A. Employ a steel shell having L/D ratio of 1.5 to 3.0
B. Is useful for handling sticky materials
C. Employ steel rods of 2-12 cms diameter extending over full length of the mill
D. All A , B & C
Related Mcqs:
- Size reduction of the ______________ can be suitably done by ball mills, crushing rolls and rod mills?
A. Metalliferous ores
B. Non-metallic ores
C. Basic slags
D. Asbestos & mica - ____________ mills fall in the category of tumbling mills ?
A. Ball and pebble
B. Rod and tube
C. Compartment
D. All A., B. & C. - Ball mills and tube mills with flint or porcelain balls are used for size reduction of_______________?
A. Asbestos
B. Rubber
C. Non-metallic ores
D. Limestone - 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__________________?
A. Bronze
B. Stainless steel
C. Flint or porcelain
D. Concrete - 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 - 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 - _____________ mills are termed as impactors?
A. Hammer
B. Cage
C. Rolling-compression
D. None of these - Balls for ball mills are never made of_________________?
A. Forged/cast steel
B. Lead
C. Cast iron
D. Alloy steel - Colloid mills achieve size reduction mainly by___________________?
A. Impact
B. Attrition
C. Cutting
D. Compression - Stamp mills are generally used for crushing__________________?
A. Iron ores
B. Gold ores
C. Talc
D. Diamond
