IMPROVEMENTS IN. TREATING ORES TO OBTAIN COPPER THEREFROM AND IN. EVAPORATING BRINE
Year: 1868

page_text: LETTERS PATENT to Thomas Johnson, of Runcorn, in the County
of Chester, for the Invention of "IMPROVEMENTS IN. TREATING ORES
TO OBTAIN COPPER THEREFROM AND IN. EVAPORATING BRINE."
Sealed the 9th June 1868, and dated the 3rd March 1868..
PROVISIONAL SPECIFICATION left by the said Thomas Jolinson at
the Office of the Commissioners of Patents, with his Petition, on
the 3rd March 1868..
I, THOMAS JOHNSON, of Runcorn, in the County of Chester, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN TREATING.
ORES TO OBTAIN COPPER THEREFROM AND IN EVAPORATING BRINE," to be as.
follows:-
This Invention has for its objeet improvements in treating; ores to
obtain copper therefrom and in evaporating brine. Ores containing
copper and sulphur are now commonly calcined with common salt,.
and so a chloride of copper is obtained, which can afterwards be washed.
out; this has heretofore been done by burning coal or solid fuel in the
immediate vicinity of the ore, and allowing the flame therefrom either
to play directly on to the ore itself or on to a surface on which the

page_text: ore rests; it is difficult in this way to regulate the heat to the nicety
which the process requires, and great care and highly skilled labor is
therefore requisite.
According to this Invention I substitute gas for solid fuel, and by
so doing I obtain a furnace which will remain at a uniform heat for
any desired time with scarcely any attention, and of which the heat
may be instantaneously increased or diminished by opening or closing
more or less suitable valves or dampers. I prefer to arrange under
the bed on which the ore rests a number of longitudinal flues, at one
end of each of which the gas is admitted by a pipe, and is there
ignited, the air necessary to support combustion being admitted by
an opening into the flue surrounding the gas jet. Both the gas and
air supply are capable of regulation by valves or dampers. The flame
and heat traverse the flues to their further ends, and there ascend
and return over the bed of the furnace and in contact with the ore
thereon, the draft then escapes by side openings in the walls which
surround the bed and passes to a chimney. The gas may be con-
veniently obtained by passing air in limited quantity through ignited
fuel. The arrangement for heating pans for evaporating brine is very
similar. The pan is set over a number of flues running from end to
end of the pan. Gas is admitted at one end of each of these flues
and burnt by means of air which is simultaneously admitted. The
gas and air admissions are both capable of regulation by dampers or
valves, and the heat and flame traverse the flues and pass away at their
further ends.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Johnson in the Great Seal Patent Office
on the 3rd September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JOHNSON, of Runcorn, in the County of Chester, send greeting.
3
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of March, in the year.
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of. Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Thomas Johnson, Her 3

page_text: special licence that I, the said Thomas Johnson, my executors;
administrators, and assigns, or such others as I, the said Thomas
Johnson; 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 TREATING ORES TO OBTAIN COPPER THERE-
FROM AND IN EVAPORATING BRINE," upon the condition (amongst others)
that I, the said Thomas Johnson, my executors or administrators,
by an 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.
NOW KNOW YE, that I, the said Thomas Johnson, 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 :-
This Invention has for its object improvements in treating ores to
obtain copper therefrom and in evaporating brine. Ores containing
copper and sulphur are now commonly calcined with common salt,
and so a chloride of copper is obtained, which can afterwards be washed
out; this has heretofore been done by burning coal or solid fuel in the
immediate vicinity of the ore, and allowing the flame therefrom either
to play directly on to the ore itself or on to a surface on which the
ore rests. It is difficult in this way to regulate the heat to the nicety
which the process requires, and great care and highly skilled labor
is therefore requisite.
According to this Invention I substitute gas for solid fuel, and by
so doing I obtain a furnace which will remain at a uniform heat for
any desired time with scarcely any attention, and of which the heat
may be instantaneously increased or diminished by opening or closing
more or less suitable valves or dampers. I prefer to arrange under
the bed on which the ore rests a number of longitudinal flues, at one
end of each of which the gas is admitted by a pipe and is there
ignited, the air necessary to support combustion being admitted by

page_text: ure 1 is a plan of a furnace for treating or roasting ore mixed with
salt to obtain copper therefrom; Figure 2 is a side view, partly in section,
of the same; Figures 3 and 4 are end views of the same in Figure 3. A
portion of the furnace is shown in section.
a, a, are the main walls of the furnace, and 6 is an arch enclosing it
at the top, forming a chamber, say, thirty feet long and eleven feet wide,
more or less; c is the bed of the furnace; it is constructed conveniently
of fire-tiles about three inches thick; it is supported on a series of longi-
tudinal dwarf walls d, d, and between these are flue spaces e, e,
communicating at one end by the vertical passages f, f, with the
horizontal chamber or flue g which connects them all with the main gas
channel h leading the gaseous fuel to the furnace; at h¹ there is a damper
regulating the passage of gas into the chamber or flue g; and f¹, ƒ³,
are other dampers regulating the distribution of the gas to the several
flues e, e; k, k, are longitudinal air channels; there is one under each
of the flues e; they communicate with vertical air passages 1, 1, and the
mouth of each air passage is immediately in front of the mouth of the
corresponding gas passage f. By arranging the air channels k, k, to run
from end to end of the furnace, the air becomes warmed before it mixes
with the gas, but the air passages may be otherwise arranged. k¹ are
doors to regulate the entry of the air into the passages k. At the

page_text: further ends of the flues e there are openings in the bed by which the
draft ascends, and it returns over the bed to the end at which the gas
and air enter, where by an opening at the centre of the arched roof bit
passes into a flue / leading to the chimney; is a regulating damper
in this flue; m, m, are hoppers mounted on the top of the furnace and
communicating with openings in its arched roof; m', m', are slides closing
the bottoms of these hoppers; they are opened to allow the charge to
fall into the furnace and are then closed. The ore which is usually
pyrites which has been burnt to obtain sulphurous acid for the
manufacture of vitriol is mixed with common salt in the manner
commonly practiced, the proportions being regulated as heretofore. The
mixture is charged into the furnace through the hoppers, and is by the
workmen raked into an even layer, covering the bed to a depth of six or
seven inches.
n, n, are the working doors through which the workmen
operate; o is a platform with a railway upon it along which the
trucks run which bring the ore to the furnace. The gas is lighted in
the flues e, e, by applying a torch at the openings e¹, e¹, which are
provided with closely fitting doors; these openings serve also as sight
holes by which the workman can observe the progress of the combustion
in the flues. e, e², are other similar sight holes at the other ends of
the flues e; p, p, are sight holes fitted with doors for observing the
flame over the bed of the furnace.
The roasting operation is conducted by the same rules as when solid
fuel is used. The ore is raised to a dull red heat barely visible by day-
light, and great care is taken to keep the heat uniform throughout the
charge and to prevent agglomeration from partial fusion. In con-
sequence of the facility which the use of gas affords in regulating the
heat, the roasting can with safety be more rapidly effected than when
solid fuel is used; with this furnace six charges may be roasted in the
twenty-four hours. The workman regulates the heat mainly by means
of the dampers f¹ and the air doors k', and frequently he will extinguish
the flame altogether in one or more of the flues e; also the workman
in some cases allows the gas in one of the flues e, say, the centre one,
to remain unfired, the air being shut off from this flue, and he then fires
the gas as it rises over the bridge c¹ on to the bed by means of a torch
inserted at one of the sight holes p. When the roasting of one charge
of ore is complete it is raked out of the furnace and another charge is
at once let down on to the bed. The lixiviation of the ore to dissolve
out the copper and the subsequent operations are conducted as heretofore.

page_text: For evaporating brine the arrangement is similar up to the level of the
furnace bed; the bottom of the salt pan takes the place of the bed c, and
is similarly supported on the dwarf walls d. The pan is of the ordinary
construction, and it may conveniently be about sixty feet long, the
flues e running from end to end of it; the flues e at the further end
of the pan do not ascend as in the furnace, but at once enter the
chimney.
The apparatus which I prefer to employ for the production of the
gas is shown at Figures 5, 6, 7, and 8; Figure 5 is a longitudinal and
vertical section; Figure 6, a front view; Figure 7, a vertical section taken
at the line 1, 1, Figure 5; and Figure 8 is a transverse and vertical
section taken in part at the line 2, 2, and in part at the line 3, 3,
Figure 5.
The apparatus consists of two or other numbers of brickwork chambers
arched over at the top and say seven feet six inches wide and ten feet
six high, but the dimensions may be varied; any number of these
chambers may be used where several furnaces are to be supplied; one
chamber is sufficient to supply a furnace, but it is not convenient to
work with a single chamber. At the front of the chamber there is an
open arch, and from the crown of this arch at a (Figure 5) to a cross
bearer at b a dead plate extends across the chamber; it is protected
by fire-brick on its face. From the bearer at 6 to the back of the
chamber at c there are fire-bars set at an angle, underneath the fire-
bars a water trough is placed. Through the top of the chamber are
charging holes d, d; they are fitted with hoppers not shown in the
Drawings; they are furnished with slides which are drawn out to let
the fuel enter the chamber and then immediately replaced. e, e, are
working holes, through which when necessary the workman introduces
tools to spread the fuel in the chamber so as to keep every part of the
fire-bar surface thickly covered so that no air may enter the chamber
except by permeating the heap of burning fuel. The working holes
are furnished with stoppers with which they are closed when not actually
in use to prevent the escape and loss of gas. The gas passes from the
chamber by an arched passage at the back into a vertical flue f fitted
with a damper; this flue is closed at the top, and the gas is made to
descend the flue g, from whence it escapes by the arched
h into
passage
the main gas channel leading to the furnaces; the flues ƒ and g are
provided with sight holes at the top. It will be observed that the

page_text: workman has ready access to the under side of the fire-bars, and he clears
them from time to time whenever he finds the heat in the chamber is
becoming insufficient.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that what
I claim is, the roasting ores containing copper and mixed with salt in a
furnace heated by the burning of gas therein; and also the conducting
the said roasting process in a gas furnace constructed substantially as
above described,
I also claim the evaporating brine to produce common salt by the
burning of gas as above described; and also the use in the said process
of evaporating apparatus constructed substantially as above described.
In witness whereof, I, the said Thomas Johnson, have hereunto
set my hand and seal, this First day of September, in the year
of our Lord One thousand eight hundred and sixty-eight.