Product Overview:
Clay brick is made by hard clay, calcined clay and bonding agent through pelletizing and milling, mixing as per certain ratio, pressing molding and burning under high-temperature. Fire-resistant clay bricks can be divided into special clay bricks (including clay bricks for blast furnaces, clay bricks for glass kilns and clay bricks for hot-blast furnaces) and general clay bricks.
General clay bricks can be divided into such three grades as PN-1, PN-2 and PN-3 as per physical and chemical indexes.
Special clay bricks can be divided into such three grades as ZN-45, ZN-40 and ZN-36 as per physical and chemical indexes.
Physical and chemical indexes of general clay bricks：
| Item | Indexes | ||
| PN-1 | PN-2 | PN-3 | |
| 0.2MPa load softening starting temperature ℃ ≥ | 1300 | 1250 | 1200 |
| Changes in heating permanent line (1350°C×2h) % | -0.2～+0.1 | -0.3～+0.1 | -0.4～+0.1 |
| Apparent porosity % ≤ | 24 | 26 | 28 |
| Ambient compression strength Mpa ≥ | 30 | 25 | 20 |
Physical and chemical indexes of special clay bricks：
| Item | Indexes | ||
| ZN-45 | ZN-40 | ZN-36 | |
| Al2O3 % ≥ | 45 | 40 | 36 |
| 0.2MPa load softening starting temperature ℃ ≥ | 1430 | 1380 | 1350 |
| Changes in heating permanent line (1350°C×2h) % | -0.2～+0.1 | -0.3～+0.1 | -0.4～+0.1 |
| Volume density g/cm³ | 2.0～2.3 | ||
| Apparent porosity % ≤ | 16 | 19(22) | 22(24) |
| Ambient compression strength Mpa ≥ | 60 | 40(35) | 35(30) |