IMPROVEMENTS IN THE PRODUCTION OF IRON AND STEEL
Year: 1872

page_text: LETTERS PATENT to Frederick William Gerhard, of Wolverhampton,
in the County of Stafford, Metallurgical Chemist, and James Light,
junior, of Bradley, in the County of Stafford, Ironfounder, for the
Sealed the 30th August 1872, and dated the 16th March 1872.
PROVISIONAL SPECIFICATION left by the said Frederick William
Gerhard and James Light, at the Office of the Commissioners of
Patents, with their Petition, on the 16th March 1872.
WC, FREDERICK WILLIAM GERHARD, of Wolverhampton, in the
County of Stafford, Metallurgical Chemist, and JAMES LIGHT, junior, of
Bradley, in the County of Stafford, Ironfounder, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE PRODUCTION OF
IRON AND STEEL," to be as follows:-
The said improvements consist, firstly, in the production of what we
term "iron coke," which is composed either of iron scales, alone or

page_text: mixed with any description of powdered iron ores, whether calcined or
not, or is composed of such ores taken by themselves or mixed together,
such ores being by preference hematites and magnetites. The said
scales or ores being mixed (by preference into a paste) with pitch or
other bituminous or sticky substance, and with carbonate or milk of
lime, and in sufficient proportions to cause it to adhere together, are
placed in coke or similar ovens and treated in the same way as coke is
prepared; or the said scales and ores or mixture thereof may be mixed
with coal tar and treated in a similar manner as is employed in the
manufacture of Patent fuel (a mixture of fine coal and tar compressed
into cakes), or the paste or mixture may be dried in a similar manner to
that employed for drying bricks.
The proportions in forming the said first described mixture or paste
are in 100 parts about 77 scales, 11 pitch or other bituminous or sticky
substance, and 11 carbonate or milk of lime when the said scales are
used; or for hemitite ore about 73 of the ore, 13½ of pitch or other
bituminous or sticky substance, and 13 of carbonate or milk of lime,
about the same relative proportions being used in the case of a mixture
of scales with ore according to the proportions of the mixture.
To produce wrought iron we employ a convenient size of furnace, say
about 2 or 3 feet diameter, constructed with a combustion chamber to
produce carbonous oxide gas by blast, to act as the reducing agent on
the "iron coke," which is broken into pieces and added as required with
or without the addition of iron scraps, coke, charcoal, or other carbona-
ceous matter.
To produce steel from about one to five per cent. of the oxide of
manganese according to the quality of the steel required is added to the
"iron coke," in its preparation, and steel produced in a similar furnace
to that described as employed in the production of wrought iron; in this
case also iron scraps, coke, charcoal, or other carbonaceous matter can
be added.
In the production of cast iron the above mixture as described for the
production of wrought iron may be used, with also the addition of coke,
charcoal, or other carbonaceous matter, and reduced in a furnace similar
to the ordinary type of blast furnace. Or the "iron coke" can be mixed
as follows-In 100 parts about 70 scales, ores or mixture, 12 lime,
10 pitch or other bituminous matter, and 7 charcoal or any description

page_text: of carbon, and the "iron coke" for the production of wrought iron and
steel may be prepared in a similar manner; fluxes may be added in
the production of the "iron coke" or in any other way such as chloride
of sodium, carbonate of soda, fluor spar, and fire-clay.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick William Gerhard and James Light
in the Great Seal Patent Office on the 12th September 1872.
SHALL COME, WC,
TO ALL TO WHOM THESE PRESENTS
FREDERICK WILLIAM GERHARD, of Wolverhampton, in the County of
Stafford, Metallurgical Chemist, and JAMES LIGHT, junior, of Bradley,
in the County of Stafford, Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of March, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Frederick William Gerhard and James Light,
junior, Her special licence that we, the said Frederick William Gerhard
and James Light, junior, our executors, administrators, and assigns, or
such others as we, the said Frederick William Gerhard and James
Light, junior, our 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 PRODUCTION OF IRON AND STEEL,"
upon the condition (amongst others) that we, the said Frederick William
Gerhard and James Light, junior, our executors or administrators, by an
instrument in writing under our, or their, or one of their hands and
seals, should particularly 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.

page_text: NOW KNOW YE, that we, the said Frederick William Gerhard and.
James Light, junior, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement (that is
to say):
:-
Our improvements have for their object a considerable reduction in
the cost of producing iron and steel, and consist, firstly, in the production
of what we term “iron coke," which is composed either of iron scales
alone or mixed with any description of powdered iron ores, whether
calcined or not; or is composed of such ores taken by themselves or
mixed together (such ores being by preference hematites and magnetites),
the said scales or ores whether taken by themselves or mixed together
being moistened with water and mixed (by preference into a paste) with
pitch or other bituminous or sticky substance in sufficient proportion
to cause it (the mixture) to adhere together when prepared and with
carbonate or milk of lime (by preference carbonate), and placed in coke
or similar ovens and treated in the same way as coke is prepared; or
the said scales and ores or mixture thereof may be mixed with coal
tar instead of the pitch and treated in a similar manner as is employed
in the manufacture of Patent fuel (a mixture of fine coal and tar); or
the paste or mixture may be dried in a similar manner to that employed
for drying bricks.
The proportions in forming the said first described mixture or paste
are in 100 parts about 7 scales, 11 pitch or other bituminous or sticky
substance, and 11 carbonate or milk of lime when the said scales are
used, or when hematite ore is used then in 100 parts about 73 of the ore,
13 pitch or other bituminous or sticky substance, and 13 of carbonate
or milk of lime, the same relative proportions being used in the case of
a mixture of scales with ore according to the proportions of the
mixture.
To produce wrought iron we employ a convenient size of furnace
constructed with a combustion chamber to produce carbonous oxide gas
by blast to act as the reducing agent on the "iron coke," which is
broken into pieces and added as required. Iron scraps may be added, as
may also coke, charcoal, or other carbonaceous matter.
To produce steel from about 1 to 5 per cent. of the oxide of
manganese, according to the quality of the steel required, is added to the

page_text: "iron coke" in its preparation, and steel produced in a similar furnace
to that described as employed in the production of wrought iron. In
this case also iron scraps may be added, as also coke, charcoal, or other
carbonaceous matter.
In the production of cast iron the above mixtures as described for the
production of wrought iron may be used, with also the addition of coke
or other carbonaceous matter and reduced in a furnace similar to the
ordinary type of blast furnace; or the "iron coke" can be mixed as
follows: In 100 parts about 70 scales, ores or mixtures, 12 lime, 10
pitch or other bituminous or sticky matter, and ½ charcoal, or any
description of carbon; and the "iron coke" for the production of
wrought iron and steel may be prepared in a similar manner. Fluxes,
such for instance as chloride of sodium, carbonate of soda, fluor spar,
and fire clay, may be added in the production of the "iron coke" or in
any other way.
The proportions of carbon (carbonate of lime by preference), and
silicate of alumina or fire-clay (when required to form a fusible slag),
can only be ascertained from an analysis of the ores or scales, as for
instance:
The protoxide of iron containing 77-78 per cent. of
Carbon.
iron requires
21.43
=
The magnetic oxide of iron containing 72·41 per cent.
of iron requires
28.56
The peroxide of iron containing 70,00 per cent. of
iron requires
32.17
and the intermediate per-centages of iron will require carbon in a pro-
portionate ratio.
We have given these proportions according to their chemical
equivalents, but in practice the proportions will be somewhat exceeded.
If there should be a difficulty in procuring pitch or tar we distil good
slack or fine coal in a suitable vessel; the coke remaining after the tar
has been extracted can be used instead of charcoal, if required, in the
proper proportion after pulverising with the iron ore or scale and
carbonate of lime.
In the drying of the mixtures before described we find that a low
temperature of from 200 to 300 degrees of Farenheit's scale or there-

page_text: abouts is sufficient in the furnace or oven, and that if carefully heated
there is little or no waste of carbon.
"
Having now particularly described and ascertained the nature of our
said Invention, and in what manner the same may be performed, we
declare that we claim, the manufacture of "iron coke as herein-before
described with the production therefrom as herein explained of wrought
iron, steel, and cast iron; and though we have given certain proportions
for the ingredients of the mixtures with the method of mixing and
drying, we do not limit ourselves to the exact proportion and description
as set forth, but claim such proportions, mixtures, and method of drying
as follow obviously, and are in harmony with the general description of
this our Invention.
In witness whereof, I, the said Frederick-William Gerhard, on behalf
of myself and the said James Light, junior, have hereunto set my
hand and seal, this Eleventh day of September, in the year of our
Lord One thousand eight hundred and seventy-two.
F. W. GERHARD. (L.S.)