AN IMPROVEMENT IN THE MANU- FACTURE OF IRON
Year: 1855

page_text: LETTERS PATENT to Charles Sanderson, of Sheffield, in the County of
York, Merchant, for the Invention of "AN IMPROVEMENT IN THE MANU-
FACTURE OF IRON."
Sealed the 11th April 1856, and dated the 24th November 1855.
PROVISIONAL SPECIFICATION left by the said Charles Sanderson at the
Office of the Commissioners of Patents, with his Petition, on the 24th
November 1855.
I, CHARLES SANDERSON, of Sheffield, in the County of York, Merchant, do
hereby declare the nature of the said Invention for "AN IMPROVEMENT IN THE
MANUFACTURE OF IRON," to be as follows:-
This Invention relates to a mode of refining iron or ridding it of various
impurities. To this end, I propose to employ sulphate or other suitable
metallic salt, produced by the combination of sulphuric or hydrochloric acid
with metallic bases.
The iron to be operated upon may be obtained in a fluid state, either by
melting common pig iron in an ordinary reverberatory furnace, or it may be
run out direct from a blast furnace. The operation of refining must be con-
ducted in a reverberatory furnace, and when the chemical re-agent is added,
it should be mixed with the iron by stirring or working up the fluid mass.
The quantity of the sulphate of iron which I bave found necessary for
refining one ton of pig iron is from 20 to 40 pounds weight, according to the
quality of the iron. These proportions, however, will vary, not only from the
varying quality of the iron operated upon, but also according to the nature of
the re-agent employed.

page_text: The sulphate of iron should be allowed to act upon the fluid iron for about
one hour, and the workman will know that the operation is completed when
he finds the iron thicken or become creamy; the furnace may then be tapped
and the refined metal run off' into moulds.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Sanderson in the Great Seal Patent Office on the
22nd May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
SANDERSON, of Sheffield, in the County of York, Merchant, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of November, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Sanderson, Her special license that I; the said Charles
Sanderson, my executors, administrators, and assigns, or such others as I,
the said Charles Sanderson, 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 "AN IMPROVEMENT IN THE MANUFACTURE OF IRON," upon the
condition (amongst others) that I, the said Charles Sanderson, by an instru-
ment in writing under my hand and seal, 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 Charles Sanderson, 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): :-
This Invention of "An Improvement in the Manufacture of Iron" relates
to a mode of refining iron, or ridding it of various impurities by the admixturo
of certain chemical ingredients with the raw iron when in a fluid state. Το
this end, I propose to employ, some suitable metallic or non-metallic salt
capable of disengaging oxygen when decomposed.

page_text: From the experiments hitherto made I have found that sulphate of iron is
the most convenient and economical substance to be used for the purposes of
my Invention in the following description, therefore I will consider this as the
substance to be employed. As I believe it to be the acids or that part of the
substance which contains oxygen that act principally on the impurities which
I desiro to remove from the iron, I would have it understood that I do not
intend to confine myself rigidly to the use of the above or other metallic salts,
as other combinations of materials; such as earthy or alkaline salts containing
oxygen, may be employed. in proper proportions in conjunction with other
materials, such as manganese and clay, and added to the fluid iron with great
advantage. When these materials are added to the fluid iron, carbonic acid
gas or carbonic oxide will be produced by the decomposition of these substances,
and by the union of the oxygen contained therein with the carbon contained
in the fluid iron. The carbon is eliminated from the iron, and the gas so
produced either passes off in the form of vapor, or acts upon the silicates or
earthy metallic compounds which may be contained in the crude iron, and by
so doing will separate the metallic particles from the earthy matters,' and pre-
cipitate the former, the earthy parts being allowed to flow away in the shapo
of slag; the iron may then be run off in a much purer state than heretofore.
The iron to be operated upon may be obtained in a fluid state, either by
melting common pig iron in an ordinary reverberatory furnace, or it may bo
run out direct from a blast furnace. The operation of refining should be con-
ducted in a reverberatory furnace, and having skimmed off the slag which rises
to the surface of the metal, the chemical re-agent may be added, and, if
required, it may be mixed with the iron by stirring the fluid mass.
The quantity of the sulphate of iron or other re-agent which I have found
necessary for refining one ton of pig iron is from twenty to forty pounds weight,
according to the quality of the iron and the nature of the re-agent employed.
For instance, for mottled forge iron I add twenty pounds of sulphate of iron to
the melted iron; for grey iron, I add thirty pounds; and for No. 1 foundry pig
iron, I employ forty or more pounds to the ton of metal. These proportions,
however, will necessarily vary, not. only from the varying quality of the iron
operated upon, but also according to the nature of the re-agents employed.
The sulphate of iron or other chemical re-agent should be allowed to act
upon the fluid iron for about one hour, and the workman will know that the
operation is completed when he finds the iron thicken or become creamy.
The furnace may then be tapped, and the refined metal run out into any
convenient receptacle, so that the metal so refined should by its gravity
separate itself from the flux and impurities, which may be removed in any

page_text: convenient manner, and an iron of very superior quality will then be produced
and may be run off into moulds....
I would observe that I am aware that heretofore crude iron has been
decarbonized and refined to some extent by the employment of a blast of air;
this, however, is an expensive, inconvenient, and unsatisfactory process, and I
therefore propose to dispenso with it altogether, and employ instead thereof
the chemical fluxes and re-agents above referred to, which will be found more
economical and much more effectual in their operation.
Having now described my Invention of "An Improvement in the Manu-
facture of Iron," and explained the manner of carrying the same into effect,
I claim, as the Invention secured to me by Letters Patent as aforesaid, the
decarbonization of raw or crude pig iron, melted on the bed of a reverberatory
furnace, or obtained in a molten or fluid state direct from the blast furnace,
as before described, by adding to such melted metal any chemical re-agent
which by its decomposition will evolve elements capable of combining with
the carbon, and reacting upon silicon, aluminum, sulphur, phosphorus, arsenic,
or any other deleterious substance or impurity contained in the iron, and will
by the generation of carbonic oxide or carbonic acid gases (which will not
combine with the iron, and will necessarily fly off or enter into combination
with the scoria and earthy matters), cause them to separate from the iron,
the impurities contained in the metal being thus got rid of either by vola-
tilization, or by reason of the difference in the specific gravity of the various
substances.
I also claim the use of sulphate of iron or its chemical equivalent for the
required purpose, as herein-before described, by adding it to cast iron when it
is being melted for the purpose of producing castings of beams, shafts, and
other articles requiring a particularly good iron, and thereby purifying such
metal by discharging the earthy and other deleterious matter contained therein,
and adding greatly to the strength of such castings.
In witness whereof, I, the said Charles Sanderson, have hereunto set my
hand and seal, the Twentieth day of May, in the year of our Lord
One thousand eight hundred and fifty-six.
CHARLES SANDERSON. (L.S.)
Witness,
JOHN FIELD, Sheffield.