Geovariances: Where no one has gone before

How would you take the constraints due to deleterious quality minerals into account to get a reliable assessment of the resources for the main economic mineral of your orebody? Or how would you predict the recoverable resources of a secondary mineral according to a cut-off applied to the main economic mineral?

These are kinds of financial stakes mining companies are facing today.

This is why, Geovariances, together with "le Centre de Géostatistique de l’Ecole des Mines de Paris", offers a new research project through a consortium named MULTIVARIATE RECOVERABLE RESOURCES CONSORTIUM (M2RC).

 News from M2RC (dec. 2007)
 M2RC third year development program (feb. 2008)

Carajas

The Multivariate Recoverable Resources Consortium (M2RC) is a 3-year research-development project (ending in 2009) whose objective has been to develop multivariate non-linear geostatistics algorithms in Isatis. Indeed, univariate techniques are often not sufficient for estimating in a reliable way the recoverable resources in the main economic mineral of an orebody when secondary minerals are a constraint at the extraction or processing stages but ignored in the estimation.

A good example of this issue lies in gold exploitation. As sulfurs penalize the gold ore processing, estimating the recoverable grades of these sulfurs according to a given cut-off applied to gold is of crucial importance. Conversely, the presence of silver being often associated with the presence of gold, assessing the recoverable resource of silver according to a given cut-off on gold presents a definite economic interest.

We are fully in the domain of Multivariate Recoverable Resources.

For many years now, Isatis has been offering outstanding non-linear techniques such as Uniform Conditioning, global corrections (through the anamorphosis function) or conditional simulations to estimate local or global recoverable resources with high level of precision.
These techniques have proved their efficiency in the univariate case.

Grade Tonnage Curves according to SMU size

Block simulation outcomes

Le Centre de Géostatistique de l’Ecole des Mines de Paris and Geovariances are willing to develop new software tools to extend these techniques to the multivariate case combining the Centre past research on this subject and Geovariances expertise in applying non-linear geostatistics.

The main lines of this project are:

• a 2-years project starting in January 2006, with possible one-year extensions;
• to provide the consortium partners with new Isatis plugs-in;
• to investigate 3 topics:

• the global recoverable resources which involve the histogram fitting and the global support correction;
• the local recoverable resources with the Uniform Conditioning technique;
• the block simulation approach.

Bases for the first developments are:

• equation reformulation and translation in algorithms;
• current algorithms improvement if possible;
• classical research work.

This international project is open to all companies. Today, our sponsors are:

• AngloGold Ashanti
• Areva NC
• BHP Billiton
• Codelco
• Lihir Gold Ltd
• Newcrest Mining Limited
• Rio Tinto

For more information, please contact Julien Tan.

Bibliography

• Rivoirard J. 1984, Une méthode d’estimation du récupérable local
  Cahiers du centre de Géostatistique N-894
• Emery X. and Ortiz J. 2005, Internal Consistency and Inference of Change-of-Support Isofactorial Models
  Proceedings Of Banff