Brick manufacturing — function of a pug mill In clay brick manufacture, a pug mill is primarily used for which operation?

Introduction / Context:
Quality bricks require well-prepared clay. The pug mill, a mechanical mixing device with rotating knives and paddles, ensures a homogeneous, plastic mix before moulding or extrusion.

Given Data / Assumptions:

• Traditional clay preparation steps: winning, weathering, tempering, moulding.
• Pug mill operation involves mixing, kneading, and de-airing.

Concept / Approach:
Tempering turns worked clay and water into a uniform plastic mass suitable for moulding. The pug mill’s augers and knives shear and knead the clay, distributing moisture and breaking down lumps.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturers’ literature and construction texts describe pug mills specifically for tempering; other steps use different equipment (e.g., brick presses for moulding).

Why Other Options Are Wrong:

• Softening by soaking (A): weathering/soaking may precede, but the pug mill’s purpose is active mixing.
• Moulding (B): done by hand moulds or machines, not by the pug mill itself.
• Providing clay (D): excavation equipment handles winning; the pug mill does not dig.
• All of the above (E): overbroad; the pug mill’s role is tempering.

Common Pitfalls:
Confusing tempering with weathering; weathering is passive exposure, tempering is mechanical mixing to a plastic state.

Final Answer: