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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.
Experimental Procedure
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


Jaw Crusher
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.

Code Jaw Size Feed Size Output Size Power 440 Volts
SHJ-600A 4 x 10" 25-30mm 6-20mm 3HP
SHJ-600B 6 x 12" 45-50mm 10-22mm 5HP
SHJ-600C 8 x 16" 65-70mm 12-25mm 10HP
SHJ-600D 12 x 20" 90-100mm 20-30mm 10HP
SHJ-600E 15 x 24" 100-150mm 25-30mm 15HP