IMPROVEMENTS IN THE MANUFACTURE OF IRON SPONGE, IRON AND STEEL and in what manner the same is to be performed, to be particularly described and ascertained in the
Year: 1885

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co Patent Agents,
Southampton Buildings, in the county of Middlesex, do hereby declare the nature
of my invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON SPONGE,
IRON AND STEEL and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement
"
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This invention relates to the manufacture of iron sponge, wrought or steely iron
and steel directly from the ore
The said invention comprises a process which consists in intermingling, with the
ore (in its natural state, and without added flux), graphitic carbon, and subjecting
the mixture, in an ordinary reverberating or other suitable furnace, to a sustained
dull red heat and subsequently, in some cases, to a higher and sustained
temperature.
Heretofore, in the manufacture of iron sponge and iron direct from the ore, the
most commonly employed deoxidizing agent has been charcoal. The most common
method of procedure has been to mix, with prepared or separated iron ore,
pulverized charcoal, then to place the charge of ore and charcoal in an hermetically
sealed chamber, which is heated externally, and not to allow the charge to come in
contact with the flame until it has been deoxidized The main objections to the
method commonly practised may be briefly stated as follows, viz-First, the
length of time required to deoxidize the ore Secondly, the cost of preparing the ore
and separating it from its gangue, and mixing pulverized charcoal with the ore,
thirdly, the separation of the charcoal from the ore when in the deoxidizing
chambor, by reason of the difference in specific gravity, causes imperfect deoxi-
dation of the charge, and consequent loss of ore, fourthly, the reoxidation of the
ore when passing from the deoxidizing chamber to the furnace
Again, when charcoal, plumbago, or the like is used in the ordinary condition,
that is to say, as a powdered mass admixed with the prepared ore, it cannot be
uniformly distributed or kept properly distributed, it is drifted or carried out by
the blast, producing irreguluity in the results obtained, and, when used in
conjunction with a fusible slag covering for the ore, it rises into the fusible slag
and the greater portion is lost without obtaining any useful results.
To these objections must be added the material one of the high price of
plumbago, and the large amount of charcoal, and other forms of soft carbons

page_text: required in former processes, which add materially to the expense of producing
wrought iron or steel from the ore by the methods now commonly practised
In carrying out my invention, I make use of a reverberatory or other suitable
furnace, in which the charge may be subjected to the direct action of the flame, and
a moderate and controllable temperature can be maintained
The ore, as taken from the mines, is intermingled with lumps of graphitic
carbon, the said graphitic carbon constituting such a per centage of the charge as
shall approximate the quantity required to deoxidize the ore and to carburize it
to the extent desired (which percentage can be readily ascertained by analysis),
say about from thirty (30) to fifty (50) per cent The layer of intermingled ore
and graphitic lumps composing the charge should preferably be from four (4) to
eight (8) inches in depth
The graphitic carbon referred to is an impure graphitic agglomeration con-
taining considerable quantities of earthy matters, iron and other substances, and
of a character such as is found in the United States at Cranston, Rhode Island,
and elsewhere, and known in the trade as graphitic carbon
The furnace having been charged with the mixture of ore and graphitic carbon,
above specified, is raised to, and maintained at, a dull red heat, say from fifteen
hundred (1500) degrees, to two thousand (2000) degrees Fahrenheit (the tem-
perature being varied according to the more or less refractory nature of the ores),
at which temperature deoxidation will take place without danger of fusion This
temperature is sustained for from five (5) to seven (7) hours, by which time
deoxidation will have been completed and an iron sponge, containing the free
metal enclosed in its earthy matrix, will have been obtained The heat is then
raised sufficiently to cause an agglomeration of the mass, or the agglutination of
the contained metal, (say to a temperature of from two thousand (2000) degrees to
two thousand five hundred (2500) degrees Fahrenheit or more), but not sufficiently
high to fuse the mass When this temperature has been maintained for from
one (1) to two (2) hours, the mass can be balled and removed to the blooming
apparatus for reduction to wrought iron, but, if a steely iron is desired, this higher
heating must be prolonged some six (6) or seven (7) hours, which time can be
readily determined by the operator, and necessarily varies according to the more or
less retractory character of the ore, as above specified The steelitied mass is then
balled and removed to the blooming apparatus, as above specified During this
higher beating or second stage of the process, care should be taken to avoid
excessive temperature, as fusion of the metal would ensure the formation of slaggy
sponge of deteriorated character
Some of the advantages of my process are that the lumps of graphitic carbon
interposed between the lumps of ore lighten up the mass and permit the circulation
of the heat-bearing gases through it, while the carbon is immediately presented to
the ore to be deoxidized, and in such form that it can be kept uniformly distributed
throughout the charge and is not drifted about, and not swept off by the blasts of
gas, or the action of the heated mass, or otherwise
My invention, moreover, comprises the use of a graphitic paste in place of the
lumps of graphitic carbon herein before described
I form a stiff paste or mortar from pulverized graphite, and an adhesive car-
bonaceous binder, such as coal-tar, wood-tar, molasses, or like material, preferably
using as much of the graphite and as little of the binder as is consistent with the
formation of a paste or mass which can be readily applied as an adhesive covering
to the ore
1t desired, a certain per centage of pulverized fire-brick, or its
equivalent, may be added to the mixture By the term equivalent, as applied to
the fire-brick addition, I mean an ingredient which will not vitrify and destroy
the friable character of the covering under the influence of heat.
The ore in the form of lumps, as it comes from the mine, or broken into smaller
lumps if desired, is then covered or coated with the graphitic paste or plastic mass,
this operation can be conveniently effected by means of a rotating cylinder, a tank
and rakes, or other suitable devices,

page_text: The one so prepared is then subjected, in a suitable furnace, to a dull red
sustained heat, varying from fifteen hundred degrees (1500°) to two thousand
degrees (2000°) Fahrenheit, (according to the nature of the ore operated on),
for from five (5) to seven (7) hours, more or less, until deoxidation has taken
place, when an iron sponge will be obtained The temperature of the furnace 18
then raised sufficiently high to cause the agglutination of the metal, and the mass
can be balled, drawn and subjected to the blooming a paratus, if it is desired to
obtain wrought iron If, however, a steely iron is desired, the temperature of the
furnace is raised to a temperature of say from two thousand degrees (2000°) to two
thousand five hundred degrees (2500°) Fahrenheit, or sufficiently high to induce
the free metal contained in the sponge to absorb carbon, and this temperature is
maintained for from three (3) to six (6) hours longer, according to the degree of
carburization required, after which the temperature is brought to the stage which
will cause the metal to agglomerate, and the mass is balled and treated as herein-
before specified
By preference, my improved processes are conducted on a friable graphitic sole
or hearth, and with a covering of graphitic lumps, but I wish it understood that
I do not herein claim such hearths and coverings, nor do I limit myself to the use
thereof in carrying my present invention into practice
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to me
by my foreign Correspondent, I declare that what I claim 18
First The process herein described for producing iron sponge direct from the ore,
which process consists in intermingling the ore, in its natural state, with lumps of
graphitic carbon, and subjecting the mixture, in a reverberatory or other suitable
furnace, to a dull red sustained heat until deoxidation is accomplished, substantially
as, and for the purposes, set forth
Second The process herein described which consists in intermingling the ore,
in its natural state, with lumps of graphitic carbon, subjecting the mixture, in a
reverberatory or other suitable furnace, to a dull red sustained heat until deoxidation
is accomplished, and then to a higher sustained heat for a suitable period of time
to agglomerate the mass so that the sponge can be balled and removed to the
blooming apparatus for the production of wrought iron, or for a suitable longer
period for the production of steelified iron, all substantially as, and for the purposes,
set forth
Third The process herein described for the deoxidation, or deoxidation and
carburization, of ore, in the manufacture of iron sponge, wrought iron and steely
iron, which process consists in coating the lumps of ore with a graphitic paste,
and then subjecting them to a dull red sustained heat in a suitable furnace,
substantially as, and for the purposes, specified
Fourth The process herein described which consists in coating the lumps of oie
with a graphitic paste and then subjecting them, in a reverberatory or other
suitable furnace, to a dull red sustained heat until deoxidation is accomplished, and
then to a higher sustained heat for a suitable period of time to agglomerate the
mass so that the sponge can be balled and removed to the blooming apparatus for
the production of wrought iron, or for a suitable longer period for the production
of steelified iron, all substantially as, and for the purposes set forth.
HASELTINE, LAKE & Co,
For the Applicant.