An Improved Rotating Filtering Apparatus, principally applicable for the Separation of Gold and Silver Bearing Solutions from Tailings, Slimes, and the like.
Year: 1898

page_text: Date of Application, 31st Oct., 1898-Accepted, 17th Dec., 1898
COMPLETE SPECIFICATION.
An Improved Rotating Filtering Apparatus, principally applicable
for the Separation of Gold and Silver Bearing Solutions from
Tailings, Slimes, and the like.
I, ASKIN MORRISON NICHOLAS, of Bulong, in the Colony of Western Australia,
Mining Manager, 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:-
-
This invention has been devised for the purpose of providing means whereby
solids or insoluble material may be separated from liquids carrying same in sus-
pension, but more particularly for the purpose of providing means whereby the
separation of gold and silver bearing solutions from tailings, slimes, pug or
pulverized ore, may be carried on continuously and in such a way that a clean
or partially clean filter cloth will be continuously brought into operation with-
out necessitating stoppages for recharging as required with the appliances at
present in use.
The essential feature of the invention consists in the use of a rotating wheel,
disk, or table, formed with a series of air-tight compartments covered with cloth
or other filtering material, supported upon a metal screen, or perforated plate, and
adapted to be automatically placed in communication with a vacuum pump, in
turn, for a sufficient time to enable the liquid to be drawn through the filtering
material, leaving the solid constituents upon the filtering surface whence they
can subsequently be removed by brushes, jets of water, scrapers or similar con-
trivances, provision being made for automatically allowing air to enter into the
various compartments, at the desired period of the operation, to facilitate the
removal of the solids from the outer surface of the filtering material.
The invention will more readily be understood by reference to the accompany-
ing drawings in which :-
Figure 1 is a vertical central section, and
Figure 2 a vertical transverse section of a rotating filter constructed accordin
to this invention.
Figure 3 is a cross section through the rim of the rotating filter on line 3-
Figure 1.
Figure 4 is a transverse section on line 4-4 Figure 2 illustrating the construc-
tion of a valve hereinafter described.
Figure 5 is a front elevation of a modified form of my invention.
Figure 6 is a vertical transverse section on line 6-6 Figure 5.
Figure 7 is a front view of the inner face of the valve used with this form of
apparatus, and
Figure 8 is an end view of the shaft or spindle illustrating the arrangement of
ports or passages therein.
The same letters of reference indicate the same or corresponding parts in all
the figures.

page_text: The arrangement illustrated in Figures 1 to 4 consists of a wheel (say twelve
feet in diameter and four feet breast) mounted upon a shaft A rotating in bear-
ings B. This wheel may be driven at a speed of say from one to five feet per
second at the periphery by worm and worm wheel gear C or otherwise.
The wheel is made with a number of compartments on its periphery marked D
to D7 each communicating with one of the hollow spokes E and covered with
filter cloth For other material as shewn clearly in Fig. 3, resting upon a screen G
of wire work or perforated sheet metal.
Each of the hollow spokes E is in communication through ports or passages o
in the axle A with a stationary valve H communicating through a suction'
pipe with a suction pump. This valve H is constructed and arranged as illus-
trated in Figure 4 so as to place only two of said hollow spokes E in
communication with said suction pump at the same time.
The valve H is provided with an air admission cock I whereby air may be
admitted to each hollow spoke in turn as it passes the said valve. This enables
the solid material to be more easily removed.
J represents a distributing launder for feeding the slimes tailings or other
material on to the filter, whilst K K represent perforated water supply pipes
whereby jets of water may be delivered on to the filtering medium in order to
remove the solid particles therefrom. L L represent brushes which can also
be used for this purpose.
In using the above described apparatus, the material to be filtered, or from
which the liquid is to be extracted, is fed by the launder J on to the upper part
of the wheel, say for instance on to the compartment D. As the wheel con-
tinues to rotate in the direction of the arrow shown in Figure 1 this compartment
will be placed in communication, through its spoke E, port or passage e¹, and the
valve H, with the suction pump whereby the gold and silver bearing solution or
other liquid will be drawn through the filter and delivered into storage tanks or
elsewhere, leaving the solid constituents on its surface. This operation will
be continued until the material has been carried round through about one-fourth
of a revolution of the wheel when the valve H will shut off the compartment
from the vacuum, pump, and the solid material can then be removed by washing
or brushing it off the surface. This operation can be assisted by the admission
of air through the valve I, and if adhesive material, such as clay, has to be treated,
air under pressure can be forced into the compartment through the said valve
as will be readily understood.
Where necessary water may be added to the partially dried slimes, or other
material, while on the surface of the filter, and be drawn through into the vacuum
chambers in the wheel so as to still further impoverish the residues. The inven-
tion is also applicable for the recovery and re-use of water from ordinary
battery tailings. In such a case there is no necessity to use water jets to remove
the sand from the filter as it does not adhere closely thereto and can be removed
by brushes alone.
In the arrangement above described the sludge is shewn as being distributed
upon the periphery of the wheel but it is obvious that the slimes or other
material can be brought into contact therewith at any desired part, for instance
the arrangement illustrated in Figures 5 and 6 may be used, the various vacuum
compartments being formed in sections upon the face of the disk or table instead
of on the periphery and the slimes being fed on to it through. jets J as indicated
in Figure 5. In this arrangement the wheel is shown as being driven by an
endless rope C, instead of the worm and worm-wheel gear above described, but
it is obvious that any convenient form of driving gear may be employed..
In operation the flow of pulp on to the rotating filter is continuous from the
vessel in which it is stored. The speed of rotation of the filter and the rate of
supply of pulp thereto are regulated so as to keep the film of solid material just
sufficiently thick as not to resist the external atmospheric pressure.

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 what I
claim is:-
1. The herein described rotating filtering apparatus consisting of the various
parts constructed, arranged and operating substantially as and for the purposes
herein described and illustrated in the accompanying drawings.
2. A rotating filtering apparatus consisting of a revolving wheel drum, disk,
or table, having chambers or compartments covered with a filtering material
(such as cloth supported upon a metal screen or perforated plate) and adapted to
be automatically and alternately placed in and out of communication with a
suction pump substantially as and for the purposes herein described with reference
to the accompanying drawings.
3. In a rotating filtering apparatus a revolving wheel drum, disk, or table,
having compartments covered with filtering material (such as cloth supported
upon a metal screen or perforated plate) each such compartment communicating
with a passage or port (such as e¹) in the shaft of said wheel, drum, disk, or table,
in combination with a valve (such as H) whereby one or more of said compart-
ments may be placed in communication with a suction pump, substantially as and
for the purposes herein described with reference to the accompanying drawings.
Dated this 31st day of October One thousand eight hundred and ninety-eight.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.