Fuel preparation terminology: Coal that is first dried and then ground to a fine powder in a pulverizing mill is called what?

Introduction / Context:
Large steam generators and some industrial furnaces use coal in a finely divided form to increase surface area, promote rapid combustion, and improve flame stability. Correct terminology helps avoid confusion with other prepared fuels such as briquettes or coke.

Given Data / Assumptions:

• Coal is first dried to reduce moisture.
• Then crushed and ground to a fine powder in a pulverizer.
• Combustion occurs in a burner designed for dust-firing.

Concept / Approach:
The product is called pulverized coal (or pulverized fuel). The small particle size enables near-complete burnout within milliseconds in suspension firing, leading to high combustion efficiency and easier control. This is distinct from briquetted coal, which is made by compacting fine coal with a binder into larger lumps, and from wood charcoal, which is a carbon-rich solid derived from wood, not coal.

Step-by-Step Solution:

Verification / Alternative check:
Boiler manuals and combustion texts describe PF (pulverized-fuel) firing systems with mills, classifiers, burners, and cyclones or ESPs—terminology matches the process described.

Why Other Options Are Wrong:

• Briquetted coal: Agglomerated, not powdered; used for domestic or small industrial firing.
• Wood charcoal: Derived from wood via pyrolysis; not coal.
• Bituminous coal (lumped): Raw size-graded coal, not pulverized.

Common Pitfalls:
Assuming any prepared coal is a briquette; ignoring moisture control prior to pulverizing which is vital for mill performance and flame stability.

Final Answer:
pulverized coal (pulverized fuel)