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All crucibles, alumina, magnesia and zirconia to name a few, are manufactured in Capital's own modern purpose-built facility in the Czech Republic where we press, cast and fire various materials into crucibles.
Capital Refractories is able to supply a full range of isostatically pressed crucibles from 2 kg capacity to 75 kg, in different grades and qualities. We use a state-of-the-art semi-automated cold isostatic press. Cold isostatic pressing applies pressure to the workpiece in all directions producing products of uniform density.
The advantages of Isostatically Pressed Crucibles are:
Crucibles are produced by vibration casting (vibrocast) when the required size or shape is uneconomical or impractical by the isopressing production method.
Capital Refractories can offer a range of vibration cast crucibles, including T-Pot Ladles:
Benefits
Complex shapes, e.g. internal pouring siphon
To complement our range of crucibles we also offer numerous ancillary products and materials used within the investment and related foundry industries.
| Quality | Description | |
| Alumina | ..... | General purpose crucible with good resistance to acidic and basic slags. Used for a wide range of alloys. |
| ..... | AL97I | Superior erosion resistance. |
| ..... | AL88I | Improved thermal shock resistance. |
| ..... | AL90C | Combines excellent strength and thermal shock resistance with low reactivity. |
| ..... | AL92C | Superior thermal shock resistance. |
| ..... | AL97C | High resistance to slags. |
| Chrome Alumina | ..... | High resistance to slags. Preferred to alumina in more arduous applications. |
| ..... | CA93I | Superior erosion resistance |
| ..... | CA84I | Improved thermal shock resistance. |
| ..... | CA91I | Specially formulated to withstand the most severe thermal shock applications. |
| ..... | CA93C | Have a high resistance to slags and are preferred to alumina in more arduous applications. |
| Magnesia | ..... | High resistance to basic slags. Used in vacuum melting of Ni, Co and Fe based alloys. |
| ..... | MG88I | Used in vacuum melting of Ni, Co and Fe based alloys. |
| ..... | MG95 | Resistant to the special alloys used in semi-conductor and sputter target industries. |
| Mullite | ML72I | High thermal shock resistance. Resistant to basic slags. |
| Zircon | ZN66I | Good resistance to acidic slags. It is used for non-ferrous and precious metals. |
| Zirconia | ..... | High resistance to acidic slags. Used in the vacuum melting of superalloys and precious metals. |
| ..... | ZC93I | General applications. |
| ...... | ZC95I | High thermal shock resistance for noble metals. |
| ...... | ZC96I | Fine grained structure for noble metals. |
| ..... | ZM94I | Magnesia-stabilised with enhanced thermal shock resistance for superalloys. |
| ..... | ZY97I | Suitable for cobalt & nickel superalloys. |
| Sillimanite | ..... | High performance with good thermal shock resistance. |
| ..... | SL58C | Good resistance to iron and nickel based alloys. |
| ..... | SL70C | Good resistance to thermal shock with good hot strength and resistance to iron and nickel based alloys. |
Products suffixed "I" are isopressed, products sufficed "C" are cast.
| Quality | Al₂O₃ | SiO₂ | MgO | CaO | Fe₂O₃ | Cr₂O₃ | ZrO₂ + HfO₂ |
| Alumina AL97I | 97.5 | 1.6 | - | 0.1 | <0.1 | - | - |
| Alumina AL97C | 96.6 | 2.5 | - | 0.1 | <0.1 | - | - |
| Alumina AL92C | 92.1 | 7.2 | - | 0.1 | <0.1 | - | - |
| Chrome Alumina CA93I | 93.4 | 2.2 | - | 0.1 | <0.1 | 3.6 | - |
| Chrome Alumina CA84I | 84.3 | 9.0 | - | 0.1 | 0.2 | 4.8 | - |
| Chrome Alumina CA91I | 91.5 | 2.2 | - | 0..1 | <0.1 | 5.3 | - |
| Chrome Alumina CA93C | 93.0 | 2.8 | - | 0.1 | <0.1 | 3.6 | - |
| Magnesia MG88I | 3.5 | 3.8 | 88.0 | 3.8 | 0.2 | - | - |
| Magnesia MG95I | 0.5 | 0.8 | 95.0 | 2.5 | 0.1 | - | - |
| Mullite ML72I | 71.8 | 25.7 | - | 0.2 | 0.5 | - | - |
| Zircon ZN66I | 0.8 | 32.5 | - | 0.2 | 0.1 | - | 66.6 |
| Zirconia ZC93I | 0.8 | 1.2 | - | 4.0 | 0.1 | - | 93.0 |
| Zirconia ZC95I | 1.0 | 1.5 | - | 3.8 | <0..1 | - | 92.9 |
| Zirconia ZC99I | 0.6 | 0.9 | - | 4.4 | 0.1 | - | 94.0 |
| Sillimanite SL58C | 59.1 | 35.9 | 0.2 | 0.2 | 0.7 | - | - |
| Sillimanite SL63C | 63.8 | 34.2 | 0.1 | 0.2 | 0.5 | - | - |
| Quality | Bulk Density (g / cm³) | Apparent Porosity (%) | Thermal Expansion (x10⁻⁶ / K) | Thermal Conductivity (W / m K) | Maximum Service Temperature (°C) |
| Alumina AL97I | 2.95 | 23.8 | 8.0 | 4.2 | 1700 |
| Alumina AL88I | 2.59 | 23.8 | 8.0 | 4.2 | 1700 |
| Alumina AL90C | 2.9 | 18.0 | 7.7 | 4.0 | 1750 |
| Alumina AL92C | 2.95 | 24.8 | 8.0 | 4.2 | 1750 |
| Alumina AL97C | 3.1 | 19.6 | 8.0 | 4.1 | 1800 |
| Chrome Alumina CA93I | 3.05 | 23.0 | 8.2 | 3.4 | 1800 |
| Chrome Alumina CA84I | 2.85 | 20.0 | 7.6 | 3.4 | 1730 |
| Chrome Alumina CA94I | 3.10 | 21.5 | 8.2 | 3.4 | 1800 |
| Chrome Alumina CA93C | 3.14 | 19.3 | 8.2 | 3.0 | 1750 |
| Magnesia MG88I | 2.83 | 17.0 | 14.5 | 2.4 | 1700 |
| Magnesia MG95I | 2.95 | 15.0 | 13.0 | 2.5 | 1750 |
| Mullite ML72I | 2.32 | 21.5 | 4.2 | 1.8 | 1700 |
| Zircon ZN66I | 3.60 | 21.9 | 4.6 | 2.1 | 1750 |
| Zirconia ZC93I | 4.35 | 20.0 | 8.4 | 1.5 | 1850 |
| Zirconia ZC95I | 4.50 | 18.5 | 8.5 | 1.6 | 1850 |
| Zirconia ZC96I | 4.50 | 18.5 | 8.5 | 1.6 | 1850 |
| Sillimanite SL58C | 2.42 | 18.7 | 4.5 | 1.6 | 1650 |
| Sillimanite SL63C | 2.32 | 22.0 | 4.5 | 1.6 | 1650 |
