IMPROVEMENTS IN ECONOMIZING THE MANUFACTURE OF SULPHURIC ACID, AND IN OBTAINING COPPER FROM ORES USED IN SUCH MANUFACTURE
Year: 1861

page_text: LETTERS PATENT to Peter Spence, of Newton Heath, near Manchester,
in the County of Lancaster, Manufacturing Chemist, for the Invention of
"IMPROVEMENTS IN ECONOMIZING THE MANUFACTURE OF SULPHURIC ACID, AND IN
OBTAINING COPPER FROM ORES USED IN SUCH MANUFACTURE."
Sealed the 31st December 1861, and dated the 3rd July 1861.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the
Office of the Commissioners of Patents, with his Petition, on the
3rd July 1861.
I, PETER SPENCE, of Newton Heath, near Manchester, in the County of
Lancaster, Manufacturing Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ECONOMIZING THE MANUFACTURE OF SULPHURIC
ACID AND IN OBTAINING COPPER PROM ORES USED IN SUCH MANUFACTURE," to be as
follows:-
My Invention relates to a peculiar method of roasting or calcining ores of
copper containing sulphur, whereby I am enabled to extract a larger portion
of the sulphur than has hitherto been practicable, which sulphur passing off as
sulphurous acid gas is converted into sulphuric acid; and the said method is
also applicable to the treatment of ores in their native or other condition for
the purpose of calcining them in order that copper may be obtained therefrom
according to the method for which Letters Patent were granted to me bearing
date 3rd November 1860 (No. 2703).

page_text: My present Invention consists in submitting such ores to the action of heat
in batches, which are successively moved on from one end of a furnace to the
other, and in causing a current of air to pass over them in the opposite direc-
tion, and to accomplish this I use a furnace with several doors, through which
an instrument may be introduced for effecting the aforesaid transference.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Peter Spence in the Great Seal Patent Office on the
3rd January 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
SPENCE, of Newton Heath, near Manchester, in the County of Lancaster,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of July, in the year of our Lord
One thousand eight hundred and sixty-onc, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Peter Spence, Her special license that I, the said Peter Spence,
my exccutors, administrators, and assigns, or such others as I, the said Peter
Spence, 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 "IMPROVEMENTS IN ECONOMIZING
THE MANUFACTURE OF SULPHURIC ACID, AND IN OBTAINING COPPER FROM ORES AND
IN SUCH MANUFACTURE," upon the condition, amongst others, that I, the said
Peter Spence, by an instrument in writing under my hand and seal, 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.
NOW KNOW YE, that I, the said Peter Spence, do hereby declare the
nature of my 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 and accompanying Drawings (that is to say) :-
My Invention relates to a peculiar method of roasting or calcining ores of
copper containing sulphur for the purpose of obtaining sulphuric acid; and
the said method is also applicable to the treatment of ores in their native or

page_text: other condition for the purpose of calcining them in order that copper may be
obtained therefrom according to the process for which Letters Patent were
granted to me bearing date the Third day of November-One thousand eight
hundred and sixty, No. 2703.
The essential feature of my Invention consists in submitting such ores to
the action of a roasting heat as they are passed from one end of a furnace to
the other, during which transference a current of air is caused to travel over
them in an opposite direction; to accomplish this I use a furnace of consider-
able length, having several doors for the purpose of introducing apparatus by
which the transference may be effected: It will be obvious that by this
arrangement the ores may be submitted to heat in a thin stratum, that the
amount of roasting may be modified by a quicker or slower transference, and
that the heat communicated may be greater towards the termination of the
operation than at the commencement thereof.
In order that my Invention may be fully understood I have appended to
this my Specification Drawings of apparatus which I have found to answer
the purposes of my Invention.
Fig. 1 is a side view of the furnace, and Fig. 2 a longitudinal section, in
both of which the two ends only are shewn, the whole being of considerable
length. One I have now in operation is fifty feet long, with twelve doors for
the tranference of the ores, but these dimensions may be varied, and are only
mentioned for the purpose of explaining that the furnace should be of con-
siderable length. Fig. 3 represents a cross section, and in describing the
apparatus I will will in the first instance suppose that the manufacture. of;
sulphuric acid is the object in view.
At a are the fire-bars of the furnace, and at the fire chamber, formed by
channels, as seen in Fig. 3; extending under a partition c of fire brick, which
partition forms the bottom of another and distinct chamber d furnished at
one or both sides with a number of doors e¹; e, &c. At f is an aperture
formed through the brickwork, and constituting a communication from the
external atmosphere to the chamber d. The ores from which sulphuric acid
is to be obtained are passed through the door e' into the chamber din sufficient
quantity to lie about two or three inches in thickness upon the bed'c, and to
extend, say, halfway towards the door e. This batch having been submitted
to heat, passing from the fire chamber for the required' time, is pushed
forward by any convenient instrument, so as to be brought opposite the door e³;
and another batch is introduced through the door e¹; then the first charge is
removed from e to es, and the second from e¹ to e², and so on until the first
deposited batch shall have arrived at the other end of the furnace at e¹, and it'

page_text: is then pushed through the aperture finto any receptacle placed to receive it
During this transference of the material it has gradually become heated, and
a current of air entering at f has been passing over it, and the operation has
caused the sulphur to be driven off from the ore and conveyed through the
channel 2 to the ordinary sulphuric acid apparatus. The end of the fir
chamber d leads to a flue at i. The degree of roasting to be effected, and so
as to secure the best results, can be ascertained only by experience; but I may
state, by way of guidance, that working with a furnace fifty feet long and with
twelve doors, I allow the first charge to remain for one hour, then transfer it
to the second position and put a fresh charge into the first, and so on, waiting
an hour between each change.
An advantage arising from my Invention is its capability of being applied
to the manufacture of sulphuric acid from any description of ores. It is well
known to those engaged in the extraction of copper from ores that the sulphur
thereof is frequently wasted from the impracticability of roasting certain mixed
ores so as to render them into a fit condition for reduction, and also for the
manufacture of sulphuric acid, but I find that by my improved method ores of
any description, large or small, may be roasted so as to produce sulphuric acid
with economical results. In calcining the mixed copper ores preparatory to
smelting, as practiced at the Swansea and other copper works, and with the
view of economizing the manufacture of sulphuric acid, the process of calcina-
tion by my method is effected with equal advantage as by the modes now
practiced, as the heat is made to act on a large body of the ore without an
exhaustive, but with an accumulative effect, so that the heat which has cal-
cined or driven off nearly the last portion of sulphur from the ore which lies
at the exit end of the furnace then passes on, heating every successive charge,
and gaining strength from the combustion of the sulphur until it comes into
contact with the cold charge, which it rapidly heats to ignition, partly from
the under heat of the bed derived from the fire, which after leaving the
furnace is passed to a chimney, and partly from all the hot gases passing over
it on their way out of the furnace to the vitriol chamber, into which they are
conveyed after being mixed with nitrous gases, as is well known. I have spoken
of ores as large and small, and these terms will be well understood by all
those who are acquainted with the manufacture in question. I may, however,
state that when I receive ores in large pieces I generally break them up into
fragments of about the size of stones called "road metal."
As another advantage arising from the use of my Invention, I may state
that I have found, in the practical carrying out thereof, that the production of
a given amount of sulphuric acid is effected by the expenditure of far less nitre

page_text: than is commonly used, a certain amount of sulphuric acid being formed in the
chamber of the furnace and passing forward in a state of vapour. Thus far
I have spoken of my Invention as applicable to the manufacture of sulphuric
acid, but it is also applicable to roasting ores of copper preparatory to
reduction by that method for which Letters Patent were granted to me as
aforesaid. In this application the operation is precisely that above described, and
will not, therefore, need a repetition of descriprion, it being of course understood
that if the ores have been previously used for the manufacture of sulphuric
acid, and contain, therefore, but a small amount of sulphur, the vapours from the
chamber d may pass into the atmosphere instead of into the vitriol chamber
if desired.
Having thus described and ascertained the nature of my said Invention, and
the manner of carrying the same into effect, I desire it to be understood that
I claim as secured to me under the above recited Letters Patent, and for the
purposes above set forth, the use of the furnace, substantially as above
described, and provided with means for allowing a current of air to pass over
the material in a direction contrary to that in which it is moved.
In witness whereof, I, the said Peter Spence, have hereunto set my hand
and seal, this Second day of January, in the year of our Lord, One
thousand eight hundred and sixty-two.