Q1: Length/diameter ratio of a ball mill is

ANS:C - < 1

The length/diameter ratio of a ball mill typically varies, but it is generally greater than 1.

Explanation:

• Ball Mill: A ball mill is a cylindrical drum (or tube) with a rotating shaft containing steel balls that grind materials as the drum rotates.
• Length/Diameter Ratio: This ratio refers to the ratio of the length of the cylinder (drum) to its diameter. It is an important factor in determining the efficiency and capacity of the ball mill.
• Typical Values:
  • Ball mills commonly have length/diameter ratios ranging from around 1 to 1.5. Ratios higher than 1 indicate that the cylinder is longer than it is in diameter.
  • A higher length/diameter ratio can improve the efficiency of grinding by providing a longer path for the material to be ground and increasing the residence time of the material in the mill.
• Effect on Performance: The length/diameter ratio affects the grinding efficiency, residence time of the material in the mill, and the eventual product size distribution.