D. K. Sinha, Atomic Minerals Directorate for Exploration and Research (AMD)

Subject: Comments to the Draft Guidelines for the Application of UNFC-2009 to Uranium and Thorium Resources: from D. K. Sinha, Atomic Minerals Directorate for Exploration and Research (AMD), Department of Atomic Energy, Government of India
29 June 2015

1. The document (Application of United Nations Framework Classification for Fossil Energy and Mineral Reserves and Resources 2009 for Uranium and Thorium Projects: A Guidebook) is a commendable effort to normalize various methodology of defining a resource / reserve figure of different mineral deposits by different countries.  The document has very nicely bridged different classification system of mineral  wealth adopted in different countries into a common numerical language which breaks the barrier of learning the language and understanding different parameters / sub-parameters.  
2. As far as resources / reserves of Uranium and Thorium are concerned (it can also be similar with other mineral deposits), many a time the mining and processing activity are carried out much later to the geological investigations, sometimes delayed in decades.  It is possible to define ‘F’ and ‘G’ axis of the deposit during exploration stage.   But the value under ‘E’ axis is completely a dynamic figure with respect to time.  More often than not, it is primarily due to (a) land being grabbed for construction or cultivation (b) opposition to any developmental project.  In such a situation, the value assigned under ‘E’ axis during exploration stage might go haywire if mining is delayed. Therefore, it may not be inappropriate to assign a factor of time while defining the three axes of the deposit.  Alternatively, the social issue can be de-linked and made into a separate category.  In that case, the values under ‘E’, ‘F’, ‘G’ categories may be decided during exploration stage and the value under social factor would be decided during the decision of commercial exploitation.
3. Sometimes different minerals co-exist as co-products, which necessitates separation of all the minerals.  For example, in case of beach placer deposits of the heavy minerals, be it titanium bearing minerals or garnet or zirconium or monazite, all have high commercial value.  In such a situation, as mentioned under para 3.2.1.1.4, the value under ‘E’, ‘F’, ‘G’ axis may be appropriately assigned considering total value of the commercial mineral products.
4. The ‘G’ axis is normally defined by the confidence level of the resource estimate of the deposit which is directly based on spacing of the drilling patterns and resultant correlatability of the ore horizon.  The drill hole spacing and pattern are again based on the configuration of the ore body.  Some explorers, without making any statistical study, tend to drill at closer grid interval, particularly in Beach Sand Heavy mineral deposits.  In India too, drill holes in Beach Placer deposits had been drilled, in the past as close as 30 m interval.  Recent Statistical studies has revealed that the Range in the semivariogram of a Beach Mineral deposit is of the order of 400 m.  Secondly, in deposits of vast extension (of the order of 20-30 km stretch) the resource / reserve figure found to vary within 10% when estimated at 200 m x 100 m grid interval to as wide as 1000 – 2000 m x 200 m grid.  Therefore, considering the unconsolidated but vast continuity with low variation in grade and thickness of the Beach Minerals (Total Heavy Minerals), the drilling pattern at 200 m x 100 m grid is felt appropriate to define it as G-1 and upto 1000 m x 200 m grid pattern for G-2 category.

Overall, the team deserves congratulations for their painstaking efforts to bring out a uniformity in the classification of Uranium and Thorium resources which can easily be adopted by various countries.
These comments are sent with the approval of Director, AMD.
Comments from D. K. Sinha, Atomic Minerals Directorate for Exploration and Research (AMD), Department of Atomic Energy, Government of India, to the Draft Guidelines for the Application of UNFC-2009 to Uranium and Thorium Resources.