logo

CuriousTab

CuriousTab

Discussion


Home Chemical Engineering Mechanical Operations Comments

  • Question
  • Balls for ball mills are never made of


  • Options
  • A. forged/cast steel
  • B. lead
  • C. cast iron
  • D. alloy steel

  • Correct Answer
  • lead 


  • Mechanical Operations problems


    Search Results


    • 1. Froth floatation is the most suitable for treating

    • Options
    • A. iron ores
    • B. sulphide ores
    • C. quartzite
    • D. none of these
    • Discuss
    • 2. Pick out the correct statement:

    • Options
    • A. Removal of iron from ceramic material is necessitated (by magnetic separation method) so as to avoid discolouration of ceramic products.
    • B. The operating cost of shaking screen is more than that of a vibrating screen.
    • C. Screen capacity does not depend upon the specific gravity of the minerals.
    • D. Asphalt is best crushed using toothed roll crusher.
    • Discuss
    • 3. In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the

    • Options
    • A. square root of the velocity.
    • B. square of the viscosity.
    • C. filtration time only.
    • D. washing time only.
    • Discuss
    • 4. Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of

    • Options
    • A. bronze
    • B. stainless steel
    • C. flint or porcelain
    • D. concrete
    • Discuss
    • 5. For a non-spherical particle, the sphericity

    • Options
    • A. is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle.
    • B. has the dimension of length.
    • C. is always less than 1.
    • D. is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle.
    • Discuss
    • 6. Which of the following is not categorised as a "mechanical operation"?

    • Options
    • A. Agitation
    • B. Filtration
    • C. Size enlargement
    • D. Humidification
    • Discuss
    • 7. In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is

    • Options
    • A. 4
    • B. 1/4
    • C. 1
    • D. 1/2
    • Discuss
    • 8. In case of a hammer crusher,

    • Options
    • A. crushing takes place by impact breaking.
    • B. maximum acceptable feed size is 30 cms.
    • C. reduction ratio can be varied by adjusting the distance from cage to hammers.
    • D. all (a), (b) and (c).
    • Discuss
    • 9. Pick out the wrong statement pertaining to the roll crushers.

    • Options
    • A. Maximum feed size determines the required roll diameter.
    • B. For hard material's crushing, the reduction ratio should not exceed 4.
    • C. Both the rolls run necessarily at the same speed.
    • D. Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced.
    • Discuss
    • 10. The value of 'angle of nip' is generally about

    • Options
    • A. 16°
    • B. 32°
    • C. 52°
    • D. 64°
    • Discuss


    Comments

    There are no comments.

Enter a new Comment