ATH
ATH (aluminium tri hydrate, chemical formula Al(OH)3) is a side stream of aluminium production, characterised by:
- High purity
- High whiteness
- Relatively low density of 2.4g/cm3 compared to other mineral fillers, which are typically at 2.7g/cm
- Medium Mohs hardness of 3
- Decomposition around 180°C, releasing water.
Basic properties
| Property | Value | Unit |
| Moisture | < 0.4 | [%] |
| pH | 9 | [-] |
| Hardness (Mohs) | 3 | [-] |
| Refractive index | 1.57 | [-] |
| Electrical conductivity | 60 | [µS/cm] |
| L.O.I. | 34.5 | [%] |
| Density | 2.4 | [kg/ dm3] |

Product overview
| Product | Grade | D50
[µm] |
D97
[µm] |
OA
[g/ 100 g] |
L* |
| Portafill | A7 | 2.4 | 6.5 | 27 | 98.5 |
| A10 | 3.8 | 10 | 27 | 98.4 | |
| A25 | 7.3 | 24 | 21 | 97.0 | |
| A40 | 11.5 | 36 | 20 | 96.5 | |
| A25/10 | 13 | 35 | 18 | 98 |
Production locations Portaflame SG, Portafill A
Application
ATH will provide:
- Ease of tinting: due to the combination of refractive index, brightness and color, paints including ATH will provide excellent reproducible colour results when working with tinting systems.











