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

page_text: Date of Application, 22nd Jan., 1892
Complete Specification Left, 15th Oct., 1892-Accepted, 19th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Iron and Steel.
I WILLIAM HUTCHINSON, of The Ferus Pennfields, Wolverhampton, in the
County of Stafford, Manager of Steel Works do hereby declare the nature of
this invention to be as follows:-
In the manufacture of wrought iron by puddling pig or cast iron there is
produced a slag rich in oxide of iron and phosphoric acid. This slag is allowed to
run from the puddling furnace by tapping the said furnace at the end of the
puddling process. The cooled and solidified slag is commonly called tap cinder.
My invention consists in the utilization of the said tap cinder in the manufacture
of iron and steel by the Bessemer process conducted in a converter having either a
basic or neutral lining.
I employ the said tap cinder either in the form of lumps cold or heated, or in a
molten state. I prefer to introduce a portion of the tap cinder into the converter
with the lime and previous to the introduction of the melted cast iron to be
operated upon the remaining portion of the said tap cinder being introduced at
intervals but the whole of the said tap cinder is introduced before the "after blow"
sets in.
By treating the molten cast iron and lime in the converter during the blowing
process with the said tap cinder the oxide of iron contained in the cinder is reduced,
its oxygen oxidising any remaining silicon and carbon as well as the phosphorus
and any manganese contained in the iron under treatment. The phosphoric acid
contained in the tap cinder together with the other oxidation products pass into
the slag while the reduced iron increases the yield of the iron produced by the
Bessemer treatment. The slag produced in the converter is richer in phosphoric
acid than it otherwise would be by the addition to it of the phosphoric acid
contained in the tap cinder.
The slag thus obtained is valuable as a manure in consequence of the large
proportion of phosphoric acid which it contains.
The addition of the tap cinder as hereinbefore described shortens the "after
blow."
I do not limit myself to any particular proportion between the iron under treat-
ment and the tap cinder but I have found that one part by weight of tap cinder to
about fifteen parts by weight of the iron under treatment answers well in practice.
Dated this 22nd day of January 1892.
W. T. WHITEMAN,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Iron and Steel.
I, WILLIAM HUTCHINSON, of "The Ferns," Pennfields, Wolverhampton, in
the County of Stafford, Manager of Steel Works, do hereby declare the nature of
my invention and in what manner the same is to be performed to be particularly
described' and ascertained in and by the following statement :-
In the manufacture of wrought iron by puddling pig or cast iron there is
produced. a. slag rich in oxide of iron and phosphoric acid. This slag is allowed to
run. from the puddling furnace by tapping the said furnace at the end of the
puddling process. The cooled' and solidified slag is commonly called tap cinder.
My invention consists in the utilization of the said tap cinder in the manufacture

page_text: of iron and steel by the Bessemer process conducted in a converter having either a
basic or neutral lining.
.
I employ the said tap cinder either in the form of lumps, cold or heated or in a
molten state. I prefer to introduce a portion of the tap cinder into the converter
with the lime and previous to the introduction of the melted cast iron to be
operated upon, the remaining portion of the said tap cinder being introduced at
intervals during the blow.
By treating the molten cast iron and lime in the converter during the blowing
process with the said tap cinder the oxide of iron contained in the cinder is
reduced, its oxygen assisting to oxidise the silicon and carbon as well as the
phosphorus and manganese contained in the iron under treatment. The phosphoric
acid contained in the tap cinder together with the, other oxidation products with
the exception of the oxidized carbon pass into the slag while the reduced iron
increases the yield of the iron produced by the Bessemer treatment.
The slag
produced in the converter is richer in phosphoric acid than it otherwise would be
by the addition to it of the phosphoric acid contained in the tap cinder.
The slag thus obtained is valuable as a manure in consequence of the large
proportion of phosphoric acid which it contains. The addition of the tap cinder as
hereinbefore described shortens the "after blow."
Having described the nature of my invention I will now proceed to describe in
detail the manner in which the same is to be performed.
The pig iron on which I operate is of the kind known as "basic" pig iron but
preferably higher in phosphorus than such iron generally is.
The pig iron is melted in a cupola or taken direct from the blast furnace and the
molten metal is run from the cupola or .blast furnace into a ladle. I prefer
to operate upon about eight tons at a time and I prefer to employ one part
by weight of tap cinder to about fifteen parts by weight of pig iron. About
one half of the tap cinder to be employed in the charge under treatment is
preferably introduced into the ladle in which the molten iron is run from the cupola
or blast furnace. When the tap cinder is used in the solid form I prefer it in
lumps of about the size of walnuts. When the tap cinder is melted before being
put into the ladle the treatment in the ladle is somewhat shortened but on the
whole I prefer to introduce the tap cinder into the ladle in the solid form. The
reaction between the melted cast iron and tap cinder rapid at first gradually
slackens and at the end of about a quarter of an hour practically ceases..
During the treatinent in the ladle the silicon wholly or in great part oxidizes.
After the lapse of about a quarter of an hour the contents of the ladle are poured
into the converter to which the tap cinder is added either at the commencement or
at a later stage of the blow. I find it advisable to add the tap cinder before the
" after blow is half over, otherwise all the oxide added is not reduced.
Although I have described the way in which I prefer to employ the tap cinder;
that is to say, in portions added at different times yet the whole of the tap
cinder may. be added at once to the metal in the ladle, that is, before its intro-
duction into the converter with the same or nearly the same result.
Or the whole of the tap cinder may be added in the converter with good
results.
When the cast iron operated upon is rich in silicon I prefer to add the tap
cinder in portions as the addition of the whole at the early stage of the process
results in "boiling" and loss of metal.
The proportion which I have described of tap cinder to the iron under treat-
ment answers well for use generally but must be varied according to the quality
of the iron under treatment.
In the rolling of iron and steel and in the manufacture of iron and steel tubes
large quantities of scale or oxide of iron called roll scale and tube scale respectively
are produced. These scales consist of tolerably pure oxide of iron and may be
employed wholly or in part in place of tap cinder in carrying my invention into
effect.

page_text: The iron made according to my invention as hereinbefore described may be
converted while in a molten state into steel by the importation into it before its
removal from the converter of the requisite amount of carbon. This may be
effected by means of the compounds of iron, manganese and carbon commonly called
spiegeleisen and ferro-manganese as in the ordinary manufacture.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that I claim
as my invention of "Improvements in the manufacture of iron and steel:
"
Treating molten cast iron by means of the slag obtained in the puddling of iron,
commonly called tap cinder either added in the ladle by which the iron is
transferred from the cupola or blast furnace in which it is melted to the converter
in which it is treated by a blast of air or added in part to the molten iron in the
said ladle and in part to the molten iron when under treatment in the converter, or
added only to the molten iron in the converter; whether the said tap cinder be used
alone or in conjunction with or replaced by roll scale or tube scale substantially as
hereinbefore described.
Dated the 15th day of October 1892.
W. T. WHITEMAN,
Agent for the Applicant.