A. Forged/cast steel
B. Lead
C. Cast iron
D. Alloy steel
Related Mcqs:
- 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 - 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. - 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 - Critical Speed (Nc) of a ball mill is given by (where R1 and R2 are radii of ball mill and the ball respectively) ?
A. Nc = (1/4π). √(g/R1 – R2)
B. Nc = (1/2π). √(g/R1 – R2)
C. Nc = (1/π). √(g/R1 – R2)
D. Nc = (1/2π). √(R1 – R2/g) - For achieving maximum capacity of the ball mill, the ball charge should be equal to about ______________ percent of the ball mill volume?
A. 10
B. 25
C. 50
D. 75 - Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) ?
A. D
B. 1/D
C. D2.5
D. 1/D2.5 - 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 - _____________________ baffles are provided in ball mills ?
A. Horizontal
B. No
C. Only two
D. None of these - What is the critical rotation speed in revolutions per second, for a ball mill of 1.2 m diameter charged with 70 mm dia balls ?
A. 0.5
B. 1.0
C. 2.76
D. 0.66
