Classification term: separation of particles of the same density but different sizes by exploiting their different flow (settling/transport) rates is called what?

Introduction / Context:
In fluid–solid operations, particles of equal density but different sizes can be separated because their drag and settling behavior differ. Recognizing the correct term helps in selecting appropriate equipment.

Given Data / Assumptions:

• Particles have the same density.
• Separation leverages different settling/transport velocities in a fluid stream.

Concept / Approach:
Elutriation uses an upward fluid velocity to selectively carry smaller or lighter particles while larger ones fall or remain. It is distinct from simple screening (sizing), which uses geometric apertures, and from flocculation, a particle–particle aggregation process.

Step-by-Step Solution:
Match the mechanism (hydrodynamic velocity discrimination) to the term.“Elutriation” specifically means removal of fines by an upward stream, often in classifiers.Choose “elutriation.”

Verification / Alternative check:
Hydraulic classifiers, elutriators, and air classifiers apply elutriation principles to effect size separations for density-equal solids.

Why Other Options Are Wrong:
Sorting: generic term; lacks the hydrodynamic feature.Sizing: uses screens; geometric separation.Flocculation: chemical/colloidal aggregation, not a hydraulic size split.

Common Pitfalls:
Confusing elutriation with pneumatic conveying; conflating density separation (e.g., heavy media) with velocity-based size splits.

Final Answer:
elutriation