Related Questions

Rate of low temperature oxidation of coal due to bad storage conditions
A Decreases with increase in surface area
B Does not vary with increase in surface area
C Is more for low volatile coal compared to high volatile coal
D Is accelerated by storage in large heaps with small surface to volume ratio
Low temperature oxidation and spontaneous combustion of freshly mined coal is accentuated, if
A It contains large amount of volatile matter
B It is stored in tall heaps
C Smaller fines are stored in large quantity
D All of the above
Low temperature oxidation of stored coal results in the
A Decrease in its caking power & calorific value
B Decrease in its carbon & hydrogen content
C Increase in its oxygen content
D All of the above
Low temperature oxidation of coal during storage does not decrease its
A Oxygen content
B Caking power
C Calorific value
D None of these
To avoid fire by spontaneous combustion of coal due to its low temperature oxidation, it should be stored in
A Shallow and small piles
B Fine sizes without the presence of any lump
C Closed space without any ventilation facility
D Large heaps with small surface to volume ratio
Low temperature oxidation of coal resulting from bad storage conditions does not decrease its
A Caking power
B Calorific value
C Hydrogen content
D Oxygen content
Calorific value of coal middling generated in coal washeries during washing of coal may be around __________ Kcal/kg.
A 1000
B 4000
C 6000
D 8000
A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon
A Is less liable to spontaneous combustion on storage
B Is more difficult to ignite and produces a shorter flame
C Requires smaller combustion space and less secondary air
D None of these
The bright glow of a combustion process is the characteristic of __________ temperature oxidation of coal.
A Fast & high
B Slow & low
C Slow & high
D Fast & slow
Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent.
A 10 & 3
B 3 & 10
C 15 & 8
D 10 & 20

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