Washability curve based on float and sink test enables an assessment to be made of the possibility of cleaning a coal fraction based on the____________________?

Related Mcqs:

1. Float and sink test determines the possibility of cleaning of coal by a process based on the___________________?

   A. Gravity separation
   B. Wettability
   C. Particle shape
   D. None of these

2. The study on washability of coal is done by using the _____________ technique?

   A. Tabling
   B. Elutriation
   C. Heavy media separation
   D. None of these

3. Which of the following is the most suitable for cleaning of fine coal dust (<0.5 mm) ?

   A. Trough washer
   B. Baum jig washer
   C. Spiral separator
   D. Froth floatation

4. A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________?

   A. 0.50
   B. 0.58
   C. 0.68
   D. 0.62

5. A cottrell precipitator makes use of the ______________ for dusty air cleaning?

   A. Electric spark
   B. Corona discharge
   C. Alternating current
   D. None of these

6. In coal washeries, three products namely the valuable product (i.e. clean/washed coal), discarded product (i.e. mineral matter) and an additional concentrated product called _____________ is produced?

   A. Concentrate
   B. Tailing
   C. Middling
   D. None of these

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. In case of a hammer crusher, the final product size depends on the____________________?

   A. Feed rate
   B. Rotor speed
   C. Clearance between hammer & grinding plates
   D. All A., B. and C.

9. Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of ____________ mm?

   A. 0.007
   B. 0.30
   C. 50
   D. 0.014

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

    A. Rittinger’s law
    B. Kick’s law
    C. Bond’s law
    D. None of these