A New or Improved Furnace for the Reduction or Smelting of Zinc, Lead, Silver, Gold, and other Ores.
Year: 1892

page_text: Date of Application, 7th Oct., 1892-Accepted, 12th Nov., 1892
COMPLETE SPECIFICATION.
A New or Improved Furnace for the Reduction or Smelting of Zinc,
Lead, Silver, Gold, and other Ores.
I WILLIAM SMETHURST of 49 Mimosa Street Fulham Road, London, Engineer
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to the construction of ore smelting or reducing furnaces and
is particularly applicable to furnaces for use in the treatment of ores of zinc, lead,
silver and gold the object of my said invention being to render the treatment of
the ores more economical and more thorough than where furnaces of ordinary con-
struction are used.
My said invention consists chiefly in constructing the furnace in such a manner
that as soon as the metal is separated from the ore, it leaves that part of the
furnace where the heat is most intense and runs into receptacles arranged to receive
the same whereby the losses due to overheating are reduced to a minimum.
The furnace may be so constructed that the loading and unloading may be
carried on continuously or it may be constructed so that successive loads of the ore
may be treated in it the unloading being effected after the smelting of each entire
load is accomplished.
For the production of metallic zinc I dispense entirely with the use of retorts
and thus effect considerable economy not only on account of the price of the retorts
which require to be often replaced but also owing to the saving of labour in the
loading of the furnaces.
In order that my invention may be fully understood I will describe the same
with reference to the accompanying drawings in which
Figure 1 is a side elevation partly in vertical section and Figure 2 a front
elevation partly in vertical section of a furnace constructed according to my
invention for the treatment of ores in successive loads.
Figure 3 is a side elevation partly in vertical section showing the arrangement of
the parts of a furnace for continuous loading and unloading.
Figure 4 is a side elevation partly in vertical section of a furnace for continuous
loading and unloading the construction of the said furnace being modified in order
to carry out a special method of heating.
Figure 4 shows a modification of a detail.
Figure 5 is a front elevation partly in vertical section taken on the line Y Y
Figure 4 of the front part of the furnace and
Figure 6 is a horizontal section of the same taken on the line X X Figure 4.
In carrying my invention into effect I construct the furnace as shown in
Figures 1, 2 and 3 with an inner arch or vault a forming with the two doors b, b
an entirely closed chamber designed to receive the ore to be treated and with an
outer arch or vault A. concentric with the arch a: the space between the arches a
and A which is in direct communication with the fireplace D forming a heating
chamber surrounding the chamber a throughout its length. The heat and the
products of combustion from the coke or gas in the fireplace D pass through the
openings E between the arches A and a and escape through the flue F without
coming into contact with the ore in the closed chamber a.
The ore to be treated is placed upon a tray I of any suitable fire-proof material
which covers almost the whole surface of the sole a¹ of the chamber a; and on
each side of the space occupied by this tray I channels g, g are formed in the sole a¹
of the chamber a the said chanuels extending longitudinally from one end to the

page_text: other of the sole a¹ and being inclined towards the front of the furnace where they
each lead to a chamber c containing a receptacle or mould designed to receive
the molten metal which runs from the tray I into the channels g, g.
The tray I is furnished on each side with vertical flanges i, i in which are formed
holes or slots j, j and is constructed in such a manner as to be higher in the centre
than at the sides so that the metal may run through the holes or slots j, j of the
flanges into the sloping channels g, g.
Instead of one single tray I, several trays may be placed end to end in the
chamber a or by modifying the construction of the furnace as shown in Figure 3 a
series of trays or plates may be arranged end to end and pushed gradually through
the furnace the said trays as they enter the furnace being continuously loaded
with ore passing from a hopper k arranged outside the bottom of the chamber a.
Figures 4, and 6 show another mode of carrying my invention into practice
according to which the furnace comprises one chamber a only, heated directly by a
suitable mixture of gas and air and on the sole of which rest as in the above case
the trays containing the ore to be treated which is continuously loaded through
the hopper k arranged outside and against the door of the chamber a and which
may be made in one piece with the said door b. Near the top of the two sides of
the chamber a are formed a series of holes leading to conduits or pipes which
conduct into the chamber a the mixture of gas and air the flames from which come
into direct contact with the ore on the trays. The products of combustion escape
through a flue m at the bottom of the chamber a into the stack m'.
The conduit by which the gaseous mixture passes to the holes e, e, e may be
formed in the brickwork of the furnace when the latter is constructed as shown
at on the right hand side of Figures 5 and 6; or a pipe f¹ as shown on the
left hand side of the said Figures 5 and 6 may be used the said pipe being placed
along the outer wall of the furnace.
The gas and air used for heating should be mixed in such proportions as to
ensure perfect combustion.
When the furnace is heated as above described, the vapours evolved from the
ore are very scanty, but to avoid loss of vapour in the upper part of the flue m
1 arrange in the said flue a trough or reservoir n containing water or a mixture of
water and acid or of any other condensing liquid which is continuously supplied
thereto in the form of spray from an outer reservoir o through a number of
perforations formed in the upper wall of the flue as shown in Figure 4. A
conduit p conveys the water to the reservoir o and the water from the reservoir n
escapes through the outlet
A damper r near the opening of the stack m' allows
the outflow of the products of combustion to be regulated and the vapours to be
compelled to pass into the liquid in the reservoir n. Instead of a damper ↑ as
above described I in some cases use a series of plates or sheets jointed to the
upper wall of the flue m the position of which plates or sheets may be regulated
by means of a rod t manipulated from the outside as shown in Figure 44.
arrangement causes the vapours to pass repeatedly through the condensing liquid
of the reservoir n.
9.
This
Instead of constructing the furnace as shown in Figures 4, 5 and 6 for the
continuous loading of the trays I it may be modified for intermittent operations
like the furnace shown in Figures 1 and 2 by dispensing with the hopper and the
openings for the passage of the trays at the bottom of the chamber a and under
the door b, as will be readily understood.
Instead of the channels g on the two sides of the chamber a being alone inclined
towards the front of the furnace the whole sole of the chamber a may be inclined
the effect being to greatly facilitate the forward motion and the loading of the
trays in the furnaces arranged for continuous loading.
By constructing the furnace with one chamber having a sole inclined towards
the front of the oven, the trays could be dispensed with the ore being loaded
directly upon the sole of the chamber the surface of which may be similar to that
of the trays above described.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that I claim:
:-
First A furnace for smelting zinc, lead silver, gold and other ores, characterized
by the use of fire proof trays carrying the ore to be treated and resting upon the
sole of a closed chamber formed with channels inclined on both sides to collect
the molten metal and convey it into moulds or receptacles designed to receive the
same, the said closed chamber being heated either indirectly by a surrounding
chamber through which travel the products of combustion proceeding from a fire
place arranged under the closed chamber, or directly by the flames of a mixture of
gas and air directed upon the ore under treatment through holes formed in the
walls of the chamber the whole as hereinbefore described and illustrated in
Figures 1, 2 and 3 and in Figures 4, 5 and 6 of the accompanying drawings.
Secondly-The use in a furnace of the kind claimed in the preceding claim of
trays of fire-proof material having a surface sloping from the centre to each side,
and the sides of which are provided with flanges having holes or slots formed in
them substantially as herein before described and illustrated in the accompanying
drawings and for the purpose set forth.
Thirdly-In a furnace of the kind claimed in my first claim the arrangement
whereby the furnace may be continuously loaded and unloaded and the trays
introduced into the furnace one after the other without interruption through
openings formed for this purpose in the front and rear walls, the said trays being
successively loaded with ore which passes continuously from a hopper onto the said
trays as they enter the furnace, substantially as herein before described and
illustrated in Figures 3, 4, 5 and 6 of the accompanying drawings.
:-
Fourthly In a directly heated furnace of the kind claimed in my first claim
the means for preventing the loss of the vapours carried towards the stack with
the products of combustion, consisting in the arrangement in the flue leading to the
stack of a trough or reservoir containing a condensing liquid and means for causing
the said vapours and products of combustion to pass once or several times through
the liquid, substantially as hereinbefore described and illustrated in Figures 4
and 4 of the accompanying drawings.
Dated the Fifth day of October 1892.
W. T. WHITEMAN,
Agent for the Applicant.