A large steel mill in Northern China uses rotary kiln technology to treat 1.2 million tons of BF dust and converter sludge annually, aiming for efficient recovery of zinc and iron.
However, operations were hindered by:
- Difficulty controlling bed thickness, leading to unstable kiln atmosphere and fluctuating Fe reduction;
- Frequent ring formation in high-temp zones (1300–1400°C), causing blockages;
- Chlorides and ZnO/PbO vapors in off-gas reduced metal purity and added purification cost;
- Short lining life (less than 30 days), requiring 5–7 unplanned shutdowns per year.
The plant urgently needed a durable refractory solution to resist thermal shock, chemical attack, and extend campaign cycles.
JHY Ref Solution:
Zonal Lining Design + High-Performance Phosphate Bricks. The kiln was divided into three zones, with tailored brick selection:
Brick Advantages of Phosphate bonded high alumina bricks:
- ≥30 cycles thermal shock resistance (1100°C water quench)
- ≥80 MPa compressive strength
- 20%+ improved chemical resistance (FeO + alkali + Cl⁻)
- Strong joints, low spalling risk
- Withstands thermal shocks <1300°C
Results After Application
| Metric | Before | After | Change |
| Campaign life | 28–35 days | 120–140 days | ↑ 4x+ |
| Unplanned stops/year | 6 | 1 | ↓ 83% |
| Metal recovery (Fe+Zn) | 82.5% | 90.1% | ↑ 7.6% |
| ZnO purity in gas | 56% | 69.3% | ↑ 23.7% |
| Extra dust processed | – | +170,000 tons/year | ↑ |
| Economic gain | – | +¥5.1M/year | ↑ |
Client Testimonial
“JHY’s refractory bricks solved our ring formation problem. Kiln runs are now stable and reliable. No more frequent shutdowns – this is real cost reduction and efficiency improvement.”
— Mr. Zhou, Equipment Supervisor
