Chemical Engineering Mcqs

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

Answer

Submitted By :Ali Uppal

Which of the following is not used as a surface active agent in a flocculation operation ?

• (A)  Sodium silicate
• (B)  Quartz
• (C)  Lime
• (D)  Alumina

Answer

Submitted By :Ali Uppal

For transporting pasty material, one will use a/an__________________?

• (A)  Apron conveyor
• (B)  Belt conveyor
• (C)  Screw conveyor
• (D)  Bucket elevator

Answer

Submitted By :Ali Uppal

Dispersion of a gas through liquid is done by using a__________________?

• (A)  Sparger
• (B)  Kneader
• (C)  Masticator
• (D)  None of these

Answer

Submitted By :Ali Uppal

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_________________?

• (A)  0.5 Wi
• (B)  Wi
• (C)  1.34 Wi
• (D)  3.34 Wi

Answer

Submitted By :Ali Uppal

Which of the following oxides is not present in hematite iron ore ?

• (A)  Titanium oxide
• (B)  Calcium oxide
• (C)  Cobalt oxide
• (D)  Manganese oxide

Answer

Submitted By :Ali Uppal

In filtration, the use of ‘filter aid’ helps in__________________?

• (A)  Reducing the filtration pressure
• (B)  Accelerating the rate of filtration
• (C)  Deplugging the filter medium
• (D)  Enhancing the cake porosity in case of a dense impermeable cake

Answer

Submitted By :Ali Uppal

What is the reduction ratio in a fine crushing operation having following feed and product sizes ?

• (A)  0.5
• (B)  2
• (C)  5
• (D)  10

Answer

Submitted By :Ali Uppal

For a sphere falling in the constant drag co-efficient regime, its terminal velocity depends on its diameter D. as_________________?

• (A)  d
• (B)  √d
• (C)  d2
• (D)  1/d

Answer

Submitted By :Ali Uppal

For efficient grinding, ball mills must be operated__________________?

• (A)  At a speed less than the critical speed
• (B)  At a speed more than the critical speed
• (C)  At a speed equal to the critical speed
• (D)  With minimum possible small balls

Answer

Submitted By :Ali Uppal