Improvements in the Manufacture of Steel and Iron.
Year: 1892

page_text: Date of Application, 23rd Jan., 1892
Complete Specification Left, 22nd Oct., 1892--Accepted, 26th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Steel and Iron.
We, THOMAS TWYNAM of 10 Blandford Road, Bedford Park, Chiswick, in
the County of Middlesex, Metallurgical Chemist, and JOSEPH COLLEY, of
44 Wellington Road, Bilston, County of Stafford, Steel Manufacturer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to improvements in the manufacture ingot of iron and steel
by the Bessemer process, but more especially by the basic Bessemer process, and
has for its object both to increase the yield, and, in basic working, to oxidize the
phosphorus at an earlier period in the blow, and thereby to diminish the afterblow
required.
For this purpose we add before the commencement of, or at some period during
the blow, a certain amount of oxide of iron, which should be preferably low in
silica, but need not be free from phosphorus.
This oxide may be added either alone, or better in admixture with a certain
amount of lime.
When the carbon and phosphorus have been removed from the metal we add to
the charge a sufficient amount of solid carbon to remove from the metal the excess
of oxygen or dissolved oxide which are always apt to be present when oxide of iron
is added at any period during the blow.
We prefer to add the oxide with the lime before the metal is run into the
converter, or so soon as the silicon is burnt out and the combustion of the carbon
begun. We have found however that we can add it at a much later period of the
basic blow and good results can be obtained by adding it (preferably in the form
of scale) even after the carbon flame has dropped. When obtainable we always
prefer to use an oxide containing a large percentage of ferrous oxide, the presence
also of manganese in the oxide employed is advantageous. The cinder which
comes from reheating furnaces having basic slag bottoms we have found to give
very good results, both for shortening the afterblow period, and for giving quiet
metal in the moulds after the addition of the carbon. That form of oxide known
as pottery mine also gives good results.
fron scale is also a convenient and pure form of oxide to employ, but when it is
used, more care must be taken to remove the dissolved oxide.
We have found the best way to add the solid carbon for the purpose of getting
rid of the dissolved oxide, is to introduce it in a wooden box, weighted with ferro-
manganese, spiegel, hematite, or scrap, so that the box sinks partially or wholly
beneath the slag. The oxide can be added without, stopping the progress of the
blow, by throwing it into the converter from some convenient staging.
Dated this 22nd day of January 1892.
THOMAS TWYNAM.
JOSEPH COLLEY.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Steel and Iron.
We, THOMAS TWYNAM of 10 Blandford Road Bedford Park, Chiswick, W.
Metallurgical Chemist, and JOSEPH COLLEY, of 44 Wellington Road, Bilston, in
the County of Staffordshire, Steel Works Engineer, do hereby declare the nature
of this invention and in what manner the saine is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in the manufacture of ingot iron. or steel
by the Bessemer process, but more especially the basic Bessemer process and has
for its object oxidizing the phosphorus at an earlier period of the blow so as to
diminish the "afterblow" required, and also to increase the yield of steel obtained
from a given quantity of pig iron.
For this purpose we add. before the commencement of, or at some period during
the blow a certain amount of oxide of iron, preferably low in silica, but which need
not be free from phosphorus when used in connection with the basic process.
The oxide may be added to the metal either alone, or better in admixture with a
certain amount of lime, the same amount of lime being added to the charge as is
usually employed in basic working. When the blow is finished, and the carbon, or
carbon & phosphorus in basic working, have been removed from the metal, we
add to the charge a sufficient amount of solid carbon in the form of ground coke,
wood charcoal, anthracite, or other convenient form of solid carbon, and tar or its
like to remove from the metal the excess of oxygen or dissolved oxides which are
always apt to be present when oxide of iron is added at any period during the
blow, and which would, if not thus removed, spoil the steel.
We prefer to add the oxide with the lime before the pig iron is run into the basic
converter, or as soon as the silicon has been burnt out of the metal. We have
found however that we can add it at a much later period of the blow, and good
results can be obtained by adding it (preferably in the form of scale) even after
the carbon flame has dropped and the phosphorus is burning.
When obtainable we always prefer to use an oxide containing a large percentage
of ferrous oxide, the presence also of manganese in the oxide is advantageous. The
cinder which comes from reheating furnaces having basic slag bottoms, and the
cinder from puddling furnaces, known as tap-cinder we have found to give very good
results both for shortening the afterblow period, and for giving quiet metal. Those
forms of oxide of iron known as "pottery mine" and scale we have also found
useful.
We find the best way to add the solid carbon for the purpose of getting rid of
the dissolved oxide, is to encase it.in a thin sheet iron or wooden receptacle, which
may conveniently be weighted with ferro-manganese, spiegel, hematite or scrap, so
that it sinks well into the slag.
We may also deoxidize the metal by adding the solid carbon in the ladle, or
bringing it into contact with the iron whilst transferring the latter to the ladle.
We have found that by the above described method of procedure, from, one to
two cwts., of iron oxide may be used per ton of pig iron treated. The oxide may be
added without stopping the progress of the blow by throwing it in from some
convenient, staging.
We are acquainted with the Specifications of the following Letters Patent which
we believe are owned at the date of this Specification by John Henry Darby,
namely No. 418 of 1888 granted to John, Henry Darby for "Improvements in the
manufacture of steel or iron; " No. 20,586 of 1889 granted to John Henry Darby
for Improvements in the manufacture of steel or ingot iron; " No. 4030 of 1890
granted to John Henry Darby for "Improvements in the manufacture of steel or
iron; No. 2673 of 1891 granted to John Henry Darby for "Improvements in the
manufacture or purification of steel or homogeneous metal;" No. 6303 of 1891
:

page_text: granted to John Henry Darby for "Improvements in the manufacture of steel; "
No. 4386 of 1890 granted to J. Von Ehrenwerth for "A method for producing iron
or steel from ores and other materials containing iron" No. 4384 of 1891 granted
to J. Von Ehrenwerth for " Improvements in processes and appliances for the
manufacture of iron and steel," No. 16,344 of 1890 granted to R. S. Casson for
"Improvements in the manufacture of steel and ingot iron; No. 13,888 of 1891
granted to J. E. Stead for "Improvements in carburising fluid iron or steel
15 and
No. 18,990 of 1891 granted to J. Colley for "Improvements in adding metallic and
non-metallic substances to steel and iron or any other liquid metals," and we do not
claim any improvements set forth in any of these.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In the manufacture of steel or ingot iron by the Bessemer process, the addition
of. oxide of iron or ferruginous cinder to the molten metal, in conjunction with a
subsequent deoxidation of the metal by the addition of solid carbon, substantially
as and for the purposes set forth.
Dated this 20th day of October 1892.
THOMAS TWYNAM.
JOSEPH COLLEY.