Improvements in Apparatus for Concentrating or Sorting Minerals.
Year: 1893

page_text: Date of Application, 23rd Nov., 1893-Accepted, 4th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in Apparatus for Concentrating or Sorting Minerals.
I, BASIL JOHN ATTERBURY, of Leadenhall Buildings, Leadenhall Street,
London, Gentleman, 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 relates to apparatus for sorting minerals, and especially ores after
they have passed through the stamps or crushing machine.
The apparatus chiefly comprises an inclined table on which rests a grating or a
sheet of wire gauze or perforated metal plate fixed to a frame which can be lifted
off the table, when required. When a stream of water and crushed ore is passed
down the table, the meshes in the grating or wire-gauze or the perforations in the
inetal plate (as the case may be) produce a series of eddies or whirlpools, thereby
causing the heavier particles to deposit themselves in such meshes or perforations.
When such tables have been in use for some time, it becomes necessary to remove
the deposited material from the table, for which purpose the wire gauze etc. is lifted
off, so as to give sufficient space for the flushing water to carry away the said
material. The same object may be attained by lowering the tabie, but the means
for effecting it would be more complicated and inconvenient.
In order to lift and lower the frame carrying the wire gauze etc., it may be hinged
or pivoted at the upper end, but I prefer to suspend it from a pair of horizontal
shafts by means of short levers or links in such a manner, that by turning one of
the said shafts on its axis, by means of a hand lever, the said plate or wire gauze is
lifted from its base at both ends simultaneously, and that it is also drawn forward,
the upward motion being sufficient for giving free access to the current of water,
with which the table is flushed, and which carries away the deposited material into
a flume leading into a suitable receptacle.
I prefer, to turn the two horizontal rocking shafts mentioned above, by means of
a lever mounted on one of the said shafts, while the other shaft serves only as a
guide which follows the motion of the frame holding the sheet or plate of
wire gauze.
Usually I arrange two or more of these tables end on to each other, the first one
discharging into the second, and so on, the waste being carried off at the tail end
of the series, and the valuable material being deposited in the meshes or perforations;
but when the wire gauze or perforated plate (as the case may be) is raised, the act
of doing so opens a discharge into a flume specially provided to convey the valuable
material away.
In further describing the invention, reference will be made to the accompanying
drawings, of which
Fig. 1 is a longitudinal vertical section showing the principal parts of a
concentrator composed of two sections placed in series ;
Fig. 2 is a plan of the first or upper section ;
Fig. 3 is a cross section of the same.
The other figures represent details of construction.
In these drawings A indicates the first table or the table of the upper section,
B the second table,
C a screen or strainer, over which the coarse waste material passes from the first
table into a transverse trough or discharge channel F.
D is a launder, over which the fine material (that has not been concentrated)
and the water which have passed through the strainer C flow down to the table B.

page_text: and are flumes for carrying off the valuable material, and
F and F are flumes for carrying off the waste.
The table B is inclined at a smaller angle than the table A.; it serves for the
concentration of slime and delivers it into a transverse trough E¹.
a (Fig. 1) is an inclined plate, which receives the ground raw material and the
water from a shoot or shaft and allows it to drop upon the upper end of the table A.
This table has a flat wooden (or metal) bottom (Fig. 6) and wooden (or metal)
sides c.
The bottom b is covered with a sheet of india rubber d, which may be
fastened thereto directly, but is preferably made to rest on a sheet of baize or other
suitable packing material adapted to form a bed or cushion for the rubber blanket,
so as to prevent it from being cut by the wire cloth. e is the wire gauze or
perforated plate (as the case may be), which is fastened to the underside of its
wooden frame f..
To the right and left side of the frame f there are fixed a pair of plates, which
carry studs h, h, serving as pins for the lower ends of the short levers or suspending
arms ii fixed on the shafts k k. These shafts pass horizontally across the table,
and are held in bearings mounted on the sides of the same. On one of the
said shafis is fixed at one end a hand lever m, which in its normal position, that is,
when the bottom of the moveable frame rests on the india-rubber face d of the
table, is approximately perpendicular to the table.
As shown in Fig. 1, the sides of the frame c extend beyond the lower end of the
table b, and are connected by a transverse board f³, so as to form a continuation of
the said table.
The mode of operation is as follows:-
The material to be treated, together with a sufficient quantity of water, is
conveyed over the distributing or deflecting plate a to the head of the table, from
whence it is carried by the stream of water over the wire gauze or perforated plate
(as the case may be) depositing its valuable particles in the meshes of perforations
and on the indiarubber table below. The waste material may flow off its end and
over the board f¹ into a waste flume (F). Under ordinary circumstances, however,
I use two or more of these tables in series, so that the residue which escaped
concentration on the first table (that is deposition in the meshes of the same) is
first carried with the water over the screen C, in order to separate the finer material
from the coarse waste and render its subsequent concentration easier and more
perfect, the said material being carried with the water through the screen, and
passing on to the head of a second table B of similar construction, but generally set
at a less incline, where it is of course subjected to a similar treatment. By setting
the second table at a less incline, than the first, lighter material is deposited, and
thus concentrates of different classes may be obtained.
Ordinarily the flume E situated below the edge of the table b is covered by
the board of the frame ; but when the latter is raised into the position
shown in Fig. 1 by dotted lines, the perforated plate e and board fi rise with it, so
as to allow the flushing water which subsequently flows over the table, to carry into
the flume E the valuable particles which had previously been deposited in the
meshes of the wire gauze e.
The entire apparatus is mounted on a suitable bed or stand, of which Fig. 1
indicates the outlines. In order to vary the inclination of the table, its upper end
rests on the stand by means of a pair of screw brackets o, o, fixed to the table, as
shown by Fig. 7. By turning the screw spindles in their nuts p held by the said
brackets, the upper end of the table may be raised or lowered.
The wire gauze is preferably woven from steel wire, and may be galvanized,
bronzed or electroplated, if desired. The width of the meshes in the wire cloth or
grating, or the size of the holes in the perforated plate, depends on the class of ore
to be concentrated.
For the treatment of finely divided ore, or battery tailings, about 420 meshes
per square foot of wire cloth may be suitable, but for the treatment of coarser
material, such as alluvial wash, which is a mixture of stones, gravel, sand and clay,

page_text: the construction of the apparatus is modified, so as to separate the stones and gravel
from the finer material before it reaches the wire cloth.
For this purpose perforated plates suitable for the material to be treated are
placed above the wire cloth, so as to retain the stones and gravel, while allowing
the same to pass down with the water. The wire cloth in this case is preferably
made of steel wire inch diameter, the size of the meshes is about one square inch,
and cocoa nut matting is preferably used insteal of the rubber blanket. Or the
bottom may be plain metal or wood, and the wire cloth may be replaced by
perforated cast metal plates.
For treating large quantities of ores, two or more sections are placed side by side
or in tiers one over the other, each section communicating separately at the top
with a common feed channel which supplies water and ore to the different sections
at the same time.
Two sections placed end to end (as represented by the drawings) with a suitable
inclination for each section, or two sections placed in one frame at different angles
may serve to concentrate two minerals of different specific gravities at the same
time, and in a similar manner three sections placed in series may concentrate three
minerals of specific gravities.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:―
1. A concentrator or sorting apparatus comprising in its construction an inclined
table, a sheet of wire cloth, perforated plate or grating mounted on a frame and
resting on the said table or in close proximity thereto, and mechanism for producing
a clearance space for a stream of flushing water, the whole being adapted to operate
substantially as described.
2. A concentrating or sorting apparatus comprising in its construction an
inclined indiarubber table and a sheet of wire cloth, perforated plate or grating
mounted on a moveable frame and resting on the said table or in close proximity
thereto, the whole being adapted to operate substantially as described.
3. In table concentrators for concentrating minerals, the combination of an
inclined table, with a wire gauze, perforated plate or grating held in a moveable
frame and resting on the said table or immediately above the same, and two or
more rocking shafts connected with the said frame, so that the latter may be
simultaneously lifted and drawn forward by turning one of the said shafts,
substantially as described.
4. In table concentrators for concentrating minerals, the combination of au
inclined table, with a wire gauze, perforated plate or grating held in a moveable
frame and resting on the said table or immediately above the same, a pair of rocking
shafts mounted on the sides of the said table and connected with the sides of the
moveable frame by a pair of levers, and a hand lever mounted on one of the said
rocking shafts, substantially as described.
5. In table concentrators for concentrating minerals, the combination of a
stationary table, with a wire gauze, perforated plate or grating held in a moveable
frame and resting on the said table or immediately above the same, means for lifting
the said frame above the said table a flume situated near the lower end of the said
table and adapted to receive the material flushed from the same, and a flume cover
connected with the said moveable frame in such a manner, that it closes the flume
as long as the frame remains in its lowest and working position, but opens the same
when the frame is lifted, substantially as described.
6. In table concentrators, for concentrating minerals, the special arrangement of
the flume E and its cover in relation to the table and moveable frame, the cover of
the flume being attached to the said frame and forming a prolongation of the table,
substantially as described.
7. A table concentrator composed of two or more sections placed in series, each
section having a differently inclined table, a moveable wire cloth, grating or

page_text: perforated plate covering the said table, and accessories for supplying it with raw
material, delivering or guiding and sifting the product, and moving the wire
cloth etc., substantially as described.
Dated this 22nd day of November 1893.
FAIRFAX & WETTER,
433, Strand, London, Patent Agents for the Applicant.