AN IMPROVED FURNACE FOR THE CALCI- NATION OF COPPER ORES AND OTHER MINERAL SUBSTANCES
Year: 1854

page_text: LETTERS PATENT to Alfred Trueman, of Swansea, in the County of
Glamorgan, for the Invention of "AN IMPROVED FURNACE FOR THE CALCI-
NATION OF COPPER ORES AND OTHER MINERAL SUBSTANCES."
Sealed the 17th August 1854, and dated the 15th March 1854.
PROVISIONAL SPECIFICATION left by the said Alfred Trueman at the
Office of the Commissioners of Patents, with his Petition, on the 15th
March 1854.
I; ALFRED TRUEMAN, of Swansea, in the County of Glamorgan, do hereby.
declare the nature of the Invention for "AN IMPROVED FURNACE FOR THE
CALCINATION OF COPPER ORES AND OTHER MINERAL SUBSTANCES to be as
follows:-
"
In this furnace are arranged several retorts or tubes, preferably, side by
side, and on the same level. These retorts are cylindrical, and one end of each
communicates with the one next to it. They are heated by a fire at one end of
the series, the flame from which passes under and over each retort. By this
means the retort nearest the fire is heated most, and that furthest from it
least, and the others in proportion according to their distance from the fire.
It is not necessary that the retorts should be placed side by side, and on
the same level; they may be placed on an incline, or one above the other, .
suitable arrangements being made for heating each retort to a different
temperature.

page_text: The ore or other mineral substance is introduced at or near one end of the
retort farthest from the fire, suitable apparatus being provided to admit a
requisite quantity from a hopper placed above. A worm or screw is caused to
revolve by suitable motive power through the whole length of the retort, in
such manner that the ore or other mineral substance introduced at or near
one end of the first retort may be moved through to the other end.or near to
the end, whence it passes to the second retort, and by the action of a screw is
moved through it to the opposite end, and thence to the third retort, and so
After the ore or other mineral substance has passed through the last
retort of the series, it is pushed out by the action of the screw, and falls into a
receptacle provided for that purpose. Air may or may not be admitted to the
ore or other mineral substance, according to the effect wished to be produced by
the calcination.
By
The object of the above arrangement of furnace is to cause the ore or other
mineral substance to be subjected at first to a low heat, which is gradually
encreased as the ore or other mineral substance approaches the fire.
this means it is prevented caking into lumps, which it frequently. does if
exposed at once to a high heat. The continued action of. the screws, stirs the
ore or other mineral substance, and also aids in preventing caking. This
continued action of stirring by the screws saves manual labour, and admits of
air being entirely excluded, if desirable, or of only such quantity being admitted
as is necessary for the process; whilst in the calcining furnaces now in ordinary
use for calcining copper and other ores it is necessary to open the doors for
the purpose of stirring, and introducing and withdrawing the charges, thereby
preventing the total exclusion of air, or of the quantity being regulated as
desired
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Trueman in the Great Seal. Patent Office on the
15th September 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
TRUEMAN, of Swansea, in the County of Glamorgan, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alfred Trueman, Her special licence that I, the said Alfred Trueman,
my executors, administrators, and assigns, or such others as I, the said Alfred

page_text: Trueman, 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 FURNACE FOR THE
CALCINATION OF COPPER ORES AND OTHER MINERAL SUBSTANCES," upon the condition
(amongst others) that I, the said Alfred Trueman, 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 Alfred Trueman, 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):-
In this furnace are arranged several retorts or tubes, preferably side by side,
and on the same level. These retorts are cylindrical, and one end of each
communicates with the one next to it. They are heated by a fire at one end
of the series, the flame from which passes under and over each retort. By this
means, the retort nearest the fire is heated most, and that furthest from it least,
and the others in proportion according to their distance from the fire.
..
:
It is not necessary that the retorts should be placed side by side, and on
the same level. They may be placed on an incline, or one above the other,
suitable arrangements being made for heating each retort to a different
temperature.
to
or near
near
The ore or other mineral substance is introduced at or near one end of the
retort farthest from the fire, suitable, apparatus being provided to admit the
requisite quantity from a hopper placed above. A worm or screw is caused
revolve by suitable motive power through the whole length of the retort, in
such manner that the ore or other mineral substance introduced at
one end of the first retort may be moved through to the other end, or
the end, whence it passes to the second retort, and by the action of a screw is
moved through it to the opposite end, and thence to the third retort, and so
After the ore or other mineral substance has passed through the last
retort of the series, it is pushed out by the action of the screw, and falls into a
receptacle provided for that purpose. Air may or may not be admitted to
the ore or other mineral substance, according to the effect wished to be pro-
duced by the calcination.
on.
.
The object of the above arrangement of furnace is to cause the ore or other

page_text: of the series, the heat from which passes first under the whole of the retorts
or tubes in the series, and afterwards returns over the tops of the retorts or
tubes. By this means the retort or tube nearest the fire is heated most, and
that farthest from it least, and the others in proportion, according to their
respective distances from the fire. The ore or other mineral substance is
admitted at or near one end of the retort or tube farthest off from the fire,
and is caused to pass through each of the others successively. A worm or
screw, or its equivalent, (as parts of a screw, or a series of discs set angularly
to the shaft,) the entire length of each retort or tube, is caused to revolve in
the interior of cach retort or tube, so that the ore or other mineral substance
introduced at or near one end of any one retort or tube is propelled to the other
end by the revolution of the screw or its equivalent, which is set in motion by
any suitable moving power applied to its shaft (which shaft passes through to
the outside of the cover of the retort or tube), and the contents of the retort
or tube are constantly stirred at the same time, and are caused to pass into
the adjoining retort or tube by the action of the screw or its equivalent, aided
by several paddles or cross pieces placed on the screw shaft. The ore or other
mineral substance as it passes into the adjoining retort is acted upon by the
screw or its equivalent revolving within it, which is made the reverse hand to
the previous screw or its equivalent, and is caused to revolve in the same
direction. The ore or other mineral substance is thus propelled to the
opposite end of the retort or tube, and thence into the next in succession, and
so on through as many retorts or tubes as may be in the furnace. I prefer to
have about ten retorts or tubes in the furnace, of about two feet internal
diameter, three inches thick, and ten or twelve feet long. The screws or
worms or their equivalents are made of the sanie diameter as the inside of the
retorts or tubes, and of about one foot pitch. A suitable quantity of ore or
other mineral substance to be acted upon at one time in retorts or tubes of
these dimensions is three quarters of a cubic foot. Between each thread of the
screw or its equivalent, over the part of the retort or tube where the ore-or
other mineral substance is admitted, I place a hopper, and between the hopper
and retort or tube an apparatus consisting of a fan with several arms or
blades revolving in a box, open at the top to the hopper, and at bottom to the
retort or tube, and revolving at such a speed as to feed the desired quantity of
ore or other mineral substance into the first or furthest retort or tube from the
fire, through which, and successively through the others, it is propelled by the
action of the screws or their equivalents, until the ore or other mineral sub-
stance arrives at the end of the last retort or tube nearest the fire, where
it is delivered into a receptacle underneath provided for that purpose, the

page_text: delivery of the ore or other mineral substance into this receptacle being
regulated by a fan similar to that.used, for feeding, revolving in, a box-
open at
top to the retort or tube, and at bottom to the receptacle, the fan being made
to revolve at such a speed as to pass through it,, all the ore or other mineral
substance.coming..from. the retort or tube, and yet so.. slowly as to keep one
compartment between the blades constantly. (or nearly. so) full, so as to prevent
the passage of air into or from the retort .or, tube. When copper ore. is the
mineral to, be acted upon, and the object is to obtain sulphurous. acid, which
may be.afterwards converted into sulphuric acid, and to. so calcine it as to fit
it for the after process of smelting, the ore being placed, in the hopper, and
the retorts or, tubes heated (those nearest to the fire to a red heat), the motive
power is put in action, and the ore allowed to enter the retort or tube furthest
from the fire, and to pass through the several retorts or tubes into the recep-
tacle, from whence it is removed when a sufficient quantity has accumulated,
and the hopper is. kept constantly replenished, so that the calcining action may
be continuous.
During the passage of the ore through the retorts or tubes a sufficient
quantity of air to convert the sulphur evolved into sulphurous acid, and also
to oxidize the metals from which the sulphur is liberated, may be either forced
or drawn through a hole or holes, in the cover of the first retort or 'tube, and'
passed over the whole of the ore in the several retorts. or tubes, and the
sulphurous acid formed may, if desired be afterwards passed into a leaden
chamber or other apparatus to convert it into sulphuric acid. In place of
forcing or drawing air in at one-retort or tube only, and drawing or forcing it
out at one point only, it may be forced or drawn in at several places, and
also forced or drawn out at several places.. If it is desired to obtain
sulphur in the working of this furnace, the calcination must be conducted
with the admission of sufficient air only to oxidize the metals from, which
the sulphur is liberated. The sulphur evolved may be condensed in a
chamber provided for that purpose. When other minerals than copper ore
are operated upon in this furnace, then the treatment must be varied according
to the mineral employed, and the result which it is desired to produce. The
Drawings, show several views of a furnace having ten retorts or tubes, and
apparatus constructed according to my Invention; the nature of each view
being written thereon, it will not be necessary to repeat the same. A, A, are
the retorts or tubes, supported on bearers B, B, which form partitions to the
flues B', B', which pass under the retorts or tubes; C, C, are fire-places or
furnaces for heating the retorts or tubes; B³ are passages from the under to
the upper flues B³, from which the products of combustion pass away to the

page_text: chimney D is a passage communicating with the hopper E, from which
the ore or other mineral is fed into the first retort of the series, the ore or
other mineral being delivered through the passage D₁ at the end of the last
retort or tube of the series; F, F, are screws carried by the shafts F', F',.
which revolve in bearings formed on the ends or covers A', A', of the retorts
or tubes A; on the end of each shaft F¹ is fixed a worm wheel F2, which
receives motion from a worm G, fixed on the shaft or axis G', which is driven
by a bevil pinion H, fixed on the axis H¹, taking into the teeth of the bevil
wheel G, fixed on the axis G¹, the axis H¹ receiving motion by a band over
the pulley H² from a steam engine or other motive power; the screws F, F,
are alternately formed right and left, so as to propel the contents of the retorts
or tubes in opposite directions; F3 are what I call paddles or cross pieces,
fixed near the ends of the screws to assist in propelling the ore or other
mineral substance through the passages or openings, which connect the ends
of the retorts or tubes together; I, I, are uprights connected together at each
end of each pair by longitudinal and transverse tie rods, to keep the covers
A¹ of the retorts or tubes in their places, and to strengthen the brickwork.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the precise details herein described, so long as the peculiar character of my
Invention be retained; but what I claim is,-
The improved construction of furnace for the calcination of ores or other
mineral substances as herein described.
In witness whereof, I, the said Alfred Trueman, have hereunto set my
hand and seal, this Seventh day of September, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
RICH JAMES,
Loughor,
Glamorganshire.
ALFRED TRUEMAN. (L.s.)