IMPROVEMENTS IN THE PREPARATION OF CERTAIN IRON ORES OR. RESTDues for USE IN THE BLAST FURNACE
Year: 1865

page_text: LETTERS PATENT to Frederic Claudet, of No. 6, Coleman Street, in the
City of London, for the Invention of "IMPROVEMENTS IN THE PREPARATION
OF CERTAIN IRON ORES OR. RESTDues for USE IN THE BLAST FURNACE."
PROVISIONAL SPECIFICATION left by the said Frederic Claudet at the
Office of the Commissioners of Patents, with his Petition, on the 25th
February 1865.
I, FREDERIC CLAUDET, of No. 6, Coleman Street, in the City of London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
PREPARATION OF CERTAIN IRON ORES OR RESIDUES FOR USE IN THE BLAST FURNACE,"
to be as follows:-.
In the treatment by humid way of burnt cupreous pyrites of low per-
Icentage, as at present practised' at Newcastle, Mostyn, and other places, a
residual product is left in a finely powdered state chiefly composed of per-
oxide of iron, and when the ore operated on contains but little siliceous gangue
or other impurities (as in the case of the Portugese pyrites now largely im-
ported into this country) the lixiviated residue may be considered as nearly pure
peroxide of iron, and as such would be valuable as an iron ore if its fine state
admitted of its advantageous employment in the blast furnace.
attempts have been made with a view to aggregate the pulverised residues from
ordinary iron pyrites by means of clay and water, and moulding the pasty
mixture in the form of blocks or bricks, but they have failed owing to a want
Various

page_text: of consistence in the bricks when dried, and also to the large proportion of
useless matter introduced. By my method I propose to remedy these defects
by availing myself of the property possessed by bydraulic cements (such, for
instance, as Portland cement) when mixed in small proportions with the
moistened residues, of forming a body which, after compression and a few days
exposure to the air, becomes a hardened compact mass. The addition of
bydraulic cement to the oxide of iron is in no way objectionable as it contains
in itself elements that are of necessity employed as fluxes in the manufacture
of pig iron, and the amount required to give sufficient consistency to the
moulded mixture in order that it may be able to bear handling and charging
being but small, the quality or richness of the ore is not thereby materially
.affected. The amount of cement need not exceed 5 per cent., although the
hardening property is increased in proportion to the quantity of cement used.
The hardened air-dried bricks produced from these materials have also the
advantage of not crumbling or falling to powder when rapidly heated, and can
even be charged into a red-hot furnace without breaking up.
According to my plan I proceed as follows:-The residual oxide of iron
when thrown out of the tanks after lixiviation is generally too wet to be
immediately used; when this is the case it is spread out on a floor in order
that part of the water may evaporate, or, if more convenient, a portion may
be dried by heat and mixed again with the wet ore, so as to reduce the pro-
portion of water contained to about 15 per cent. In this state, although
moist, it does not wet the hand, can be easily passed through a sieve, and is
fit to mix with the powdered hydraulic cement. To every 20 cwt. of the above
I add about 1 cwt. of Portland cement, (but I do not confine myself strictly to
these proportions), and incorporate the two thoroughly together by turning them
over and over on a flat surface or mixing floor, and finally passing the mixture
through a sieve. After the cement has been properly worked up with the
oxide of iron it is ready for moulding and compressing; this may be effected
in various ways. I employ a cast-iron framework so divided as to contain a
number of hollow spaces or compartments of the size of the bricks to be made,
which I prefer should be about 1 in. x 3 in. x 6in. This framework is laid down on
a-flat surface or paved floor, and the prepared mixture shovelled into and over
the hollow spaces, and pressed well into them by ramming with a heavy wooden
block or otherwise by strong pressure, so as to fill them as compactly as possible.
The excess of ore is cleaned off the surface and the frame lifted up, when the
bricks, which are slightly tapered, detach themselves and remain on the
ground. They will already be found to possess sufficient consistence to admit
of their being carried away to the drying floor, and at the end of a few days,

page_text: according to the size of the bricks, they will have set very firmly and be dry
enough to charge into the blast furnace and be employed precisely in the
same way as ordinary iron ores. On a large scale all this could be per-
formed by machinery. In the first place by the employment of hoppers.of
different sizes through which the ore and cement could be delivered by
mechanical contrivance in the requisite proportions on to a sieve, whence
they would pass into a species of pug-mill or a horizontal semicircular trough
with a revolving one bearing blades, in. which the mixture could be made
and the stuff conveyed to the moulding and pressing machine constructed on
the principle of the well-known brick-making machines and- machines for
moulding patent fuel.
I would remark that the process above described is not confined to the
treatment of the residues from cupreous pyrites, for although it is particularly
applicable to the treatment of these residues still it may also advantageously
be applied to the treatment of other finely divided oxide of iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederic Claudet in the Great Seal Patent Office on the
25th August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
CLAUDET, of No. 6, Coleman Street, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of February, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Frederic Claudet, Her special licence that I, the said
Frederic Claudet, my executors, administrators, and assigns, or such others
as I, the said Frederic Claudet, my 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 "IMPROVE-
MENTS IN THE PREPARATION OF CERTAIN IRON ORES OR RESIDUES FOR USE IN THE.
BLAST FURNACE," upon the condition (amongst others) that I, the said Frederic
Claudet, my executors or administrators, by an instrument in writing under
my, 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:

page_text: 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 Frederic Claudet, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed; to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
+
In the treatment by humid way of burnt cupreous pyrites of low per-centage,
as at present practised at Newcastle, Mostyn, and other places, a residual:
product is left in a finely powdered state chiefly composed of peroxide of iron,
and when the ore operated on contains but little siliceous gangue or other
impurities (as in the case of the Portugese pyrites now largely imported into
this country) the lixiviated residue may be considered as nearly pure per-
oxide of iron, and as such would be valuable as an iron ore, if its fine state of
division admitted of its advantageous employment in the blast, furnace.
Various attempts have been made with a view to aggregate the pulverized
residue from ordinary iron pyrites by means of clay and water, and moulding
the pasty mixture in the form of blocks or bricks, but they have failed owing
to a want of consistence in the bricks when dried, and also to the large pro-
portion of useless matter introduced. By my method I propose to remedy
these defects by availing myself of the property possessed by hydraulic cements
(such, for instance, as Portland cement or Roman cement when mixed in
small proportions with the moistened residues) of forming a body which, after
strong compression and a few days exposure to the air, becomes a hardened
compact mass. The addition of bydraulic cement is in no way objectionable
as it contains in itself elements that are of necessity employed as fluxes in the
manufacture of pig iron, and the amount required to give sufficient consistency
to the moulded mixture in order that it may be able to bear handling and
charging being but small, the quality or richness of the ore is not thereby
materially affected. With a moderately strong pressure the amount of cement.
when Portland cement is employed need not exceed 5 per cent. although the
hardening property is increased in proportion to the quantity used. The
hardened air-dried bricks produced from these materials do not crumble or fall
to powder when rapidly heated, and answer practically all the purposes of a
first-class iron ore.
According to my plan I proceed as follows:-The residual oxide of iron
when thrown out of the tanks after lixiviation is generally too wet to be
immediately used; when this is the case it is spread out on a floor in order
that part of the water may evaporate, or, if more convenient, a portion may. be

page_text: dried by heat and mixed again with the wet ore, so as to reduce the proportion
of water contained to about 15 per cent. In this state, although moist, it
does not wet the hand, can be easily passed through a sieve, and is fit to
mix with the powdered hydraulic cement. To every 20 cwt. of the above I
add about.1 cwt. of Portland cement (but I do not confine myself strictly to
these proportions), and incorporate the two thoroughly together by turning
them over and over on a flat surface or mixing floor, and finally passing the
mixture through a sieve. Or I effect this mixture on a larger scale by
employing hoppers of different sizes through which the ore and cement are
delivered by mechanical contrivance in the requisite proportions on to a sieve,
whence they pass into a species of pug-mill with a revolving axis bearing
blades, in which the mixture is made and the stuff conveyed to the moulding
and pressing machine. After the cement has been properly worked up with
the oxide of iron it is ready for moulding and compressing. To form the
brick I employ brick-making machinery such as is employed in the manu-
facture of bricks by strong pressure from nearly dry clay, or such as is used in
making patent fuel. It is important that in the machinery employed the
brick should be subjected to heavy pressure, and the greater the amount of
pressure the better will be the brick produced.
I would remark that the process above described is not confined to the
treatment of the residues from cupreous pyrites, for although it is particularly
applicable to the treatment of these residues still it may also advantageously
be applied to the treatment of other finely divided oxide of iron.
In witness whereof, I, the said Frederic Claudet, have hereunto set my
hand and seal, this Twenty-fourth day of August, in the year of our
Lord One thousand eight hundred and sixty-five.
FRED. CLAUDET. (L.S.)