CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSIAH
MARSHALL HEATH, of Allan Terrace, Kensington, in the County of Middlesex
Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Fifth day of April, in the second year of Her reign, and
in the year of our Lord One thousand eight hundred and thirty-nine, did, for
Herself, Her heirs and successors, give and grant unto me, the said Josiah
Marshall Heath, Her especial licence, full power, sole privilege, and authority,
that I, the said Josialı Marshall Heath, my executors, administrators, and
assigns, and such others as I, the said Josiah Marshall Heath, my executors,
administrators, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL;" in which said Letters
Patent is contained a proviso, obliging me, the said Josiah Marshall Heath,
by an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the
same is to be performed, and to cause the same to be enrolled in Her
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in

page_text: and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the above proviso, I, the said
Josiah Marshall Heath, do declare the nature of my said Inventions to be,
first, the extraction of pure cast iron. from certain ores of that metal without
the intervention of any earthy, alkaline, or saline matter, to form a vitreous
flux, cinder,-or-slag.
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Secondly, the formation of cast steel, by fusing the said pure cast iron along
with malleable iron or certain metallic oxides, in such proportion as may
decarburate the cast iron to a certain degree, and by completing the decar-
buration in a suitable cementing furnace.
Thirdly, the use of a certain portion of oxide of manganese in the process
of converting cast iron into malleable iron, by the process of puddling.
And, fourthly, the use of carburet of manganese in any process whereby
iron is converted into cast steel.
And in further compliance with the said proviso, I, the said Josiah Marshall
Heath, do declare the manner in which my said Inventions are to be per-
formed, by the following general explanations and particular details of the
several processes:
Malleable iron is at present produced by smelting the richer iron ores with
just as much charcoal or other carbonaceous matter as shall be adequate to
abstract all the oxygen from the ore and bring it into the malleable state, or
by smelting the ore in contact with carbonaceous matter in such excess as to
form with the metal the compound called carburet of iron by chemists, and
cast iron by manufacturers, and then to separate the carbon by a distinct and
subsequent process.
The first of these methods is that practised upon the purer native oxides
of iron in the Catalan forges of the Pyrenees, in the stück ofen of Carinthia,
and in the bloomeries of India; the second is that practised in the blast
furnaces of Great Britain upon the argillaceous ores of iron. By the first
process malleable or bar iron of very unequal quality in its different parts is
produced; by the second process a cast iron is obtained which is contaminated
to a very considerable degree with sulphur, phosphorus, arsenic, silicon,.
aluminum, &c., and by both processes a very large proportion of the metal is
wasted into cinder under the blast as well as in the operations of puddling.
and reheating the blooms. A pure native oxide or carbonate of iron is alone
capable of producing a pure metal covertible into good steel, but such pure
ores have been hitherto debased and deteriorated in the smelting by mixture
with earthy, saline, or alkaline matters under the name of fluxes, added with

page_text: the intention of promoting the reduction of the metal, and of protecting it
when reduced from the oxidizing influence of the blast. I have discovered,
after an extensive course of experiments, that such earthy or other mixture
are not necessary towards the reduction of the pure native oxides and carbo-
nates of iron; and this discovery constitutes my first Invention under the
present Letters Patent.
This Invention consists in smelting such pure ore without the formation
of any vitreous flux, slag, or cinder, in manner as follows:-I commence
the operation by filling progressively my blast furnace with coke, charcoal,
or other equivalent fuel, leaving the tap hole open, that the flame of the
fuel urged by the blast may play in all directions, downwards as well as
upwards, so as to bring the whole interior of the furnace into a uniform state
of incandescence; and whenever the furnace is thus filled with ignited fuel I
close the tap hole, and immediately throw into the mouth of the furnace
twenty pounds of ore for every hundred pounds of fuel; and I continue to
charge the furnace at this rate until such time as it is calculated that three or
four hundredweight of fluid iron are collected in the hearths, at which time I
tap the furnace and run off the melted metal into pigs; after this first discharge
or casting, I begin to add the ore, at the rate of twenty-five pounds for every
hundred pounds of fuel, and continue to charge the furnace at this rate during
a period of twelve hours, at which time I tap and run off a second casting of
pig iron; after this second discharge I add ore at the rate of thirty pounds for
every hundred pounds of fuel during the third working period of twelve hours,
and thus in each successive period of twelve hours I increase the burthen of
ore at the rate of five per cent. of the weight of the fuel, till eventually the
proportion of ore shall amount to about sixty-five or seventy pounds for every
one hundred pounds of fuel. By proceeding in this way, and by throwing in
the ore merely reduced to the size of peas, or thereabouts, but not wasted, I
find that if the furnace be well attended to by the workmen, it will turn out
about fifty pounds of pure pig iron for every hundred pounds of fuel that
are consumed. I prefer to run the fused metal into iron moulds, because I
have found that when it is run into sand, as is commonly practised by the iron
smelters, it is apt to get covered with a coat of silicious matter, and is thereby
contaminated and subject to waste in the subsequent process of conversion
into malleable iron or steel; but I do not claim running the iron into iron
moulds as any part of my Invention. Having by the said process obtained a
pure cast metal, or a simple carburet of iron uncontaminated with the sulphur,
phosphorus, silicon, and other metalloids present in ordinary cast iron, I next
proceed to convert that carburet into steel of any degree of hardness, which

page_text: conversion I perform as follows:-I first melt the said cast iron in a cupola
furnace by the heat of coke as free from sulphur as possible, or by a mixture
of such coke and anthracite, or, in certain localities, by wood charcoal; but
in all cases I use no more fuel than is merely requisite to melt the iron, so that
the oxygen of the blast shall serve to burn away the carbon of the carburet
in a considerable degree, while I neutralize or remove a further portion of
the carbon by the addition of scraps of metallic iron, or by the oxides of iron
or of manganese, always taking care not to decarburate the metal to such a
degree as to render it infusible, but to leave about as much carbon in it as
exists in cast steel. For the purpose of producing a superior article of cast
steel from my said pure cast iron obtained by the above-described process,
I introduce sesquioxide of manganese, or peroxide which had been previously
ignited, in quantities not exceeding five per cent. into the cupola, while I
employ no more fuel than the blast can readily burn into carbonic acid, for
otherwise the excess of the carbonaceous fuel would deoxidize the manganese,
nullify its decarburating action upon the cast iron, and thus prevent it from
reducing the metal to that lower stage of carburet which constitutes cast steel.
I also sometimes introduce into the cupola for the same decarburating purpose
a portion not exceeding five per cent. of chrome ore, which consists of the
oxides of chrome and iron, or a like proportion of pure oxide of iron. When
the decarburation has been carried on in the cupola to the proper pitch, as has
been already defined, the steely metal is to be run out and cast into iron
moulds. The ingots thereby formed are now to be converted into steel of any
desired degree of mildness, by a further process of decarburation, which con-
sists in stratifying the said ingots alone with peroxide of iron or peroxide of
manganese without charcoal, in a steel cementing or other suitable furnace,
such furnace being lined with iron, if it is constructed of fire bricks or stone,
to prevent the action of the peroxides upon the stone or bricks of the furnace;
the ingots are to be bere subjected to a cementing heat for a certain period
proportional in duration to the softness required in the metal. I farther pro-
pose to improve the quality of malleable or bar iron by adding to the pig or
plate iron in the puddling furnace, while in fusion, from one to five per cent.
or thereabouts of any pure oxide of manganese, but without mixture of any
other substance; the sesquioxide being that which I prefer.
Lastly, I propose to make an improved quality of cast steel, by introducing
into a crucible bars of common blistered steel, broken as usual into fragments,
or mixtures of cast and malleable iron, or malleable iron and carbonaceous
matters along with from one to three per cent. of their weight of carburet
of manganese, and exposing the crucible to the proper heat for melting the

page_text: materials, which are, when fluid, to be poured into an ingot mould in the usual
manner; but I do not claim the use of any such mixture of cast and malleable
iron, or malleable iron and carbonaceous matter, as any part of my
Invention,
but only the use of carburet of manganese in any process for the convertion
of iron into cast steel. I claim,-
First, the reduction of the pure native oxides and carbonates of iron into
cast iron, without the intervention of flux or the production of cinder.
Second, the production of cast steel, by decarburating cast iron to a certain
degree in a cupola or other suitable furnace or crucible, with the addition of
malleable iron or certain metallic oxides, and completing the decarburation to
the required degree by subsequent cementation in a suitable furnace with an
oxide of manganese or an oxide of iron, without any admixture of carbona-
ceous matter.
Third, the employment of oxide of manganese alone in the puddling of
cast iron.
And, fourth, the employment of carburet of manganese in preparing an
improved cast steel.
In witness whereof, I, the said Josiah Marshall Heath, have hereunto
set my hand and seal, this Fourth day of October, in the year of our
Lord One thousand eight hundred and thirty-nine.