IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR DRESSING OR PREPARING ORES
Year: 1882

page_text: LETTERS PATENT to Frank Wirth of the firm of Wirth and. Company
Patent Solicitors at Frankfort on the Main in the Empire of Germany for an
Invention of IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR
DRESSING OR PREPARING ORES A communication from Heinrich Hochstrate
a person resident at Homberg on the Rhine in the Empire of Germany
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office of
the Commissioners of Patents on the 4th July 1882.
FRANK WIRTH of the firm of Wirth and Company Patent Solicitors at Frankfort
on the Main in the Empire of Germany IMPROVEMENTS IN THE METHOD OF
AND APPARATUS FOR DRESSING OR PREPARING ORES," [A communication from
Heinrich Hochstrate a person resident at Homberg on the Rhine in the Empire of
Germany]
This Invention relates to a method and apparatus for dressing or preparing ores,
in which the lighter particles are winnowed out by an air current and the heavier
particles dressed or separated by means of water as hereafter described.
The crushed ore to be dressed is delivered by a revolving screen and falls into a
series of hoppers corresponding to the length of the screen, from each of which it is
delivered into the lower part of an upwardly inclined spout or channel, wherein it
meets & current of air produced by a fan or other apparatus working continuously
or intermittently. The current of air passing upwards through the channel carries
off the light dusty particles of the ore into a dust chamber divided into compart-
ments of progressively increasing dimensions wherein the whole of the dust is
deposited.
The heavier and granular particles of the ore by reason of their greater weight
separate from the air current, fall on to the lower inclined surface of the channel
and roll down the same to the bottom, their descent against the air current being
facilitated by deflecting plates fixed obliquely at intervals within the channel just
above its inclined lower surface so as to deflect and weaken the air current at the
lower side of the channel so that even the smallest particles may fall back regularly.

page_text: An adjustable vertical baffle plate at the upper end of the channel changes the
direction of the air current from an inclined to the vertical direction in order that
the thin splints and flakes moving in the direction of the air current may be
caused to fall and slide downwards onto the lower side of the channel.
The heavier particles are received at the lower end of the inclined channel in a
rotating feeder which discharges the granulated ore regularly into the apparatus
next described. The ore falls into still water in a hopper leading into a vertical
spout or channel through which there is an ascending flow of water and sinks with
a velocity corresponding to its specific gravity until it meets the ascending stream
of water whose velocity is so regulated that the specifically lighter particles are
carried off by the ascending current which overflows into the well of an elevating
apparatus to be returned to the supply reservoir. The specifically heavier particles
sink through the ascending stream of water to the hopper shaped bottom of the
apparatus common to two adjacent separating spouts or channels having an
elevator working between them by which the said particles are regularly
removed.
.
The water is supplied to the entire series of separating apparatus by pipes from
the reservoir to which it is returned after use, as before mentioned.
By a continuous flow of fresh water and a ready overflow for the surplus water
a constant level of the surface of the water in the reservoir above the overflow
gutter of the separating apparatus is ensured.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frank Wirth in the Great Seal Patent Office on the 4th January
1883.
FRANK WIRTH. of the firm of Wirth and Company, Patent Solicitors at
Frankfort-on-the-Main in the Empire of Germany.
"IMPROVEMENTS IN THE
METHOD OF AND APPARATUS FOR DRESSING OR PREPARING ORES." A commu-
nication to me from Heinrich Hochstrate a person resident at Homberg-on-the-
Rhine in the Empire of Germany.
This Invention relates to a method and apparatus for dressing or preparing ores
in which the lighter particles are winnowed out by an air current and the heavier
particles dressed or separated by means of water as hereafter described.
In order that the Invention may be more readily understood, I have illustrated
it in the accompanying drawings, in which Figures 1 and 2 represent part sectional
elevations, and Figure 3 a part plan of the apparatus. The same letters of reference
indicate like parts in all the figures.
The crushed ore to be dressed is delivered by a revolving screen A. and falls into
a series of hoppers A' corresponding to the length of the screen, from each of
which it is delivered to winnowing and dressing apparatus of which there is one
beneath each hopper. The ore is delivered at point a into the lower part of an
upwardly inclined spout or channel C wherein it meets an upwardly directed
current of air produced by a fan B or other apparatus working continuously
or intermittently and communicating with the lower end of channel C. The
current of air passing upwards through the channel C carries off the light dusty
particles of the ore into a dust chamber D divided into compartments of pro-
gressively increasing dimensions wherein the whole of the dust is deposited.. The
heavier and granular particles of the ore by reason of their greater weight, separate
from the air current, fall onto the lower inclined surface of the channel C and roll
down the same to the bottom, their descent against the direction of the air current
being facilitated by deflecting plates b and c c c, &c, the latter being fixed obliquely
at intervals within the channel C just above its inclined lower surface so as to
deflect and weaken the air current at the lower side of the channel so that even the
smallest particles may fall back regularly. An adjustable vertical baffle plate ƒ at
the upper end of the channel changes the direction of the air current from an
inclined to the vertical direction in order that the thin splints and flakes moving
in the direction of the air current may be caused to fall and slide downwards onto
the lower side of the channel C. The heavier particles pass under plate b at the
lower end of the inclined channel and are received in a rotating feeder E which
discharges the granulated ore regularly into the apparatus next described.
The ore falls from the rotating feeder E into still water in a hopper that leads
into a vertical spout or channel o through which there is an ascending flow of
water; it sinks with a velocity corresponding to its specific gravity until it meets
the ascending stream of water in spout o whose velocity is so regulated by adjusting
the overflow gutter g and the slide valve h which controls the inlet, that the
specifically lighter particles are carried off by the ascending current which overflows
at a gutter g into the well G of an elevating apparatus to be returned to the
supply reservoir. The specifically heavier particles sink through the ascending
stream of water in a to the hopper shaped bottom common to two adjacent
separating spouts or channels o as shown in Figure 2. In the space k between these
two spouts an elevator t is arranged to work, by which the heavier particles that
have settled in the hopper are regularly removed therefrom.

page_text: The water is supplied to the entire series of separating apparatus by pipes H
through inlets controlled by adjustable slide valves h, the pipes H leading from the
reservoir to which the water is returned by elevator G after use, as before men-
tioned. By a continuous flow of fresh water and a ready overflow for the surplus
water, a constant level of the surface of the water above that of the overflow gutter
of the separating apparatus is ensured.
Having described the nature of the Invention and the manner of performing
the same, I declare that what I claim; as the Invention to be protected by the
hereinbefore in part recited Letters Patent is.
The combination of apparatus for dressing minerals wherein the lighter particles
are first winnowed out by an air current and the heavier particles dressed or
separated by means of water, substantially as herein shown and described.
In Witness whereof I the said Frank Wirth have hereunto set my hand and
seal this twenty seventh day of December A.D. 1882.
FRANK WIRTH 17.01