Dry tonnes and wet tonnes in antimony concentrate discussions

Understanding the subject

Moisture creates a difference between the total shipment weight and the dry material weight. Concentrate enquiries should record both the moisture basis and the basis on which Sb grade is reported.

What it means in practice

For an illustrative 100 wet tonnes with 8% moisture, the dry weight is 92 tonnes. If the dry-basis grade is 25% Sb, theoretical contained antimony is 23 tonnes. These are mass calculations, not a quotation or recovery forecast.

Bring it into your next discussion

Do not use wet tonnage with dry-basis grade without making the moisture adjustment explicit. The parties should agree where and how weight and moisture are measured, because both can affect the commercial calculation.

• State moisture as a percentage with its method.
• Match Sb grade to the correct weight basis.
• Separate contained metal from payable metal.