Description
The JH-DRI Series Dry Ramming Refractory is a family of ten dry ramming and vibrating grades engineered for coreless induction furnace linings. The series is divided into three subfamilies, each tailored to specific molten metal requirements. The first subfamily combines high‑alumina corundum with magnesia and chromium oxide to form a complex spinel bond that provides resistance to chemical erosion in steel melting applications. The second subfamily, designated the A Series, maintains a corundum‑magnesia composition without chromium oxide and is optimized for carbon steel, stainless steel and high‑alloy steel melts, achieving higher density through controlled particle distribution. The third subfamily, the S Series, uses silica‑based formulations with zirconia additions to serve grey, ball, ductile iron and low‑temperature alloy steel operations, delivering a dense, defect‑free lining under dry installation. All JH‑DRI grades are installed by dry ramming or vibration, simplifying lining work and reducing setup time. Operating temperature windows range from 1200 °C to 1815 °C, matching the demands of batch and continuous melt‑and‑hold cycles.
Key Features
- Dry ramming or vibration installation eliminates the need for wet mixing, reducing labor and setup time on the shop floor.
- Complex spinel bond formed by Al₂O₃, MgO and Cr₂O₃ provides high thermal stability and resistance to chemical attack.
- Optimized particle distribution in A Series grades yields maximum density and a thicker sintered layer at lower firing temperatures.
- During normal operation the top layer remains unsintered, allowing quick reline and minimizing downtime for maintenance.
- Silica‑based S Series grades control quartz phase transformation, delivering low thermal expansion and consistent volume stability.
Application
- Corundum‑based Cr₂O₃ grades are suitable for high‑temperature steel melting, including low‑carbon steel and high‑temperature alloys.
- A Series grades without Cr₂O₃ target carbon steel, stainless steel and high‑alloy steel, emphasizing clean melt chemistry.
- S Series silica formulations serve grey iron, ductile iron and ball iron in batch or continuous melt‑and‑hold operations.
- S Series also covers low‑temperature alloy steel applications, providing a dense lining where temperature does not exceed 1680 °C.
- All JH‑DRI grades are installed by dry ramming or vibration, suitable for batch, semi‑continuous and fully continuous induction furnace lines.
Technical Specifications
The tables below list chemical composition and physical properties for each grade, grouped into three sub-families by base material and target metal.
Corundum-based (for Steel)
| Chemical Composition [%] | JH-DRI-927CR | JH-DRI-968CR |
| Al₂O₃ | 81.5 | 83.0 |
| MgO | 14.7 | 11.7 |
| Cr₂O₃ | 3.3 | 4.7 |
| Technical Data | JH-DRI-927CR | JH-DRI-968CR |
| Bulk Density (g/cm³) | 3.03 | 2.96 |
| Max Grain Size (mm) | 8 | 8 |
| Max Working Temp (°C) | 1760 | 1815 |
| Min Working Temp (°C) | 1427 | 1493 |
| Installation Method | Dry ram or vibrate | Dry ram or vibrate |
A Series (Carbon Steel / Stainless Steel / High-Alloy Steel)
| Chemical Composition [%] | JH-DRI-682A | JH-DRI-697A | JH-DRI-975A | JH-DRI-985A |
| Al₂O₃ | 84.1 | 86.4 | 85.0 | 86.0 |
| MgO | 13.8 | 10.5 | 12.2 | 12.2 |
| SiO₂ | 0.2 | 0.29 | 0.2 | 0.2 |
| CaO | 0.2 | 0.3 |
| Technical Data | JH-DRI-682A | JH-DRI-697A | JH-DRI-975A | JH-DRI-985A |
| Bulk Density (g/cm³) | 3.04 | 3.04 | 3.12 | 3.12 |
| Max Grain Size (mm) | 8 | 8 | 6 | 8 |
| Max Working Temp (°C) | 1760 | 1815 | 1760 | 1815 |
| Min Working Temp (°C) | 1427 | 1493 | 1427 | 1493 |
| Installation Method | Dry ram or vibrate | Dry ram or vibrate | Dry ram or vibrate | Dry ram or vibrate |
S Series Silica-based (Grey / Ductile Iron, Carbon Steel, Low-Temp Alloy Steel)
| Chemical Composition [%] | JH-DRI-458CR | JH-DRI-400Z | JH-DRI-201S | JH-DRI-460S |
| Al₂O₃ | 0.49 | 0.28 | 3.6 | 0.5 |
| SiO₂ | 5.6 | 6.7 | 94.1 | 99.2 |
| ZrO₂ | 2.8 | 12.5 |
| Technical Data | JH-DRI-458CR | JH-DRI-400Z | JH-DRI-201S | JH-DRI-460S |
| Bulk Density (g/cm³) | 2.0 | 2.4 | 2.1 | 2.15 |
| Max Grain Size (mm) | 8 | 6 | 8 | 8 |
| Max Working Temp (°C) | 1680 | 1680 | 1650 | 1650 |
| Min Working Temp (°C) | 1200 | 1200 | 1450 | 1450 |
| Installation Method | Dry ram or vibrate | Dry ram or vibrate | Dry ram or vibrate | Dry ram or vibrate |
Silica phase transformation note: without mineralizer, the quartz phase transforms slowly across 1200–1470 °C with ±15.4% dimensional change.
