Length/diameter ratio of a ball mill is

Answer: Option C

A ball mill is a type of grinder used in mechanical operations to grind and blend materials for use in mineral dressing, paints, pyrotechnics, ceramics, and selective laser sintering.

The design of a ball mill is typically cylindrical with a horizontal axis, partially filled with the material to be ground plus the grinding medium (like steel balls).

The length to diameter (L/D) ratio of a ball mill is an important design factor as it affects the grinding efficiency and operational stability.

For ball mills, the L/D ratio is usually less than 1, meaning the diameter of the mill is greater than its length.

This configuration helps in achieving a better cascading action of the grinding media and efficient grinding performance.

Therefore, the correct answer is: < 1 (Option C).