Year: 1886

page_text: I, CHARLES LUDWIG HARTSFELD, of No 90 Thornton Street, Newport, Kentucky,
United States of America, Mechanical 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 apparatus for obtaining precious metals from crude ores
its object being to produce an economical and efficient portable plant for use in
remote regions, where transportation and repairs are difficult and expensive.
In order to present clearly the nature of my invention, it is necessary to remark
that the process of obtaining precious metals, such as gold and silver, is attended
with great difficulties, owing partly to the usual inaccessibility of the localities
where found, and other circumstances. Such ores are commonly found associated
with other metals, notably copper and lead, sometimes zinc, and also, in various
chemical combinations with other substances. The mode of procedure varies
according to the surrounding conditions. Of these, the leaching process consisting
in treating the ore, previously crushed, with some solution which will dissolve out
the desired metals but not the other constituents of the ore, and then separating
the metals from the chemical solution-is usually expensive, and require certain
conditions not often obtainable, secondly, the amalgamation or milling process,
which consists in treating the crushed ore with quicksilver and water, in which
the quicksilver having a great effinity for gold and silver, takes up and dissolves
those metals, thus forming an amalgam; and afterwards separating the metal by
heat is also practiced, and likewise requires certain conditions not always
attainable. My invention applies to a third, and, on many accounts, more desirable
method; which consists in smelting the ore in connection with suitable fluxes in
a blast furnace. The construction of a blast furnace, such as ordinarily used for
iron ore, would, of course, be impracticable in many of the remote localities where
precious metals are found; and the object of my invention is the construction and
arrangement of a plant, and particularly of a portable blast furnace, which may be
transported in comparatively small sections easily put together and taken apart;
efficient in its operation, at the same time durable and not liable to become
disorganized and require expensive repair.
.
To this end it consists, primarily, in the novel construction of a portable blast
furnace for the reduction of such ores by smelting; and in the construction and

page_text: combination therewith of subsidiary apparatus, to be used in connection with it in
the process of smelting the crude ores, and in recovering the metal carried over in
the processes of combustion; all as hereinafter more fully set forth.
In the drawing I have exhibited a general elevation of the entire plant, including
the furnace proper, the ore and fuel elevator, air-blast, driving engine, condenser,
circulating pump and the supplemental pot-furnace; the blast furnace being
sectioned to show the construction.
Referring now to the drawing, in which the parts hereinafter referred to are
designated by the letters of reference; A designates the blast furnace proper;
Bits "uptake" or "bleeder-"chimney; C, a pipe connection leading to the con-
denser D; E, the fuel and ore elevator; F, the driving engine for operating the
elevator E, and the "blower" I; T, the air-pipe feeding the tuyere blast; H the
"pot" or grading furnace for receiving the out-put of metal issuing from the furnace;
and P, the circulating pump. These parts constitute the general features to which
my improvements relate; and, excepting as hereinafter more particularly described,
are of ordinary and known construction and of any of the convenient forms of
such individual apparatus in common use for kindred purpose and may be varied
at will.
The furnace proper A, consists of two shells, preferably made of boiler plate of
steel or iron, in detachable sections divided horizontally; the inner shell being
formed of sectional components a and the outer shell of components a¹. These
components may be formed in the ordinary manner of steam boiler shells, by
uniting one or more plates together, each sectional component when completed
being of slightly conical form open at both ends, made to fit in series in the general
make-up of the furnace. The sectional components thus described, are provided
with external marginal flanges b, made of angle iron, securely riveted to the
sections so as to present the horizontal flanges of adjacent sections face to face as a
means of securing the sections together by bolts passed vertically through the same
as indicated in the drawings. The annular space between the shell sections when
completed, constitutes a water-jacket, and it will be understood, that, in bolting the
sections together, asbestos or other suitable packing is to be employed to secure
perfect joints and keep all water tight.
I have shown the furnace as being generally conical in opposite directions from
the "boshes;" and for convenience in setting up, the joints of the inner shell are
arranged to be slightly above those of the outer shell so that the building up of
the shells can proceed alternately by sections, and, if necessary, the testing of the
joints of the completed portion of the jacket may be done as the work proceeds.
The number of sections is not material; as this will depend upon the size of the
furnace and the conditions of transportation.
Suitable man holes p, can be arranged in any section by the interposition of a
suitable marginal ring around the orifice, and bolts passed horizontally through the
outer and inner shells and the ring, as in ordinary cases. Surmounting the furnace
proper is a bell-portion terminating in a similarly jacketted up-take B; the water
space of the furnace extending preferably to or nearly to the top of the chimney.
The chimney may however be extended to any desired height above the jacketted
portion. At opposite sides of the bell portion of the furnace, are arranged
apertures, opening through both shells and the intervening water space (and
suitably protected as described for the man holes p) From one of these a pipe C
of sufficient size to convey the gaseous products of combustion, leads to the con-
denser D. The other aperture is closed by a hinged valve h opening inward, and
arranged to swing freely, being held to its seat by a counterweighted arm d. From
the mouth of the latter orifice leads a fuel-slide G, upon the higher extremity of
which is discharged the fuel and ore, suitably prepared and mixed with the fluxes,
(where used), by the endless belt elevator E, operated over an idler pulley by the
driving engine F. The swinging valve h, is arranged to yield to a given charge of
fuel acting by gravity upon it, to admit the charge and immediately close again.
To the valve h, is attached a link g, connecting with the actuating arm ƒ of a

page_text: pivoted pleeder valve e, closing the opening of the uptake B; in such manner
that the opening of the hopper valve h, also opens the main uptake B, in order to
prevent the escape of gases through the hopper-aperture, and allow the same to pass
upward temporarily through the uptake.
The circulation of water in the jacket of the furnace, is maintained by a pump P,
being preferably introduced at the bottom by a pipe P³, (the connection with
the pump is not shown in the drawing) and allowed to overflow at the top from
the uptake B by a pipe p¹. The overflow pipe p¹ leads downward to a distributing
ring p*, arranged within the pipe C; said ring being perforated around its inner
periphery with numerous fine holes so that the escaping water may form a sheet of
fine interlacing jets across the path of the escaping gases and thus condense the
same in their passage through said pipe C, whence the condensed matters may pass
downward into the scrubber D, with the water used in condensation.
I may however, also supply the jet ring p*, direct from the pump with cooler
water through the pipe på connected with p¹ or I may connect the pipe p* direct
with p and provide an independent overflow for the water from the furnace
jacket, such as p³, arranged at any convenient point.
The furnace A, rests upon a suitable base plate or pedestal A¹, and supporting
walls or pillars A2, and is provided with suitable openings S, for the escape of slag;
m for drawing off the metal; and t for the tuyere blast, the latter being supplied
from reservoir pipes T, charged by a suitable blower I, driven by the engine F.
The "boshes" and "hearth" of the furnace are provided with a removable lining c
of fire brick or other refractory material extending upward to a convenient
beight. As in the reduction of precious ores the metals are obtained of a mixed
character separable to some extent by gravity, I provide a small crucible furnace H,
arranged to receive the molten metal issuing from the tap hole m, and maintain
its fluidity while gravity causes a practical separation of the constituents; when
it may then be run off into a mould M, having separate compartments suitably
numbered, into which the molten metal flows filling them successively, the heavier
constituent first and the lighter last in series; but the form of the crucible furnace
and the partitioned mould are well known and need no detailed description.
The condenser or scrubber D, consists of a tank preferably cylindrical, made of
sheet iron, and provided with a central vertical partition K, terminating in a
horizontal partition 7, extending only part way across the area of the tank close to
the surface of a body of water contained in the tank. The water is supplied by
the flow through the pipe C, which enters the tank at the top, and is maintained
at the desired level by an overflow orifice r, at the side of the tank.
The general operation may be inferred from the drawing, which exhibits the
arrangement and connection of parts in use.
The circulation of water in the jacket between the shells a, a, of the furnace
prevents overheating. The conical form of the furnace above the boshes tends to
prevent scaffolding, which danger is also lessened by the cooling effect of the
jacket upon the layer of ore and fuel nearest the sides of the furnace.
The gaseous products of combustion pass outward through the exit pipe C,
through the condensing jets of water from the ring p³, and into the condenser D,—
the uncondensable gases passing beneath the horizontal partition 1, and thence
upward and out by the final exit pipe C¹.
Man holes are also provided in the scrubber tank to facilitate access for
removing the condensed matters and metallic dust which it is the prime object of
the condenser to recover. In this connection it may be mentioned as one of the
chief desiderata of the construction as a whole, that the cooling effect of the
water jacket at the upper part of the furnace, and the water jets in the pipe C,
condenses the vaporized metals and in the condensation and washing of the
ordinary gases of combustion, precipitates the metallic dust, which otherwise
would escape and be lost, and carries all into the scrubber whose arrangement is
such as to further assist the recovery of the same by gravity and precipitate them
to the bottom, to be removed from time to time as necessary.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The portable, water-jacketed blast furnace, constructed as shown and described,
of two sheet-metal casings in double conical form, each formed in horizontally-
separable sections, substantially as and for the purpose set forth.
2. In combination with the body of the blast furnace constructed as described,
of the top bell-portion, provided with fuel and exit openings and extended above
by the vertical uptake or "bleeder " pipe, substantially as set forth.
3. In combination with the furnace, constructed as described, a hopper-valve
and a bleeder-valve, with connecting mechanism so arranged that the opening of
the hopper-valve opens the bleeder-valve, substantially as and for the purpose
set forth.
4. In a furnace of the character described, a hinged or pivoted hopper-valve,
arranged to open inwardly, provided with a counterweighted arm to hold the
same normally' shut, in combination with a hopper or chute arranged to bring
the fuel and ore against said valve so as to open the same by gravity to admit
the charges, substantially as set forth.
5. The combination in a furnace plant of the character described, of the furnace
proper, its counterweighted hopper-valve, the bleeder-valve connected therewith;
the fuel-chute, and the power driven fuel-elevator, substantially as set forth.
6. The combination in a furnace plant of the character described, of the water-
jacketed furnace, the condenser or "scrubber," the pipe connecting the two, and a
force pump for maintaining the circulation of water in both, substantially as set
forth.
7. In combination with the water jacketed furnace, and the "scrubber," the
pipe connection between the two arranged upon a descending incline, and the
perforated pipe-ring for projecting jets of water across the path of the outgoing
gaseous products of combustion and carrying the condensed matters forward into
the "scrubber," substantially as set forth.
8. The combined plant embodying the sectional jacketed furnace, fuel-elevator,
"scrubber," and circulating pump, with their pipe and other connections, combined,
arranged and operating substantially as and for the purpose set forth.
Dated this 23rd day of Morah 1886