For coarse reduction of hard solids, use ____________________?

Related Mcqs:

1. The capacity of a classifier in ‘tons of solid/hr’ is given by (where, A = cross-sectional area in m2, V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3)_________________?

   A. 3.6 AVS.ρ
   B. 3.6 A.V.ρ
   C. 3.6 A.S. ρ
   D. 3.6 AVS/ρ
   Answer: Option

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

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

3. Which of the following is a coarse crusher ?

   A. Smooth roll crusher
   B. Toothed roll crusher
   C. Gyratory crusher
   D. Tube mill

4. The optimum moisture content in solids to be crushed/ground ranges from _______________ percent?

   A. 3 to 4
   B. 8 to 10
   C. 10 to 15
   D. 15 to 20

5. The process by which fine solids is removed from liquids is termed as _____________________?

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

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. A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index is 4.5, the volume fraction of solids in the suspension is_____________?

   A. 0.1
   B. 0.4
   C. 0.6
   D. None of these

8. Mixing of plastic solids is generally facilitated by___________________?

   A. Dispersion
   B. Mastication
   C. Kneading
   D. None of these

9. The basic filtration equation is given as dt/dV = (μ/A ΔP). [(α .CV/A) + Rm], where, V is volume of the filtrate; A is the filtration area, a is specific cake resistance, μ is viscosity of the filtrate, and C is the concentration of the solids in the feed slurry. In a 20 minutes constant rate filtration, 5 m3 of filtrate was obtained. If this is followed by a constant pressure filtration, how much more time in minutes, it will take for another 5 m3 of filtrate to be produced? Neglect filter medium resistance, Rm; assume incompressible cake ?

   A. 10
   B. 20
   C. 25
   D. 30

10. 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