Third-Grade High-Alumina Brick
Higher refractoriness than ordinary fireclay bricks, outstanding cost-performance, good thermal-shock stability, and less prone to cracking or spalling under thermal cycling. Compared with fireclay bricks, high-temperature strength and slag-erosion resistance are significantly improved; good volume stability, low re-heat shrinkage, convenient processing and laying, and it can be installed with matching high-alumina refractory mortar.
| Grade | Al₂O₃ Content | Long-term Service Temp. | Typical Applications |
| Lz-55 Third-Grade High-Alumina Brick | ≥55% | 1350‑1400℃ | Boiler furnaces, waste-heat flues, heat-treatment furnaces, annealing furnaces, medium/low-temperature sections of lime kilns, low-temperature zones of waste incinerators, hot blast stoves, rear kiln sections of rotary kilns; upgraded linings replacing fireclay bricks. |
| Lz-65 Second-Grade High-Alumina Brick | ≥65% | 1400‑1450℃ | |
| Lz-75 First-Grade High-Alumina Brick | ≥75% | 1450‑1500℃ |

