IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON
Year: 1866

page_text: LETTERS PATENT to Warren de la Rue, of Bunhill Row, in the City of
London, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
STEEL AND IRON."
Sealed the 24th July 1866, and dated the 2nd May 1866.
PROVISIONAL SPECIFICATION left by the said Warren de la Rue at
the Office of the Commissioners of Patents, with his Petition, on the
2nd May 1866.
I, WARREN DE LA RUE, of Bunhill Row, in the City of London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF STEEL AND IRON," to be as follows:-.
This Invention has for its object improvements in the manufacture of steel
and iron. It is well known in the manufacture of steel and iron by what is
called the Bessemer process that it is difficult to separate phosphorous from
the metal; now my Invention consists in the introduction of lead or com-

page_text: pounds of lead into the converting vessel so that the same may be thoroughly
diffused amongst the fluid metal therein, thus the phosphorous is separated
from its combination with the iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Warren de la Rue in the Great Seal Patent Office on the
1st November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WARREN
DE LA RUE, of Bunhill Row, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of May, in the year of our Lord One
thousand eight hundred and sixty-six, in the twenty-ninth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Warren de la Rue, Her special licence that I, the said Warren de la Rue,
my executors, administrators, and assigns, or such others as I, the said Warren
de la Rue, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF STEEL AND IRON," upon the condition (amongst others) that
I, the said Warren de la Rue, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Warren de la Rue, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
thereof, that is to say:-
This Invention has for its object improvements in the manufacture of steel
and iron. It is well known in the manufacture of steel and iron by what is
called the Bessemer process that it is difficult to separate phosphorus from
the metal; now my Invention consists in the introduction of lead or com

page_text: pounds of lead into the converting vessel so that the same may be thoroughly.
diffused amongst the fluid metal therein, thus the phosphorus is. separated:
from its combination with the iron.
Having thus stated the nature of my said Invention I will proceed more
fully to describe the manner of performing the same.
Into the converting vessel used in the Bessemer process of converting cast
iron into steel or homogeneous iron either metallic lead or compounds of lead
are introduced with the object of removing the phosphorus which the metal
may contain. If metallic lead be employed it is introduced in a molten state
(in proportions considerably greater than would be required by theory to
combine with the quantity of the phosphorus contained in the metal to
be acted upon) directly into the converting vessel, and the blast continued with
the object of oxidizing the lead and the phosphorus. When metallic lead is
employed it should be introduced as soon as the blast has been turned into the
converting vessel. If compounds of lead are used it is convenient to cause
them to enter with the blast in the state of powder by placing them in a
funnel-shaped vessel, which may be closed air-tight, and in which there is
a provision for communicating (both at the top and the bottom of the vessel)
with the blast pipe, the powder is caused to fall by means of a tappet motion or
otherwise to cause a vibration in the vessel and its contents, and the feed is
regulated by a suitable slide which will open and close at will. Peroxide of
lead, red lead, litharge, nitrate of lead, are convenient to employ, but I do
not restrict myself to the use of these oxy-compounds as other compounds may
be used; but in all cases I use the lead or compounds of lead in combination
with the blast in the converting vessel of the Bessemer process, and I would
state that I am aware that it has been proposed to use litharge in the puddling
process, to which I make no claim. The proportion of lead or lead com-
pounds used should be in large excess over that which analysis would show to
be required for combining with the phosphorus present in the iron or steel in
the converting vessel, for an excess of lead or lead compounds will not
prejudice the process, but will only increase the cost. About 200 lbs. of lead
to each ton of cast iron, or so much of the compounds of lead as would
contain about 200 lbs. of lead to each ton of cast iron, are generally sufficient,
but as much depends upon the mode of conducting the operation, by variations
of which more or less lead is carried off without producing any useful effect,
it is not possible to give any exact proportions of lead or lead compounds in
relation to the per-centage of the phosphorus impurities, which seldom indeed
exceed one per cent. of the weight of the iron to be operated on. If much

page_text: lead is carried off by the blast without acting usefully the quantity before
stated must be increased.
In witness whereof, I, the said Warren de la Rue, have hereunto set
my hand and seal, this Thirtieth day of October, in the year of our
Lord One thousand eight hundred and sixty-six.
WARREN DE LA RUE. (Ls.)