Trommels separate a mixture of particles depending on their_____________________?

Related Mcqs:

1. Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) ?

   A. m/ρ . Vp
   B. m . ρ/Vp
   C. m . Vp/ρ
   D. Vp/m . ρ

2. Trommels are revolving screens which normally operate in the range of _______________ rpm?

   A. 1 – 2
   B. 15 – 20
   C. 40 – 50
   D. 60 – 75

3. Trommels employ _____________ for screening of materials?

   A. Fibrous cloth
   B. Woven wire screen
   C. Punched plate
   D. None of these

4. ______________ are used for the separation of coarse particles from a slurry of fine particles?

   A. Thickeners
   B. Classifiers
   C. Hydrocyclones
   D. Decanters

5. 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 μm is________________?

   A. 6.35 kWh/ton
   B. 9.0 kWh/ton
   C. 18 kWh/ton
   D. 25.4 kWh/ton

6. If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the __________________?

   A. Sedimentation
   B. Flocculation
   C. Dispersion
   D. Centrifugation

7. In screen analysis, the notation +5 mm/-10 mm means particles passing through ____________________?

   A. 10 mm screen and retained on 5 mm screen
   B. 5 mm screen and retained on 10 mm screen
   C. Both 5 mm and 10 mm screens
   D. Neither 5 mm nor 10 mm screen

8. Separation of a suspension or slurry into a supernatant clear liquid (free from particles) and a thick sludge containing a high concentration of solid is called__________________?

   A. Classification
   B. Sedimentation
   C. Clarification
   D. Decantation

9. Half the angle of nip, (α), for a roll crusher is given by (where, dr, dp and df are diameters of crushing rolls, feed particles and rolls gap respectively) ?

   A. cos α = (dr + dp)/(dr + df)
   B. cos α = (dr + df)/(dr + dp)
   C. tan α = (dr + dp)/(dr + df)
   D. sin α = (dr + dp)/(dr + df)

10. Separation of solid particles based on their densities is called_________________?

    A. Sizing
    B. Sorting
    C. Clarification
    D. Dispersion