IMPROVE- WOWS TV MUD MANUFACTURE OF IRON
Year: 1852

page_text: LETTERS PATENT, to Sir Francis Charles Knowles, of Lovell Hill,
in the County of Berks, Baronet, for the Invention of "IMPROVE-
WOWS TV MUD MANUFACTURE OF IRON "
Scaled the 5th March 1853, and dated the 16th December 1852.
PROVISIONAL SPECIFICATION left by the said Sir Francis Charles
Knowles at the Office of the Commissioners of Patents, with
his Petition, on the 16th December 1852.
I, Sir FRANCIS CHARLES KNOWLES, of Lovell Hill, in the County
of Berks, Baronet, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF IRON" to be as follows:-
The several parts or divisions of my Invention are as follows:
1st. In order to supply to the richer ores of iron the earthy
matters in which the same are deficient, which earthy matters are
necessary in order to form, with an appropriate flux, a cinder to
protect the melted. iron from the blast during the process of
smelting, I take slags or wasted scoriæ thrown out from copper
works, and I add them to such rich iron ores in such a proportion
as that the total iron contained in the aggregate charge to be put
into the blast furnace, including the requisite flux or fluxes, shall

page_text: be from 35 to 50 per centum, or thereabouts, of the said aggregate
charge. The said copper slags admit of classification, according to
their contents in silica, and must be separated and treated
accordingly. The other earths--namely, alumina, lime, and magnesia
-must also be taken into account, after chemical analysis of the slags
of the fluxes and of the ores of iron to be smelted, reckoning every
5 parts of magnesia as equivalent to about 7 parts of lime in the
combination or aggregate of the charge to be formed, and to be put
into the blast furnace. This combination or aggregate is to be so
calculated as that it should contain every 3 parts of silica, 2 parts of
lime, and one part of alumina, allowing for magnesia its equivalent
in lime as aforesaid. As all the said slags contain an excess of
silica, it is best to select iron ore containing alumina, if they can be
cheaply obtained; but if not, a very aluminous shale must be used,
with the due proportion of lime or limestone in all cases, and in
forming the charge the iron contained in the copper slags (which
averages about 25 per centum, and is obtained incidentally,) must
be taken into the account.
2nd. The iron ore called "Blackband" is found to be after
calcination a heterogeneous mass, some parts of it being very rich,
others very poor in iron; these being thrown into the furnace
together indiscriminately, form charges of variable composition,
leading to great irregularities in the going of the furnace, and to
the production of coarse and weak cast iron. The richer parts are
readily distinguishable by their weight, and their dark purple
colour, and are in their earthy composition tolerably uniform: I
select these from the rest of the mass, and I combine them with an
appropriate shale, and lime or limestone, in such a manner that
the earths shall enter into the aggregate charge in the proportions
above described, and so that the working burden on the iron in the
aggregate charge shall be from 35 to 50 per centum of the shalc,
according to the strength of the fuel, and the degree of greyness of
the iron to be made. By this treatment I avoid the irregularities
at present occurring in the smelting of this ore, and I obtain cast
iron of superior quality as well as larger yields. The poorer parts

page_text: of the vein of Blackband may be used with appropriate fluxes with
rich forge cinders.
3rd. Where felspar is to be obtained cheaply, I use it as a flux in
smelting iron ores generally, for the purpose of adding potash to
fuel deficient therein, or soda in the case of soda felspar. The
potash or soda will be partially set free in the furnace, according to
the excess thereof in the charge beyond what is requisite for the
saturation of the silica of the charge with the other earths of the
same. The earths in the aggregate are to be calculated in the same
proportions as above; reckoning magnesia as above, and reckoning
59 parts of potash as equivalent to 35 of lime, and 39 parts of soda
as equivalent to the same. The effect of such addition of potash or
soda is to give liquidity to the cinders, and to furnish by its excess
the cyanide of potassium or of sodium, a powerful agent in reducing
the iron oves to be smelted.
4th. In order to make iron suitable to the manufacture of steel,
I take the richer ores of iron, and I use them, in conjunction with
peat coke, or charcoal of peat, in the common Catalan forge, or in a
forge resembling the same; using convenient fluxes to take up the
small quantities of earthy matters contained in such ores, adjusting
the said carthy matters in the charges as above; and I then work
and draw out the iron as in the Catalan method.
5th. In order to make inalleable or bar iron directly from the
richest ores of iron, I reduce the said ores to about the size of small
gravel, and I "boil" the same in the ordinary puddling furnace, in
conjunction with powdered or crushed peat, or wood charcoal,
powdered coke, where the same is rich in carbon, or powdered
anthracite coal, adding a convenient flux adjusted as above described,
in order to form a proper cinder, and to take up the small quantities
of carthy matter in the said rich iron ores. The iron is then to be
hammered and rolled as usual.
6th. I use in puddling or balling furnaces for the manufacture of.
iron, the gases obtained from the dry distillation of peat or of coal
in the ordinary way of making gas, or I use similar gases however
obtained. I introduce these gases through pipes of convenient size,

page_text: and under adequate pressure, into such furnaces which are of the
ordinary construction, except that they are closed up at the place
of the fire-bars and ashpit. The pipes admitting air are separate
from those admitting gas, but unite in one common pipe with them
at their extremities. Each pipe is to be furnished with cocks, so as
to regulate the quantity of air or gas introduced into the furnace,
and thus to afford any required supply of oxygen beyond that
requisite for the combustion of the gas, and necessary to the process
of puddling iron. The place occupied by the gas and air pipes is
that of the fire at present used, a little below and behind the bridge
of the fun
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said Sir Francis Charles Knowles in the
Great Seal Patent Office on the 15th June 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I
Sir FRANCIS CHARLES KNOWLES, of Lovell Hill, in the County of
Berks, Baronet, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of December, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs, and
successors, give and grant unto me, the said Sir Francis Charles
Knowles, Her special licence that I, the said Sir Francis Charles
Knowles, iny executors, administrators, and assigns, or such others
as I, the said Sir Francis Charles Knowles, my executors, admi-
nistrators, 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 "IMPROVE-
MENTS IN THE MANUFACTURE OF IRON," upon the condition (amongst
others) that I, the said Sir Francis Charles Knowles, by a
an instru-
ment in writing under my hand and scal, should particularly
describe and ascertain the nature of the said Invention, and in what

page_text: 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 Sir Francis Charles Knowles,
do hereby declare the nature of my said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:
First. In order to supply to the richer ores of iron the earthy
matters in which the same are deficient, which earthy matters are
necessary in order to form, with an appropriate flux or fluxes, a
liquid cinder to protect the melted iron from the blast during the
process of smelting, I take the slags or refuse scoriæ thrown out
from the furnaces of copper works, and I add them to such rich iron
ores, rich black bands, or rich forge cinders in such proportion as
that the total iron contained in the aggregate charge to be put into
the blast furnace, including the requisite flux or fluxes, may be from
35 to 50 per centum, or thereabouts, of the said aggregate charge.
The said copper slags admit of classification according to their
contents in silica, and must be separated and treated accordingly.
The other earths-namely, alumina, lime, and magnesia-must also
be taken into account after a chemical analysis of the said slags of
the fluxes, and of the ores of iron, black bands, or forge cinders to
be smelted, reckoning every five parts of magnesia as equivalent
to about seven parts of lime in the combination or aggregate to
be formed and put into the blast furnace. This combination or
aggregate, including the limestone or other fluxes added, is to be so
calculated as that it should contain for every three parts of silica,
two parts of lime and one part of alumina, allowing for magnesia its
equivalent in lime as aforesaid. As all the said slags contain an excess
of silica, it is best to select rich iron ores containing alumina, if
they can be had; but if not, a very aluminous shale or clay must be
used, with the due proportion of lime (burned or in limestone) as
above; and in forming the charge, the iron contained in the copper
slags (which averages about 36 per centum, and is obtained
incidentally) must be taken into the account. I recommend the

page_text: addition also of a moderate quantity of common salt to take up any
sulphur present in the slags or in the fuel used; but I do not claim
this as any part of my Invention.
Second. I use felspar as a flux in smelting iron ores: I employ
both soda felspar and potash, combined, when both can be
obtained ; but if only potash felspar, then I cither use it alone,
or I use with the latter common carbonate of soda; but in both
cases where soda and potash are to be present, I adjust the
mixture in such proportion that the potash may be to the soda
as 589 to 387, or thereabouts. The potash or the soda, or both,
will be partially set free in the furnace, according to the excess
of such bases beyond what is requisite with the other earths or
base's present for the saturation of the silica in the charge. In so
adjusting the silica and the bases, the earths present are to be
calculated as in division (1), reckoning 59 parts of potash as
equivalent to 35 parts of lime, and to 39 parts of soda to 25% parts
of magnesia. If peroxide of manganese be present in any sensible
quantity, 34 parts must be reckoned as equivalent to 35 parts of
lime, and the calculation modified accordingly to neutralize the
silica. The effect of such addition of potash or soda, or both, is to
give liquidity to the cinders, and to furnish cyanide of potassium
or of sodium, or both, a powerful agent in the reduction of the ores
to be smelted.
Third. In order to make iron of a superior quality, or iron
suitable to the manufacture of steel, I take the richest ores of
iron, or rich forge cinders, and I use them in conjunction with peat
cokc, or charcoal of peat in the common Catalan forge or fire, or in
some forge resembling the same; and in order to avoid the waste
of iron in the common Catalan method, I use convenient fluxes to
unite with the small quantities of earthy matter present in the ores,
adjusting the same as above; and I then work the aggregate of ores
and fluxes as in the Catalan method, and draw the iron out into
bars by hammers or rolls. The Catalan method is well described in
books on iron making, and is well known from the same; but I
claim only the use of peat coke, or charcoal of peat in such method,
with or without fluxes, as above.

page_text: Fourth. In order to make malleable or bar iron directly
from the richer ores of iron, or from richer parts of the black
band, or from rich forge cinders, I first reduce the same, and
the fluxes also, to the size of small gravel, or smaller; and I
then work the ore and fluxes in a common puddling furnace
with powdered or crushed peat, or wood charcoal, or with very
finely powdered coke, coal, or anthracite coal, when the same
is very free from sulphur and from earthy matters. The fluxes
are to be adjusted as above to the earthy ingredients of the
ores or cinders used; but in order to obtain the iron at as low a
temperature as possible, I employ as many bases, lime, magnesin,
potash, soda, and manganese, as I can obtain, using magnesian
limestone, or serpentine rock, in order to obtain magnesia, and
calculating these bases either as above or so that the oxygen of the
silica may be to the total oxygen in the bases in some one of these
proportions, namely, as 1 to 1, as 2 to 1, or as 3 to 2. When the
iron ore and fluxes mixed with the powdered charcoal, or coke, or
coal, is put into the furnace, a layer of charcoal is to be thrown over
it, and the furnace is to be gradually raised to a cherry red heat, or
a little above it, for about one hour and a half. The charge is after-
wards to be worked in the usual way of boiling puddling iron, and
the iron squeezed, shingled, hammered, and rolled out in the
ordinary mode of manufacture.
Fifth. I use in puddling or baling furnaces for the manufacture
of iron, the gases obtained by the dry distillation or coking of pent,
or of coal, in retorts in the ordinary way of making gas for purpose
of illumination. I introduce these gases through pipes of con-
venient size, and under adequate pressure in the gasholders, into
the furnaces, which are to be of the ordinary construction,
except that they are closed up at the place now occupied by
the fire-bars and the ashpit. The pipes admitting air are to
be separate from those admitting gas, but are to unite in one com-
mon pipe at or near the orifices or extremities of the pipes. Each
pipe is to be furnished with stop-cocks, such as to admit of regulation
of the gas or air allowed to enter the furnace, and thus to afford any
.

page_text: supply of oxygen in the air beyond that required for the perfect
combustion of the gas, and necessary to the process of puddling
iron, or reheating it for the forge. The place occupied by the gas
and air pipes is that of the fire-place iron, used a little below and
behind the bridge of the furnace.
And having now described the nature of the said Invention, and
the manner in which the same is to be performed, I declare that I
do not claim any particular form of construction for this application,
but that I do claim,.
-
First, the use of such gas as the above, with a due proportion of
atmospheric air, however the same may be introduced into the
furnace.
Secondly, the use of the slags thrown out from copper smelting
furnaces, with rich ores of iron, rich black band, or rich forge
cinders, in order to form, with appropriate fluxes, a cinder for the
iron made.
Thirdly, the use of felspars in the smelting of iron ores, with or
without carbonate of soda, and other fluxes.
Fourthly, the use of peat coke or peat charcoal with the Catalan
forge.
Fifthly, the use of rich ores, rich black band, or rich forge
cinders, with peat or other charcoal, and fluxes, in the puddling
furnace, to make bar iron directly from the same.
Sixthly, the use of peat or coal gas in puddling and balling
furnaces, used for the manufacture of iron.
In witness whereof, I, the said Sir Francis Charles Knowles,
have hereunto set my hand and seal, the Fourteenth day of
June, One thousand eight hundred and fifty-three.
FRANCIS CHARLES KNOWLES. (L.S.)