrites, which process consists in
first heating the said liquor in an evaporating tank and extracting a portion of the
copperas therefrom, then heating the remaining liquor and gradually adding the fine
dry floury portion of "Iron Borings' Waste" or hydrated sesqui-oxide of iron whether
in the form of "waste" or not, in fine dry powder for neutralizing a portion of the
free sulphuric acid, and afterwards running the heated liquor into a mixing tank and
gradually adding and well mixing therewith per-oxide of manganese in fine dry
powder until the proto sulphate of iron is sufficiently oxidized substantially as hercin
described.
2. In the manufacture of ferric sulphate or sesqui-sulphate of iron as herein
described, the extraction of a portion of the copperas from the liquor under treatment
on completion of the first process of evaporation, prior to the partial neutralizing
and subsequent oxidizing operations taking place as and for the purpose' herein
set forth.
3. In the manufacture of ferric sulphate or sesqui-sulphate of iron as herein
described, the partial neutralizing of a portion of the sulphuric acid present in the
liquor (after a portion of the copperas has been extracted) by means of the fine dry
floury portion of "Iron Borings" Waste" or hydrated sesqui-oxide of iron, whether in
the form of
" waste or not, in fine dry powder, and the subsequent oxidizing of the
liquor by means of per-oxide of manganese, substantially as herein set forth.
"
4. The process or method of manufacturing ferric sulphate or sesqui-sulphate of
iron from copperas (sulphate of iron) which process consists in dissolving the copperas
in water adding sulphuric acid thereto, partially neutralizing the heated dilute
solution with the fine dry floury portion of "Iron Borings' Waste" -or hydrated
sesqui-oxide of iron whether in the form of " waste or not in fine dry powder, and
"

page_text: subsequently oxidizing the solution with per-oxide of manganese substantially as
herein set forth.
5. In the manufacture of ferric sulphate or sesqui-sulphate of iron from copperas,
the use of the fine dry floury portion of "Iron Borings' Waste" or hydrated sesqui-
oxide of iron whether in the form of "waste" or not in fine dry powder as the partial
neutralizing agent, and per-oxide of manganese as the oxidizing agent, substantially
as and for the purposes herein set forth.