High-Temperature Converter Magnesia-Chrome Refractory Brick Selection Guide: Key Performance Metrics Explained

How to Choose Magnesia-Chrome Refractory Bricks for High-Temperature Converter Linings

As a refractory engineer with over 15 years in steelmaking applications, I’ve seen firsthand how poor brick selection leads to premature furnace lining failure—costing mills thousands in downtime and safety risks. If you're responsible for choosing magnesia-chrome bricks for your converter, this guide will help you avoid costly mistakes.

Key Performance Metrics You Can’t Ignore

When evaluating magnesium-chrome bricks for high-temperature converters, focus on four core metrics:

• Refractoriness (≥1750°C): Ensure the brick maintains structural integrity at typical converter temperatures (1550–1650°C).
• Volume Stability (±0.5% after 1000°C heat treatment): Excessive expansion or shrinkage causes cracks and spalling.
• Thermal Expansion Coefficient (≤1.8 × 10⁻⁶/°C): Lower values reduce stress during rapid heating/cooling cycles.
• Slag Resistance (≥90% mass retention after 10-hour slag immersion test): This is where many bricks fail under basic slags like CaO-SiO₂-Al₂O₃.

Why Silicate-Bonded Technology Matters

Many suppliers still use traditional dead-burned magnesia chrome bricks. But modern silicate-bonded bricks—especially those with controlled MgO/SiO₂ ratios—offer superior performance. In our lab tests, these bricks showed up to 25% better thermal shock resistance and 15% longer service life compared to conventional ones.

The key? A dense microstructure formed by sintering at 1450–1500°C under controlled atmosphere. This minimizes porosity and strengthens bonding between grains—critical for resisting molten slag penetration.

Your Practical Selection Checklist

Real Case: How One Mill Extended Furnace Life by 30%

A mid-sized Chinese steel plant switched from standard magnesia-chrome bricks to a silicate-bonded variant based on our checklist. Within six months, their average furnace campaign increased from 1,200 heats to 1,560—saving over $80,000 annually in maintenance and labor costs. The real win? Zero unplanned shutdowns due to lining failure.