CERTAIN IM- PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN THE MEANS EMPLOYED THEREFOR
Year: 1877

page_text: LETTERS PATENT to John Hollway, of the Firm of Hollway Brothers, of 7;
Jeffrey's Square, in the City of London, for the Invention of "CERTAIN IM-
PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN THE MEANS
EMPLOYED THEREFOR."
Sealed the 16th November 1877, and dated the 17th May 1877.
-
PROVISIONAL SPECIFICATION left by the said John Hollway at the Office
of the Commissioners of Patents on the 17th May 1877.
JOHN HOLLWAY, of the Firm of Hollway Brothers, of 7, Jeffrey's Square, in the
City of London. "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL, AND IN THE MEANS EMPLOYED THEREFOR."
The primary object of this Invention is the utilization of iron ores containing
phosphorus for the production of steel and the better qualities of iron, and to avail
of the heated state in which the metal produced from smelted ore or remelted iron
or steel leaves the furnace, and also of gravitation to economise labour.
The following are the usual methods of producing iron and steel-The ore is
smelted in a blast or other furnace, and the metal run into pigs, which are remelted
and purified by the action of oxygen.
Among the processes employed for purification may be mentioned the Bessemer,
in which the oxygen is obtained entirely from ordinary air; the Siemens'-Martin
process, where oxides are thrown into the bath of molten metal; the puddling
process, where oxides are introduced in the fettling; and the refinery, in which
oxygen is obtained from ordinary air and oxides.
By the Bessemer process, the silicon, nearly the whole of the carbon, and a small
proportion of the sulphur can be removed from the metal, and in the refinery,
puddling. Siemens'-Martin, and other kindred processes, not only are similar objects
attained but also a proportion of the phosphorus is eliminated.
In order to avail myself of the researches and experiences of others I have com-
pared these various processes, and find that, in Bessemer's process air is blown
through the molten metal at a pressure of about 20 lbs. per square inch; the metal
is thus brought into direct contact with oxygen, and most of the silicon, and
carbon, and a little of the sulphur are eliminated, the nitrogen of the air protecting

page_text: the iron from excessive oxidation. The operation takes about 25 minutes, and
when completed, the metal has dissolved or entangled in it carbonic oxide, the
elements of air, and oxide of iron. Oxygen is eliminated by the addition of
spiegel eisen or ferro-manganese, and a fusible slag results, containing oxides of iron
and manganese, which naturally removes oxide of iron formed by oxidation during
blowing a little of the sulphur passes off in this slag. The carbonic oxide can be
partially if not wholly removed by the addition of silicides of iron or of iron and
manganese, care being taken not to use an excess, otherwise silicon would remain
in the steel.
In the refinery cold air is blown into a shallow hearth containing molten iron;
after two or three hours the impurities are sufficiently oxidised, and the metal and
slag are run into shallow cast-iron moulds or chills, where the separation of the slag
is facilitated by throwing water on its surface. The cooling of the metal is thus
effected from the bottom upward, the top being protected by slag.
In puddling, the furnaces are lined or fettled with metallic oxides, thus removing
carbon and silicon by oxidation. A liquid slag results, which, passing upward
through the molten metal, carries with it phosphates formed by oxidation of the
phosphide of iron; the puddling or agitating of the mass, the fluid state, and the
comparatively low temperature of the operation assist the elimination, and may
account for the removal of phosphorus, which does not take place in Bessemer's
process.,
In the Siemens'-Martin process the metal is melted, and the bath in which this
is effected is lined with silica, in order to withstand a great temperature. Metallic
oxides are thrown into the molten metal to remove by oxidation carbon, silicon,
and other impurities. The temperature of the bath can either be increased or
lowered at the discretion of the operator. The great heat to which the bath is
raised, causing the metal to be very liquid, the gradual cooling, and the slag rising
through the molten metal assist, to eliminate phosphorus.
I propose to run the molten metal from the furnace into a channel, or preferably
into a channel or reservoir connected with other reservoirs and channels, so arranged
that the metal by its own gravity would flow from one receptacle to another, and
arrive at its exit in a sufficiently fluid state to produce sound castings. The stream
of metal could be continuous, or be temporarily arrested, cooled, and reheated for
especial operations.
propose to maintain the reservoirs and channels at any desired temperatures
and to utilize the heat therefrom, so as to avoid or diminish as much as possible
any application of external heat.
I propose to use metallic oxides with carbon for lining some of the channels and
reservoirs, adding, when required, materials to form slag, and also partially or
wholly line and fettle such of the reservoirs and channels as the operation in hand
may require, with oxides as in an ordinary puddling furnace; or the oxides could
be introduced as in the Siemens'-Martin bath; or the reservoirs and channels could
be partially or wholly lined with other materials that may be suitable for especial
purposes. Metals, alloys, metalliferous, and other substances could be introduced at
suitable times and places.
Steam, air, or other gases, or combinations thereof, useful either for purifying,
maintaining the heat, cooling the metal, or for any other purposes, could be blown
through or into the molten metal, or introduced in any other convenient manner.
Suitable exits could be provided for gases required to be withdrawn, and these
gases could be collected and utilized.
If. it should be required to puddle or agitate, suitable appliances for so doing
could be introduced; this could be done in one or more of the reservoirs.
Arrangements could be made for sampling, inspecting, and tapping the molten
metal, also for removing slag and for arresting or prolonging an operation at any
desired place or stage.
To reinstate silicon or carbon, or both, in the molten metal, I propose to run it
over carbon and silica, or a mixture thereof, with or without other materials mixed

page_text: therewith, such articles or mixtures being placed at such parts of the channel or
channels, reservoir or reservoirs, as may be required for reinstating the same as often
as may be necessary.
In treating iron containing an excess of phosphorus or other objectionable ingre-
dients, I should first run the molten metal, preferably in a thin stream, into my channels
or reservoirs, which I would line and fettle with suitable materials, and in one or
more of these channels or reservoirs I should blow air through the molten metal,
and when needful allow it to continue its course along channels or reservoirs lined
and fettled with carbon and silica to reinstate carbon and silicon; I would then, if
necessary, again drive air through the molten metal, and, if the phosphorus should
not be sufficiently eliminated, allow the metal to continue its course along channels
or reservoirs suitably lined and fettled, if requisite, with carbon, silica, and slag-
producing materials, with or without oxides of iron, and I should also puddle the
metal if necessary.
I would so arrange the channels and reservoirs that the molten metal could bo
agitated while running its course, so as to cause the slag formed to pass through it,
and by intimate contact assist in eliminating phosphorus; I should draw off the
slag when required.
It might be advisable to line and fettle certain parts of the channel with oxides
of manganese and titanium in addition to oxides of iron; and, further on, to reinstate
the necessary carbon, and, if desired, silicon, and add other substances to assist in
climinating the objectionable ingredients, or to protect the iron from being unduly
oxidized; afterwards, if necessary, reverting to oxidizing by blowing in air, either
to raise the temperature of the metal or to complete the decarburisation.
this way the operations could be extended, varied, and repeated as often as
desired, and a larger proportion of the objectionable ingredients eliminated.
In
The whole apparatus inight when desired be arranged in the form of a continuous
channel, such as a trough, either closed or open; this channel could be enclosed in
a culvert, or otherwise protected, so as to utilize the heat and retard radiation.
The molten metal would flow along the channel, and to expose a large surface
thereof it could be made to flow in a thin stream. This channel might descend in a
zig-zag, or any other manner that might be found best adapted relatively to the
position of the furnaces, and to the extent, nature, and surroundings of the ground
on which the channel had to be placed.
I should, if required, interrupt or vary the downward inclination of the channel,
and form at appropriate distances pockets or reservoirs which would partially or
wholly fill with the metal; which metal running out again would in this way be
dispersed.
I propose to utilize these pockets or reservoirs for inspecting and sampling the
metal, and for introducing any substances requisite for eliminating objectionablo
ingredients, or for producing any desired combinations.
The process could be arrested or prolonged at any period of its course, and when
desired the metal or slag could be partially or wholly drawn off.
As it would be necessary to maintain the metal in a sufficiently fluid state, I
should surround the channel with non-conducting materials, or enclose it in a
culvert or fluc, into which could be introduced at suitable places heated gases, or
heat could be supplied in any other convenient way. These gases could be con-
veniently obtained from the blast furnaces, and might, if desired, be passed over
incandescent, carbon, so as to reduce any carbonic acid to carbonic oxide.
The channel could be made of siliceous materials, or of cast iron or steel,
enamelled if necessary, and lined with siliceous slag or any other suitable
materials.
I propose to arrange the channels and reservoirs so that the metal would readily
flow from one to another, and arrive at its exit in a sufficiently fluid state for
casting sound ingots, or for any other purposes that might be required.
I propose that the metal should flow from the exit of the channel into a reservoir,
where it could accumulate and be kept fluid until required for casting, which

page_text: reservoir should be enclosed in a heating jacket or chamber surrounded by non-
conducting substances.
I propose having a series of chambers so arranged that the castings would be
run directly from the reservoir, and when required the whole of the metal might be
thus withdrawii.
The castings could be removed to other chambers and cooled gradually.
In one or more of the cooling chambers arrangements could be made for
enamelling the castings or oxidising them by Professor Barff's process, or for
applying pressure, so as to consolidate the castings while at a convenient
temperature.
I should when required arrange hydraulic presses or steam hammers and rolling
mills, so that ingots could be hammered; and in some cases even rolled without
reheating. The temperature of each of the chambers could be regulated. as might
be required.
The loss of heat by radiation, escape of heated gases, convection, and otherwise,
would be compensated to some extent by the heat evolved in the chemical com-
binations of the operations; if, however, the net loss should be too great to allow-the
metal to issue from the channel in a sufficiently fluid state, additional heat, by
combustion of gases or by other ineans, could be applied.
Excessive loss of heat could be avoided by so arranging the channels and
réservoirs that the heat escaping from one part would be taken up by another; for
instance, by placing one portion of the channel above the other, much in the way of
an ordinary superheater.
Arrangements could be made in any of the channels and reservoirs for exhausting
the gases.
-
The slag, if desired, could be passed through the channels, or even utilized as a
non-conductor of heat.
The gases from the culvert making their exit upward, and passing over, and if
necessary into the top reservoir, would assist in keeping the metal therein
snfficiently molten.
I do not wish to confine myself to the use of channels or reservoirs for the
removal or elimination of phosphorus and other impurities, as, if desired, the
oxidation could be effected by means of the Bessemer converter, Siemens'-Martin
bath, or any other convenient method. I should, however, prefer using a shallow
receptacle, suitably lined and fitted, to facilitate the production of slag, which,
passing upward through the molten metal would carry away phosphates formed by
oxidation.
In order to prevent these phosphates from being deoxidized, it is desirable to
have sufficient slag, for the probabilities of iron again taking up phosphorus are
increased by the slag and phosphates having to pass upward through a greater
quantity of metal, and also by the slag containing phosphates remaining in contact
therewith, consequently it is advisable to operate on a thin stratum of metal, and to
draw off the slag as soon as it rises to the surface.
The slag should contain peroxide of iron, or other oxides, to assist the oxidation
of the phosphide of iron.
By having shallow receptacles in lieu of the ordinary Bessemer converter, more
surface of metal would be exposed, and the temperature of the blown metal would
be lower, and it would not be necessary to use so great a pressure of air; if necessary
superheated steam could be introduced with the air, so as to lower the temperature
of the metal whilst oxidizing it.
The puddling could be performed, if desired, in rotary or other puddling
furnaces.
In the use of channels or reservoirs the first object is to eliminate phosphorus
and other impurities, and the second to reinstate when requisite, carbon or silicon,
so as by repetition to extend the length of the operation, and also to form slag,
which by its chemical action upon and passing upward through the molten metal,
would carry away phosphorus and other impurities, to avail of the heated state in

page_text: which the metal from smelted ore or remelted iron or steel leaves the furnace, and
to utilize the heat produced by the chemical combinations; I also propose by
gravitation to economise labour.
When sufficient carbon and other impurities have been removed, the metal could
be converted into steel by adding spiegel eisen, ferro-manganese, or silicide of iron,
or of iron and manganese in the usual way.
Another object of this Invention is the elimination of carbonic oxide and other
gases from iron or steel after it has been either partially or wholly decarburised, the
making of larger castings than are at present usual, and also the annealing of the
metal by gradual cooling.
It is well known that decarburised iron contains oxide of iron and occluded gases,
such as carbonic oxide and the elements of air, which it is of the greatest im-
portance to eliminate in order to render castings sound and free from blow holes ;
and for this object it has been proposed to use silicides of iron, or of iron and manganese,
instead of, or in addition to, ferro-manganese or spiegel eisen.
For the same purpose, and to avoid also the hardening property of silicon in iron
and steel, I propose to run the decarburised metal in a thin stream over a large
surface into moulds simply heated, or containing liquid slag sufficiently free from
phosphorus and other objectionable ingredients, and cool the castings from the
bottom upward in a very gradual manner, so as to facilitate the escape of dis-
engaged gases; it being well known that when castings, particularly those of soft
steel, are run into cold moulds, the outer surfaces become chilled, and the carbonic
oxide and other gases attempting to escape cause the exterior portions of the
castings to be honeycombed and fluted with blow holes; and in these castings will
be found other blow holes, and a cavity termed a pipe, caused by escaping gases.
In making large castings, I propose to arrange reservoirs of sufficient capacity,
so that the molten metal therein accumulated may be kept in a sufficiently fluid
state for running sound castings.
I propose to obtain the metal more free from gases by accumulating it in a
reservoir partially filled with liquid slag sufficiently free from phosphorus and
other objectionable ingredients, keeping it all fluid, exhausting gases and air from
this reservoir if necessary, and tapping the metal from near the bottom.
I also propose to anneal the castings by gradually cooling them from the bottom
upward, thus facilitating the escape of the gases liberated at or near the point of
solidification.

page_text: 1
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Hollway in the Great Seal Patent Office on the 17th
November 1877.
JOHN HOLLWAY, of the Firm of Hollway Brothers, of Jeffrey's Square, in the
City of London. "CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL, AND IN THE MEANS EMPLOYED THEREFOR."
The primary object of this Invention is the utilization of iron ores containing
phosphorus, for the production of steel and the better qualities of iron. I propose
to avail myself of the molten state in which the metal produced from smelted ore,
or re-melted iron or steel leaves the furnace, and by means of a direct and continuous
operation, or repetition of operations as herein-after described, to eliminate phosphorus
and other impurities, and to economize labour and the cost of re-melting the iron
when making the better qualities of iron and steel.
I propose in order to inaintain iron fluid at a sufficiently low temperature to
permit of its dephosphorisation, to reinstate carbon, and partially or wholly replace
by carbon the silicon which has been oxidized in the process of purifying the
metal.
I propose to reinstate and introduce carbon by operating in receptacles lined with
carbonaceous materials, and also when required to blow, force, or otherwise introduce
carbon into the molten metal.
The carbon could be conveniently blown or forced into the molten metals in a
free or combined state, with a stong current of carbonic oxide or other suitable gases,
or my object could be attained by the introduction of hydro-carbons.
The following are the usual methods of producing iron and steel. The ore is
smelted in a blast or other furnace, and the metal run into pigs, which are re-melted
and purified by the action of oxygen.
Among the processes employed for purification may be mentioned the Bessemer,
in which the oxygen is obtained entirely from ordinary air; the Siemens'-Martin
process, where oxides are thrown into the bath of molten metal; the pudling process,
where oxides are introduced in the fettling; and the refinery, in which oxygen
obtained from ordinary air and oxides.
By the Bessemer process, silicon, carbon, and a small proportion of the sulphur
can be removed from the metal, and in the refinery, puddling, Siemens'-Martin, and
other kindred processes, not only are similar objects partially attained, but also a
proportion of the phosphorus is eliminated.
I have compared these various processes, and find that in Bessemer's process, air is
blown through the molten metal at a pressure of about 20 lbs. per square inch;
the metal is thus brought into direct contact with oxygen, and most of the silicon
and carbon, and a little of the sulphur, are eliminated. The operation takes about
twenty-five minutes, and when completed, the metal has dissolved or entangled in
it carbonic oxide, the elements of air, and oxide of iron. Oxygen is eliminated by
the addition of spiegel eisen or ferro-manganese, and a liquid slag results, containing
oxides of iron and manganese, thus deoxidizing or removing the oxide of iron
formed by oxidation during blowing. A little of the sulphur passes off in this
slag. The carbonic oxide can be partially, if not wholly removed by the addition
of silicides of iron, or of iron and manganese, care being taken not to use an excess,
in which case I have found silicon remains in the steel.
In the refinery, cold air is blown into a shallow hearth containing molten iron,
and oxide of iron in the shape of hammer scale or some similar product, also molten ;
after this operation has been carried on two or three hours, the impurities are
sufficiently oxidized, and the metal and slag are run into shallow cast-iron moulds
or chills, where the separation of the slag is facilitated by throwing water on its
Burface.
In puddling, the furnaces are lined and fettled with oxides of iron, thus removing

page_text: carbon and silicon by oxidation. A liquid slag results, which passing upward through
the molten metal, carries with it phosphates formed by oxidation of the phosphide
of iron; the puddling or agitating of the mass, the comparatively low temperature,
and the fluid state of the metal in the earlier stages of the operation assist the
elimination, and account for the removal of phosphorus, which does not take place
in Bessemer's process.
In the Siemens'-Martin process, the metal is melted, and the bath in which the
purification is effected is lined with silica, in order to withstand a great temperature.
Oxides of iron are thrown into the molten metal for the purpose of removing by
oxidation carbon, silicon, and impurities generally. The temperature of the bath
can either be increased or lowered at the discretion of the operator. The great
heat to which the bath is raised causes the metal to be very liquid; the gradual
cooling, and tho contact between the slag and the molten metal may assist to
eliminate phosphorus.
In all the processes for the purification of iron by oxidation by which a propor-
tion of the phosphorus is eliminated, as soon as the carbon present is oxidized, and
so reduced below the quantity sufficient to ensure fluidity at a low temperature,
the elimination of the phosphorus cannot be continued. It is for this reason that
I find it necessary to reinstate and introduce carbon, and I am then able to continue
the elimination, and thus remove a larger proportion of the phosphorus.
As an example of my process for purifying and dephosphorizing crude iron, and
producing by a continuous operation or series of operations, steel and malleable iron,
propose to cause the molten metal to run from the furnace into a channel, or
preferably into a channel or reservoir connected with other reservoirs, and channels
so arranged that the metal by its own gravity would flow from one end of the
channel to the other, or from one receptacle to another, and arrive at its exit in a
sufficiently fluid state, either to produce sound castings, or for any other purposes
that may be required. The stream of metal could be continuous, or be temporarily
arrested, cooled, and re-heated for special operations.
The apparatus might, when desired, be arranged in the form of a continuous
channel, such as a trough, either closed or open; this channel could be enclosed in a
culvert, or otherwise protected so as to utilize the heat and retard radiation.
The channel or channels could be made of siliceous materials, or of cast iron or
steel, enamelled, if necessary, and lined with siliceous slag or any other suitable
materials overlaid with carbonaceous substances where requisite, in order to introduce
carbon.
The molten metal would flow along the channel, and it could be made to do.so
in a thin stream in order to expose a large surface thereof. This channel might
descend in a zigzag or any other manner that might be found best adapted relatively
to the position of the furnaces, and to the extent, nature, and surroundings of the
ground on which the channel had to be placed.
I should in certain cases interrupt or vary the downward inclination of the
channel or channels, and form at appropriate distances pockets or reservoirs which
the metal would partially or wholly fill, and passing out would be again distributed.
These pockets or reservoirs would be utilized for the purpose of inspecting and
sampling the metal and for introducing carbon or substances requisite for eliminating
objectionable ingredients, or for producing any desired combinations.
The molten metal could be agitated in channels and reservoirs when desired while
running its course, so as to cause the slag formed to pass upward through it,
and by intimate contact therewith assist in eliminating phosphorus and other
impurities.
I should draw off the slag from the surface in order to prevent the iron retaking
phosphorus from the slag.
Suitable exits could be provided for gases required to be withdrawn, and for
exhausting them if required.
If it should be required to puddle or agitate, suitable appliances for so doing

page_text: could be introduced; this could be done in one or more of the reservoirs or
channels.
Arrangements could be made for tapping the molten metal, also for removing
slag and for arresting or prolonging an operation at any desired place or stage.
When it is required to introduce carbon rapidly, I would blow or force into the
molten metal, carbon, in a free or combined state.
Carbonaceous materials in powder could be readily blown into the molten metal
with a current of carbonic oxide and nitrogen or other suitable gases.
The volatile hydrocarbons could be introduced in the form of vapour, and, if
desired, with suitable gases. The carbon thus introduced would not only cause the
metal to be fluid at a comparatively low temperature, but would also help to
maintain the temperature of the metal by its alternate oxidation.
I propose to maintain the reservoirs and channels at any desired temperatures,
and also to utilize the heat therefrom so as to avoid or diminish as much as possible
the necessity for the application of external heat.
In order to maintain the metal at the desired temperatures in a sufficiently fluid
state I should clothe the channel or channels with non-conducting materials, and, if
necessary, enclose them in a culvert or flue, wherein heat could be generated by
combustion of gases, which might be conveniently obtained from the blast furnace.
In any of the channels or reservoirs, steam, air, carbonic acid, carbonic oxide,
nitrogen, or other gases or mixtures thereof, useful either for maintaining the heat,
cooling or purifying the metal, or for any other purposes, could be blown or forced
through, into, or upon the molten metal, with which might be introduced oxides and
other slag-producing materials, carbon, silicides, and other substances.
It might be advisable to line and fettle certain parts of the channel with car-
bonates of manganese and iron, or oxides of manganese or titanium, in addition to
or in lieu of oxides of iron, and further on to reinstate the necessary carbon, and, if
desired, silicon; and also to add other substances to assist in removing objectionable
ingredients, or to protect the iron from being unduly oxidized.
To introduce silicon or carbon, or both, in the molten metal I propose to cause it
to run through or over carbonaceous substances, or metallic silicides, or a mixture
thereof, such substances being placed at the parts of the channel or channels,
reservoir or reservoirs, that may be required for introducing the same as often as
may be necessary.
In the same manner metals, alloys, metalliferous and other substances could be
introduced at suitable times and places. When desired oxides and other substances
could be thrown into the molten metal in the same manner as oxides are added in
the Siemens'-Martin bath, or the oxides could be introduced in a molten state.
The loss of heat by radiation, escape of heated gases, convection, and otherwise,
would be compensated to some extent by the heat evolved in the chemical combina-
tions produced in the operations. If however the net loss should be so great that
the metal became viscous, or did not readily flow, additional heat by combustion
of gases or by other means could be applied.
By introducing, reinstating, and substituting carbon, as before mentioned, and
keeping the metal fluid, the operations can be extended, varied, and repeated as
often as desired, and thus a larger proportion of the objectionable ingredients
eliminated.
To remove phosphorus and other objectionable ingredients from iron I should first
cause the molten metal to run, preferably in a thin stream, into my channels or
reservoirs, which I would line with carbonaceous substances and fettle with suitable
materials, and into one or more of these channels or reservoirs I should blow or
force air and or other gases or mixtures thereof through the molten metal, intro-
ducing therewith oxides and other substances, and when needful to reinstate or
introduce carbon allow the metal to continue its course along channels or reservoirs
lined and fettled with carbonaceous materials; and, if required, I would also blow,
force, or otherwise introduce carbon into the molten metal; I would afterwards

page_text: again drive air and or other gases or mixtures thereof, with oxides and other
substances, through the molten metal; and if the phosphorus should not then be
sufficiently eliminated I would repeat the operations until the desired object was
attained.
To convert the metal into steel after the carbon and impurities have been suffi-
ciently removed, spiegel eisen, ferro-manganese, or silicides of iron, or of iron and
manganese, could be added in the usual way.
The channels, reservoirs, or other apparatus in which the molten metal is treated
for dephosphorization should be lined with carbonaceous materials, whereas thoso
intended for the decarburization should be lined with metallic oxides, so that
the decarburization could be effected without the aid of the ordinary Bessemer
converter.
A convenient form of the apparatus would be a series of inclined channels con-
nected with each other, and finally with a Bessemer converter, these channels being
suitably lined; and in any of these channels could be introduced air or other gases
with oxides and slag-producing materials for purifying the metal, and in others;
carbonaceous materials, and, if requisite, hydrocarbons and gases, in order to supply
the necessary carbon. The metal running along in a thin stream would thus be
brought into intimate contact with the linings, and the slag formed could be easily
removed immediately it came to the surface of the metal. After the metal has been
sufficiently dephosphorized I propose when making Bessemer steel to reinstate
carbon and silicon; and, if desired, introduce manganese. I would then allow the
metal to flow by its own gravity into an ordinary Bessemer converter suitably
placed, and the decarburization would then be effected in the usual manner.
I do not wish to confine myself to the use of channels or reservoirs for elimina-
tion and removal of phosphorus and other impurities, as, if desired, the oxidation
thereof and the reinstatement or introduction of carbon could be effected by similar
operations, carried on in modification of the Bessemer converter, Siemens'-Martin
bath, puddling furnace, refinery, or any other convenient apparatus, I should
however line the apparatus intended for the dephosphorization with carbonaceous
materials to reinstate carbon, and introduce into the molten metal the oxidizing
and slag-producing materials, and, when requisite, additional carbon; and preferably
I would operate in shallow receptacles and on a thin stratum of metal, and cause an
oxidizing slag to pass upward through it.
If the operations for purifying the metal, and introducing, reinstating, or substi-
tuting carbon, when carried on in a Siemens'-Martin bath or in a Godfrey and
Howson's puddling furnace, the metal therein could be conveniently re-heated, and
consequently the operations could be repeated as often as required, and by so doing
the metal could be practically freed from phosphorus.
After the metal has been dephosphorized it could be decarburized and converted
into steel by any of the ordinary methods.
I propose to introduce air, other gases, or mixtures thereof, metallic oxides, and
other slag-producing materials, also to reinstate or introduce carbon in order to
maintain the metal fluid, and thus oxidize the impurities therein, and produce an
oxidizing slag at a low temperature, this slag, by its chemical action upon and
passing upward through the molten metal, will assist in oxidizing the phosphorus
and carry away the phosphates formed by oxidation. In order to prevent phosphates
thus formed from being deoxidized it is desirable to have an abundance of liquid
basic slag. The facilities of iron again taking up the phosphorus are increased if
the phosphates formed by oxidation are not protected, diluted, or dissolved by slag,
and if they have to pass upward through a thick stratum of metal, also if the slag
containing the phosphates remains in contact with the metal, consequently it is
advisable to operate on a thin stratum of metal, and to draw off the slag as soon as
it rises to the surface.
The materials to form slag should contain peroxide of iron and or other oxides to
assist the oxidation of the phosphide of iron, and should be basic so that any

page_text: phosphoric acid formed would be converted into phosphate and carried off by the
slag, and also to prevent re-absorption of the phosphorus, as molten iron can more
readily abstract phosphorous from a slag rich in silica, such as an ordinary Bessemer
slag, than from a slag rich in bases.
By using shallow receptacles or channels in lieu of the ordinary Bessemer
converter, and operating on a thin stratum of metal, more surface thereof would be
exposed, it would not be necessary to use so great a pressure of air, and the
temperature, if the blown metal would be lower; if required, superheated steam or
carbonic acid could be introduced with the air, so as to lower the temperature of
the metal when oxidizing it.
In the foregoing I have contemplated the possibility of the process of dephos-
phorization being a lengthy one, whereas it would be of very short duration, provided
the temperature be kept sufficiently low, the metal fluid, and a rapid and intimate
contact be obtained between the particles of the metal and the oxygen or oxidizing
substances. This intimate contact cannot be obtained when the inetal is viscous,
care must therefore be taken to introduce air and other gases or mixtures thereof
with carbon, oxides, and slag-producing materials in the proportions that would
oxidize the impurities therein, and produce sufficient slag, preferably liquid and
basic, fusible at a low temperature; also by oxidization of the metalloids, and, if
requisite, by combustion of gases to produce enough heat to maintain the metal
fluid, and yet avoid or diminish the excessive heat evolved by the chemical actions
produced in the operation. If the operation is not so rapid more carbon would
have to be introduced, and the metal might have to be re-heated partially or wholly,
after which the dephosphorization could be continued.
To be commercially successful the dephosphorization should be effected at a cost
not exceeding the difference in price between Bessemer and Cleveland pig; conse-
quently it is important that the metal should be purified and converted into stcel
while inolten from the blast furnace without having to be handled or remelted.
As another example of my process, I adopt the following plan, availing myself of
the fluid state in which iron leaves the blast furnace:-I cause the metal to flow
into a shallow Bessemer converter provided with a lining of carbonaceous materials
to reinstate carbon that may be oxidized; if desired, I would partially overlay this
lining with oxidizing and other materials to form preferably a liquid basic slag
fusible at a low temperature, or I would partially or wholly introduce these materials
with air, gases, or mixtures thereof, reinstating and introducing carbon whenever
necessary, and afterwards continuing the dephosphorization, my object being to keep
the metal fluid at a low temperature, to bring about a rapid and intimate contact
between the metal to be dephosphorized and oxygen and oxidizing substances,
taking care to have sufficient slag to protect, carry upward, and thus remove the
phosphates formed by oxidation. This shallow converter I would connect with an
ordinary Bessemer converter by a channel through which the metal would run by
its own gravity, and I would line this channel with a mixture of carbon and silicide
of iron, or preferably silicides of iron and manganese, in order to reinstate part of
the carbon and silicon oxidized.
Provided the metal arrived in the second converter in a sufficiently fluid state to
run, the heat would be raised therein by the oxidation of the silicon, carbon, and
manganese present, and the decarbonization completed in the usual Bessemer method,
and, if requisite, I would throw into the molten metal an additional quantity of
Bilicides of iron or of iron and manganese.
As to that portion of my process that relates to the production of large castings,
I propose that the metal, after it has been converted into molten steel, should flow
into a reservoir or reservoirs of sufficient capacity where it could accumulate and be
kept fluid until required for casting, and thus castings of almost any size could be
produced; the reservoir or reservoirs should be enclosed in a heating jacket or
chamber surrounded by non-conducting substances.
I propose having a number of chambers so arranged that the castings would be

page_text: run directly into them from the reservoir, and, when required, the whole of the
metal might be thus withdrawn.
The castings could be removed to other chambers and cooled gradually.
In one or more of the cooling chambers arrangements could be made for
enamelling the castings or oxidizing them by Professor Barff's process, or for
applying pressure so as to consolidate the castings while at a convenient
temperature.
The temperature of each of the chambers could be regulated as might be required.
I should, when required, arrange, hydraulic presses or steam hammers and rolling
mills, so that ingots could be hammered, and in some cases even rolled, without
re-heating.
Another object of this Invention is the elimination of carbonic oxide and other
gases from iron or steel after it has been either partially or wholly decarburized, the
making of larger castings than are at present usual, and also the annealing of the
metal by gradual cooling. It is well known that decarburized iron contains oxide
of iron and occluded gasses, such as carbonic oxide and the elements of air, which
it is of the greatest importance to eliminate in order to render castings sound and
free from blow-holes; and for this object it has been proposed to use silicides of
iron, or of iron and manganese, instead of or in addition to ferro-manganese or
spiegel eisen.
-
For the same purpose, and to avoid also the hardening property of silicon in
iron and steel, I propose to run the decarburized metal in a thin stream over a large
surface into moulds simply heated or containing liquid slag sufficiently free from
phosphorus and other objectionable ingredients, and cool the castings from the
bottom upward in a very gradual manner, so as to facilitate the escape of disengaged
gases; it being well known that when castings, particularly those of soft steel, are
run into cold moulds, the outer surfaces become chilled, and the carbonate, oxide,
and other gases attempting to escape, cause the exterior portions of the castings to
be honeycombed and fluted with blow-holes, and in these castings will be found
other blow-holes and a cavity termed a "pipe" caused by escaping gases.
I propose to obtain the metal more free from gases by accumulating it in a
reservoir partially filled with liquid slag sufficiently free from phosphorus and other
objectionable ingredients, keeping it all fluid, exhausting gases and air from this
reservoir if necessary, and tapping the metal from near the bottom.
I also propose to anneal the castings by gradually cooling them from the bottom
upward, thus facilitating the escape of the gases liberated at or near the point of
solidification.
Having now described the nature of my said Invention together with the manner
of performing the same, I wish it to be understood in conclusion that what I claim
as new and as of my Invention,―
Firstly. Introducing and reinstating, as described, carbon in iron when purifying
it, and partially or wholly replacing by carbon the silicon oxidized in the operation,
so that the metal can be maintained fluid at a sufficiently low temperature to permit
of its dephosphorization.
Secondly. Dephosphorizing the iron by introducing air, gases, or mixtures thereof
with carbon, oxides, and slag-producing materials, in proportions which would
oxidize the phosphorus and other impurities, and by introducing carbon permit of
the metal being maintained at almost the lowest temperature consistent with
complete fluidity, so that sufficient oxidizing slag would be produced and caused to
pass upwards through the metal in order to carry off phosphoric acid and phosphates
formed by oxidation, operating on the metal in shallow receptacles or in a thin
stream, and drawing off the slag directly it comes to the surface of the metal, thus
preventing it retaking phosphorus from the slag, introducing and reinstating silicon
and carbon into the dephosphorized metal, when desired, to convert it into steel
by the Bessemer process.
Thirdly. By the introduction and reinstatement of carbon, and keeping the metal
fluid at a low temperature, as before described, repeating as often as desired the

page_text: operations for oxidizing the impurities in order that the purification may be more
thoroughly effected than may have been done in one operation.
Fourthly. A simple and direct process by which ores and iron containing even
large per-centages of phosphorus, after being smelted or remelted, can by gravita-
tion be run from the furnace and so on from one receptacle to another, and be
dephosphorized and converted into sound steel castings, even of large size, without
having to be handled or remelted, all as substantially herein set forth.
In witness whereof, I, the said John Hollway, have hereunto set my hand
and seal, this Tenth day of November, in the year of our Lord One
thousand eight hundred and seventy-seven.
Witness,
THO³. WRIGLEY,
75, Chancery Lane,
London,
W.C.
JOHN HOLLWAY. (L.S.)