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Isatis for resource classification and confidence intervals

Isatis for resource classification and confidence intervals Classification of the resources in different categories, measured, inferred, or indicated, implies reliable calculations of the confidence level in the grade estimates, at a local scale (SMU) and at greater scales (quaterly or yearly exploitation areas).
ISATIS provides several tools to calculate reliable and realistic Confidence Intervals of these different estimates. Among them, the exclusive and rapid application Confidence Intervals.

The kriging variance is certainly not the best way to classify your deposit’s resources. There are two main reasons for this. The error distribution is unlikely to be gaussian and the kriging variance is data-independent (though greater uncertainty is expected in high grade areas than in low ones). The distribution of mining data is, by nature, skewed; standard linear Confidence Intervals are, consequently, not relevant since they are not consistent with the data.

A better approach would be to obtain the error distributions from simulations. But this is extremely time-consuming, only to get two numerical values. A shortcut involving similar hypothesis is proposed in Isatis.

This original methodology was first applied in 1996 by Roth and Armstrong (from the Centre of Geostatistics of the “Ecole des Mines de Paris”) on gold grades of the Witwatersrand basin.

A more recent application has been succesfully made by Rio Tinto and has reduced drastically the time required for updating reserve classifications.

The basic idea is to use the Discrete Gaussian Model to calculate the Confidence Intervals directly from the gaussian grade estimates.

The figures above compare these Confidence Intervals to standard linear Confidence Intervals and to those derived from stochastic simulations.

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Análisis de Datos y Estimación de Recursos

March 15 - 19, 2010

March 22 - 26, 2010

Los fundamentos de los principales conceptos y técnicas usados en la geoestadística minera - Curso de 5 días

Analyse de données et estimation de ressources avec Isatis

March 15 - 19, 2010

Maîtrisez les concepts essentiels et les méthodes indispensables de la géostatistique minière - Durée : 5 jours

Multivariate Non-linear Resource Evaluation - NEW!

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Be at the forefront of mining geostatistics and learn how to improve your resource evaluation with innovative multivariate non-linear geostatistics - 3-day course

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Intersol’ 2010

March 16 - 19, 2010

Geovariances to present a paper: "Characterization of radio-contaminated soils in France: challenges and outcomes". We’ll also be present with a stand. Please come and discover our solutions!

Nantes 2010

March 29 - April 1, 2010

Geovariances to present a paper "Quantifying the transferability of hydraulic parameters using geostatistics: the Boom Clay case"

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April 27 - 29, 2010

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June 2 - 4, 2010

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