| Project | Indicator | |
|
Calcium carbonate content (dry basis)% |
GB1898-2007 | USP35 |
| 98.0-100.5 | 98.0-100.5 | |
| Loss on drying ≤% | 2 | 2 |
| Hydrochloric acid insoluble matter ≤% | 0.2 | 0.2 |
| Iron ≤% | ---- | 0.1 |
| Heavy metal (Pb) ≤% | ---- | 0.002 |
| Lead (Pb) ≤ ppm | 3 | 3 |
| Arsenic (As)≤ppm | 3 | 3 |
| Fluoride (F)≤% | 0.005 | 0.005 |
| HG≤ppm | 1 | 0.5 |
| Magnesium salt and alkali metal ≤% | 1 | 1 |
| B≤% | 0.03 | qualified |
| cadmium≤% | 0.0002 | ---- |
| Free base content | qualified | ---- |