| Sintering additive | T (˚C) wt% | 0.1 | 1 | 3 |
| Na3PO4 | 900 | 0.83 | 0.86 | 0.82 |
| 1000 | 0.96 | 0.95 | 0.95 | |
| Na2CO3 | 900 | 0.88 | 0.93 | 0.91 |
| 1000 | 0.95 | 0.95 | 0.94 | |
| NaF | 900 | 0.90 | 0.88 | 0.81 |
| 1000 | 0.95 | 0.92 | 0.87 | |
| Li2CO3 | 900 | 0.92 | 0.86 | 0.85 |
| 1000 | 0.91 | 0.89 | 0.87 | |
| KCl | 900 | 0.64 | 0.62 | 0.6 |
| 1000 | 0.68 | 0.7 | 0.7 | |
|
K2CO3 | 900 | 0.94 | 0.91 | 0.87 |
| 1000 | 0.93 | 0.91 | 0.88 |