Improvements in the Manufacture of Steel.
Year: 1897

page_text: Date of Application, 29th May, 1897
Complete Specification, Left, 28th Feb., 1898-Accepted, 7th May,
1898
Improvements in the Manufacture of Steel.
We, JOHN PARRY, of Oakfield, Caerau Park, Newport, Monmouthshire, Analytical
Chemist, and GEORGE HENRY LLEWELLYN, of Pencraig, Caerau Park, Newport,
Monmouthshire, Solicitor, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object the economical and rapid production of a
pure cast steel similar to that now produced by either the acid or basic open
hearth processes.
Steel by the first or acid process as is well known being manufactured from
pure hematite pig iron with the aid of scrap iron, cinder, pure ores or other
suitable oxides.
The second or basic process from impure crude iron usually containing large
quantities of sulphur and phosphorus which are eliminated by the method of
procedure termed the basic process.
To accomplish our object we take crude iron cast in plates of any suitable
thickness, length and width. The plates are charged and heated in any suitable
furnace in the following manner, viz.:-First a layer of ore, cinder, or other
suitable material such as lime, alkalies, or other purifying agents, or a suitable
mixture of these ingredients, or any material affording oxygen and capable
when necessary of dephosphorizing and desulphurizing crude iron; is made;
next, on this we charge the plates of metal, repeating this operation by successive
layers of ores with the refining and purifying agents, and metal plates, until the
furnace is fully charged. By this method the metal and oxidizing purifying
material being in more intimate contact, the crude metal is freed from silicon,
carbon, sulphur and phosphorus more rapidly and efficiently than by the ordinary
methods of procedure. The resulting slag formed containing sulphur and phos-
phorus being at the proper time tapped out, thereby freeing the metal of these
impurities.
The waste heat from the furnace previously described may be utilized for the
purpose or refining and purifying another charge of plates and mixed oxides
and purifying material as before described by attaching another hearth in close
proximity to the hearth of the furnace previously described, thus constituting a
double hearth furnace, the hearths of which may be alternately used as desired,
the one for the final melting, whilst the other charge is being refined and purified.
A more convenient form of furnace may however be constructed as follows:
The hearth of the furnace firstly described being used only for the fusion and
manipulation of steel of the desired quality. To accomplish this we propose that
in lieu of the single or double hearth furnace before described, the portion or hearth
required for the refining and purification of the crude materials used, is inclined
at any suitable angle, and upon which the waste heat passing away from hearth
number 1 strikes, we charge the usual mixtures of plates, ores and purifying
materials as before described in successive layers on this inclined hearth. During

page_text: this operation the slag containing sulphur and phosphorus flows from the mixture
of iron, ores and purifying materials which is being refined, to a small hearth
placed between the main or number 1 hearth and the inclined hearth and is thence
tapped out.
The temperature of the furnaces previously described is so regulated that
the partially or wholly decarbonized and desiliconized metal is left on the hearth
whilst the more fluid slag containing the extracted impurities, flows away and is
separated as before described. When the flow of slag has ceased, the heat of the
furnace is increased by any suitable means whereby the necessary temperature
can be obtained with ease and certainty to fuse the purified metal which first
flows into the small hearth and then overflows into the main or number 1 hearth,
and is afterwards treated in the ordinary manner.
It is obvious that in a furnace with one hearth only, one charge only can be treated
at a time by one operation. By means of the double hearth furnace as described
one charge may be refined whilst another is being treated in the usual manner.
The waste heat passing over from the melting or number 1 hearth being most
suitable for the refining and purifying, and therefore practically better for that
purpose than the higher temperature required for the fusion of steel.
JOHN PARRY.
GEO. H. LLEWELLYN.
We, JOHN PARRY, of Oakfield, Caerau Park, Newport, Monmouthshire, Analytical
Chemist, and GEORGE HENRY LLEWELLYN, of Pencraig, Caerau Park, Newport,
Monmouthshire, Solicitor, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
1
This invention has for its object the economical and rapid production of a
pure cast steel similar to that now produced by either the acid or basic open
hearth processes.
Steel by the first or acid process, as is well known is manufactured from
pure hematite pig iron with the aid of scrap iron, cinder, pure ores or other
suitable oxides.
In the second or basic process it is manufactured from impure crude iron usually
containing large quantities of sulphur and phosphorus which are eliminated by
the method of procedure termed the basic process.
It is known that when a mixture of finely powdered iron ore and carbon and lime
is made in suitable proportions; and placed in a closed chamber or crucible, it
requires the application only of a graduated heat to produce metallic crude iron
or steel or wrought iron direct, without the intervention of a blast furnace.
The relative qualities of these metals of course depend on the amount of carbon
added. With a large proportion or charcoal or carbon in any form cast iron is
obtained. With somewhat less carbon steel is produced and with still less carbon,
very soft steel or even wrought iron is produced. The proportions would be
ascertained by the previous analysis of the ore, from which the amount of carbon
necessary for these qualities can be calculated.
The quantity of lime is regulated by the amount of siliceous and other matter
contained in the ore. Very siliceous and earthy ores or ores containing sulphur

page_text: and phosphorus of course requiring a corresponding greater quantity of lime or
other suitable purifying substances.
The above and allied processes are usually termed the direct process of iron
making.
It is understood that the ordinary or blast furnace process results in the pro-
duction of a material containing an excess of impurities such as silicon, carbon,
sulphur and phosphorus which have afterwards to be eliminated by suitable
secondary or puddling processes or modifications thereof.
The impurities, contained in the ore when such ore is treated by the direct pro-
cesses above mentioned come off at a comparatively low temperature and pass
away in slag form, whereas in the blast furnace, in consequence of the high
temperature necessary for efficient working, so that all material may pass away
in a fluid condition, (the iron through the tapping hole and the slag through the
cinder notch) these impurities are retained and remain in combination with the
iron.
Theoretically, the direct is the best process, as the temperature may be regulated,
as also the amount of flux required in such a manner as to produce the required
quality of metal. Or in other words the fusion point of cast iron, steel or wrought
iron being so much greater than the fusion point of the impure slags formed,
when the latter fusion point is first reached, the impure slags are tapped out leaving
the pure metal on the bed of the furnace requiring only to be fused by increasing
the heat or temperature and cast into ingots or the like in the usual way.
The ordinary Siemen's furnace or other forms of reverberatory furnaces are not
adapted to the smelting and purification of ores by the direct processes as above
described, inasmuch as no means are provided for regulation of temperature, which
according to our process is of the utmost importance.
It is true that by the basic proce, phosphorus when in excess in the ore of
metal used, is largely removed, but the basic process is of no value for the
purification of materials containing small or medium quantities of phosphorus.
It also practically fails to remove sulphur.
Our method would therefore be of great advantage in dealing with that class
of ore which contains comparatively small amounts of phosphorus (which would
be too much for the acid and not enough for the basic) and therefore as is well
known not suited to either of these processes.
Our process therefore enables iron ores and iron to be used which are at present
not marketable and may be purchased at low rates.
It has also the further advantage of removing sulphur.
It disposes of objections hitherto met with to the direct process, viz;-
(a) It is a continuous one.
--
(b) It is more effective in the purification of the crude material used.
(a) By the utilizing of the waste heat, a marked saving in fuel is effected.
(d) A larger make of iron and steel is obtained of a better and more even
quality and at less cost.
of
It was known that by the proper admixture of suitable materials that metal
any desired quality could be produced on a small scale in the laboratory and on
a larger scale in the usual pot melting steel furnaces. Thus both wrought iron
and steel free from sulphur and phosphorus have been produced, but these were
mere laboratory experiments, correct and feasible in theory, but too costly and
slow for commercial purposes.
The present methods of manufacturing steel by either the acid or basic pro-
cesses fail to meet modern requirements on account of their uncertainty slowness
and consequent cost.
It still remains to work out a cheap, rapid and more efficient process, whereby
from any crude metal or ores containing varying amounts of sulphur and phos-
phorus and silicon and carbon, a pure steel of any desired quality can be pro-
duced.
Our methods are specially suited to overcome the difficulties, uncertainties and

page_text: waste of time experienced in the present methods as practised by the acid or basic
processes.
With this object in view we take crude iron cast in plates (preferably in iron
moulds) of any suitable thickness, length and width. The plates are charged
and heated in any suitable furnace in the following manner, viz.-First a layer
of iron, next a layer of ore, cinder or other suitable material such as lime, alkalies,
or other purifying agents, or a suitable mixture of those ingredients or a material
affording surplus oxygen (such as the binoxide or sesquioxide of manganese and
capable when necessary of dephosphorizing and desulphurizing crude iron is
made; Next, on this we charge the plates of metal. We repeat this operation
by successive alternate layers of ores or other suitable oxides with other refining
and purifying agents, and metal plates, until the furnace is fully charged. By
this method of charging the metal and oxidizing purifying material being in more
intimate contact, the crude metal is freed from silicon, carbon, sulphur, and
phosphorus more rapidly and efficiently than by the ordinary methods of pro-
cedure and at a comparatively low temperature. The resulting slag formed,
containing sulphur and phosphorus is at the proper time tapped out thereby
freeing the metal of these impurities. The temperature may then be raised so
that the metal may be melted made into steel and run out.
The waste heat from the furnace previously described especially when the heat
has been raised may be utilized for the purpose of refining and purifying another
charge of plates and mixed oxides and purifying material as before described
on another hearth placed in close proximity to the hearth of the furnace previously
described, thus constituting a double hearth furnace, and hearths of which may
be alternately used as described, the one for the final melting, whilst the other
charge is being refined and purified.
A convenient form of furnace may however be constructed as follows wherein
one hearth only of the furnace is used for the fusion and manipulation of steel
of the desired quality and the other hearth required for the refining and purifi-
cation of the crude material used, is inclined at any suitable angle and upon this
the waste heat passing away from hearth No. 1 strikes. We charge the usual
mixtures of plates, ores and purifying material as before described in successive
layers on this inclined portion or hearth. During the heating the slag containing
sulphur and phosphorus, flows from the mixture of iron ores and purifying
material, which is being refined, to a small hearth placed between the main or
No. 1 hearth and the inclined hearth, and is thence tapped out.
The temperature of the furnaces previously described is so regulated that the
partially or wholly decarbonized and desiliconized metal is left on the hearth,
whilst the more fluid slag containing the extracted impurities, flows
away and is separated as before described. When the flow of slag
has ceased, the heat of the furnace is increased by any suitable means, but in
the process as worked by us we are convinced that ordinary draught, or even
combined forced blast & draught as now used for the production of gas used
do not afford the absolute control of the heat positively necessary in our combined
process of purification and final melting.
It is part of our method of working that forced high pressure blast only be used
as by this means the absolutely necessary temperature at the proper stage for the
removal of sulphur and phosphorus can be controlled and the requisite heat
obtained with ease and certainty to fuse the purified metal which first flows into
the small hearth and then overflows into the main or No. 1 hearth to be there
treated in the ordinary manner.
It is obvious that in a furnace with one hearth only, one charge only can be
treated at a time by one operation. By means of the double hearth furnace as
described, one charge may be refined whilst another is being treated in the usual
manner.
The waste heat passing over from the melting or No. 1 hearth is most suitable

page_text: for the refining and purifying and therefore practically better for that purpose
than the higher temperature required for the fusion of steel.
:
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed we declare that what we
claim is:-
1. The process for manufacturing steel consisting in charging a hearth with
alternate successive layers of crude iron and of refining and purifying material
substantially as herein specified, applying just sufficient heat to melt out the
resulting slag and afterwards raising the heat sufficiently to melt the metal sub-
stantially as described.
2. The process for manufacturing steel consisting in charging a hearth with
alternate successive layers of crude cast iron plates and of refining and purifying
material substantially as herein specified, applying sufficient heat to melt out the
resulting slag and afterwards raising the heat sufficiently to melt the metal sub-
stantially as described.
3. The process for manufacturing steel consisting in charging an inclined hearth
with alternate successive layers of crude iron and refining and purifying material
substantially as specified herein applying heat sufficient to melt out the resulting
slag, running off the slag, subsequently raising the heat sufficiently to melt
the metal and running same onto another hearth for further treatment in the
usual way substantially as described.
:
4. The process for manufacturing steel consisting in providing two hearths,
charging each of them alternately with alternate successive layers of crude iron
and of refining the purifying material as specified subjecting such layers to a
comparatively low heat sufficient to melt out the slag, running off the slag and
afterwards increasing the heat for the melting and further treatment of the
metal, the lower heat for refining in such hearth being derived from the waste
heat during the melting and further treatment of the metal in the other hearth
substantially as described.
5. The process for manufacturing steel consisting in providing two hearths
one of which is inclined, placing on the inclined hearth successive alternate
layers of crude iron and of refining and purifying material as specified, subjecting
such layers to the waste heat from the other hearth in order to melt out the slag,
running off the latter at the lower end of the inclined hearth, raising the heat to
melt the metal and running same into the other hearth for further treatment
in the usual manner and recharging the inclined hearth substantially as described.
6. The improved method of manufacturing steel substantially as herdin
described.
Dated this our day of February 10.
HERBERT HADDAN & Co.,
Agents to Applicants, 18, Buckingham Street, Strand, London,