Im- PROVEMENTS IN THE MANUFACTURE OF STEEL AND SOFT IRON FROM CAST IRON
Year: 1867

page_text: LETTERS PATENT to James Hargreaves, of Appleton-within-Widnes, in
the County of Lancaster, Analytical Chemist, for the Invention of "Im-
PROVEMENTS IN THE MANUFACTURE OF STEEL AND SOFT IRON FROM CAST
IRON."
Sealed the 7th January 1868, and dated the 12th July 1867.
PROVISIONAL SPECIFICATION left by the said James Hargreaves at
the Office of the. Commissioners of Patents, with his Petition, on the
12th July 1867.
I, JAMES HARGREAVES, of Appleton-within-Widnes, in the County of
Lancaster, Analytical Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND SOFT IRON.
FROM CAST IRON," to be as follows:―
My Invention relates, first, to the economizing of certain salts used in
making steel from crude, cast, or pig iron; these salts are such as yields
oxygen on the application of heat and carbonaceous matter, such as nitrates,
chlorates, manganates, and chromates, and which for brevity I call "oxydising
salts," the object being to complete the conversion with a smaller quantity of
the said salts than bitherto has been required.
In carrying this part of my Invention into operation I remove a portion of
the carbon and other impurities by (a.) subjecting the crude, cast, or pig iron
to the action of currents of air or other suitable gas through it, and (b.) fusing

page_text: or smelting the said iron, mixed or in contact with what I call "steel slag,"
that is, the slag obtained in the process of converting cast iron into steel and
soft iron when oxydising salts are used, or by steel slag and other substances;
I then complete the extraction of the impurities by oxydising salts in a con-
verting vessel, or otherwise.
And, second, to the improvement of the quality of iron and steel produced
in the ordinary puddling and refinery furnaces, and also in the process best
known as the "Bessemer process," by the use of steel slag obtained as above
mentioned, or a mixture of steel slag and other materials.
According to this part of my Invention,―
A. When making puddled iron or steel by the ordinary process I add steel
slag, or a mixture of steel slag, oxide of manganese, and lime to the materials
composing the hearth or bed of the furnace, and work the iron in the usual
manner.
B. When making "fine metal" by the use of the refinery I add steel slag,
or a mixture of steel slag, oxide of manganese, and lime to the charge of iron.
The metal thus treated possesses many of the properties of steel, and may be
used for many purposes for which cast steel is at present employed.
C. When making steel or soft iron by the "Besseiner process" I add steel
slag, or a mixture of steel slag with oxide of manganese and lime.
I prefer
to add them at the beginning of the process.
"SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Hargreaves in the Great Seal Patent Office on the
11th January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, JAMES
HARGREAVES, of Appleton-within-Widnes," in the County of Lancaster,
Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of July, in the year of our Lord' One
thousand eight hundred and sixty-seven, in the thirty-first year of Her.
reign, did, for Herself, Her heirs and successors, 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

page_text: 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 THE MANUFACTURE OF STEEL AND SOFT IRON FROM
CAST IRON," upon the condition (amongst others) that I, the said James
Hargreaves, ny 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 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 thereof, that is to say:-
My Invention relates, first, to economizing certain salts used in making
steel and soft iron from east iron; the said salts are such as yield oxygen on
the application of heat and carbonaceous matter, such, for instance, as the
nitrates, chlorates, manganates, and chromates, and which for brevity and the
purpose of this Specification I call "oxydising salts," the object being the con-
version of cast iron into steel or soft iron by the use of a much smaller
quantity of the said oxydising salts than has hitherto been required.
. In carrying this part of my Invention into effect I.remove a portion of the
carbon and other impurities as follows:-I refine the cast or crude iron by
passing currents of air through it by any of the means which are now well
known; or I pass currents of air over or in contact with it, such as is
practised in the, ordinary iron refinery; I then treat the partially decarbonised
and refined iron with the said oxydising salts by pouring it when in a fused
condition upon a mass of the said oxydising salts placed or fixed at the bottom
of a suitable vessel. The said oxydising salts are thereby decomposed, and
the products of their decomposition rise through the fused iron and complete
its conversion into steel or soft iron. I prefer to employ the oxydising salts
and mode of treatment.described in the Specification of an Invention for which
Letters Patent were granted to me and Thomas Robinson, of date the 22nd
day of May 1867, No.. 1520, and. in making steel I prefer to employ iron
partially purified by air. or otherwise, and treated with steel slag according to
the second part of my Invention, hereafter described.
The second part of my said. Invention relates to the improvement of the quality
of iron produced in puddling and refinery furnaces, and also in the well-known
Bessemer process, by the use of a material which for brevity and the purpose¨¨*

page_text: of this Specicfication I call "steel slag." The said steel slag is produced by
the reaction of crude or cast iron, or by partially decarbonised and refined
iron upon the said oxydising salts, and consists, when nitrate of soda is the
oxydising salt used, of carbonate, silicate, phosphate, sulphate, and sulphite of
soda, sulphide, chloride, cyanide, and ferrocyanide of sodium, together with
oxide of iron; when nitrate of potassa is the oxydising salt used the corre-
sponding salts of potassium form a portion of the constituents; and when
oxide of manganese is used, as is directed in the Specification, No. 1520 of
the year 1867, before mentioned, or when a manganate of soda or potassa is
one of the oxidising salts used, oxide of manganese is present in the said steel
slag. When a chromate of soda or potassa is used as one of the oxydising
salts, oxide of chromium is a constituent of the said steel slag. By the
employment of the said steel slag as herein-after directed the removal of a
great proportion of the silicium, sulphur, and phosphorous from the iron is
effected.
In carrying this part of my Invention into effect I proceed as follows:-
A. When making iron or steel from crude cast iron or from "fine
metal" by the puddling process, I add steel slag to the fettling of the furnace,
or I throw it into the furnace along with the charge of iron, either above or
mixed with other materials, and work the charge in the usual manner.
B. When making "fine metal" by the use of the finery I add steel slag to
the metal. The manner in which I prefer to prepare and use the said steel slag
for this purpose consists in grinding it into a plastic condition by moistening
with water, adding oxide of iron, oxide of manganese or lime, and causing the
mass to adhere to the bottom of the refinery; I then pile the iron to be
refined upon the top of the steel slag, and proceed in the usual manner.
Owing to the more thorough extraction of impurities from the iron thus
treated in the refinery the metal possesses many of the valuable characteristics
of steel, and may be used for many purposes for which steel is employed.
C. When making steel or malleable iron by the Bessemer process I add
steel slag, or a mixture of steel slag and oxide of manganese or lime in any
desirable proportion. I prefer to add the steel slag at the beginning of the
process.
I
D. When making steel or soft iron by the use of oxydising salts I prefer
to use the iron which has been refined by the use of currents of air in contact
with fused cast iron, together with steel slag, as berein-before described.
make use of the air and steel slag to remove a great portion of the impurities,
and then complete their removal and the conversion of the iron into steel or
soft iron by the use of oxydising salts.

page_text: Having now described the nature of my said Invention, and particularly
ascertained the same, I desire it to be understood I do not claim as of my
Invention to refine cast iron by the use of currents of air through or in
contact with the same when in a molten state, as this has long been known
and practised; neither do I confine myself under the first head of my Inven-
tion to the specified modes of removing a portion of the carbon and other
impurities by the use of currents of air or other means, such as boiling or
puddling can be used; what I claim is,--
First, the partial removal of the impurities of cast iron by the use of
currents of air, together with the subsequent use of the said partially purified
cast iron with oxydising salts to complete the conversion of the cast iron into
steel or soft iron, substantially as described.
Second, the use of steel slag to effect the removal of the impurities con-
tained in cast iron, substantially as described.
And, third, the use of iron treated by currents of air, with or without steel
slag, substantially as herein described, for the manufacture of steel and soft iron
by subsequent treatment with oxydising salts.
In witness whereof, I, the said James Hargreaves, have hereunto set
my hand and seal, this Ninth day of January, in the year of our
Lord One thousand eight hundred and sixty-eight.
In the presence of
JOHN T. KING,
Patent Agent,
Liverpool.
JAMES HARGREAVES. (L.S.)