The value of work index does not change materially from one equipment to another. If the value of work index determined for close circuit grinding is Wi, then the same for open circuit grinding will be_________________?

Related Mcqs:

1. Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with ______________ to get the same for dry grinding?

   A. 1.0
   B. 0.5
   C. 1.34
   D. 4.34

2. In closed circuit grinding as compared to open circuit grinding, the_________________?

   A. Specific surface of product is more
   B. Product has lesser size uniformity
   C. Production rate at a given limiting size is lower
   D. Operation is economical

3. Close circuit grinding by a ball mill with air sweeping employs a _______________________?

   A. Classifier
   B. Cyclone separator between mill & classifier
   C. Both A. & B.
   D. Neither A. nor B.

4. Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines ?

   A. Compartment mill
   B. Rod mill
   C. Pebble mill
   D. Tube mill

5. Use of ‘grinding aids’ is done in _______________ grinding?

   A. Dry
   B. Wet
   C. Ultrafine
   D. Intermediate

6. Wet grinding in a revolving mill ______________ as compared to dry grinding ?

   A. Gives less wear on chamber walls
   B. Requires more energy
   C. Increases capacity
   D. Complicates handling of the product

7. A _____________ mill is a revolving mill divided into two or more sections by perforated partitions in which preliminary grinding takes place at one end and the finishing grinding at the discharge end?

   A. Compartment
   B. Tube
   C. Rod
   D. Pebble

8. For grinding of cereals, grains, spices, pigments, saw dust, cork etc., the most extensively used size reduction equipment is a__________________?

   A. Buhrstone mill
   B. Ball mill
   C. Crushing rolls
   D. Hammer mill

9. In a grinding operation, the limiting particle size is the size of the _______________ particle in the sample?

   A. Smallest
   B. Largest
   C. Either A. or B.
   D. Neither A. nor B.

10. _______________ mill is normally used for grinding of talc?

    A. Tube
    B. Compartment
    C. Ring-roll
    D. Pebble