Refractory kiln furniture Cordierite kiln shelf use for tunnel kiln
1. Details
Cordierite ceramics are well known for their low thermal expansion and refractory character. Although cordierite is available as a powder, when we use the term we are generally talking about ceramic that went into the kiln as ordinary composite of ceramic powders but emerges as a cordierite crystalline matrix (grown by the firing process tuned to its needs).
Cordierite makes the ceramic manufacture of products like catalytic converters possible. They constantly heat up and cool down quickly and must not crack because of the shock. These converters get their thermal shock resistance properties from a bonded matrix of low-expansion cordierite crystals. These crystals form during firing between 1300 to 1400C (interestingly, cordierite crystals have a lesser thermal expansion along one axis than another). Thus, the better the density of the precursor mix and controlled the firing the better the properties of the cordierite material are.
The ideal chemistry to produce the crystals is 13.8% MgO, 34.8% Al2O3 and 51.4% SiO2 (2MgO, 2Al2O3, 5SiO2). Talc, kaolin and raw alumina powder can be blended to produce this chemistry (other materials are also used e.g. aluminum hydroxide, steatite and other MgO minerals). Compound materials (like kaolin and talc) react better than pure oxide materials (like MgO, Al2O3, SiO2). Materials of finer particle size react better.
A simple firing to 1300C (about cone 11 and within the reach of many ordinary kilns) and soaked may produce some crystal development. However firing (actually sintering) at 1400C+ with significant soaking time is needed for the best results. Thermal expansion measuring equipment is needed to determine if your firing is actually developing the crystal matrix or not.
As noted, a continuous crystal matrix is the object of cordierite creation (not just the presence of the crystals in an otherwise typical ceramic). Notwithstanding this, cordierite powder is available, it is prefired and finely ground. It can be plasticied for forming and bonded during firing (at much lower than normal cordierite creation temperatures) to produce a ceramic that certainly has lower expansion.
2. Product Technical parameter
| Item |
Unit |
Index |
| Al2O3 |
% |
50 |
| SiO2 |
% |
40 |
| MgO |
% |
5 |
| Fe2O3 |
% |
＜1 |
| Cao |
% |
＜2 |
| Other |
% |
＜2 |
| Max. Service Temp. |
℃ |
1300 |
| Refractoriness≥ |
℃ |
1420 |
| M.O.R at 20 ℃ |
Mpa |
18 |
| M.O.R at 1250℃ |
Mpa |
17 |
| Apparent Porosity |
% |
20-28 |
| Specific heat at 20℃ |
Kg/kg.k |
1.1 |
| Bulk Density |
g/cm3 |
2.0-2.2
|
3. Package
We use Packed in wooden cases with plastic foam., there is no need to do fumigation, it is very strong and eco-friendly material for package.
4. Application
Cordierite kiln furniture is widely used in santary ceramic, pottery , porcelain insulator and so on.
Commonly customer use it under 1280℃.
5. Our service
We can reply within 8 hours, if we are not online, you can also send email to us, we will get back to you after we are back. Sometimes we are on business travel, so it takes time.
Product Tags:
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Cordierite Kiln Shelves Refractory Kiln Furniture Yellow Color 500 * 500 * 15mm Images
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