Terminology: separation of materials into products primarily on the basis of size differences is called what?

Introduction / Context:
Process engineers use specific terms to describe separations. When the split is governed predominantly by particle size—often by screens or trommels—the operation is referred to as sizing. Using the correct term avoids confusion with other mechanisms like density-based separation or agglomeration.

Given Data / Assumptions:

• Primary discriminant: particle size (aperture-based or equivalent cut size).
• Devices: screens, trommels, or sieves.
• Objective: create size-based products or prepare feeds for downstream units.

Concept / Approach:
“Sizing” indicates a size-aperture controlled separation. “Classification” often refers to hydraulic or pneumatic devices that separate according to terminal settling velocity, which depends on size and density. “Sorting” is a generic term for separating by various properties (e.g., color, magnetism). “Flocculation” is not a separation but a pretreatment step that agglomerates fines.

Step-by-Step Solution:
Identify the controlling property: size only.Map to terminology: this is “sizing.”Exclude density/shape-influenced hydraulic classification; exclude non-size properties (sorting) and pretreatment (flocculation).

Verification / Alternative check:
Plant flowsheets label screen stations as “sizing screens” and classifying hydrocyclones as “classification,” reflecting the difference in mechanism.

Why Other Options Are Wrong:
Sorting: typically property-based selection beyond size.Classification: velocity-based (size+density) in fluids.Flocculation: agglomeration step, not a direct separator.

Common Pitfalls:
Calling hydrocyclone splits “sizing”; while size is influential, density effects make it classification, not pure sizing.

Final Answer:
sizing