AN IMPROVED APPARATUS FOR ROASTING IRON PYRITES
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," Southampton Buildings, London, Consulting
Engineer, for the Invention of "AN IMPROVED APPARATUS FOR ROASTING
IRON PYRITES."-A communication from abroad by William Helbig,
Director of Chemical Works, Heinrichshalle, and Robert Hasenclever,
Director of Chemical Works, Holberg, both in the Kingdom of
Prussia.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, on
the 30th December 1869.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
3 Southampton Buildings, London, Consulting Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED APPARATUS FOR
ROASTING IRON PYRITES," a communication, to be as follows:-
In roasting iron pyrites for the production of sulphuric acid the
combustion of the waste or dust from the beating in pieces of the iron

page_text: pyrites is not completely done. If this dust is formed with clay into
small balls and roasted, or if the greuts are charged with the pieces, the
waste is consumed, but with great loss of the sulphur contained in the
ores. The small greuts obstruct or fill the canals formed between the
pieces of ore, impede the draught, and cause bad roasting; on the other
hand they fall through the grate if the orc is moved during charging, and
form sulphurous residues. The same difficulty arises if the small balls
formed of pyrite powder and clay contain such impurities as blend a
heavy spathe, which cause the production of powder. Besides this, the
residues are in the most favorable case insufficiently roasted. Moreover,
the roasting of blend has not succeeded in such a manner that the escape
of large masses of sulphurous acid into the open air could be prevented.
Although the furnace known as the "Gerstenhofer "furnace in roasting
blends delivers such gaseous products which are fitted for the production
of sulphurous acid, the disulphuration of the ores is notwithstanding very
incomplete, and the ores leave the furnace with half the amount of
sulphur which they contained before roasting, and therefore a second
This incon-
roasting in the ordinary puddling furnace is necessary.
venience is avoided by means of a new apparatus for roasting iron pyrites,
which I will now describe. This apparatus can be connected with a suitable
furnace, it has a series of plates one below the other; the dry ore is
supplied through a hopper and passes from one plate to the other down
the series. In every story or floor the orc forms an angle of about
33 degrees, and rests in its place if the furnace is filled. In proportion as
the ore is carried away at the bottom it passes or runs from the hopper
to the plate, and by the uniform motion during its passage down it
continually presents fresh surfaces. The angle which the plate forms
with the horizon can be varied; the smaller it is the thinner will be the
layer or stratum of ore, and the more complete will be the mixing and
roasting. The space below the plates and above the ores serves as a
canal for the gaseous products of the roasting. The ore may be roasted
in a muffle which is surrounded by the fiery gases of the grate, or the
ore may be roasted by the escaping gases of the pyrite furnace. In
the two cases the gases pass upward and enter at last a cylinder, through
which they are conducted into the heat chamber.
This new roasting device differs essentially from that of "Gerstenhofer"
above mentioned, as the ore is not roasted in the free fall, but upon a
surface as in an ordinary puddling furnace. It also allows the roasting
of the greuts, which is not the case in the furnace of "Gerstenhofer."

page_text: In the same manner this arrangement differs from the so-called story
furnace of the Pereire, as in this furnace the workman has to push
the ore from one story to the other, and during this operation the
doors are opened and permit a very disagreeable escape of sulphurous,
acid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,.
filed by the said William Robert Lake in the Great Seal Patent
Office on the 30th June 1870.
TO ALL TO WHOM THESE. PRESENTS SHALL COME; I, WILLIA
ROBERT LAKE, of the "International Patent Office," Southampton
Buildings, London, Consulting Engineer, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of December, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did,, for Herself,. Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence
that I, the said William Robert Lake, my executors, administrators,
and assigns, or such others as I, the said William Robert Lake, 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 "AN IMPROVED
APPARATUS FOR ROASTING IRON PYRITES," a communication to me from abroad
by William Helbig, Director of Chemical Works, Heinrichshalle, and
Robert Hasenclexer, Director of Chemical Works, Holberg, both in the
Kingdom of Prussia, upon the condition (amongst others) that I, the
said William Robert Lake, my executors or administrators, by au
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 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.

page_text: NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification.
In roasting iron pyrites for the production of sulphuric acid the
combustion of the waste or dust from the beating in pieces of the iron
pyrites is not completely effected. If this dust is formed with clay into
small balls and roasted, or if the greuts are charged with the pieces, the
waste is consumed, but with a great loss of the sulphur contained in
the ores.
The small greuts obstruct or fill the canals formed between
the pieces of ore, impede the draught, and cause bad roasting, while on
the other hand they fall through the grate if the ore is moved during
charging, and form a sulphurous residue. The same difficulty arises
if the small balls formed of pyrite powder and clay contain such
impurities as blend or heavy spathe, which will cause the production of
powder. Besides this, the residue in the most favorable case is in-
sufficiently roasted. Moreover, the roasting of blende has not succeeded
in such a manner that the escape of large masses of sulphurous acid into
the open air could be prevented. Although the furnace known as the
"Gerstenhofer " furnace in roasting blends delivers such gaseous products
as are fitted for the production of sulphuric acid, the desulphurization of
the ores is notwithstanding very incomplete, and the ores leave the
furnace with half the amount of sulphur which they contained before
roasting, and therefore a second roasting in the ordinary puddling
furnace is necessary. This inconvenience is avoided by means of
my improved apparatus for roasting iron pyrites, which I will now

page_text: Figure shows another variation of the construction wherein the
plates are horizontal. A cone is formed by the dead ore, and fresh ore
runs over the cones at the plates; this ore is delivered from the hopper,
and when roasted taken away below the furnace.
The dry ore is supplied through a hopper A and passes over the
plates a, b, c, d, e, f, g, h, down to i or k. In every story or floor the
ore forms an angle of about 33°, and rests in its place if the furnace is
filled. In proportion as the ore is carried away at the bottom it passes
from the hopper to the plate, and by the uniform motion during its
passage down it continually presents fresh surfaces. The angle which
the plate forms with the horizon can be varied; the smaller it is the
thinner will be the layer or stratum of ore, and the more complete will
be the mixing and roasting. The space below the plates and above the
ores serves as a channel for the gaseous products of the roasting. The
plates may be of any suitable material and the minerals may pass over
vaults or plates of iron or stone or other material. The ore may be
roasted in a muffle which is surrounded by the gases of the grate k, or
the ore may be roasted in the escaping gases of the pyrite furnace. In
both cases the gases pass upward and enter a cylinder D, through which
they are conducted into the lead chamber.
My furnace differs essentially from that of Gerstenhofer. As above
stated the ore is not rosted in the free fall, but upon a surface, as in an
ordinary puddling furnace. It also allows the roasting of the grouts,
which is not the case in the aforesaid furnace of Gerstenhofer. In
the same manner this arrangement differs from the so-called story
furnace of Perret, of Lyons, France, where the workman has to push
the ore from one story to the other, and during this operation the
doors are opened and permit a very disagreable escape of sulphurous
acid.
The accompanying Drawing illustrates some applications of this
Invention, but does not represent all the forms in which the same may
be employed.
Having thus fully described the said Invention as communicated to
me by my foreign correspondents, and shown how the same may be
conveniently and advantageously carried into practice, I claim,-
First. The roasting apparatuss as described, and other constructions
based upon the same principle for the purpose specified.

page_text: Second. Roasting the ores at the surface of the angle which they form
if they are stored in heaps in the open air, and effecting the renewal
of the surfaces and the passing of the ore through the said furnace
by taking away the ore at the bottom of the same, so as to cause a
sliding movement of the ore in the furnace, substantially as set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Thirtieth day of June, in the
year of our Lord One thousand eight hundred and seventy.
Witness,
D. L. WAGNER.
WILLIAM ROBERT LAKE. (L.S.)