- Tungsten Content (by weight): ≥ 95%
- Carried-waste (such as wood, paper, plastic, rubber, textile, glass, powdery substance etc. ) : ≤ 1.0% (by weight)
- Radioactive: shall not contain radioactive pollutants.
- Hazardous Waste: must not be mixed in.
- Physical Form: should not contain liquids, sludge, etc.