MECHANICAL OPERATIONS QUIZ

Activators are those chemicals which help buoying up one mineral in preference to the other in the froth floatation process. Which of the following is an activator?

Sodium carbonate

Copper sulphate

Cresylic acid

Calcium carbonate

TRUE ANSWER : ?
YOUR ANSWER : ?

The unit of specific cake resistance is

Cm/gm²

Gm/cm²

Gm/gm

Cm/gm

TRUE ANSWER : ?
YOUR ANSWER : ?

Sphericity of pulverised coal is

>1

1

∞

TRUE ANSWER : ?
YOUR ANSWER : ?

What is the selectivity index, if the grade of tailings & concentrate is the same?

∞

1

0.5

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately ?

None of these

Bond's law

Rittinger's law

Kick's law

TRUE ANSWER : ?
YOUR ANSWER : ?

In the cyclone separator used for separation of dust from dust laden gas, the gas

Develops a helical motion inside the chamber

Is admitted tangentially at high velocity

Enters the cyclone from the top

Both B and C

TRUE ANSWER : ?
YOUR ANSWER : ?

As particle size is reduced

Screening becomes progressively easier

Screening becomes progressively more difficult

Capacity and effectiveness of the screen is increased

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Size reduction of ice and gypsum can be accomplished suitably by a __________ crusher.

Blake jaw

Gyratory

None of these

Toothed roll

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is a coarse crusher?

Tube mill

Gyratory crusher

Smooth roll crusher

Toothed roll crusher

TRUE ANSWER : ?
YOUR ANSWER : ?

For efficient grinding, ball mills must be operated

At a speed less than the critical speed

At a speed more than the critical speed

With minimum possible small balls

At a speed equal to the critical speed

TRUE ANSWER : ?
YOUR ANSWER : ?

↑