Improvements in the Production of Steel and in the Refining of Iron Ore.
Year: 1896

page_text: Date of Application, 18th Aug., 1898-Accepted, 24th Dec., 1896
[Communicated from abroad by HUGO SOHWEITZER, of the City of New York,
and EMILE LUNGWITZ, of Brooklyn, in the County of Kings, both in the
State of New York, United States of America, Chemists.]
Improvements in the Production of Steel and in the Refining of
Iron Ore.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement:-
In the manufacture of steel after the method introduced by Bessemer, it has
been essential to have at command iron ore of good quality, free from sulphur and
phosphorus, because the sulphuric and phosphoric acid formed during the process
owing to the oxidation of sulphur and phosphorus were reduced again by the
melted iron at white hent.
In this
The ore free from sulphur and phosphorus being, considerably more expensive
than iron ore, containing a larger percentage of sulphur and phosphorus,
Thomas & Gilchrist introduced the use of lime in the Bessemer process.
manner they effected the formation of lime salts of sulphuric and phosphoric acid.
These lime salts could not be secondarily reduced by the iron, even at the highest
temperatures, and were removed from the metal in the form of slags. Thus the
Thomas & Gilchrist process permits the use of iron oro for the manufacture of
steel which contains larger amounts of sulphur and phosphorus.
In the Thomas & Gilchrist process, however, the metal does not come in perfect
contact with the lime, which is in different ways prevented from reacting on the
formed acids.
Again it is a known fact that the Thomas & Gilchrist process works only
satisfactorily with iron containing a quantity of phosphorus, not less than about
from 2 to 3 per cent. This amount of phosphorus being necessary to produce
a heat sufficiently high for keeping the mass liquid.
.
On the other hand, the Bessemer process works only with iron poor in phosphorus.
Thus it is seen that there are a great variety of ores which cannot be utilized for
the manufacture of iron wbich is to be converted into steel.
My process, however, permits the utilization of any kind of iron ore containing
much or little phosphorus, that is, ore of any purity whatever for the conversion of
iron into steel.
I propose to convert iron into steel by using calcium carbide. In doing so we
have the following advantages:
1st. Thorough mixing of the calcium carbide and the iron.
2nd. The formation of lime in statu nascendi from the calcium carbide.
3rd. A very strong reaction between the lime in statu nascendi and the formed
acids.
4th. A higher temperature in the converter, owing to the formation of lime from
calcium carbide.
5th. Carburization of steal by the carbon of the calcium carbide.

page_text: In carrying out my invention I introduce into the converter an excess over the
quantity of calcium carbide, either in pieces or in a melted state, which is necessary
to furnish the lime for the combination with the sulphuric aud phosphoric acid
formed from sulphur and phosphorus, and proceed otherwise in the manner well
known in the art of manufacturing steel.
The calcium carbide may be introduced into the converter at the beginning of
the operation, although it is proferable to charge the converter, with it some time
after the blast has been started. All this depends on the chemical composition of
the raw iron.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manuer the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is :-
1. The step in the process of manufacturing steel from iron, which consists in
treating the melted iron with carbide of calcium in a converter, substantially as
described.
Dated this 18th day of August 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.