994

THE COLLIERY GUARDIAN.

May 17, 1918.

The average length of column is 72*5 ft., and the
ground area 6,730 sq. ft. The cubical contents is
48,792 cu. ft. The roof area is 7,400 sq. ft., and the
metal sides 18,500 sq. ft. The floors are 3| in. thick,
of concrete laid on deep-rib Hy-rib. The hoppers,
chutes, and jigs are of wood, and waterproofed to
protect the iron work from the mine water. The
structural steel was painted with two coats of red
lead and graphite paint. The arrangement of the
jigs along each side of the breaker gives them the
maximum amount of light. The machinery and shaft-
ing are accessible, and the rope drives are located in
one bay, not scattered throughout the addition, as
is frequently the case. The building is well lighted
throughout, and contains 6,700 sq. ft. of glass.

The cast iron columns of the old breaker were prac-
tically the only members re-used. New columns, girts,
machinery supports, hoppers, chutes, and stairs, are
of wood. Distortion of the old structure and the
difficulty of plumbing it prohibited the use of the
steel except at great expense. The worn-out sheet-
metal sides and roof were duplicated, using 16,500

Fig. 4.—Longitudinal Section through the Mineral Spring Breaker.

Roils.

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N?4 Shaker

Shaker

!N? I Shaker-
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sq. ft. of siding and 5,720 sq. ft. of roofing. Its
cubical content is 389,000 cu. ft. The window area is
5,700 sq. ft.

The new plant is designed to prepare 1,500 tons
of coal in an eight-hour working day.

The new preparation plan (fig. 6) required more
height than was available in the old breaker;
additional height was obtained by using elevators, and
the addition was erected without seriously interfering
with the operation of the colliery. While the use of
elevators to handle prepared coal is not recommended,
yet the conditions at Drifton did not warrant the
adoption of a plan involving a shut-down, or the
expenditure required to replace the entire old breaker
by a new and costly one.

The best daily output to date is 1,735 tons, and
it is expected that the breaker will be able to prepare
and load 2,500 tons daily. At present, the average
dump is approximately 600 mine cars a day, 35 per
cent, of this coming from the Latimer stripping. This
coal is of medium quality, one-half being good big-
vein coal, and the other half of poorer quality that
is mined from a small vein containing about 15 per
cent, of divider rock. Three per cent, of the input
comes from the Buck Mountain stripping, and is
a very poor grade of coal, shaly and full of clay;
the remainder of the breaker input is mine coal, hand
loaded and of good quality.

The force on preparation is as follows:—1 breaker
boss, 1 jig boss, 1 picking table boss, 1 ticket taker
and docking boss, 2 dumpers, 4 pickers on platform,
3 pickers on broken coal, 2 pickers on jig refuse, 2
jig runners, 4 machinery attendants (screen men and
roll tenders), 1 breaker engineer, 1 oiler, 1 ropeman,
1 breaker cleaner; total, 25 men.

The force loading coal and charged against loading
is: —1 loader engineer, 4 loaders, 2 runners; a total
of 32 men in the breaker.

One man attends the rock crusher in the breaker,
but part of his time is charged against the disposition
of refuse. The rock crusher is driven by its own
engine, so that it may be independent of the breaker,
which permits of refuse disposition after quitting
time, a necessary measure, because rock may accumu-
late on the picking head when there is an interruption
in the operation of the refuse conveyor.

For elevating the run-of-mine coal there are two
hoists, a single barney plane hoist from the surface
for all coal transported over ground from distant
openings and strippings, and a balanced gunboat or
skip hoist on the slope which connects a dump in
the mines with the receiving hopper in the head of
the breaker. The gunboat also serves a surface dump,
which is used to handle the cars in excess of the barney
hoist capacity. The receiving hopper is large and
permits continued dumping during short stops of
the breaker. From this hopper, the run-of-mine
gravitates to a reciprocating feeder, which delivers on

to a bifurcated chute, which directs the flow on to
two banks of mud screen shakers of four decks each,
sizing lump, steamboat, broken and egg. The first
two sizes gravitate to their respective moving picking
tables. It is intended that pure coal shall be made
in the future, but at present all prepared coal is
jigged, and the pickers on the moving tables only
“ skin ” the pure coal product of impurities. No
hand chipping is done, all half-and-half or capped
pieces are left on the tables. The picked rock and
impurities are thrown into a large chute of sufficient
capacity to store a day’s run, should any delay or
breakdown occur to the refuse-handling machinery.
This chute delivers to a No. 9 Gates gyratory crusher,
which reduces the material to about 3 in. lumps,
and delivers it to a refuse conveyor to be conveyed
to the rock bank.

The lump and steamboat products from the tables
flow to a slow-speed No. 1 roll, breaking to steamboat
and smaller, with a small percentage of steamboat
oversize. The broken-down material flows to two
banks of two-deck shakers, sizing steamboat and

broken. The former size is broken down in a slow-
speed re-breaker, or No. 3 pure coal roll, to egg
and smaller. The broken is inspected, any impurities
being removed by hand picking, and then flows to
the main broken loading pocket, or is switched to a
separate pocket for use on the locomotive.

When there is no sale for broken, it mixes with the
steamboat going to the pure coal roll. The re-broken
product from the pure coal roll gravitates to the pure

Fig. 5.—Construction of Barney.

coal elevator feeding pocket, of 20 tons storage
capacity, to act as a reservoir in front of the fixed
capacity elevators, and is stored there during periods
of fast dumping.

The mud-screen broken and egg is run over
anthracite spirals, three for each size. These are
adjusted to remove the maximum amount of rock, so
that one picker on the refuse, from each set of three
spirals, can clean the product by hand picking out
the pure coal. The refuse from all spirals flows to
the rock handling machinery. The spirals, in addi-
tion to relieving the jigs of handling this refuse
material, also protect the re-breaker rolls,' receiving
the spiralled product, as it has been found that rock
dulls the roll teeth more quickly than the coal,
thereby reducing the roll efficiency and the prepared
sizes.

The spiralled mud-screen broken flows to its slow-
speed re-breaker, or No. 3 mud-screen roll, which
breaks to egg, stove, and smaller. The spiralled
mud-screen egg flows to its No. 3 roll, or, when there
is a demand for it, the egg is switched around the
roll. The entire mud-screen product from both of the
No. 3 rolls, also the egg (when not broken down) is
mixed in the mud-screen coal elevator feeding pocket,
a duplicate of the one for the pure coal.

Two elevators, one for pure and one for mud-screen
coal, lift the products from the elevator feeding
pockets to the top of the plant (fig. 7). There are
four banks of five-deck shakers, arranged parallel,
the two outside banks being for pure coal, and the
inside banks for mud-screen. At present (as already

mentioned) no pure coal is made, as it has been found
cheaper to remove refuse by jigging. This method of
preparation will be continued until the quantity of
the run-of-mine is increased to such an extent that
it is necessary to make a pure coal product; or, if
the quality of the present run-of-mine should change,
producing a tremendous quantity of large lumps of
pure coal, the hand picking force will be increased
in order to clean the product on the moving tables.

With the present plan, the elevated pure and mud-
screen products are dumped into the mud-screen
bifurcated chute delivering to the two mud-screen
shakers (the outside, or pure coal shakers, are not
operating). These shakers size egg, stove, chestnut,
pea and buckwheat. Each size flows into its respec-
tive jig storage pocket. The jig pocket acts as a
reservoir behind the jigs, storing up during rush
periods and feeding out when no coal is coming.
These pockets are equipped with adjustable partitions,
arranged so that the capacity of any one pocket may
be increased, by decreasing the capacity of the
adjacent one. The partitions are changed to accom-
modate the quantity of each size made, and thereby
increase or decrease the number of jigs on any one
size,- where it is necessary to handle a greater c>r
lesser quantity of any size, to meet the varying
market demands. For example, when breaking down
all coal to stove and smaller, no egg jigs are needed;
therefore egg jigs can be run on stove, and vice versa.

The coal from the jig pockets flows to the jigs,
which are equipped with automatic starting and stop-
ping devices, actuated by the weight of coal in the
chute, connecting the jig pocket to the jig, and
operating a belt shifter through a system of levers.
By means of this control, jigs will stop when no
coal is coming and the jig pocket is empty, and will
start up as soon as the feed starts again.

The clean coal from the jigs gravitates to the load-
ing pockets, while the refuse is conveyed to the refuse-
conveyor line. The coal is loaded into cars by a belt
■ conveyor. The pocket gates are located at the end
of the chute leading to the belt, instead of several
feet up the chute, at the point where the chute enters
the loading pocket, thereby reducing the initial
breakage resulting from the sudden rush of coal
down the chute when the gate is opened, and permit-
ting the use of a lifting check gate rather than a
cut-off gate. The latter gate requires more power to
operate than the former, and was steam operated
on previous installations of the company. The latter
is opened by the weight of coal against the gate, when
the operating chain is raised, and is closed by the
belt loader operator, who pulls a chain connected to
the gate.

The rice and smaller from the buckwheat shakers
flows to two banks of two-deck shakers, sizing rice and
barley. The material falling through the lower deck
flows to settling tanks. The chutes from the rice and
barley shakers are arranged so that both or either
size may go to its respective loading pocket, or to
the boilier-house conveyor line.

The jig slush or hutch product is delivered on a
single-deck shaker, the material passing over is con-
veyed, together with the lip screenings, to a screen-
ing storage pocket. The product falling through goes
to the settling tanks. Condemned coal is dumped
into a hopper connected to the foot of the elevators by
a conveyor. This conveyor will deliver to either the
pure or the mud-screen coal elevator, by changing a
switch in the discharge chute. Coal condemned for
impurities can be switched to the mud-screen elevator,
while coal condemned for screening can be sent to
the pure coal elevator. The condemned coal con-
veyor also handles the lip screenings from their
storage pocket. When the pocket is full, the conveyor

is started and operates until the pocket is empty.
When it is necessary to make a pure coal product,
the pure coal elevator will discharge into the pure
coal bifurcated chute leading to the outside pure coal
shakers. The sized coal from the shakers will mix
with the clean coal from the jig and flow to the
loading pockets.

Breakage.—No controls to handle the coal have been
installed, as the breakage is practically nil. Abrupt
turns and high drops are avoided as much as possible.
Elevator breakage is minimised by proper feed at
bottom and proper discharge at the top. In the
addition, White chute controls are used where thought
necessary, and vertical stepped telegraphs for lower-
ing into jig and loading pockets. Spiral chutes are
installed to lower pure coal. A movable pocket-
filler chute is used on broken. The adjustable boom
on the end of the belt conveyor, with curved chute,
prevents a high drop into cars, and assures a fairly
uniform distribution of any screenings through the
loaded car.

Breaker Water.—Water for preparation is pumped
direct from the mines to a 6,000 gal. wooden storage
tank, placed in the top of the old breaker. A cast
iron distributing main is connected to the bottom of
the tank; branch lines run from this main (1) to
the pure coal and mud-screen shakers; (2) to the
jigs; and (3) to the lip screen. Outlets are placed
throughout the breaker for hose connections for wash-
ing down, and for fire; cut-out valves are placed on
each branch line. At present, an outlet is furnished
for each jig, but this is to be changed to an automatic