» Laboratory Instruments
Coal Testing Instruments
Hardgrove Grindabllity Apparatus
The Grindability Of Coal is a measure of the ease
with which it can be ground fine enough for use as a pulverised fuel, &
it also shows the physical properties of coal like hardness, tenacity and
fracture. There is a fixed relationship between Grindability and rank of
coal in the natural series from brown coal to lignite & anthracite.
Coals easier to grind have 14 to 30 percent volatile matter Coals with
higher volume matter are more difficult to grind. However petrographic &
mineral constituents influence grindability. The hardgroove index of coal is
affected by its moisture content and hence on the humidity of the atmosphere
in which the test is carried out.
1 kg of coal sample was taken and crushed to pass
through 4.73mm sieve. The resulting sample was put in two steve of 1.18mm
sieve (upper sieve) and +600 size(kwer sieve). Sieve the materiol for 2
minutes until the entire material pass through 1.18mm sieve* The 1.18mm by
600 size coal was mixed thoroughly and 120 gm of the sample was removed for
sample divider The 30gm sample was taken in a ball mill along with 8 iron
baits with diameter 234*0 003 mm. The mouth of the ball mill was closed and
it was set to rotate for about 60 revolutions, when the rotation is
achieved, the machine was stopped. The sample left in the ball mill was then
collected along with any powdered substance sticking to the surface of the
machine by help of a brush* This sample was then put in a sieve of 73 size
and was shaken for about 10 minutes. After sieving for about 3 minutes, the
sample which passes through 73 size was weighed on the balance.
Calculation - The hard groove grindobility index of coal is calculated using
the following formula. HGI = 13 + 6.93 W. W = weight of the test sample
passing through 73 sieve after grinding
Laboratory Crusher is designed to speed up the
crushing of aggregate, ores, minerals. Coal, Coke, Chemicals and other
similar materials. It is compact and of rugged construction for general
laboratory or small pilot plant operations.
Two taws of manganese steel ore provided in the jaw crusher The moveable jaw
produces two blows for every revolution thus reducing over sizing to a
minimum. A combination of forward and downward and strokes with a rooking
action exerts pressure on the coarse material yet permits the finished
material to pass through the taws. A hopper is provided at tfw top for
feeding materials. The smooth jaws ensure a uniform product and easy
cleaning is possible. The out put size can be adjusted by the lock nut
provided to adjust the jaws.
||Power 440 Volts
||4 x 10"
||6 x 12"
||8 x 16"
||12 x 20"
||15 x 24"