https://www.tanb.org/about-tantalum/tantalum-valuation-basisTo calculate the value of a tantalum mineral, the main principle is that only the quantity of Ta2O5contained is paid for, not the whole bulk of material. Basically the weight of material is multiplied by the percentage grade e.g. 30%, then multiplied by the pricing rate of X$/lb Ta2O5. Note that while our industry statistics have moved to metric units, the traditional valuation basis of $/lb Ta2O5 contained is likely to continue.
[Value tantalite] = weight of material x 30% [x conversion to lb if necessary] x X$/lb Ta2O5
In theory it does not matter whether the material is 30% or 40%, by applying the percentage the quantity paid for is automatically adjusted; sliding scales according to grade are not known of. There may possibly be fixed discounts or premiums for grades significantly below or above the 30% to 50% range.
