Improvements in the Manufacture of Steel or Malleable Iron from Cast Iron.
Year: 1898

page_text: Date of Application, 26th Mar., 1898
Complete Specification Left, 10th June, 1898-Accepted, 23rd July, 1898
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Steel or Malleable Iron from
Cast Iron.
•
I, JOHN ALEXANDER HUNTER, of 1925, South Broad Street, in the City and
County of Philadelphia, State of Pennsylvania, United States of America, Doctor
of Medicine, do hereby declare the nature of this invention to be as follows:-
My invention relates to the process of converting cast iron into steel, or malleable
iron, by subjecting the cast iron, while highly heated, to the action of oxygen.
evolved by chemical action, or reaction of materials contained in a crucible, or
retort, or upon the hearth where the treatment is effected, the object of my inven-
tion being to effect the evolution of the oxygen without the formation of salts
which have a tendency to combine with, and destroy, the lining of the furnace, and
in the case of the use of the crucible, or retort, without such ebullition as would
cause them to leave the crucible and gain access to the lining of the furnace.
In carrying out my invention, I employ sulphuric acid and an oxide, or salt,
which when subjected to the action of the acid will be decomposed, so as to liberate
oxygen and form, with the sulphuric acid, a sulphate of its original base.
The iron to be treated may be contained in a closed crucible, sagger, or retort,
into which the sulphuric acid and oxide, or salt, are also introduced, the vessel,
with its contents, being then subjected to heat in a furnace. Or the iron may be
first heated, and the chemical compound then be introduced into the vessel contain-
ing the heated iron. Or the iron may be heated upon the hearth of a closed, or
muffle, furnace, and, after the proper degree of heat has been reached, the chemical
compound contained in a suitable vessel, may be introduced into the furnace. so as
to provide for the necessary evolution of oxygen for action upon the heated iron.
In no case, however, is the treating agent packed around the iron in the crucible,
sagger, or retort, as in the ordinary cementation process; the aim on the contrary
being to expose as much of the surface of the iron as possible to the action of the
gas generated in, or introduced into, the vessel containing the said iron.
My invention may be carried out by the use of sulphuric acid with any of the
oxides, or salts, which will be decomposed by the acid, so as to free oxygen, and
form a sulphate of the original base, which will have no tendency to escape from
the vessel in which it is contained, and which, even if it do escape therefrom, will
have no injurious effect upon the fire-brick lining of the furnace.
I may, for instance, use oxide of manganese, hypochlorite of lime, chlorate, or
nitrate, of potash, or other compound having a metallic, or earthy, base.
Dated this 26th day of March 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Steel or Malleable Iron from
Cast Iron.
I, JOHN ALEXANDER HUNTER, of 1925, South Broad Street, in the City and
County of Philadelphia, State of Pennsylvania, one of the United States of
America, Docter of Medicine, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to the process of converting cast iron into steel or malleable
iron by subjecting the cast iron, while highly heated, to the action of oxygen evolved
by chemical action, or reaction of materials contained in a crucible, or retort, or upon
the hearth where the treatment is effected, the object of my invention being to effect
the evolution of the oxygen without the formation of salts which have a tendency
to combine with, and destroy, the lining of the furnace, and, in the case of the
use of the crucible, or retort,, without such ebullition as would cause them to leave
the crucible and gain access to the lining of the furnace.
In carrying out my invention I employ sulphuric acid and an oxide, or salt,
which, when subjected to the action of the acid, will be decomposed, so as to liberate
'oxygen, and form, with the sulphuric acid, a sulphate of its original base.
The iron to be treated may be contained in a closed crucible, sagger, or retort,
into which the sulphuric acid and oxide, or salt, are also introduced, the vessel,
with its contents being then subjected to heat in a furnace. Or the iron may be
first heated and the chemical compound then be introduced into the vessel contain-
ing the heated iron. Or the iron may be heated upon the hearth of a closed, or
muffle, furnace, and, after the proper degree of heat has been reached, the chemical
compound, contained in a suitable vessel, may be introduced into the furnace, so as
to provide for the necessary evolution of oxygen for action upon the heated iron.
In no case, however, is the treating agent packed around the iron in the crucible,
sagger, or retort, as in the ordinary cementation process, the aim, on the contrary,
being to expose as much of the surface of the iron as possible to the action of the
gas generated in, or introduced into, the vessel containing the said iron.
My invention may be carried out by the use of sulphuric acid with any of the
oxides, or salts, which will be decomposed by the acid, so as to free oxygen and
form a sulphate of the original base which will have no tendency to escape from
the vessel in which it is contained and which, even if it do escape therefrom, will
have no injurious effect upon the fire-brick lining of the furnace.
I may, for instance, use oxide of manganese, hypochlorite of lime, chlorate, or
nitrate, of potash, or other compound having a metallic, or earthy, base.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
The process herein described of converting cast-iron into steel, or malleable iron,
the said process consisting in heating the iron and, without packing the iron,
introducing into the furnace, or vessel, in which the said iron is heated, a mixture
of sulphuric acid, and an agent which will be decomposed by said acid, so as to
free oxygen, and form a sulphate of its original base; substantially as hereinbefore
explained.