CERTAIN IMPROVEMENTS IN MANUFACTURING IRON;
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GOSSAGE, of Stoke Prior, in the County of Worcester, Manufacturing Chemist,
send greeting.
WHEREAS Her present inost Gracious Majesty hath granted unto me
Her Letters Patent, sealed at Westminster, the Eighteenth day of June, in the
first year of Her reign, for making, using, exercising, and vending within
that part of the United Kingdom of Great Britain and Ireland called England,
Ier Dominion of Wales, and Town of Berwick-upon-Tweed, and also in all
Her said Majesty's Colonies and Plantations abroad, my Invention of " CERTAIN
IMPROVEMENTS IN MANUFACTURING IRON;" subject to the usual proviso obliging
me to describe and ascertain the nature of my said Invention, and in what
manner the saine is to be performed, by an instrument in writing under my
hand and seal, and to cause the same to be inrolled in the High Court of
Chancery within six calendar months next after the dato of the said Letters
Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Gossage, do hereby describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, as follows (that
is to say):-
The method of converting pig or crude iron into malleable iron by first
melting the pig or crude iron in a furnace called the "finery," and separating
a considerable portion of the earthy impurities contained in such iron, and
afterwards submitting the iron to the process called "puddling," and subse-

page_text: quently to the operation called shingling, is well known. It is also known to
manufacturers of malleable iron, that during the operation called "shingling, as
conducted in the above-mentioned method of converting pig or crude iron into
malleable iron, a large quantity of black scoria, which is technically called
hammer slag, is separated from the metallic iron, and that this hammer slag
consists of iron.combined. with oxygen, and is nearly free from carthy matter.
An improvement upon the above-mentioned method of converting pig or crude
iron into malleable iron has been adopted, which improvement consists in
using the "hammer slag, obtained as before described, for the purpose of
purifying pig or crude iron, and converting such iron into malleable iron by the
operation called puddling without the previous application of the "finery"
process. In working according to this improvement, hammer slag is put into
the puddling furnace with pig or crude iron in the first instance, and the opera-
tion of puddling then proceeds according to a method well known, during
which operation a boiling up or effervescence takes place, and the earthy
impurities become fluxed into cinder, which separates from the iron. After the
operation called puddling has been completed, the iron which has been sepa-
rated is submitted to the process called shingling, in the same manner as
is practised in working upon the old method, and a black scoria, which is
also called hammer slag, is thereby separated from it, which hammer slag
consists of iron combined with oxygen; but it also contains a considerable
portion of carthy matters which render this hammer slag unfit to be used for
purifying pig or crude iron in the puddling furnace, the manufacturer is
therefore obliged to continue the "finery" process in part, in order to obtain
"hammer slag" of suitable quality to be used for purifying pig or crude iron
in the puddling furnace in the first instance. I consider that the action of
the "hammer slag" used in the puddling furnace, as herein referred to, consists
in furnishing oxygen, which disengages the carbon contained in the pig or crude
iron, and in supplying oxide of iron, which, combining with earthy impuritics
contained in such pig or crude iron, forms the fusible compound called cinder.
One of the objects of my Invention is, to supply a cheap material to be used
as a substitute for "hammer slag" in puddling pig or crude iron. For- this
purpose I use the common argillaceous iron stone, which is found generally in
the coal districts of this country. This material contains oxide of iron con-
bined with carbonic acid, and by roasting or calcining it in the ordinary
method I convert the carbonate of iron which it contains into oxide of iron,
and render the stone capable of being more easily reduced to powder. I then
powder the calcined stone, and when this is powdered it may be applied alone
to the pig or crude iron in the puddling furnaces, but I prefer to mix the

page_text: powdered stone with lime in powder either in the state of quicklime or in the
state of carbonate of lime. The quantities of materials I usually employ for
four hundred and fifty pounds of pig or crude iron of average quality are,
thirty pounds of calcined iron stono and five pounds of slacked lime. I introduce
the mixed powder into the puddling furnace at the same time as the pig or crude
iron, closing the damper of the furnace to prevent the powdery materials being
carried off by the chimney draft; I then conduct the operation of puddling in
the same manner as when "hammer slag" is employed. As argillaceous
iron stone varies in the proportions of earthy matter and oxide of iron which it
contains, so the quantity of this stone required for purifying a given weight of
pig or crude iron will consequently vary. I find the proportions which I have
stated suitable when the iron stone which I use contains from forty to fifty per
cent. of oxide of iron; and when this is applied to pig or crude iron of fair
average quality, the proportion of lime required will vary according to the
proportion of earthy matters contained in the pig or crude iron and iron stone
respectively; but as it is not customary for manufacturers of iron to investi-
gate with accuracy the constitution of the pig or crude iron or other materials
which they employ, the most convenient mode will be to judge of the suitable
proportions of iron stone and lime by the progress of the operations. If the
workman finds that the cinder produced does not become sufficiently fluid to
separate from the malleable iron he should increase the proportion of lime
employed; and if the boiling up or effervescence which occurs during tho
puddling is not sufficient he should increase the proportion of iron stone
employed; but it will be understood that these last-mentioned directions are
intended to apply only to subsequent operations, and that it will not be neces
sary in any
instance to vary the proportions of any of the ingredients employed
after the operation of puddling has been commenced.
My improvements in the manufacture of iron also consist in the construc-
tion of a more durable sole for the furnaces employed in the operation of
"puddling." In the furnaces usually employed for this purpose the sole is a
plate of cast iron, which is protected from the action of the fire by "hammer
slag" and iron "scale," but instead of a sole of cast iron which requires this
protection I use a sole of such grit stone as possesses the quality of resisting
the action of fire; the stone which is usually employed for forming the
hearths of -iron smelting furnaces is suitable for the above purpose. I make
this sole either with one entire block of stone, or with several blocks fitted
together without cement; I construct the sole in a form similar to that of
the puddling furnaces now in use to provide for running off the cinder, and
I cause it to be sufficiently dished or hollowed out to retain the cinder without

page_text: allowing it to come in contact with the walls of the furnace. I prefer that the
sole should not be less than nine inches thick in any part; and as the furnaces.
will be similar to those now in use in all respects, except as above described,
I do not consider it necessary to give any further description of them. The
qualities required in the material used for constructing the furnace sole
according to my improvements are, a capability of enduring the action of fire,
and such compactness and hardness as will best resist the chemical action of
the fluxes to which the sole will be exposed in puddling iron, and which
qualities are found in the grit stones used for the hearth stones in blast
furnaces.
Having now described the nature of my said improvements, and the mode
of carrying the same into effect, I claim as my Invention the use of argillaceous
iron stone in the conversion of pig or crude iron into malleable iron by the
process called puddling, whether this argillaceous iron stone be used with lime
or other fluxing materials, or be used alone. And I claim the use of lime as a
fluxing material when used with any kind of iron stone or oxide of iron in
the conversion of pig or crude iron into malleable iron by the process called
puddling. And I claim, lastly, the use of such kind of stone as I have herein
described for constructing the soles of furnaces for "puddling" iron.
In witness whereof, I, the said William Gossage, have hereunto set my
hand and seal, this Thirteenth day of December, in the year of our
Lord One thousand eight hundred and thirty-eight.
WILL (L.S.) GOSSAGE.
AND BE IT REMEMBERED, that on the Thirteenth day of December,
in the second year of the reign of Her Majesty Queen Victoria, the said
William Gossage came before our said Lady the Queen in Her Chancery,
and acknowledged the Instrument aforesaid, and all and every thing therein
contained and specified, in form above written. And also the Instrument
aforesaid was stamped according to the tenor of the Statute made in the fifty-
fifth year of the reign of His late Majesty King George the Third.
Inrolled the Fourteenth day of December, One thousand eight hundred
and thirty-eight.