Particle size terminology in solids handling When a particulate specification states “80% passing 200-mesh (about 74 μm)”, the material is commonly termed as what?

Difficulty: Easy

Correct Answer: Powder

Explanation:


Introduction / Context:
In mineral processing, powder technology, and process engineering, size descriptors are linked to standardized sieves (mesh) or micrometre ranges. Correct terminology helps in specifying feeders, classifiers, filters, and dust-control equipment.


Given Data / Assumptions:

  • 200-mesh corresponds to about 74 micrometres opening.
  • “80% passing” means the cumulative undersize is 80% at that cut.
  • Application is in solids handling or milling specifications.


Concept / Approach:
Material that is largely finer than 200-mesh is routinely referred to as a “powder.” Terms like “grit” and “aggregate” align with coarser fractions (sand, gravel, stone). “Smoke” refers to very fine aerosols/combustion particulates in air, not bulk solids passing sieves.


Step-by-Step Solution:

Translate 200-mesh to ~74 μm.Note that 80% passing indicates fine bulk solids typical of powders.Eliminate terms for coarser materials (grit, aggregates) and airborne particulates (smoke).Select “Powder.”


Verification / Alternative check:
Industrial datasheets classify many milled products (cement, pigments, mineral fillers) as powders at similar or finer d50/d90 values, consistent with 80% passing 200-mesh.


Why Other Options Are Wrong:

  • Smoke: airborne combustion aerosol; not a bulk solid sieve designation.
  • Grit: coarser, often millimetre-scale particles.
  • Aggregates: coarse construction materials (sand to gravel), far larger than 74 μm.


Common Pitfalls:
Equating “dust” or “smoke” (airborne) with “powder” (bulk solid capable of being sieved).


Final Answer:
Powder

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