AN IMPROVED METHOD AND IMPROVED APPARATUS FOR REMOVING IMPURITIES PROM COAL, PARTS OF WHICH INVENTION ARE APPLICABLE FOR THE SEPARATION AND CLEANSING OF ORES AND OTHER MINERALS
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by James Whitton Arundell at
the Office of the Commissioners of Patents, with his Petition, on the
4th January 1862.-A communication from abroad by Mr. Martin
Neuerburg, residing at Kalk, Rhenish Prussia.
I, JAMES WHITTON ARUNDELL, of No. 265, Gresham House, Old Broad
Street, in the City of London, Gentleman, do hereby declare the nature of
the said Invention for "AN IMPROVED METHOD AND IMPROVED APPARATUS FOR
REMOVING IMPURITIES PROM COAL, PARTS OF WHICH INVENTION ARE APPLICABLE
FOR THE SEPARATION AND CLEANSING OF ORES AND OTHER MINERALS," to be as
follows:-
The object of my Invention is to remove slate, mundic, and other impurities
from coal, and to increase the value of small coal or screenings, which from
their impurities are often nearly or wholly valueless. I attain this by the
combination of certain apparatus, parts of which have been in use separately
for the purification of minerals other than coal, and parts of which are entirely
It is at present the common practice, where any separation or cleansing
of the coal is attempted, to screen it by throwing it as it comes from the pit
mouth upon a grating which retains only the larger pieces, and permits the
smaller pieces with the impurities, usually called screenings, to pass through it.
My Invention will remove the impurities from the screenings, which are to
be treated in the following manner:-The screenings are made to fall upon
a shoot over which a stream of water flows, and with the water they are
passed by the shoot into a revolving hollow iron drum, which is slightly conical,

page_text: tapering towards the opposite end at which the screenings enter. The sides
of the drum are perforated with holes of a suitable size, which extend from
the narrower end to within about one foot of the wider end, and the drum is
placed within and attached to a larger drum of similar form, which revolves
with it. The sides of the outer drum are perforated with holes smaller than
those of the inner drum. The holes in the outer drum may be all of the same
size, or they may be in sets of different sizes, becoming smaller towards the
narrower end of the drum. The outer drum is shorter than the inner one,
and extends only to where the holes in the inner one cease. The axis of the
drums is inclined to the horizon (the wider end of the drum being the lowest)
sufficient to allow the screenings that do not pass through the holes in the
sides to readily pass out at the wider ends; those which are discharged from
the inner drum fall on to a rotating picking table. The rotation of the table
brings each portion of the screenings on it opposite to a boy, who removes
all slate and other impurities which they may contain as they pass. After
having passed him, a fixed scraper causes the cleaned coal to fall into a tram
waggon or other receptacle. The portions of the screenings which do not
pass through the holes in the outer drum are discharged at its larger end, and
fall upon an endless band of canvass of sufficient width, which passes over two
horizontal rollers. One of the rollers is made to revolve, so that the upper
portion of the endless band of canvass passes away from the drum, carrying
the screenings upon it, and discharging them into any convenient receptacle.
A boy stands by the band, and removes any impurities that may be in the
screenings as they pass. The portion of the screenings which pass through
the holes in the sides of the outer drum fall on to one or more inclined
troughs, which discharge them into a funnel-shaped receptacle into which a
stream of water flows. The screenings with the water pass into a cylindrical
or slightly conical revolving drum, the axis of which is slightly inclined to the
horizon, so as to allow the screenings which do not pass through the holes in
the sides of the drum to be discharged at its wider end. The sides of the
drum are perforated with holes of different sizes, but all smaller than the
smallest in the outer drum herein-before described. The smaller sets of holes
are nearer to the end of the drum at which the screenings enter. The size of
the holes in this drum must be such.that no portion of the screenings will be
discharged at the lower end. The holes at the upper end of the drum must
be so fine as only to allow the slime and sand coal to pass through. This falls
into a trough which conveys it to a slime-streaming apparatus, which consists
of a cast-iron vessel, somewhat in the shape of the letter U, one branch of
which is wider than the other. The top of the narrower branch is closed. A

page_text: pipe enters this branch near its top, through which a stream of water enters,
which is caused to overflow at the top of the wider branch. The overflow is
discharged into a circular trough which surrounds the wider branch of the
vessel, and communicates with a launder. There is a funnel above the wider
branch. The slime and sand coal is conveyed into the funnel, and falls
through the latter into the open and wider branch of the vessel. The coal,
which is specifically lighter than the impurities with which it is accompanied
is separated from the greater part of them, and carried by the overflow of the
water into the circular trough above described, and thence into the launder.
The latter conveys it to a continuous jigging hutch, which removes the
remainder of the impurity, as herein-after described. The heavier impurities
fall to the bottom of the U-shaped vessel, and are discharged therefrom
through a valve, which is opened as occasion requires. The sand coal after
leaving the slime-streaming apparatus, and each sized screenings which passes
through the several sets of holes in the drum lastly described, are separately
conveyed by troughs to separate continuous jigging hutches. The con-
structions of the several jigging hutches are the same, except that the size
of the holes in the sieves attached thereto must be made to suit the particular
sized screenings to be purified. The continuous jigging hutch consists of a
vessel in the shape of the letter U, the branches being of unequal height, and
open at the upper ends. Water is forced into the vessel through a pipe
opening into the lower part of it. A perforated diaphragm or sieve is fixed
in the shorter branch of the vessel a certain distance from its top. The water
passes upwards through the sieve, and flows over the sides of the shorter
branch into a trough attached to it. A weighted box fits loosely into the
upper end of the higher branch, which rises and falls by means of a hopper,
and forces the water by continually repeated shocks upwards through the
sieve. A discharge pipe furnished with a valve at its upper end passes
from the centre of the sieve through the side of the vessel; the valve can be
opened or closed by means of a lever. There is also a discharge valve worked
with a lever at the bottom of the vessel. A funnel is fixed above the shorter
branch of the vessel. The screenings to be purified are conveyed by troughs
into the funnel, through which they fall upon the sieve, and by the shocks
communicated to the water by the hopper the impurities are separated from
them. The coal, being specifically lighter than the impurities is carried by
the upward flow of the water over the side of the lower branch of the vessel
into the trough attached to it. From the trough it passes on to a shoot per-
forated-with-holes sufficient to drain off the water, and the purified screenings
are shot into any suitable receptacle. The impurities which collect on the

page_text: sieve are removed from time to time by opening the valve at the upper end
of the discharge pipe.
In the above description it has been shewn how the Invention is applicable
to the cleansing of coal, but it is obvious how it may be applied in the
separation and cleansing of refuse cinders and other minerals and ores.