Sumatra Miner 2017
In partnership with Geovariances, PT. SMG Consultants Indonesia is to present:
Why should I use non-linear estimation technics?
by Keith Whitchurch, PT. SMG Consultants Indonesia President D. and Johann Dangin, Geovariances Pty ltd Managing Director
Session 3: Mineral Exploration, Design and Planning
Wednesday – March 22, 2017
01:00 pm – 03:00 pm
“An increasing focus is being placed in commercial transactions and investment decisions on tonnes above a cut-off grade. For example, it is not uncommon to see the sale price of a project in a sales and purchase agreement specific solely in terms of tonnes at a specified grade. Estimation of tonnes at a grade almost always involves discarding low grade material below a cut-off grade such that the remaining material averages the target grade. ( e.g. 1.4% Ni cut off for a 1.8%Ni Average)
Traditional Linear estimation methods such as Inverse distance and kriging tend to smooth estimates towards the mean grade, often underestimating tonnages above a moderately high cut off.
This presentation uses a lateritic nickel deposit to explore the differences between linear and non-linear estimation techniques and show how the use of non-linear estimation techniques translates to a better commercial outcome.”