Pulverising carbon black: among the following, which unit is typically used to deagglomerate and grind carbon black to the required fineness?

Introduction / Context:
Carbon black is a soft, low-density powder that exists as agglomerates of fine primary particles. The objective in processing is deagglomeration and fine grinding without generating excessive contamination or heat. Understanding which comminution device suits such a powder is essential.

Given Data / Assumptions:

• Feed is powdery/carbonaceous agglomerates, not hard lumps.
• Goal is fine product (pigment/reinforcement grade handling).
• Choices include crushers (lump breakers) and mills.

Concept / Approach:
Crushers (gyratory, roll, hammer crushers) act on coarse, hard lumps by compression/impact and are ill-suited to fluffy powders. A tumbling ball mill (or other fine grinding mill) provides attrition and impact between media, effectively breaking agglomerates to target fineness with process control (e.g., classification, inerting).

Step-by-Step Solution:
Eliminate crusher options: designed for hard lumps, not powder deagglomeration.Select a milling device that can apply attrition/impact to powders → ball mill.Note that specialty mills (jet/air classifier) are also used industrially, but not among the listed options.

Verification / Alternative check:
Process descriptions for carbon black handling cite ball or jet mills with classification to achieve consistent fine particle distributions.

Why Other Options Are Wrong:
Hammer/Roll/Gyratory crushers: intended for coarse, brittle solids; ineffective for fluffy powders like carbon black.

Common Pitfalls:
Attempting to run powders through primary crushers leads to dusting without meaningful size reduction.

Final Answer:
Ball mill