Innovative methodology involving Isatis IK and LUC to constrain grade estimates
Geovariances has recently implemented for a series of clients an innovative methodology to constrain grade estimates. The methodology offers an alternative to the use of existing wireframes that may be considered as affected by too great a level of uncertainty in order to be used for the flagging of the estimation block model.
Resource estimation procedures usually rely on the preliminary interpretation of mineralized volumes followed by grade estimation within the interpreted geological domains. The validity of the geological interpretation is highly dependent on the density of information supporting the interpretation. Areas of sparse drilling have an increased risk of over/under estimation of the mineralized volumes. The traditional geostatistical approach in that situation is to conduct a probabilistic estimation of the mineralized volumes by Indicator Kriging (IK) of the mineralization flags interpreted at drill holes level, in keeping with the idea that away from information there is a fair degree of uncertainty placed on the occurrences and actual location of the mineralized bodies.
IK offers the ability to estimate proportions of material within a panel that are deemed to be mineralized. The panel size estimated, which is constrained by the density of information is usually too broad in comparison to the geometrical resolution required for mine design. And whilst this resolution is imposed by the actual data density one may still be interested in trying to localize that proportion in space using a resolution that is more compatible with the envisaged level of mining selectivity.
To that effect the existing Localized Uniform Conditioning module of Isatis has been used in a roundabout way aimed at retrieving the rank of the smus for which the cumulated ore proportions from smu’s match the desired ore proportion of the panel.
The procedure can be summarized as follows:
1. The mineralization intercepts along the composites are coded with an indicator function with a value 1 when mineralization is present 0 otherwise;
2. The mineralization indicator is then estimated by Indicator Kriging (IK) at the scale of estimation panels to produce a local proportion of mineralization;
3. That proportion is then localized into smu sized blocks via a migration/localization procedure that attaches an indicator of 1 to all the blocks required to reconstitute the mineralized proportion at the panel level;
To be more specific: The smu’s are ranked according to their probability of being mineralized (estimated by IK at the smu level), and the smu’s with highest probabilities are flagged as being mineralized, until the appropriate number of smu’s is reached so as to reconstitute the mineralized proportion per panel;
That part of the procedure is achieved via a roundabout use of the existing LUC procedure;
4. That way the smus are flagged as being entirely ore or waste and are amenable to receive the results of parent panels estimates (for example via the localisation of UC results at recoverable resource estimation stage).
- Resource Estimation Procedure
May 13 - 15, 2013
June 5 - 7, 2013
July 17 - 19, 2013
November 18 - 20, 2013
Get acquainted with the fundamental concepts of mining geostatistics - 3-day fundamentals course
May 16, 2013
November 21, 2013
Get a sound understanding of the Uniform Conditioning concepts for application to recoverable resource estimation - 1-day advanced course
May 20 - 24, 2013
July 1 - 5, 2013
Gain the skills you need to start using Isatis with confidence for your essential tasks in mining geostatistics - 5-day software course
May 21, 2013
Gain the skills you need to build efficient automatic workflows and audit trails in Isatis - 1-day software course
May 30, 2013
This time, Geovariances is to present: Localised Multivariate Uniform Conditioning: a powerful approach to estimating recoverable resources.
June 10 - 13, 2013
Geovariances is to exhibit at EAGE London '13 at booth #124 and give a poster presentation: "Advanced Approaches in Geostatistical Reservoir Modelling - Methods and Benefits".
July 1, 2013
Geovariances organise le 1er juillet 2013 sa toute première réunion des utilisateurs de Kartotrak, la solution logicielle tout-en-un pour la caractérisation des sites et sols pollués. Soyez-présent !
July 24 - 26, 2013
Geovariances is Silver Sponsor of the event. Please meet us at booth #18. We'll be happy to show you Isatis 2013 latest innovations.
August 12 - 14, 2013
Geovariances is to exhibit at Iron Ore 2013. Meet with our people and ask for a demo of Isatis at booth 53.
August 26 - 29, 2013
Geovariances is to exhibit at the 13th International Congress of the Brazilian Geophysical Society. Meet with our people and ask for a demo of Isatis 2013 at booth #29.
September 2 - 6, 2013
Attend Geovariances presentation: Combining Various Approaches in Geostatistical Reservoir Modelling: Methods and Benefits - Session 2: Frontier Geostatistics
September 8 - 12, 2013
Geovariances is to exhibit at ICEM 2013.
November 3 - 8, 2013
Geovariances mining geostatistics specialists are to give two paper presentations in partnership with Gold Fields, AngoGold Ashanti and Mines ParisTech. Topics are about MPS and domaining with potential method. They also give a short course about un...
December 1 - 5, 2013
Geovariances is to exhibit for the first time at Mines & Money in London. Feel free to come at booth #A22 and find out how geostatistical software Isatis helps improve your resource evaluation.