Mechanical Operations
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 μrn is

18 kWh/ton
6.35 kWh/ton
9.0 kWh/ton
25.4 kWh/ton

ANSWER DOWNLOAD EXAMIANS APP

Mechanical Operations
Pick out the wrong statement pertaining to the turbine agitator.

Generally, the diameter of the agitator is kept between l/3rd to l/6th of the tank diameter while the blade length is l/4th of agitator diameter (with central disc, it is l/8th of the agitator diamete
Recommended peripheral speed for the turbine agitator is 200-250 metres/minute
Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow
Turbine agitator should be located at a height not less than one agitator diameter length from the bottom. If the depth of liquid in the tank is more than twice the agitator diameter, two agitators sh

ANSWER DOWNLOAD EXAMIANS APP

Mechanical Operations
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?

Dry grindng of large particles in un-baffed mills
Wet grinding in low viscous suspension
Wet grinding in high viscous suspension
Dry grinding of large particles (upto 1.25 cms)

ANSWER DOWNLOAD EXAMIANS APP