mprovements in the manufacture of Steel and Iron and in Obtaining Bye Products of such Manufacture.
Year: 1887

page_text: mprovements in the manufacture of Steel and Iron and in
Obtaining Bye Products of such Manufacture.
I, CARL SCHEIBLER of Berlin in the Empire of Germany Doctor of Philosophy 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:-
This Invention relating to improvements in the manufacture of steel and iron and
in obtaining bye products of such manufacture consists in certain improvements
hereinafter described on the process described in the Specification of former Letters
Patent granted to me and dated May 7th 1885 No. 5646.
The said process consists in introducing the lime or flux used in the Bessemer
process in two different portions at different stages of the operation and removing the
slag in separate portions with the object of obtaining in the first stage, a slag rich in
phosphate of lime and in the second stage a slag that is relatively so rich in iron and
deficient in phosphorous as to be suitable for treatment in the blast furnace.
According to the prescut Invention the process is conducted in such a manner that
the ferruginous slag resulting from the second stage of the process is not contaminated
with any remains of the phosphatic slag obtained in the first stage and the two slags
are completely separated. With this object the first stage only of the process is
performed in the Bessemer converter with the basic lining the second stage, after the
phosphoric slag has been separated from the metal, being conducted in a reverberatory
furnace on a basic or neutral hearth with the addition of the second quantity of lime
or flux.
In conducting the process according to the method described in my said former
Specification it is not possible by tilting the converter to run out or separate more
than a part of the slag obtained in the first period and rich in phosphate of lime
without at the same time pouring away to waste a certain quantity of incompletely
blown or reduced metal into the receptacle for the slag. It is consequently necessary
to allow a considerable portion of the phosphatic slag produced in the first stage of
the operation to remain in the converter.
This remnant of slag containing phosphoric acid diminishes the energy of the
reaction in the second stage and contaminates the ferruginous slag secondly obtained
in such a manner as to diminish its suitability for subsequent use in the blast furnace.
013

page_text: By means of the present Invention these disadvantages are entirely obviated, the
first period of the process being conducted in the Bessemer converter with a basic
lining, as described in my said former Specification and being continued for half or
somewhat more than half the time required for completely eliminating the phosphorous
after which the whole of the metal is run out of the converter together with the
phosphatic slag. After being separated from the slag the metal is then placed as
quickly as possible on the hearth of a reverberatory furnace with a bottom of basic or
neutral materials where it is brought to the condition of cast iron or steel with the
addition of the second portion of the lime or flux.
By thus conducting the first of the two separate periods or stages of the process
described in my said former Specification Number 5646, A.D. 1885 in the converter
and conducting the second period or stage in the reverberatory furnace I obtain the
advantage that none of the first or phosphatic slag valuable for agricultural purposes,
is left in the converter as was unavoidably the case when the whole process was
conducted in the same vessel. At the same time the ferruginous slag of the second
period is preserved from the contamination resulting from combination with the
remainder of the slag produced in the first period the whole of the two slags being
removed separately and independently without being allowed to mix one with the
other. Moreover the bottom and lining of the converter require considerably less
frequent renewal through not being exposed to the more destructive action of the
final blast.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is :-
In manufacturing steel and iron and obtaining by products of such manufacture, as
described in the Specification to Letters Patent Number 5646 in the year of our Lord
1885, pouring, both the metal and the slag out of the converter after the first or
phosphatic slag is formed and completing the treatment with the addition of the
second portion of lime or flux in a reverberatory furnace having a basic or neutral
hearth all substantially as herein before described.
J. H. JOHNSON & CO.,
Agents.