IMPROVEMENTS IN APPARATUS AND MEANS FOR REDUCING IRON ORES BY A DIRECT PROCESS INTO WROUGHT IRON OR STEEL
Year: 1877

page_text: LETTERS PATENT to Philip Syng Justice, of No. 27, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer, for the Invention of
"IMPROVEMENTS IN APPARATUS AND MEANS FOR REDUCING IRON ORES BY A
DIRECT PROCESS INTO WROUGHT IRON OR STEEL." A communication from
abroad by Charles Meredith Dupuy, of Philadelphia, United States of America.
Sealed the 10th July 1877, and dated the 28th April 1877.
PROVISIONAL SPECIFICATION left by the said Philip Syng Justice at the
Office of the Commissioners of Patents on the 28th April 1877.
PHILIP SYNG JUSTICE, of No. 27, Southampton Buildings, Chancery Lane, in the
County of Middlesex, Engineer. "IMPROVEMENTS IN APPARATUS AND MEANS
FOR REDUCING IRON ORES BY A DIRECT PROCESS INTO WROUGHT IRON OR STEEL."
A communication from abroad by Charles Meredith Dupuy, of Philadelphia, United
States of America.
This Invention consists of an improved apparatus or canister in which, with a
new and peculiar process and in a properly arranged furnace, the ores of iron may
be reduced to a pasty or spongy condition, and then hammered or rolled into bars
or sheets of very superior quality without the usual loss to the iron which follows
when a reducing flame acts upon the particles of iron ore.
By this Invention the ores of iron may also be in one process changed into a
condition of steel, or semi-steel, if desired, by forcing the carbon carefully mixed
with ore which is to be treated into a proper combination with the iron, as it
becomes reduced to a pasty mass.
The saving of the iron in reducing the ore to the ball or pasty mass from which
the bar is rolled, or the bloom is shingled, is effected by using pipe canisters
made of thin sheet iron, and large enough to hold from one hundred to one
and a half hundredweight of pulverised iron ore and other suitable materials,
which are mixed with pulverised charcoal or carbonaceous matter, together with
such ingredients or fluxes as shall neutralise or purify the ore or metal from its
objectionable constituents. These ingredients or fluxes to be used being evenly
distributed with the pulverised ore and carbon, and being added of a kind and in a
[Price S27

page_text: proportion suited to the peculiar condition of the ore to be treated, form small
particles of glaze or varnish, which together with the walls of the canister prevents
the action of the oxydizing and destructive flame of the furnace upon the particles
of the heated iron, whilst the quantity of the "glaze" thus formed is not sufficient
to run freely from the mass until it comes into the squeezer or is shingled. By
this process much of the phosphorus and sulphur contained in iron ores is eliminated,
as the comparatively low temperature with which the materials in the canisters
are treated permits the union of the phosphorus with the ingredients placed
in the canister to neutralize it in a much more practical manner than heretofore
adopted.
That the heat may perfectly act on all the ore and ingredients contained in the
canisters, they the canisters are made of two hollow cylinders or pipes of thin sheet
iron, one smaller than the other, but of equal length, the smaller one having its lower
edge or rim turned outward, and the larger having its lower edge turned inward, so
that when the smaller pipe is placed centrally within the larger, an annulus or quoit-
shaped disc of sheet iron may be dropped over the smaller pipe, and resting on the
turned-up rims of both, forms a chamber or annular space between the two pipes.
Into this the pulverised ore, carbon and fluxes are packed, and on the top of them
another annulus or quoit-shaped sheet-iron disc is placed, which settles down with
the mass of pulverised ore and other material as it is reduced to its pasty condition.
The outer sides and top disc of this canister being pierced with small boles
allows free passage for the expanding gases, and the inner pipe or cylinder permits
the free access of heat to all parts of the annular chamber between the walls of the
pipes.
25
The canisters properly charged and placed in the reducing furnace, after 4 to
7 hours steady heat, gradually sink down into a cheese shape, when two or more
may be piled upon each other by means of a peel" or paddle, and they quickly
unite, form a ball or mass large enough to be taken to the squeezer, or shingled into
a bloom, or rolled with the canister into a muck bar, as required, when the slag
freely flows from the mass and a bar or bloom of iron is produced of extraordinary
purity and quality.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Philip Syng Justice in the Great Seal Patent Office on the
27th October 1877.
PHILIP SYNG JUSTICE, of No. 27, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Engineer. "IMPROVEMENTS IN APPARATUS AND
MEANS FOR REDUCING IRON ORES BY A DIRECT PROCESS INTO WROUGHT IRON
OR STEEL." A communication from abroad by Charles Meredith Dupuy, of
Philadelphia, United States of America.
This Invention consists of an improved apparatus or canister in which with a
new and improved method or process, and in a properly arranged furnace, the ores
of iron may be expeditiously and economically reduced by one process to a pasty
mass of uncommon purity, which may be then squeezed, hammered, or rolled so as
to relieve it of the slag, cinder, or flux, and be at the same heat rolled or hammered
into wrought malleable bars of iron or steel, according to the ingredients which may
be mixed together in the canisters with the iron ore. By this process the usual
loss to the particles of iron contained in the ore when it is exposed to a reducing
heat, and the oxidizing effects of the flame is reduced to a minimum, whilst the
purification of the metal from its objectionable compounds is more readily effected
than by any process now in use. This process is applied most profitably when the
richer ores of iron are used, but it may also be advantageously employed with the
leaner ores whether mixed with the richer or used alone when iron of great purity
is required.

page_text: In employing my process I prefer to remove as much of the earthy matter and
mechanically mixed impurities which are usually found in most iron ores as I con-
veniently can by the usual processes either wet or dry. The reduction of the ores
which I work may be effected in any conveniently arranged furnace, but, by
preference, I select what is known as the regenerative and the reverbratory gas
furnaces now in use, in which a more perfect control of the heat can be commanded
than in the old direct firing furnaces.
My method of working my process is substantially as follows:-After selecting
the iron ore which I propose to treat, and the accurate analysis of which I am careful
to secure, I grind or pulverize it after the earthy or mechanically mixed impurities
are removed. This ground ore is then mixed with various ingredients, also properly
pulverized, notably charcoal, washed cokes, purified coal dust, or other carbonaceous
matters, chlorides, by preference the chlorides of sodium to volatilize the objection-
able amount of sulphur, and alkalies to combine with ores containing undue pro-
portions of silica, all in proper proportions, to enable me to break the affinity of the
iron for the silica the most perfectly, and at the same time to form a non-flowing
slag, glaze, or cinder which shall remain where it forms, and thus surround and
protect the particles of ore or iron from the oxidizing and wasting effect of the
flame without preventing the action of the heat itself at the same time in effecting
the reduction of the ore into metal. In thus preserving ore from waste, my
canisters also play an important part, for although made of very thin sheet iron or
steel, and crudely formed, this sheet iron or steel forms a species of skin, which the
heat penetrates but does not melt, so that the walls of the canisters, whilst gradually
sinking with the contained material within them, still prevent the direct wasting
action of the flame from reaching the ore, whilst the whole mass, by the continuously
applied heat sinks into a cheese or cake with the iron skin or walls of the canister,
and in a great measure preserve within them all the contents until they are finally
reduced to a pasty mass of metal and cinder. I further aid in the prevention
of waste in the iron ore by mixing with the proper quantity of carbonaceous
matter and other materials, as above stated, as well as soda, lime, aluminous
clay, manganese oxide, and sometimes a small portion of spiegel eisen or ferro-
manganese, which are all placed in the sheet-iron canisters with the pulverized
iron ore after the entire contents have been moistened with water to the con-
sistency of a thick mortar, and the contents allowed to dry in the canisters
before they are placed in the furnace. The walls of the canisters and the top
annulus cover are all pierced with small holes so as to permit the free escape out-
wards of the gases formed by the combustion of the carbonaceous matter and the
other ingredients contained in the canisters.
In the practical working of my process so as to produce a pure metallic result at
the minimum of cost and in the shortest time, I have found the following system to
be most efficacious:-
:-
To make the canisters as shewn in the accompanying Drawings, Nos. 1, 2, and 3,
I usually employ ordinary quality of sheet iron or steel of about No. 24 to 28 wire
gauge, according to contents. Of these I take two sheets of same width, but
different lengths. With one sheet I form a rough cylindrical pipe by joining the
two ends with a few rivets, which may vary from 15 to 24 inches in diameter,
whilst with the shortest sheet I form a similar pipe of the same length, but having
a diameter of only 6 to 9 inches, as may be required. The larger pipe has its bottom
edge turned up inwardly at right angles to its walls, whilst the smaller pipe has a
similar flange turned up outwardly. By placing the smaller pipe centrally within
the larger one and dropping an annulus or quoit-shaped disc of proper diameter over
the smaller pipe, it will rest on these bottom flanges and form an annular space
above it into which the pulverized ore and other materials are to be charged. A
similar annulus or disc is placed on the top of the material when it is charged into
the furnace, and this top disc gradually sinks down with the material beneath it as
it is reduced.
The walls of the canister, both inside and outside, as well as the covering annulus,

page_text: are pierced with small holes for allowing the escape of gases outward, which are
formed as the contained materials in the canisters are being reduced by the heat.
The sizes of canisters which I have found most convenient to work are made to
hold about 125 to 150 lbs. of the contained materials. These canisters, weighing from
8 to 10 lbs. each, are forged or rolled into the mass of metal itself, and becomes
incorporated with it, adding its own weight to that of the ball, cake, or cheese, with
but very slight loss. I do not confine myself to the peculiar cylindrical form of
canister just described, as they may be made in various shapes, but I have found by
varied practice that whatever the form may be, it is necessary to have the walls of
the canisters containing the ore and other materials combined with it, so near
together that the heat at the temperature applied shall thoroughly permeate to all
parts of the ore and mixtures, all of which will be readily reduced at about one and
the same time, else much of the metal will be left in a raw condition. For these
reasons I have found that the pipe or annualar canisters present greater practical
advantages than any other, and are also cheaper.
In proportioning the materials to be mixed with the pulverized iron ore when
ready to change into the canisters it is necessary to know the analysis of the ore
itself, so as to determine what materials can be best employed and what the pro-
portions shall be.
In using the rich ores of Lake Champlain which are magnetic, or the specular ores
of the Republic mine of Lake Superior, I have advantageously used the following
materials and proportions:-For one ton of the magnetic ore I employ a compound
of about one-fourth to one-third of a. ton of charcoal or its equivalent, 32 lbs. of soda,
10 to 12 lbs. lime, 10 to 15 lbs. of chloride of sodium, 4 lbs. of aluminus clay, and 6 to
10 lbs. manganese oxide. This combination I find not only passes off the sulphur
and phosphorus, but it also effectually breaks the affinity (at the temperature
employed) of the "gangue" for the ore, and by uniting with it forms a glazing or
slag, which remains where formed without flowing freely, and serves as an envelope
to the particles of iron in the ore. These ingredients must in all cases be pulverized
and mixed with the ore, and as before stated I prefer to use them in a moistened
condition, but good results can be effected when the entire mixture is placed into
the canisters in a dry state.
Although I give the proportions and materials used I do not confine myself either
to these exact proportions or materials in my method of working my process; the
proportions may be and often are varied to best suit existing conditions or the
kinds of the ore to be worked, whilst other mixtures embodying the equivalents
of those I have named or producing the same effects would be equally efficaceous.
After the canisters are all properly filled with the mixtures, as stated, they are
ready for charging into the furnace. It is of course necessary to predetermine the
character and quantity of the ingredients, according to the analysis of the ore to be
worked, as before stated, and if the best washed cokes or other carbonaceous matter
be employed in the place of charcoal a due regard must be observed to proportionate
it according to its per-centage of carbon and purity.
prefer to employ what is usually known as a gas furnace in the working of my
method, and an important improvement I have made in reducing my ores is by
having the floor of such furnace covered to the depth of 6 to 12 inches with cokes
or with coals of proper character, from which the cokes may be made in the
furnace. On this bed of cokes I place the canisters with their charged contents just
so near to each other as to allow a free passage of the heat to all parts of the walls
of the canisters, whilst the hot cokes on which they stand help to properly reduce
the ore in the bottoms of the canisters and keep the inner walls of small pipe well
filled with heat.
To facilitate the charging of the canisters on to the cokes and the withdrawal of
them when properly reduced, I construct my furnace bottom or floor some inches
below the sill of the door, so the cokes may be but little above it when properly
spread. Whilst I find great advantage resulting from the use of cokes, as stated, in
the furnace bottom, I have also employed sand, fire-bricks, and similar materials, on

page_text: which the canisters may be placed whilst being reduced, but I find more raw metal
is left in the canisters when using such materials and a longer time is necessary for
completing the working.
When the canisters are all properly charged and in place, the gas furnace is fitted
with a smoky reducing flame, which is carefully maintained nearly throughout the
whole operation, continuing from 4 to 7 hours, according to circumstances; after
the first half hour and during the first hour the heat may be gradually raised,
always taking care however to keep the furnace full of flame and allowing no
currents of cold air from the door being opened to cut the canisters.
The gas heat acting on all the walls of the canisters, and added to by the cokes
on the furnace bottom, is also increased by the combustion of the carbonaceous
matter and other solid materials within the canisters as they pass into liquid or
gaseous compounds, and these gases thus formed quickly begin to force their way
outward and upward in a flaming condition through the orifices made in the canister
walls and top covering disc. At the end of 2 or 3 hours, according to the working
of the furnace or conditions of the materials, the walls of the canisters and the
contents within them begin gradually to sink, until they assume a cake or cheese-
like form, when they may be pressed or patted with a "peel" or iron puddle, and still
further flatten to aid in the quicker reduction of the solid material remaining inside
the skin or walls of the canister into a pasty mass; this however is not an essential
part of the process, except as hastoning it forward. During the latter part of the
process, after the third or fourth hour, if it has been properly conducted, the flaming
gases from the orifices in the canisters will have disappeared almost entirely; then,
after the 4th, 5th, or 6th hour, according to the working, the canisters are exposed for
a short time to a sharp welding heat, when they may be withdrawn and taken to a
squeezer, hammer, or roll, for the purpose of pressing the cinder and uniting the
solid particles of the pasty mass of iron contained within the skin of sheet iron
which formed the walls of the canisters.
If it be desirable to make larger balls or cakes than single canisters will form, I
place two or three of the cakes on each other a few minutes before I withdraw them
from the furnace, when they quickly unite and form one large ball, which, with the
skins or walls of sheet iron, is readily worked up into a solid bloom as the cinder freely
flows from it under pressure. During the entire reduction of ores by this method I
have found that so little slag, flux, or cinder escaped from the canisters or skins
during the time they were in the furnace that the floor or bottom of it was seldom
or never injured by its escaping on to it and cutting it, as such slag, flux, or cinder
usually does, thus a very great saving of the repairs to furnace bottoms has been
effected by employing my process.
The great advantages I have found, however, are in the yield of metal and their
purity by employing a process requiring but little skilled labor and the most simple
plant; when I have desired to produce a steel or semi-steel, I employ more carbon than
when making iron, and add such proportion of manganese oxide, ferromanganese,
or turnings, or fileings of cast iron as I find necessary to fix the carbon chemically in
my material, I have found that by employing the comparatively moderate heat
which I use that I successfully get rid of one-half to three-fourths of the phosphorous
which my ore may contain, and which, when a melting heat is employed, is most
difficult to get to combine with the fluxes. By taking the ball or cheese from the
gas furnace in its heated condition, and working it directly into the open hearth
steel furnace, the re-heating of the metal is saved, and any remaining portion of
impurities may be removed, whilst the metallic iron remaining will be found of the
highest purity, and can be changed into the best class of steel.
I have also worked these charged canisters in a puddling furnace for 4 or 5 hours,
and then thrown into it enough pig iron to form a bath for the canisters and their
contents, and when they are properly combined by the heat and working they are
taken to the hammer or forge fire. In this way I can combine the carbon to make
a fine wrought iron or to make steel, as I may select or work it.
I have also found great advantage in taking my balls or cheese of reduced metal

page_text: direct to what is termed a run-out fire, in which scrap iron is usually worked. Into
such a fire I sink my metal cake or ball in its white-heated condition, and with
20 to 25 bushels of charcoal to the ton of metal, I can, in about 1/, an hour, bring
out the mass of metal in a greatly purified condition. I find that by thus working
my iron that I can double the usual out-put of the forge fire, save more than half
the fuel and one-half of the labor as compared with the results usually attained in
sinking scrap and run-out metal. Beside these savings the metal produced by my
thus working it shews a purity and toughness quite surprising.
In the accompany Drawings Fig. 1 is an elevation of my canister, whilst Fig. 2
is a plan of the same, and Fig. 3 is a vertical section through the centre, showing
construction.
Having thus described the nature and objects of my improvements, what I claim
herein as new and desire to secure by Letters Patent is,―
First. The method substantially as herein described of reducing a charge of
pulverized iron ore, carbonaceous matter, and fluxes, in annular canisters, so that
these canisters and their contents are acted upon from all sides by the heat of the
furnace in which they are to be reduced.
Second. The employment of annular canisters for the uses, and, as described,
made of sheet iron or other suitable material, as shewn, but of just a sufficient
thickness, to permit of their retaining the most of their charged contents within their
skin or walls, whilst they gradually sink with the heat, and their reduced contents
assume a pasty state, when they may be squeezed or hammered into combination
with the whole metallic mass.
Third. The methods substantially as herein described of reducing a charge of
pulverized iron ore, carbonaceous matter, and flux, in annular canisters placed upon
a bed or layer of cokes or carbonaceous matter, as and for the purpose set forth.
Fourth. The combination of iron ore and carbonaceous matter with fluxing
materials of such a quality and in such proportions as to form with the gangue in
the process of reducing the ore in annular canisters a non-flowing slag or cinder,
which, remaining where it is formed throughout the charge, effectually envelopes or
glazes and protects with the canisters the particles of metal, and prevents the
wasting and deleterious action of the flame, substantially as set forth.
Fifth. The method, as herein described, of working my annular canisters in
puddling furnaces, and subjecting them with their reduced contents to a bath of
molten pig iron for the purposes mentioned.
Sixth. The method of sinking in a charcoal forge or run-out fire, my charged
annular canisters when properly reduced by heat, and working the same therein for
the purposes mentioned.
Seventh. The described processes of producing wrought iron and steel direct from
the iron ore, which consists in charging onto a furnace hearth sheet iron or other
suitable canisters of annular form, filled with a pulverized mixture of iron ore,
carbonaceous matter, and fluxing materials, and subjecting them therein to a gradu-
ally increasing heat until the reduction of the contained material is perfected. The
furnace flame being maintained throughout the operation of a reducing quality and
the resulting mass of metal being withdrawn and shingled, substantially as herein
set forth.
In witness whereof, I, the said Philip Syng Justice, have hereunto set my hand
and seal, the Twenty-seventh day of October, in the year of our Lord One
PHILIP S. JUSTICE. (L.S.)