IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1869

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF IRON."-A communication
from abroad by John Burt, of Detroit, in the State of Michigan,
United States of America.
Sealed the 30th July 1869, and dated the 3rd June 1869.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 3rd June 1869.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON," a communication
from abroad by John Burt, of Detroit, in the State of Michigan, United
States of America, to be as follows:-

page_text: 2ndly. To the production from pig or cast iron of what may be
termed a "crude bloom" to be employed in the manufacture of iron
and steel.
In carrying out the first portion of this Invention the object is to
effect a thorough and homogeneous mixture with the iron of the in-
gredients by which the same is carbonized or reduced, and to facilitate
and shorten the puddling process, and for this purpose it is proposed,
firstly, to overlay the hearth of the puddling furnace with a suitable
charge of pulverized oxide or of carbon according as the metal is to be
reduced or more highly carbonized, over which is run molten metal from
the blast or smelting furnace, or pig remelted in a cupola or other
furnace; secondly, in combination with the above process it is proposed
to introduce highly divided oxide or carbon into the mass through a tube
so that the metal shall have combined with it the requisite proportion
of the carbonizing or reducing agent to bring it to nature as speedily as
possible. As soon as the metal is decarbonized and brought to naturo
it is balled and passed through the squeezers and rolls in the usual
manner.
To produce a highly carbonized iron, such as required in the manu-
facture of Bessemer steel, the same process is employed, carbon in a
pulverized state being used in lieu of an oxide. To add to the charge
the quantity of carbon needed to complete the decarbonization I
introduce through a hollow tube inserted into the mass petroleum or
other like hydrocarbon by bydrostatic pressure, the end of the tube
being perforated so that the hydrocarbon may be discharged into the
metal in fine jets. Other carbonaceous matters can be employed if
preferred.
The object of the second portion of this Invention which relates to the
production of what I term "crude bloom" is to produce a bloom which
shall be better fitted for commercial purposes, and in which the meta
shall be more homogeneous than has heretofore been practicable. To
this end I combine in an open or closed crucible or mould, which may
or may not be subjected to heat during the operation, melted pig o
cast iron with oxides of iron alone or in combination with carbonizing
agents, the said oxide or oxides and carbonizing agents being placed o
the bottom of the crucible and the molten iron run in on the top so tha
the former ingredients shall by reason of difference in gravity ris

page_text: through and permeate the metal, thus bringing it approximately to a
homogeneous condition.
When using a closed crucible or mould I take a closed crucible or
mould having a moveable top or made in sections so that it may be
taken apart to allow the removal of the formed bloom. Into this
crucible I put the charge of pulverized oxide required for the molten
metal and then through a tap or hole in the top of the mould I pour
in the molten metal either taken directly from the blast or consisting
of remelted pig or cast iron until the mould is full. The hole can then
be closed so as to prevent escape of metal while permitting the dis-
engaged gases to pass out. The moment the molten metal is poured in
the oxides begin to rise and mix intimately with the metal. I find when
the oxide is passed only once through the metal bath that while the
upper part of the mass is brought to nearly the required condition there
is a stratum immediately above the oxide which although purified to a
certain extent is not fully acted on, and to remedy this defect as well
as to further improve the quality of the upper portion, and in fact to
render the whole mass as nearly as possible homogeneous and of equal
quality, I mount the crucible on trunnions, so that at the proper moment
it may be turned over, thus bringing the lower stratum of metal on the
top and the oxide again underneath the whole mass. The oxide is thus
caused to again pass up through the reversed bath of metal, and the
operation is carried on in this manner until the metal is brought to
proper condition, the mass being of course maintained in a melted state.
The bloom is then allowed to cool and is afterwards turned out of the
crucible or mould. In this process the metal being contained in a closed
crucible is not subjected to the action of the atmosphere and there is
therefore no oxidation. The metal moreover should be maintained in a
highly heated or liquid condition until the close of the operation, this.
being essential to the perfect mingling of the oxide with it, and it should
not be chilled until the bloom is brought to the condition required. To
this end I propose to heat the crucibles directly during the progress of
the operation either by placing them in a reverberatory furnace or by
other suitable means; or the heat may be maintained by heating the
oxides prior to placing them in the crucible to any degree below the
fusing point.

page_text: other agents, such as carbonizing agents, are employed with the oxides,
this being determined by the nature and quantity of the crude metal,
or the quality of "crude bloom" to be produced, I mix them in the
proper proportions before placing them in the crucible, for instance,
charcoal or petroleum may be mixed with the crushed or pulverized
oxides, and again I contemplate moistening the oxide with water which
when decomposed into its constituent elements by the intense heat of
the molten metal will aid considerably in bringing the mass to the proper
condition. The use of hydrocarbons in this connection is advantageous,
but I can also use nitrate of soda, or other agent, for intensifying the
heat.
In case an open crucible be employed the process is conducted in a
similar manner save that the crucible cannot be reversed, and cara
should be exercised in running in the molten metal so as not to,
materially disturb the ingredients already placed at the bottom of the
crucible.
Fine wrought or cast-iron scrap borings or turnings may be mixed
with the oxides or oxides and carbons and the molten metal run in over.
the whole mass, the operation being conducted as before specified. This
mixture works into the mass with great facility during the subsequent
reheating and rolling.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 3rd December 1869,
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, JOHN.
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Mid-
dlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of June, in the year
of our, Lord One thousand eight hundred and sixty-nine, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Henry Johnson, Her
special license, that I, the said John Henry, Johnson, my executors,
administrators, and assigns, or. such, others as I, the said John Henry

page_text: Johnson, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and all times there-
after 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 THE MANUFACTURE OF IRON," a communication from
abroad by John Burt, of Detroit, in the State of Michigan, United
States of America, upon the condition (amongst others) that I, the said
John Henry Johnson, my executors or administrators, by an instrument
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 imme-
diately after the date of the said Letters Patent..
NOW KNOW YE, that I, the said John Henry Johnson, 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, that is to say:-
The said Invention relates,-
Firstly. To the production of homogeneous iron direct from the
melted ore in a blast or smelting furnace or from the pig run off from
the same.
Secondly. To the production from pig or cast iron of what may be
termed a "crude bloom" to be employed in the manufacture of iron
and steel.
In carrying out the first portion of this Invention the object is to
effect a thorough and homogeneous mixture with the iron of the in-
gredients by which the same is carbonized or reduced and so facilitate
and shorten the puddling process, and to this end the said Invention
consists, firstly, in overlaying the hearth of the puddling furnace with a
suitable charge of pulverized oxide or of carbon according as the metal
is to be reduced or more highly carbonized, over which is run molten
metal from the blast or smelting furnace or pig remelted in a cupola or
other furnace; secondly, in introducing in combination with the above
process highly divided oxide or carbon into the mass through a tube so
that the metal shall have combined with it the requisite proportion of the

page_text: carbonizing or reducing agent to bring it to nature as speedily as
possible.
In practice I place the puddling furnace by the side of and in con-
venient proximity to the blast furnace. If the nature of the ore in the
blast furnace or the quality of the iron to be produced require the
metal to be carbonized I cover the hearth of the puddling furnace with
an oxide of iron previously crushed and pulverized varying in quantity
with the nature of the metal and the degree of decarbonization desired,
I then tap off the molten metal from the blast to the puddling furnace,
directing its course so that it shall gradually cover the pulverized oxide.
As soon as this is accomplished the oxide, owing to the difference in
gravity between it and the metal, will rise through and become fused
with the latter, and the two will be thoroughly and homogeneously
mixed, this result being hastened by stirring the rabble or by other
suitable means usually employed. It is impracticable to determine with
entire accuracy the exact quantity of oxide which shall be put in the
furnace in the first place, and the charge may happen to be more or less
than is needed, I therefore add either carbon or oxide, whichever may
be required to make the metal homogeneous. This can be accomplished
in any suitable way, but I prefer to introduce the ingredient through a
hollow tube inserted in the molten mass so that it may be quickly
As soon as the
disseminated through and incorporated with the metal.
metal is decarbonized and brought to nature it is "balled" and passed
through the squeezers and rolls in the usual manner.
To produce a highly carbonized iron, such as is required in the manu-
facture of Bessemer steel, the same process is employed, carbon in a
pulverized state being used in lieu of an oxide; the carbon rises and
intermingles with the molten mass in the same manner as the oxide
and produces also a thoroughly homogeneous metal. To add to the
charge the quantity of carbon requisite to complete the decarbonization
I introduce through a hollow tube inserted into the mass petroleum or
other like hydrocarbon by hydrostatic pressure, the end of the tube being
perforated so that the hydrocarbon may be discharged into the metal
in fine jets. Other carbonaceous matters can be employed if preferred.
The reverbatory furnace is to be heated before the metal is run in,
but owing to the mode of placing the carbonizing or decarbonizing agent
with respect to the iron the puddling is rapidly effected and a homo-

page_text: geneous metal is obtained with comparatively little expenditure of fuel
and without the labor and expence attending the process ordinarily
employed, and I am thus enabled to take the raw metal in whatever
state it may come from the smelting furnace and at once impart to it
during the puddling process the quality desired, whether it be intended
for malleable iron or steel.
The object of the second portion of this Invention which relates to the
production of what I term "crude bloom" is to produce a bloom which
shall be better fitted for commercial purposes, and in which the metal
shall be more homogeneous than has heretofore been practicable. To
this end I combine in an open or closed crucible or mould which may or
may not be subjected to heat during the operation melted pig or cast
iron with oxide of iron alone or in combination with carbonizing agents,
the said "oxide" or oxides and carbonizing agents being placed on the
bottom of the crucible and the molten iron run in on the top, so that
the former ingredients shall by reason of difference in gravity rise
through and permeate the metal, thus bringing it approximately to a
homogeneous condition.
To fully illustrate the nature of the Invention the following descrip-
tion of the process employed with a closed crucible or mould is given :-
I take a closed crucible or mould having a moveable top or made in
sections so that it may be taken apart to allow the removal of the
formed bloom. Into this crucible I put the charge of pulverized oxide
required for the molten metal, and then through a tap or hole in the top
of the mould I pour in the molten metal, either taken directly from the
blast or consisting of remelted pig or cast iron until the mould is full.
The hole can then be closed so as to prevent escape of metal while
permitting the disengaged gases to pass out. The moment the molten
metal is poured in the oxides begin to rise and mix intimately with the
metal. I find when the oxide is passed only once through the metal
bath that while the upper part of the mass is brought to nearly the
required condition there is a stratum immediately above the oxide which
although purified to a certain extent is not fully acted on, and to remedy
this defect as well as to further improve the quality of the upper portion,
and in fact to render the whole mass as nearly as possible homogeneous
and of equal quality I mount the crucible on trunnions so that at the
proper moment it may be turned over, thus bringing the lower stratum
of metal on the top and the oxide again underneath the whole mass.

page_text: The oxide is thus caused to again pass up through the reversed bath of
metal, and the operation is carried on in this manner until the metal is
brought to proper condition, the mass being of course maintained in a
melted state. The bloom is then allowed to cool and is afterwards
turned out of the crucible or mould. In this process it will be noticed
that, 1, the metal is in a closed crucible and is not subjected to the
action of the atmosphere, and there is therefore no oxidation; 2, the
metal should be maintained in a highly heated or liquid condition until
the close of the operation, this being essential to the perfect mingling
of the oxide with it, and it should not be chilled until the bloom is
brought to the condition required. To this end I propose to heat the
crucibles directly during the progress of the operation either by placing
them in a reverberatory furnace or by other suitable means; or the heat
may be maintained by heating the oxides prior to placing them in the
crucible to any degree below the fusing point.
In some cases I tamp the oxides before running in the metal, thus
preventing their flying or rising with too great rapidity, and in case
other agents, such as carbonizing agents, are employed with the oxides,
this being determined by the nature and quantity of the crude metal or
the quality of "crude bloom" to be produced, I mix them in the proper
proportions before placing them in the crucible, for instance, charcoal or
petroleum may be mixed with the crushed or pulverized oxides; and
again I contemplate moistening the oxide with water which when
decomposed into its constituent elements by the intense heat of the
molten metal will aid considerably in bringing the mass to the proper
condition. The use of hydrocarbon in this connection is advantageous,
but I can also use nitrate of soda or other agent for intensifying the
heat.
In case an open crucible be employed the process is conducted in
a similar manner, save that the crucible cannot be reversed, and care
should be exercised in running in the molten metal so as not to

page_text: their crucibles or moulds to the rolling mills on railway trucks, and
there delivered with great dispatch and saving of time.
Fine wrought or cast-iron scrap borings or turnings may be mixed
with the oxides, or oxides and carbons, and the molten metal run in over
the whole mass, the operation being conducted as before specified. This
mixture works into the mass with great facility during the subsequent
reheating and rolling.
•
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. The method herein-before described of carbonizing or decar-
bonizing the iron or raw metal by placing upon the hearth of the
puddling or other reverberatory furnace the charge of pulverized oxide
or carbon over which the metal from the blast furnace or the previously
melted pig is run, substantially in the manner specified.
Second. In combination with the above specified process I claim the
introduction into the mass of the carbon or oxide required to complete
the operation, substantially in the manner herein-before described.
Third. The manufacture of "crude bloom" by mixing the molten
cast metal and oxidizing or oxydizing and carbonizing agents employed
in an open or closed crucible or mould, substantially as specified.
Fourth. Maintaining the heat in the crucible during the formation of
the "crude bloom" by heating the same externally, or by mixing
suitable heating agents with the mass within the crucible, substantially
as set forth.
Fifth. The employment in the manufacture of the "crude bloom"
of a closed reversible crucible or mould, substantially in the manner
described.
Sixth. The mixture within the crucible or mould of the molten cast
metal with a mixture of oxides and carbons, as and for the purposes
specified.

page_text: Seventh. The addition to the molten pig or cast metal and the oxides
or oxides and carbons in the crucible of wrought-iron scrap borings or
turnings, substantially as specified.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Third day of
December One thousand eight hundred and sixty-nine.