Clinker burning temperature: during the manufacture of ordinary Portland cement, the raw mix is burned in the kiln to form clinker at approximately what peak temperature?

Introduction / Context:
Forming cement clinker requires heating a raw meal of limestone and clay to temperatures where silicates and aluminates form. Knowing the typical peak burning temperature helps understand kiln operations, fuel requirements, and clinker quality.

Given Data / Assumptions:

• Ordinary Portland cement kiln using a preheater/precalciner or long dry process.
• Clinker mineral formation (alite, belite, aluminate, ferrite) requires high temperature.
• Question asks for the order of magnitude of burning temperature.

Concept / Approach:
In the burning zone, temperatures reach roughly 1400–1450°C, sufficient to partially melt the raw mix and form nodules of clinker. Lower temperatures (1000–1200°C) are associated with calcination and early solid-state reactions; much higher temperatures (≥1600°C) are not typical and can damage refractories.

Step-by-Step Solution:
Identify the burning zone range: approximately 1400–1450°C.Select the closest listed temperature: 1400°C.Conclude that option (c) is correct.

Verification / Alternative check:
Industry texts specify nodulization and liquid phase formation near 1400–1450°C; flame temperature may be higher, but clinker equilibrium aligns with this range.

Why Other Options Are Wrong:

• 1000–1200°C: too low for alite formation and nodulization.
• 1600–1800°C: excessive; risks refractory damage and unnecessary fuel consumption.

Common Pitfalls:
Confusing flame temperature with clinker bed temperature; assuming higher is always better for clinker quality.

Final Answer:
1400°C