CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF IRON;
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
LEVER RUSHTON, of Bolton-le-Moors, in the County of Lancaster, Iron
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twenty-first day of June, in the eighth year of Her reign, did, for Herself,
Her heirs and successors, give and grant unto me, the said Thomas Lever
Rushton, my exors, adñiors, and assigns, Her especial license, full power,
sole privilege and authority, that I, the said Thomas Lever Rushton, my exors,
adiors, and assigns, or such others as I, the said Thomas Lever Rushton, my
exors, adiiors, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein expressed,.
should and lawfully might make, use, exercise, and vend, within that part of
the United Kingdom of Great Britain and Ireland called England, Her
Dominion of Wales, and Town of Berwick-upon Tweed, my Invention of
"CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF IRON;" in which said Letters
Patent is contained a proviso requiring me particularly to describe the nature
of my said Invention, and the manner in which the same is to be carried
into effect, by an instrument in writing under my hand and seal, to be
enrolled in Her Majesty's High Court of Chancery within six calendar months
next after the date of the same Letters Patent.
NOW KNOW YE, that, in compliance with the said proviso, I, the said
Thomas Lever Rushton, do hereby declare that my Invention consists of im-
provements in the manufacture of malleable iron in reverberatory furnaces, and

page_text: that the manner in which the same are to be carried into effect is fully
described and ascertained in and by the following statement:-
In the manufacture of malleable iron from pig or refined iron, it has long
been the custom to throw hammer slack, roll scale, red ore, calcined ironstone,
or other suitable material, consisting principally of oxide of iron, into the pud-
alling furnace for the purpose of protecting the sides and bottom thereof, and
with a view to "feed" or add to the weight of the product, owing to the de-
composition of their oxygen by the carbon contained in the pig iron. The
additional yield has, however, hitherto been only partially eflected owing to
the small quantity of carbon contained in the pig iron generally used for the
purpose.
My improvement in this respect consists in mixing the hammer slack, roll
scale, red ore, calcined ironstone, or other oxide, in a finely pulverized state,
with a proportion of finely pulverized charcoal, coke, or other suitable car-
bonaceous matter (which should be as free as possible from sulphur), and
introducing the mixture into the furnace before, or along with, or immediately
after the charge of pig or refined iron. The mixture of ore and carbena"eous
matter is from time to time turned over till the iron is melted, and both aro
then worked together in the usual way. This process is similar to that
described by Mr. William Neale Clay in the Specification of his Patent for
Improvements in the Manufacture of Iron, inrolled the Thirtieth of September,
One thousand eight hundred and forty, but the proportions I use vary from seven-
teen up to (but not including) twenty-eight per cent. in weight of carbonaceous
matter to the ore or oxide, according to circumstances, whilst his Invention is
confined to combining carbonaceous matters in quantities not less than twenty-
eight per cent. by weight of the iron ores employed. The proportionate weights
of carbonaceous matter and ore or oxide, which, within the limits above named,
I use, depend upon the quantity of carbon and oxygen they respectively con-
tain, the description of pig iron used with them, and the relative proportions
of pig iron to the mixture. I have found the following proportions give very
excellent quality and yield of iron. To four hundred and eighty pounds of
number four pig iron, I add eighty-four pounds of Lancashire hematite ore
pulverized and mixed with twenty pounds of powdered coke. If number one
pig iron be used a still less proportion of carbonaceous matter will suffice; but
if the charge of pig number four be reduced to four hundred and twenty
pounds, and the ore increased to one hundred and eighty pounds, the coko
should be forty-eight pounds. I do not limit myself to the definite quantities,
nor the precise proportions of iron, carbonaceous matter, and oxide here given,
as they will necessarily differ according to circumstances, but, as a general

page_text: :
principle, of the pig iron to be used be of a very fluid or highly carburetted
description, such as is generally designated as number one in the trade, then
the proportion of carbonaceous matter to the roll scale, red ore, or other oxide
of iron, should be proportionally less than if white or plate iron be employed,
and the proportion of carbonaceous matter should vary according to the relative
proportion of ore or oxide used with the pig iron, it being adviseable to use a
larger relative quantity of carbonaceous matter with the ore or oxide when the
pig is comparatively reduced in weight than when more pig is used. I may
also add that when the mixture amounts in weight to one fourth of the weight
of pig iron charged, the mixture should be introduced into the furnace sooner
than the pig iron, and turned over till it begins to adhere to the workman's
rabble or tool; when the pig may be charged, but smaller proportions, if
charged. with the pig iron, will generally "come round" by the time it is
melted. I do not prefer in any case introducing the mixture after the pig iron.
My second improvenient consists in the addition of clay, argillaceous ironstone,
or other substance containing alumina, to those ores or oxides which, manu-
factured by the aid of carbonaceous matter into malleable iron in reverberatory
furnaces, may produce iron of the quality usually denominated redshort. The
clay or other substance to be used should, like the ores and carbonaceous
matter, be ground fine and dried-before mixing, and a larger relative pro-
portion of carbonaceous matter to a given quantity of ore should be employed
than if no clay were added, as the clay, in addition to its capability when
fused of taking up some of the carbon, will, by diminishing the contact of the
carbonaceous matter with the ore or oxide, prevent so complete a decomposi-
tion as would otherwise take place, so that generally more than twenty-eight
per cent. of carbonaceous matter will be required to the ore when clay is used.
The proportion of clay to be used will vary with the nature of the ores
employed," but from four to ten per cent. in weight of the ore employed will
suffice with the Lancashire hematite ores. If too large a quantity of clay be
used the tap cinder will be very sluggish, and the ball, when under the ham
mer, will emit continued showers of darkish red cinder sparks, and if too little
be added the iron will retain some of its redshort quality. I have found the
ground fire clay from Wortley, near Leeds, very suitable as a substance for
effecting this improvement.
My last improvement consists in combining a portion of the tap or flue
cinder of puddling and ball furnaces with a portion of clay and chalk, car-
bonaceous matter and rich iron ore, or some of these substances, and manu-
facturing them, either with or without pig or refined iron, in reverberatory
furnaces into malleable iron. The same process of pulverizing, drying, and

page_text: mixing the several materials, as well as their treatment in the furnace as before
described, must, in this case, be pursued. To one hundred and fifty pounds of
tap cinder, containing seventy-one per cent. of protoxide of iron, I add one
hundred and fifty pounds of Lancashire hematite ore, fifty pounds of ground
Wortley fire clay, fifty pounds of chalk, and one hundred pounds of coke dust.
I do not, however, limit myself to these or to any proportions of the con-
stituents when tap or flue cinder are employed as above; nor do I necessarily
use iron ore with the cinder, though it is more advantageous to do so.
Having now described the nature of my said Invention, as well as the man-
ner of carrying the same into effect, I would add that I do not claim to have
discovered the manufacture of malleable iron in reverbatory furnaces, either
with or without a portion of pig or scrap or refined iron, nor the advantage of
pulverizing the ores and carbonaceous matter; but I claim, as my first im-
provement, the manufacture in reverberatory furnaces, in manner herein-before
mentioned, of malleable iron, by means of ores and carbonaceous matter
mixed in proportions limited as before defined, and combined with a portion
of pig or refined iron.
In my second improvement I do not claim to have discovered the advantage
of using a portion of clay or argillaceous ironstone in the manufacture of iron
from certain ores, that having long been done in the manufacture of pig iron
from such ores; but I claim the use of clay as an ingredient to be employed in
a pulverized state, mixed with certain ores and carbonaceous matter, also
pulverized, for the manufacture both with and without pig or refined iron of
malleable iron in reverbatory furnaces.
In my last improvement I do not claim to have first applied a portion of tap
or flue cinder, or other silicate of oxide of iron, with lime or carbonate of lime
and rich iron ore, clay, and carbonaceous matter, all these having long been
used in the manufacture of pig iron; but I claim the manufacture of malleable
iron from the combination of those substances pulverized (both with and with-
out pig or refined iron) in reverberatory furnaces as before described.
In witness whereof, I have hereunto set my hand and seal, the Eighteenth
day of December. 1844.

page_text: AND BE IT REMEMBERED, that on the Eighteenth day of December,
in the year of our Lord 1844, the aforesaid Thomas Lever Rushton came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to tenor of the Statute made for that purpose.
Enrolled the Twentieth day of December, in the year of our Lord Ono
thousand eight hundred and forty-four.