A. 10
B. 25
C. 50
D. 75
Related Mcqs:
- In a ball mill, the volume occupied by the balls (when the mill is stopped) is about _______________ percent of the volume of the mill?
A. 35
B. 50
C. 70
D. 85 - Critical Speed (Nc) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively) ?
A. Nc = (1/4π). √(g/R1 – R2)
B. Nc = (1/2π). √(g/R1 – R2)
C. Nc = (1/π). √(g/R1 – R2)
D. Nc = (1/2π). √(R1 – R2/g) - Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) ?
A. D
B. 1/D
C. D2.5
D. 1/D2.5 - Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed ?
A. Wet grinding in low viscous suspension
B. Wet grinding in high viscous suspension
C. Dry grinding of large particles (upto 1.25 cms)
D. Dry grinding of large particles in un-baffed mills - The main differentiation factor between tube mill and ball mill is the ___________________?
A. Length to diameter ratio
B. Size of the grinding media
C. Final product size
D. Operating speed - Maximum size reduction in a ball mill is done by the, ______________ action?
A. Attrition
B. Compression
C. Impact
D. Cutting - ______________ mill is not a revolving mill ?
A. Pebble
B. Compartment
C. Cage
D. Tube - Crushing of mineral particles is accomplished in a ‘cage mill’, when one or more alloy steel bars are revolved in opposite directions. It is a type of ______________ mill?
A. Impact
B. Roll
C. Vibratory
D. None of these - Grinding efficiency of a ball mill is of the order of _______________ percent?
A. 1-5
B. 40-50
C. 75-80
D. 90-95 - ______________________ balls capable of grinding the feed in a ball mill gives the maximum efficiency ?
A. Cast iron
B. Minimum size
C. Maximum size
D. Elliptical
