Mineral processing — principle of jigging Jigging (a stratification process in a pulsating fluid) primarily separates particles based on which property?

Introduction / Context:
Jigging is a classic gravity concentration method used in coal and ore beneficiation. A pulsating fluid (usually water) stratifies a bed of particles so that those with different settling characteristics separate into layers for recovery.

Given Data / Assumptions:

• Bed is pulsed vertically to promote stratification.
• Particles differ in density, size, and sometimes shape.
• Medium is water or air (less common).

Concept / Approach:
Although size can influence settling, jigging exploits differences in apparent specific gravity under pulsation. Denser particles settle more quickly and migrate downward, while lighter gangue rises. Size effects are mitigated by classification ahead of jigging and by the pulsation profile.

Step-by-Step Solution:
Recognize that jigging is a gravity separation method → density control.Denser valuable minerals settle to the bottom layers; lighter material forms upper layers.Thus, the primary separation basis is particle density.

Verification / Alternative check:
Industrial practice classifies feeds before jigging to narrow size range, confirming that density is the main discriminatory property.

Why Other Options Are Wrong:

• Size and shape matter secondarily but are not the principal mechanism in well-operated jigs.
• “Mixed” is contrary to the goal of separation.

Common Pitfalls:

• Confusing jigging with simple screening (size-based).
• Ignoring the need for proper pulsation and bed dilation for efficient density stratification.

Final Answer:
separated by particle density