Ore concentration by jigging is based on the difference in the ______________ of the particles?
A. Specific gravities
B. Wettability
C. Shape
D. None of these
Mechanical Operations
Use of baffles in agitators help in minimising the ______________ tendency?
Use of baffles in agitators help in minimising the ______________ tendency?
A. Swirling
B. Vortexing
C. Both A. & B.
D. Neither A. nor B.
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 ?
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
A tube mill compared to a ball mill__________________?
A tube mill compared to a ball mill__________________?
A. Has a higher length/diameter ratio
B. Produces a coarser product
C. Has a higher diameter/length ratio
D. Uses much larger balls
Grizzlies are used for separating _____________ solids?
Grizzlies are used for separating _____________ solids?
A. Coarse
B. Fine
C. Any size
D. None of these
In closed circuit grinding as compared to open circuit grinding, the_________________?
In closed circuit grinding as compared to open circuit grinding, the_________________?
A. Specific surface of product is more
B. Product has lesser size uniformity
C. Production rate at a given limiting size is lower
D. Operation is economical
In bag filters, filter fabrics are never made of__________________?
In bag filters, filter fabrics are never made of__________________?
A. Metallic wire woven mesh
B. Polyester fibres
C. Cotton fibres
D. Nylon fibres
For crushing of solids, the Rittinger’s law states that the work required for crushing is proportional to __________________?
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
Which of the following screens has the maximum capacity ?
Which of the following screens has the maximum capacity ?
A. Grizzlies
B. Trommels
C. Shaking screen
D. Vibrating screen
For spheres, volume shape factor is given by____________________?
For spheres, volume shape factor is given by____________________?
A. π = (A/D2)
B. 2π = (2A/D2)
C. π/6 = (V/D3)
D. AD/V