unshaped refractory
Low-Cement Castable
Low-cement castable belongs to the modern high-strength refractory castables. Ordinary conventional castables contain 15–20% cement, while low-cement castables have a CaO content ≤2.5% and generally only 3–5% cement added. By reducing cement, the formation of low-melting-point calcium-feldspar phases is reduced, greatly improving high-temperature performance, strength and slag resistance. It is currently the most mainstream working-layer castable for industrial kilns.
| Grade | Al₂O₃ Content | Long-term Service Temp. | Typical Applications |
| DL‑60 | ≥60% | 1350℃ | Boilers, heating furnaces, incinerators, rotary kiln mouths, flues, material ducts, furnace roofs, furnace walls, cooling sections, and high-temperature working linings prone to scouring and spalling. |
| DL‑70 | ≥70% | 1400℃ | |
| DL‑75 | ≥75% | 1450℃ | |
| DL‑80 | ≥80% | 1500℃ | |
| DL‑85 | ≥85% | 1550℃ |