IMPROVEMENTS IN CALCINING CERTAIN ORES AND IN THE CONSTRUCTION OF FURNACES FOR THAT PURPOSE, AND FOR CON- VERTING CERTAIN PRODUCTS ARISING IN THE PROCESS INTO AN ARTICLE OF COMMERCE NOT HERETOFORE PRODUCED THEREFROM
Year: 1852

page_text: LETTERS PATENT to Thomas Benjamin Smith, of Bristol, for the
Invention of "IMPROVEMENTS IN CALCINING CERTAIN ORES AND IN
THE CONSTRUCTION OF FURNACES FOR THAT PURPOSE, AND FOR CON-
VERTING CERTAIN PRODUCTS ARISING IN THE PROCESS INTO AN ARTICLE
OF COMMERCE NOT HERETOFORE PRODUCED THEREFROM."
Scaled the 13th April 1853, and dated the 31st December 1852.
PROVISIONAL SPECIFICATION left by the said Thomas Benjamin
Smith at the Office of the Commissioners of Patents, with
his Petition, on the 31st December 1852.
I, THOMAS BENJAMIN SMITH, of Bristol, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN CALCINING CERTAIN
ORES AND IN THE CONSTRUCTION OF FURNACES FOR THAT PURPOSE, AND FOR
CONVERTING CERTAIN PRODUCTS ARISING IN THE PROCESS INTO AN ARTICLE OF
COMMERCE NOT HERETOFORE PRODUCED THEREPROM," to be as follows:-
In the ordinary process of calcining metallic ores they are subjected
to the direct action of heat, whereby they are oxidized. For the most
part the calcining furnace is an open one, from which cause the
sulphurous and other volatile matters evolved in the process are,
together with the sinoke, passed into the atmosphere, to the damage
of health.

page_text: Now, my first improvements consist in calcining metallic ores in
closed retorts or chambers surrounded by fire, which is conducted
over and under the receptacle for the ore but not in contact with it.
The products of combustion from the fire are carried off by an
ordinary shaft.
The ores being subjected to a heat sufficient to thoroughly calcine
them in the closed receptacle, which is made of iron, fire clay, or
other suitable material, to which a pipe or flue is attached, to convey
the volatile products into suitable chambers or vessels, where they
are united with the usual ingredients for the manufacture of sulphu-
ric acid as known in England, whereby they are converted into that
article of commerce.
When the ores so calcined contain much arsenic, lead, or zinc,
I conduct the fumes through hot water previously to their con-
version into sulphuric acid. The object of my Invention is the
improved method of calcination and the use of the sulphurous
vapors evolved in the process of calcination in the manufacture of
sulphuric acid.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said Thomas Benjamin Smith in the Great
Seal Patent Office on the 30th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
THOMAS BENJAMIN SMITH, of Bristol, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first 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 suc-
cessors, give and grant unto me, the said Thomas Benjamin Smith,
Her special licence that I, the said Thomas Benjamin Smith, my
exccutors, administrators, and assigns, or such others as I, the

page_text: said Thomas Benjamin Smith, 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 night make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN CALCINING CERTAIN ORES AND IN THE CONSTRUCTION OF FURNACES FOR THAT
PURPOSE, AND FOR CONVERTING CERTAIN PRODUCTS ARISING IN THE PROCESS
INTO AN ARTICLE OF COMMERCE NOT HERETOFORE PRODUCED THEREFROM," upon
the condition (amongst others) that I, the said Thomas Benjamin
Smith, by an instrument in writing under my hand and scal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
saine 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 Benjamin Smith,
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 (that is to say):
My Invention has reference more particularly to the first operation
in smelting sulphuret copper and other ores; namely, their
calcination, by which a portion of the sulphur is expelled, and
the metals they contain are oxidized. The ordinary method
consists in subjecting the ore to heat on the floor or bed of a
reverberatory furnace for a period of eighteen or twenty-four hours, .
when the sulphur, together with a portion of the other volatile
matters, as arsenic, lead, zinc, antimony, and tin, are passed into the
air (to the great injury of vegetation), together with the products of
combustion from the fire which heats the furnace. The flame from
the furnace is allowed to play directly on and in contact with the
ore, which is stirred several times during the operation, and a large
quantity of cold air is adınitted through the side doors in the
furnace, and drawn over the ore at a rapid rate by means of a
chimney shaft..

page_text: Now, my Invention will not only obviate the nuisance and injury
caused by allowing these vapours to pass into the air, but by
condensing the metals above named, which are evolved in the process
in flues or pipes, I am enabled to use the sulphurous vapours
for the manufacture of sulphuric acid. I propose to use nearly
closed chambers, furnaces, or retorts, which 1 heat from without,
and by passing heated air into such chambers, furnaces, or retorts,
I do not admit the products of combustion from the fire, to mix
with the vapours or gasses evolved in the process of calcination, as
it would render them useless for the manufacture of sulphuric acid.
I connect suitable flues or pipes with the chamber furnace or retort
to carry away the vapours, in which I condense the metals volatilised;
and when I wish to form sulphuric acid, I carry on the sulphurous
vapours to suitable chambers, and proceed with them in the usual
manner to obtain sulphuric acid, as is well understood in this
country, and forming as a separate process no part of my Invention.
If it is not desired to make sulphuric acid, a much larger quantity
of air may then be passed in, whereby the process of calcination will
be much facilitated, and independent of the manufacture of sul-
phuric acid it will be an advantage to the smelters. I also at times
propose to use a portion of heated oxygenated air to assist the
calcination of metallic ores.
But in order that my Invention may be well understood, I will
describe the manner of carrying it into effect more particularly.
I construct a chamber furnace or retort with one bed or floor,
which I heat by passing the fire on the outside of such bed;
I blow into such chamber, furnace, or retort, hot air in sufficient
quantity to keep up the combustion of the sulphur contained in
these ores; the air is heated in pipes or flues passing through fire,
or in pipes or flues round which fire is made to play, which fire
may either be the same which heats the chamber furnace or retort,
or a separate fire, or the two combined; on the floor or bed the ore
is placed from four to six inches deep; when the hot air is blown
in through the pipes or flues, on the outside of which fire is made
to play as described, the sulphur and other volatile matters will be

page_text: given off, which I convey through pipes or flues, whereby I condense
a portion of the metals so evolved; the sulphurous vapours or
sulphurous acid, passing on, is mixed with the usual ingredients for
the manufacture of sulphuric acid, and passed into suitable chambers
for condensation, as is practiced and well known in this country, and
separately forming no part of my Invention.
Having now described the nature of my Invention, I desire it to
be understood that I do not confine myself to the precise details
thereof, as these may be varied; but what I claim as my Invention
is,―
1, The improved plan of constructing a calcining furnace as
herein-before described.
2nd, I claim the improved mode of calcining, whether the manu-
facture of sulphuric acid be combined therewith or not, as de-
scribed.
3rd, I claim the use of heated air blown into or onto the ore in
the chamber furnace or retort, whereby the calcination of the
ore is much facilitated, as described.
4th, I claim the manufacture of sulphuric acid from the sulphurous
acid obtained in and by the process of calcination.
In witness whereof, I, the said Thomas Benjamin Smith, have
hereunto set my hand and seal, this Twenty-eighth day of
June, in the year of our Lord One thousand eight hundred
and fifty-three.
D