Client: A steel plant in China
Project Scope: Full refractory supply & technical services for 2×600-ton/day Maerz parallel-flow regenerative lime kilns
Client Background
Industry: Steel metallurgy
Kiln Type: Maerz twin-shaft regenerative kilns
Key Challenges:
High sulfur fuel (0.8-1.2% S) accelerating refractory corrosion;
Frequent thermal cycling (24-30 combustion switches/day, 800°C ↔ 1350°C);
Kiln lifespan limited to 3 years due to spalling and structural cracks.
Critical Issues
Thermal Shock Damage: Rapid temperature fluctuations caused refractory spalling in calcining zones.
Chemical Attack: Sulfur + CO₂ gas synergistically eroded preheating zone linings.
Mechanical Stress: Complex geometry (arches, discharge systems) led to installation defects.
Solutions
1. Customized Refractory Design
| Zone | Material | Key Features |
| Preheating Zone | SiC-Al₂O₃ castables (SiC 25%, Al₂O₃ 60%) | CO₂ resistance, thermal conductivity ≤1.5 W/m·K |
| Calcining Zone | Magnesia-alumina spinel bricks (MgO 85%) | 3× higher sulfur resistance, 200+ thermal cycles |
| Cooling Zone | Cr₂O₃-enhanced corundum castables | Mohs hardness 8.5,耐磨性↑50% vs traditional |
| Arch/Seals | Nano-insulation modules + ceramic anchors | Reduced heat loss (surface temp ≤170°C) |
2. Advanced Services
Pre-installation Simulation: Thermal-mechanical stress analysis to optimize brick sizing;
Smart Monitoring: Embedded IoT sensors for real-time lining thickness tracking (±5mm accuracy);
Rapid Repair Kits: On-site hot patching materials (4-hour curing time).
Results
| Metric | Before | After | Value |
| Calcining Zone Life | 10 months | 20 months | Maintenance cost ↓￥3.6M/year |
| Unplanned Downtime | 12 days/year | 3 days/year | +15,000 tons annual output |
| Surface Temp | 230°C | 160°C | Energy savings ￥1.2M/year |
| CO₂ Emissions | Baseline | ↓18% | Aligns with carbon neutrality |
Client Feedback
“The refractory system eliminated unplanned shutdowns and extended kiln campaign life beyond 5 years. The IoT monitoring platform revolutionized our maintenance strategy.”
– Plant Maintenance Manager
