A. Its pulverisation (as it requires more power)
B. Combustion of fire slacks on the grates
C. Handling (e.g. when emptying wagons)
D. None of these
Related Mcqs:
- Presence of force moisture in coal is most disadvantageous during its __________________?
A. Transportation and handling
B. Washing
C. Pulverisation
D. Storage - Presence of free moisture in coal during its high temperature carbonisation _____________________?
A. Reduces the coking time
B. Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot
oven walls
C. Increases the loss of fine coal dust from the ovens when charging
D. None of these - 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 - With increase in moisture content of coal, its___________________?
A. Calorific value increases
B. Caking properties diminish
C. Swelling during carbonisation becomes excessive
D. None of these - With increase in moisture content of coal, its_____________________?
A. Calorific value increases sometimes
B. Bulk density always decreases
C. Clinkering tendency during combustion increases
D. None of these - As the equilibrium moisture content of the coal increases, its___________________?
A. Calorific value increases
B. Swelling number decreases
C. Swelling number increases
D. Bulk density decreases - Coal is heated in presence of air to a temperature of about _______________ °C, while determining its ash content for proximate analysis?
A. 500
B. 750
C. 950
D. 1100 - (64-132) rank coal (ASTM) means a coal with 64%___________________?
A. Fixed carbon and having a heat value of 13, 200 BTU/1b
B. Ash and a heating value of 13, 200 BTU/1b
C. Fixed carbon and a heating value of 132 BTU/1b
D. None of these - 64-132) rank coal (ASTM) means a coal with 64%___________________?
A. Fixed carbon and having a heating value around 13, 200 BTU/1b
B. Ash and heating value around 13, 200 BTU/1b
C. Fixed carbon and heating value around 132 BTU/1b
D. None of these - Prime coking coal is always blended with medium or non- coking coal before carbonisation__________________?
A. To check against its excessive swelling during heating, which may exert high pressure and
damage coke oven walls
B. Because, it alone produces unreactive coke
C. Both A. and B.
D. Neither A. nor B.
