IMPROVE MENTS IN EXTRACTING PHOSPHORIC ACID AND PHOSPHORUS FROM THE TAP CINDER OF PUDDLING FURNACES AND IRON REFINERIES, AND FROM OTHER COMPOUNDS OF IRON AND PHOSPHORUS
Year: 1869

page_text: LETTERS PATENT to James Hargreaves, of 108, Fylde Road, Preston,
in the County of Lancaster, Chemist, for the Invention of "IMPROVE
MENTS IN EXTRACTING PHOSPHORIC ACID AND PHOSPHORUS FROM THE TAP
CINDER OF PUDDLING FURNACES AND IRON REFINERIES, AND FROM OTHER
COMPOUNDS OF IRON AND PHOSPHORUS."
Sealed the 1st March 1870, and dated 'the 4th September 1869.
PROVISIONAL SPECIFICATION left by the said James Hargreaves at
the Office of the Commissioners of Patents, with his Petition, on
the 4th September 1869.
I, JAMES HARGREAVES, of 108, Fylde Road, Preston, in the County of
Lancaster, Chemist, do hereby declare the nature of the said Invention
for IMPROVEMENTS IN EXTRACTING PHOSPHORIC ACID AND PHOSPHORUS FROM THE
TAP CINDER OF PUDDLING FURNACES AND IRON REFINERIES, AND FROM OTHER
COMPOUNDS OF IRON AND PHOSPHORUS," to be as follows:-
1st. I dissolve the said compounds of iron and phosphorus or any of
them in hydrochloric acid and then separate the soluble portion from the
insoluble portion by washing or lixiviation.

page_text: 2nd. I convert the protochloride of iron which is contained in the
aforesaid soluble portion into perchloride of iron, and to affect the said
conversion of protochloride of iron into perchloride of iron I prefer to pass
the said solution of protochloride of iron down through a tower packed
with coke.or other suitable material. The tower which I prefer to use
is similar to those used for the condensation of hydrochloric acid in the
manufacture of sulphate of soda from common salt. Whilst the said
solution of chloride of iron is flowing down the said tower I cause a
current of the products of combustion from a furnace together with free
oxygen and also hydrochloric acid and steam arising from the concen-
tration, drying, and decomposition of chloride of iron previously passed
down the said tower to rise upwards therethrough; after passing down
the said tower the said solution which is partially concentrated is run
into the bed of a furnace, where the said chloride of iron is concentrated
to dryness and afterwards heated to redness to expel chlorine and hydro-
chloric acid, leaving oxide of iron, as set forth hereafter in the 4th
section. The said chlorine and hydrochloric acid, together with the
steam and products of combustion from the said furnace, pass, upwards
through the said tower and react upon another and succeeding portion
of solution of chloride of iron which passes down through the said tower.
The hydrochloric acid is afterwards condensed and used over again in
the manner set forth in the above first section.
3rd. I add chloride of sodium or chloride of magnesium to the said
chloride of iron in such proportion that the said chloride of sodium or
chloride of magnesium shall be equal to two or three times the weight
of phosphoric acid present in the said solution of chloride of iron. I do
not in all cases add chloride of sodium or chloride of magnesium to the
said solution of chloride of iron, neither do I confine myself to the pro-
portions herein given. When I use solutions of soda or potash to dissolve
out phosphoric acid from the said oxide of iron, as set forth hereafter
in the 5th section, I prefer to omit the addition of chloride of magnesium
and use a smaller proportion of chloride of sodium, or omit the said
chloride of sodium altogether.
4th. I heat the said chloride of iron to redness or so hot as to expel
the hydrochloric acid and chlorine and obtain oxide of iron along with
phosphoric acid. I do not however confine myself to this mode of
obtaining the oxide of iron from chloride of iron. I also obtain the said
oxide of iron from the said chloride of iron by precipitation with alkalies

page_text: or alkaline earths; but I prefer to obtain the said oxide of iron by
decomposition with heat.
5th. I lixiviate or wash the said oxide of iron with water or with
solutions of soda or potash in sufficient quantity to take all the phos-
phoric acid into solution; but when I do not want the phosphoric acid
in the form of an alkaline phosphate I lixiviate or wash the said oxide of
iron with hydrochloric acid. When I wish to obtain phosphorus I treat
the solution obtained by lixiviation, as set forth in this 5th section, by
any suitable means to reduce the-phosphoric acid to phosphorus.
6th. When treating iron ore or iron cinder, especially those containing
lime or magnesia & phosphoric acid, I roast the said ore or cinder or any
of them and then treat the said ore or cinder in the same manner as is
shewn when treating the oxide of iron in the 5th section. If the oxide
of iron in the said iron ore or iron cinder is insoluble in acid, or is soluble
in acid with difficulty, I omit the roasting of the said iron ore or iron
cinder.
Note. I prefer to use hydrochloric acid to dissolve the said compounds
of iron and phosphorus, as set forth in the first section, and I also prefer
to use hydrochloric acid when I separate the phosphoric acid from the
oxide of iron, as set forth in the 5th section, or when I separate the
phosphoric acid from iron ore or iron cinder, as set forth in the sixth
section; but I do not confine myself to the use of hydrochloric acid,
inasmuch as other acids, such as sulphuric and nitric acids, can be used,
but not to so great an advantage; I also prefer to use chloride of sodium
and chloride of magnesium, or either of them, as set forth in the 3rd
section; but I do not confine myself to the use of chloride of sodium or
chloride of magnesium, inasmuch as chlorides of potassium, calcium,
aluminium, or barium may be used, as also may soda, magnesia, potash,
lime, alumina, and baryta, or other salts be used, but not with so great
advantage. I sometimes omit to convert the protochloride of iron into
perchloride, as set forth in the above second section, inasmuch as the
protochloride may be used as the source of oxide of iron, but not with so
great advantage.

page_text: SPECIFICATION in pursuance of the conditions, of. the Letters Patent,
filed by the said James Hargreaves in the Great Seal Patent Office
on the 4th March 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HARGREAVES, of 108, Fylde Road, Preston, in the County of Lancaster,
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of September, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said James Hargreaves, Her
special license that I, the said James Hargreaves, my executors,
administrators, and assigns, or such others as I, the said James
Hargreaves, 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 EXTRACTING PHOSPHORIC ACID AND Рнов.
PHORUS FROM THE TAP CINDER OF PUDDLING FURNACES AND IRON REFINERIES
AND FROM OTHER COMPOUNDS OF IRON AND PHOSPHORUS," upon the condition
(amongst others) that I, the said James Hargreaves, my executors
or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascer-
tain 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 James Hargreaves, do hereby
declare, the nature of my said 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;-
First. I dissolve the said compounds of iron and phosphorous, such as
iron ores, iron cinders, vivianite, phosphate of iron, and other natural or
artificial compounds of iron, with phosphorous, or any of them, in hydro-

page_text: chloric acid, and then separate the soluble portion from the insoluable.
portion by washing or lixiviation. When using iron cinder of puddling
furnaces or iron refineries the said cinder may be either in the state in
which it is drawn from the furnace or refinery or it may be roasted so as
to convert the iron wholly or partially into peroxide. When the said
cinder is not roasted previously to adding the acid the solution is more
easily effected, and the insoluble matter, which consists principally of
silica, is in a very bulky state, and the iron is principally in the state
of protochloride. When the said cinder is roasted previous to adding
the acid the solution takes place more slowly, and the said insoluble
matter is rendered more dense and more easily washed or lixiviated, and
the iron is in the state of perchloride.
Second. I convert the protochloride of iron which is contained in the
aforesaid soluble portion into perchloride of iron, and to effect the said
conversion of protochloride of iron into perchloride of iron I prefer to
pass the said solution of protochloride of iron down through a tower
packed with coke, fire-bricks, or other suitable material. The tower
which I prefer to use is similar to those used for the condensation of
hydrochloric acid in the manufacture of sulphate of soda from common
salt. Whilst the said solution of chloride of iron is flowing down the
said tower I cause a current of the products of combustion from a furnace,.
together with free oxygen, and also the hydraulic acid, chlorine, and
water vapour arising from the concentration, drying, and decomposition
by heat of the said chloride of iron which has previously passed through
the said tower, to rise upward therethrough. After passing down the
said tower the said solution, which has now been heated and partially
concentrated, is run into the bed of a reverberatory furnace, where the
said chloride of iron is concentrated or boiled to dryness and afterwards
heated to redness to expel chlorine and hydrochloric acid, leaving oxide
of iron, as set forth hereafter in the fourth section. The said chlorine"
and hydrochloric acid, together with the steam and products of com-
bustion from the said furnace, pass upwards through the said tower and
react upon another and succeeding portion of solution of chloride of iron,
and also serve to heat and partially concentrate the said solution which
passes down through the said tower. The hydrochloric acid is afterwards
condensed in condensing' towers in the same manner as hydrochloric acid
is condensed in the manufacture of sulphate of soda from common salt
or by other suitable means, and is used over again to dissolve the com-

page_text: pounds of iron and phosphorous aforesaid, or any of them, as set forth in
the above first section.
Third. I add chloride of sodium or chloride of magnesium to the said
chloride of iron in such proportions that the said chloride of sodium or
chloride of magnesium shall be equal to two or three times the weight of
phosphoric acid present in the said solution of chloride of iron. I prefer
that the said chloride of sodium, or chloride of potassium, or either of
them should be in excess of the quantity necessary to saturate the
phosphoric acid present in the said solution of chloride of iron. I do
not in all cases add chloride of sodium or chloride of magnesium to the
said solution of chloride of iron, neither do I confine myself to the
proportions herein given. When I use solutions of soda or potash to
dissolve out phosphoric acid from the said oxide of iron, as set forth
hereafter in the fifth section, I prefer to omit the addition of chloride of
magnesium and use a smaller proportion of chloride of sodium, or omit
the said chloride of sodium altogether. I prefer to add the said chloride
of sodium or chloride of magnesium to the said solution of chloride of
iron before the said solution of chloride of iron is concentrated.
Fourth. I heat the said chloride of iron to redness, or so hot as to
expel the hydrochloric acid and chlorine, and obtain the iron in the state
of oxide along with phosphoric acid either in combination with the
oxide of iron or with soda or magnesia or other base. I do not however
confine myself to this mode of obtaining oxide of iron from chloride of
iron. I also obtain the said oxide of iron from the said chloride of iron
by precipitation with alkalies or alkaline earths; but I prefer to obtain
the said oxide of iron from chloride of iron by decomposition with
heat.
Fifth. When I wish to obtain phosphates of soda or potash I lixiviate
or wash the said oxide of iron with a solution of soda or potash in
sufficient quantity to take all the phosphoric acid into solution, or I add
chloride of sodium to the said solution of chloride of iron, as set forth in
the above third section, and wash or lixiviate with water the oxide of
iron produced from the said chloride of iron; but when I obtain the
phosphate of soda by the use of chloride of sodium I prefer to add a
little hydrochloric acid to remove in the form of soluable phosphate any
phosphoric acid which may be combined with alumina or other earthy
base which is generally present in the said cinder or other compound of
iron and phosphorous aforesaid; or I add an additional quantity of soda

page_text: to take the phosphoric acid into solution in the form of an alkaline phos-
phate. In some cases, such as where it is not desirable or necessary to
separate the silica or other substances insoluble in hydrochloric acid,
I omit to make use of the processes set forth in the aforesaid 1st, 2nd,
3rd, and 4th sections, and wash or lixiviate the said compounds of iron
and phosphorous or any of them with solutions of soda in such quantity
as to take the phosphoric acid into solution; but when I do not wish to
obtain the phosphoric acid in the form of an alkaline phosphate I add
chloride of magnesium to the said chloride of iron,- as set forth in the
above third section, and wash or lixiviate the oxide of iron obtained
from the said chloride of iron with a solution of hydrochloric acid.
(When I wish to produce phosphorous I treat the solutions obtained, as
set forth in this 5th section by any suitable means to reduce the phos-
phoric acid to phosphorous.)
Sixth. When treating iron ores or iron cinders, especially those con-
taining lime or magnesia, together with phosphoric acid, I roast the said
ore, or cinder, or any of them so as to render the oxide of iron insoluble
in acids. I then break the said ore or cinder into suitable sized pieces
and lixiviate the said ore or cinder with hydrochloric acid in the
manner set forth in the above fifth section, and separate the phosphoric
acid from the said ores or cinder in the form of a soluble phosphate of
lime or magnesia. If the oxide of iron in the said ore is insoluble in
acid, or is soluble slowly and with difficulty, I omit the roasting of the
said iron ore or iron cinder. In some cases where lime or magnesia is
or are absent or only present in too small quantity I add lime or
magnesia to the said ore or cinders in such quantity as to saturate the
phosphoric acid present in the said ore or cinder and then fuse the whole
together, and afterwards if necessary roast the said ore or cinder so as to
render the oxide of iron present insoluble previous to treating with
hydrochloric acid, as set forth in the fifth section. In some cases I fuse
iron cinders or other oxide of iron or iron ore containing phosphoric acid
with lime or magnesia and then roast to render the oxide of iron
insoluble, and then dissolve out the phosphate of lime or phosphate of
magnesia in the manner above set forth in this 6th section.
Note. To avoid lengthened description and frequent repitition I have
only specified hydrochloric acid as the acid used to dissolve the com-
pounds of iron and phosphorous aforesaid or any of them, as set forth in
the 1st, 5th, & 6th sections, but I wish it to be understood that I do not

page_text: confine myself to the use of hydrochloric acid, inasmuch other acids,
such as sulphuric and nitric acid, may be used, but not to so great
advantage. For the same reason I have only specified chloride of sodium
and chloride of magnesia as the salts which I use to add to the chloride
of iron, as set forth in the above third section, but I do not confine
myself to the use of chloride of sodium or chloride of magnesium,
inasmuch as chlorides of potassium, calcium, aluminium, or barium, as
also may soda, magnesia, potash, lime, alumina, and baryta, or their
salts, may be used, but not with so great advantage. I sometimes omit
to convert the protochloride of iron into perchloride, as set forth in the
above 2nd section, inasmuch as the protochloride of iron may be also
used as the source of oxide of iron.
Having now particularly described and ascertained my said Invention,
I would have it understood that I claim the improvements substantially
as herein set forth.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this First day of March, in the year of our
Lord One thousand eight hundred and seventy.
used as the source
Having now particularly described and ascertained my said Invention,
I would have it understood that I claim the improvements substantially
as herein set forth.
In witness whereof, I, the said James Hargreaves, have hereunto
set my hand and seal, this First day of March, in the year of our
Lord One thousand eight hundred and seventy.
In the presence of
ROB. Moss,
JAMES HARGREAVES. (L.S.)
Clerk to J. T. King,
Liverpool.