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

Mechanical Operations
Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is

All of these
Precoated on the filter medium prior to filtration
Added to the feed slurry
Separated from the cake by dissolving solids or by burning it off

ANSWER DOWNLOAD EXAMIANS APP