A. State or manner of application of the crushing force
B. Ultimate strength of the material
C. Elastic constant of the material
D. All A., B. and C.
Related Mcqs:
- Rittinger’s number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger’s number of a material indicates its________________?
A. Easier grindability
B. Poor grindability
C. High power consumption in grinding
D. None of these - Energy requirement (per unit mass of material crushed/ground) is highest for__________________?
A. Jaw crusher
B. Rod mill
C. Ball mill
D. Fluid energy mill - Which of the following equations is Rittinger’s crushing law? (Where P = power required by the machine, m = feed rate, k = a constant, D̅ sa & D̅ sb = volume surface mean diameter of feed & product respectively) ?
A. P/m = K/ √Dp
B. P/m = K . ln D̅ sa/D̅ sb
C. P/m = K . (1/ D̅ sb – 1/D̅ sa)
D. None of these - Pick out the material having minimum Rittinger’s number?
A. Calcite
B. Pyrite
C. Quartz
D. Galena - Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m) ?
A. 3.6 V.W.Dr.ρ
B. 3.6 V.W. ρ
C. 3.6 W.Dr.ρ
D. 3.6 V.W.Dr/ρ - The crushed material received for separation is called feed or_________________?
A. Tailing
B. Heading
C. Concentrate
D. Middling - The material is crushed in a gyratory crusher by the action of__________________?
A. Impact
B. Compression
C. Attrition
D. Cutting - The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond’s law) of the energy to grind the particles from a very large size to 50 μm is________________?
A. 6.35 kWh/ton
B. 9.0 kWh/ton
C. 18 kWh/ton
D. 25.4 kWh/ton - Rittinger’s crushing law states that_____________________?
A. Work required to form a particle of any size is proportional to the square of the surface to
volume ratio of the product
B. Work required to form a particle of a particular size is proportional to the square root of the
surface to volume ratio of the product
C. Work required in crushing is proportional to the new surface created
D. For a given machine and feed, crushing efficiency is dependent on the size of the feed &
product - For crushing of solids, the Rittinger’s law states that the work required for crushing is proportional to __________________?
A. The new surface created
B. The size reduction ratio
C. The change in volume due to crushing
D. None of these
