Blast furnace lining selection: for the upper (top) section of a blast furnace where burden movement abrades the lining, which refractory property is most critical?

Introduction:
Different zones of a blast furnace impose different stresses on refractories. The upper stack region experiences intense mechanical wear from descending burden and gas flow, making abrasion resistance a prime selection criterion.

Given Data / Assumptions:

• Location: top section (upper stack) of the blast furnace.
• Dominant stressor: rubbing/impact from coke, sinter, and pellets.
• Chemical slag attack is less severe here than at the bosh/tuyère level.

Concept / Approach:
Wear mechanisms vary with height. Upper zones require high abrasion/erosion resistance; lower zones (bosh, hearth) prioritize corrosion resistance and thermal stability against hot slag/iron. Property prioritization must match local duty.

Step-by-Step Solution:
Identify dominant mechanism: mechanical wear by burden.Map property to mechanism: high abrasion resistance minimizes lining loss.Select option: resistance to abrasion.

Verification / Alternative check:
Blast furnace lining schemes commonly grade materials from abrasion-resistant in upper stack to chemically resistant and high-temperature-stable in bosh/hearth.

Why Other Options Are Wrong:

• Slag penetration/corrosion dominate in lower furnace zones.
• High-T volume stability is important but not the top priority in the upper stack compared with abrasion resistance.
• Pure insulation focus ignores mechanical wear realities.

Common Pitfalls:
Applying the same refractory criteria to all furnace zones; optimal design uses zoned properties.

Final Answer:
Resistance to abrasion