Ultrafine grinding vs. crushers: Which machine is NOT classified as an ultrafine grinder (colloid mill) for producing sub-100 μm material?

Introduction / Context:
Comminution equipment is categorized by the fineness it can achieve. Ultrafine grinders (colloid and jet mills) reach very small particle sizes suitable for pigments, pharmaceuticals, and specialty chemicals. Crushers and coarse grinders serve much larger size ranges.

Given Data / Assumptions:

• Ultrafine range commonly targets sub-100 μm, often down to a few micrometers.
• Fluid energy (jet) mills and agitated media mills are classic ultrafine machines.
• Crushers like toothed roll units typically produce millimeter-scale product.

Concept / Approach:
Toothed roll crushers operate by nipping and shearing; they are best for friable, medium-hard solids, producing coarse to intermediate sizes, not colloidal or ultrafine powders. In contrast, micronizers exploit high-velocity gas jets and particle–particle collisions to break particles to micrometer sizes.

Step-by-Step Solution:
List ultrafine equipment: jet mills, agitated media mills, classifier mills.Identify non-ultrafine: toothed roll crusher (coarse grinder/crusher).Hence, select toothed roll crusher as NOT an ultrafine grinder.

Verification / Alternative check:
Manufacturer catalogs confirm product size ranges: crushers seldom below a few hundred micrometers; jet mills routinely achieve <10 μm.

Why Other Options Are Wrong:

• Micronizer/fluid energy mill: core ultrafine machines.
• Agitated mills: use small media for sub-100 μm grinding.
• Hammer/classifier and pin/classifier mills: with internal classification, can reach fine to ultrafine cuts.

Common Pitfalls:
Assuming higher rotor speed alone makes a mill “ultrafine”; mechanism and classification are key.

Final Answer:
Toothed roll crusher