Which step is used to obtain a specific particle size before concentration?

• A. Crushing
• B. Screening
• C. Scrubbing
• D. Sizing

Answer: (D)

Controlling the particle size entering the concentration step is essential because the efficiency and behavior of the separation depend on having ore within a specific size range. Sizing is the step that creates that defined size window, using screens or classifiers to cut material to the target range so the next concentration process works predictably. Crushing reduces rock broadly without pinning down a final distribution, so it doesn’t ensure a specific size. Screening separates into size fractions but is often used for general separation rather than delivering a single, exact target size for the following stage. Scrubbing cleans the ore surface and removes clays, not size control. Therefore, sizing best achieves the goal of obtaining a specific particle size before concentration.