IMPROVEMENTS IN ROASTING SEALT OR DISINTEGRATED
Year: 1858

page_text: LETTERS PATENT to Robert Imeary, Alkali Manufacturer, near Gates-
head and Thomas Richardson, Practical Chemist of Newcastle-on-Tyne,
for the Invention of "IMPROVEMENTS IN ROASTING SEALT OR DISINTEGRATED
Sealed the 16th November 1858, and dated the 17th May 1858.
PROVISIONAL SPECIFICATION left by the said Robert Imeary and
Thomas Richardson at the Office of the Commissioners of Patents,
with his Petition, on the 17th May 1858.
We, ROBERT IMEARY, Alkali Manufacturer, near Gateshead, and THOMAS
RICHARDSON, Practical Chemist, of Newcastle-on-Tyne, do hereby declare the
nature of the Invention for "IMPROVEMENTS IN ROASTING SMALL OR DISINTEGRATED.
PYRITES," to be as follows:-
We take the small pyrites resulting from the disintegration of the large ore
as it is raised in Spain, or we take the bisulphuret of iron, which is now sepa-
rated from the coal brasses by grinding and washing, or the small pyrites
which is produced by the action of the atmosphere in the Cleveland and other
districts, and we expose these sulphur ores to a low heat so regulated as never
to exceed a dull redness, in a reverberatory or other suitable furnace heated
from below. The furnace is constructed with several flats or distinct beds, so
that each day's charge of ore may be moved forward from a higher to a lower

page_text: flat and nearer the fire, by which means the partially desulphurized ore is
exposed to a rather higher temperature in proportion as it loses its sulphur.
By these arrangements and system of working, there will at all times be
a like evolution of gases in the furnace, the several charges under process at
any time being in different stages of the process, some just commencing,
others just finishing; and we may state that it is not essential that the
furnace should consist of several beds, and be worked by ono fire as a series
of furnaces with separate fires may be used, so connected that the gases from
the several charges in the different stages of the process may be constantly
brought together. When the desulphurization of the iron is complete, the resi-
duum is treated with water to dissolve out the sulphate of copper which will
have been formed in these cases, where the ore contains copper and the oxido
of iron, which is left is available in some cases for the manufacture of Venetian
red or Spanish brown.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Imeary and Thomas Richardson in the Great Seal
Patent Office on the 16th November 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
IMEARY, Alkali Manufacturer, near Gateshead, and TноMAS RICHARDSON,
Practical Chemist, of Newcastle-upon-Tyne, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of May, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Robert Imeary and Thomas Richardson, Ler special licence that
we, the said Robert Imeary and Thomas Richardson, our executors, adminis-
trators, and assigns, or such others as we, the said Robert Imcary and
Thomas Richardson, our exccutors, 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 "IM-
PROVEMENTS IN ROASTING SMALL OR DISINTEGRATED PYRITES," upon the condition
(amongst others) that we, the said Robert Imeary and Thomas Richardson,
our executors or administrators, by an instrument in writing under our, or their
hands and seals, or under the hand and seal of one of us or them should

page_text: particularly describe and ascertain the nature of the said Invention, and in
what manuer 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 Thomas Richardson, on behalf of
myself and the said Robert Imeary, 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
thereof, that is to say:-
We take the small pyrites resulting from the disintegration of the large ore
as it is raised in Spain; or we take the bisulphuret of iron, which is now
separated from the coal brasses by grinding and washing, or the small pyrites
which is produced by the action of the atmosphere in the Cleveland and other
districts, and we expose these sulphur ores to a low heat, so regulated as never
to exceed a dull redness, in a reverberatory or other suitable furnace heated
from below. The furnace is constructed with several flats or distinct beds, so
that each day's charge of ore may be moved forward from a higher to a lower
flat, and nearer the fire, by which incans the partial desulphurized ore is
exposed to a rather higher temperature, in proportion as it loses its sulphur.
By these arrangements and system of working there will at all times be a like
evolution of gases in the furnace, the several charges under process at any
time being in different stages of the process, some just commencing, others
just finishing; and we may state, that it is not essential that the furnace
should cousist of several beds, and be worked by one fire, as a series of
furnaces with separate fires may be used, so connected that the
gases from
the several charges in the different stages of the process may be constantly
brought together. When the desulphurization of the iron is complete,
the residuum is treated with water to dissolve out the sulphate of copper
which will have been formed; in these cases, where the ore contains
copper, and the oxide of iron which is left is available in some cases for
the manufacture of Venetian red or Spanish brown, it is of considerable
importance in the successful prosecution of our Invention to have the ore in as
fine a state of division as possible. This may be accomplished in the case of
the bisulphuret of iron found disseminated in the coal by grinding and washing,
as is at present practised for removing the organic portions. The more fincly
this mineral matter is ground the more complete is the subsequent removal of
the coaly matters in the washing process, and the more suitable is it for our
purpose. In other cases the atmospheric action accomplishes the same object
much more effectually, as is found in the instance of the pyrites, which come

page_text: from the Province of Andalusia, and the sulphur. ore which lies above the bed
of ironstone in the Cleveland district of Yorkshire. This disintegration or
weathering process is slow and tedious, and we increase the rapidity of the action
by moistening the minerals cither before or after grinding and exposing them
in a moist locality, but sheltered from the rain, and renewing the surface by
repeatedly raking the mass; or we place the ground ores in thin layers on
gratings or perforated floors, and either draw or force air and steam through
the mass.
The same effect is more quickly produced by confining the sulphur
ore in large boxes fitted with shelves, over which the air and aqueous vapor
pass from one to the other, finally escaping at the exit pipo. In minerals
containing copper the uteusils must be made of wood, and it is better to con-
struct the erections in brick or stone...
"
The furnace we employ is of the ordinary reverberatory construction, and
consists of five or six flats or divisions, either on one level or raised about three
to four inches above each other; each flat or division is about four to five feet
square, and the arch is about fifteen inches above the bed of the furnace.. A.
flue. runs from end to end, on the top of the furnaces, and communicates by
small openings in the arch of the furnace with cach flat or division. The
charge, which is from six to ten hundredweight, is thrown on the higher flat
or division farthest from the fires, which pass under the bottom of the furnaces
which is formed of quarls. The furnaces are constructed back to back, and on
the working side doors sliding in frames are fixed, corresponding with each
flat or division. Small slits are made in these doors for the admission of the
air for the combustion of the sulphur.
The workmen renew the surface of the mineral from time to time, to
facilitate the escape of the sulphurous acid, which passes through the openings
in the arch, and is conveyed to the chamber by means of the flue on the top of
the furnace. As the desulphurization of the mineral proceeds, it is pushed
forward from one flat or division to the one next adjoining for another twelve
hours, when it is again removed to the next flat or division, and so on to the
last in the series. During the whole period of the operation the heat must
never exceed a dull redness, in order to prevent the reduction of the sulphate
of copper, as is well known among chemical. manufacturers."
When a series of separate furnaces is used, in place of a series of flats in
one furnace, then the charges into the several furnaces are to be in like
succession to that above described, so that the charges in the several furnaces
may be in different stages of the process, as above explained, the only differ-
ence being that the charge in each furnace remains there till it is completed,
whereas, when a succession of flats is used, the charge is moved from flat to

page_text: flat. We would remark that a series of six flats in one furnace, or a series of
six furnaces is what we prefer, but we do not confine ourselves to the use of
that number. The nitrate of soda is decomposed in the ordinary nitre cups,
and they are used in the following manner to insure a regular supply of the
nitrous acid gases in proportion to the quantity of sulphurous acid evolved:-
At the end of the furnaces a narrow division is appropriated for these cups,
which are charged during each shift at intervals of three hours, the quantity of
nitre being regulated by the condition of the chamber. The ore which has
reached the lowest flat, or has been exposed so long in one of the smaller distinct
furnaces, until all or nearly all the sulphur has been converted into sulphurous
acid, is removed and treated with water while hot, to remove whatever copper
may exist in a soluble form, as sulphate. The liquor is boiled down to
a strength in the usual way, and set aside for crystallization.
In some cases, and more especially in those where the mineral has previously
undergone an extensive weathering or oxidation, either naturally or by artificial
means, the residuum is available for use as a raw material in the production of
Spanish brown or Venetian red.
We claim, in the treating of small pyrites, the use or application of several
flats in the same furnace, or of several separate furnaces, so worked together
as to secure a regular supply of sulphurous acid, as herein described, and by
such treatment the residuum in some cases is rendered commercially useful, as
herein stated.
In witness whereof, I, the said Thomas Richardson, have hereunto set
my hand and seal, this Eighth day of November, in the year of our
Lord One thousand eight hundred and fifty-eight.
THOMAS RICHARDSON. (L.S.)
Witness to the signature of Thomas
Richardson,
THO A. BURR,
11, Queen Square, W.C.