THE COLLIERY GUARDIAN

AND

JOURNAL OF THE COAL AND IRON TRADES.

Vol. CIX.

FRIDAY, MARCH 26, 1915.

No. 2830.

Stone Dust Grinding Plant at Cadeby Main Colliery.

The problem of providing stone dust, now generally
applied to allay the danger arising from coal dust in
mines, is expeditiously dealt with at the Cadeby Main
Colliery, Conisbro’, belonging to the well-known firm of
the Denaby and Cadeby Main Collieries Limited. The
plant, which comprises a Goodwin, Bars'oy and Com-
pany’s patent crusher and one of the “ Griffin ” mills

diluting the coal dust in the workings and roadways.
The corves travel on a track from the pithead to the
plant, the material being tipped at the foot of the
crusher, which breaks the bind into pieces of about
J in. in size. These are filled into the hopper
of the pulveriser, which is driven at a speed of
200 revolutions per minute. The dust is carried by a

are also forwarded on the private railway to the Denaby
Main Colliery, and the supply for the Cadeby Colliery
is carried from the plant in corves. The plant has a
capacity for producing about 12 tons of dust daily, and the
trouble arising from the dust caused by grinding is
minimised by the arrangement of an extractor over the
hopper of the pulveriser. The plant, which has been in
operation for several months, has solved the problem
from every standpoint.

A general description of the “ Griffin ” mills has

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Figs. 1 and 2.—Stone Dust Grinding Plant at the Cadeby Main Colliery.

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reinforced with old channel irons or
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Fig. 3.—Arrangement of 30 in. Griffin Mill Installation on the Gravity Principle.

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made by the Bradley Pulverizer Company, London, is
housed in a building at the foot of the Cadeby Colliery,
and occupies a comparatively small space. The plant
is driven by a 50-horse power motor, and the required
material (stonebind) is obtained from the pit. The result
of the operation produces a very fine powdered dust,
possessing excellent properties for the purpose of

worm conveyor from the pulveriser into a well under
the floor, whence it is picked up by a conveyor fitted
with small buckets of about 6 in. by 4 in. dimensions,
and carried overhead for a distance of about 20ft. into
a hopper of 8 to 10 tons capacity. The product is
dropped into corves or sacks as is necessary, the whole
operation involving a minimum of labour. Supplies

already appeared in the Colliery Guardian (December 19
1913, p. 1273). The mill has the advantage that it gives
a finished product to any desired degree of fineness.
The 30 in. mill installed at Cadeby gives an output of
1 to 11 tons per hour, to the following degree of fineness
—viz., 7 per cent, residue on 180 X 180 mesh sieve,
10 per cent, residue on 200 x 200 mesh sieve. Mills of