China Clay
China clay is the deposits of kaoline produced by hydrothermal decomposition or weathering of feldspar. It is relatively a pure clay consisting of predominantly the mineral Kaolinite (Al2O3, 2H2O) and associated with other clay. Minerals like dickite halloysite, nacrite and anauxite, Kaolin is commercially valued for its whiteness and fine particle size. It often contains small amounts of impurities in the form of rock fragments, hydrous oxides and colloidal materials. China clay is an important raw material of ceramic industry. In consists c partly crystalline and partly amorphous mineral of Kaoline group. So it can also be called as Kaolinite.
Key Specifications
| Brightness | 85% – 95% |
|---|---|
| Whiteness | 82% – 92% |
| Moisture Content | Max 1.5% |
| pH Value | 6.0 – 8.0 |
| Oil Absorption | 40 – 60 g/100g |
| Loss in ignition percent by wt. | 12 (min) |
| Water of Plasticity | 22% (min) |
| Bulk Density | 0.4 – 0.6 g/cm³ |
| Fineness (residue on) 44 micron IS Sieve | 1.0-2.0 |
| (a)Dry shrinkage (110°C) | 8% (max) |
| (b)Fire Shrinkage (at supercone-12) | 18% (max) |
| Alumina (as Al) percent by wt. | 36.0 (min) |
| Oxide of iron (as Fe) percent by wt. | 1.5 (max) |
| Titanium Oxide (as Ti) percent, by wt. | 1.5 (max) |
| Oxide of iron (as Fe) & titanium Oxide (as Ti) together, percent by wt. | 2.75 (max) |
| Particle size, percent by wt. of material passing through IS sieve, 8 | 99.75 (min) |
| Loss on ignition, percent by wt. | 15 (max) |
| Moisture percent by wt. | 3 (max) |
| Grit, percent by wt. | 0.2 (max) |
| Colour, reflectance to blue light of wave length 5040 Ao percent | 80 |
| Total iron (as Fe) percent by wt. | 0.35 |
| Volatile matter | Not more than 2.0 %. |
| Residue on Sieve | Not more than 0.5 %. |