143
the uncertainty related to grades, contained metal and tonnage and thus provides a better
understanding of the geological and financial risks associated with the deposit.
ACKNOWLEDGEMENTS
The authors are grateful to CMOC for their support to this paper based on a case study at
the Niobium Boa Vista Mine. We also thank the Geovariances Latin America technical support, specially Artur Saldanha e Silvia Misk for their comments and suggestions to improve
this case study and the quality of the paper. Finally, the first author expresses his gratitude to
Dr. Michael Harley, from Anglo American, who first applied non-linear techniques in Niobium Deposits in Brazil.
REFERENCES
Abzalov, M.Z. 2006. Localised uniform conditioning (LUC): a new approach for direct block modelling. Mathematical Geology, vol. 38, no. 4. pp. 393–411.
Abzalov, M.Z. “Localized uniform conditioing (LUC): Method and application case studies”. In: The
journal fo the South African Institute of Mining and Metallurgy 114 (2014), pp. 205–211.
Armstrong M. and Champigny N. 1989: A study on kriging small blocks. CIM Bull., 82, 128–133.
Deraisme, J., Rivoirard, J., and Carrasco Castelli, P. 2008. Multivariate uniform conditioning and block
simulations with discrete gaussian model: Application to the Chuquicamata deposit, Proceedings of
the VIII International Geostatistics Congress (Geostats 2008), Santiago, Chile, 1–5 December 2008.
Gecamin, Santiago. pp. 69–78.
Deraisme, J. and Assibey-Bonsu, W. 2011. Localised uniform conditioning in the multivariate case—An
application to a porphyry copper gold deposit. Proceedings of the 35th International Symposium
on Application of Computers and Operations Research in the Minerals Industry (APCOM), Wollongong, Australia, 24–30 September 2011. Baafi, E.Y., Kininmonth, R.J., and Porter, I. (eds.). Australasian Institute of Mining and Metallurgy, Melbourne.
De-Vitry, C., Vann, J., and Arvidson, H. 2007. A guide to selecting the optimal method of resource
estimation for multivariate iron deposits. Proceedings of Iron Ore2007, Perth, Australia. Australasian
Institute of Mining and Metallurgy, Melbourne. pp. 67–77.
Hansmann, K. When should uniform conditioning be applied?. J. S. Afr. Inst. Min. Metall, Johannesburg, v. 116, n. 7, p. 645–654, July 2016.
Harley, M. and Assibey-Bonsu, W. 2007. Localised uniform conditioning: How good are the local estimates? Proceedings of the 33rd International Symposium on Application of Computers and Operations Research in the Minerals Industry (APCOM), Santiago, Chile, 24–27 April 2007. Magri, E.J.
(ed.). Gecamin, Santiago. pp. 105–112.
Lantuéjoul, CH. 1994. Non conditional simulation of stationary isotropic multigaussian random functions. In: Armstrong, M., Dowd, P.A. (Eds.), Geostatistical simulations. Kluwer, Dordrecht, The
Netherlands, pp. 147–177.
Lantuéjoul, CH. Geostatistical Simulations. Models and Algorithms. Springer-Verlag Print, 2002.
Berlin. ISBN 3-540-42202-1.
Leuangthong, O., McLennan, J.A., Deutsch, C.V., 2004. Minimum acceptance criteria for geostatistical
realizations. Natural Resour. Res. 13 (3), 131–141.
Millad, M.G. and Zammit, K.M. 2014. Implementation of localised uniform conditioning for recoverable
resource estimation at the Kipoi Copper Project, DRC. Proceedings of the Ninth International Mining
Geology Conference. Australasian Institute of Mining and Metallurgy, Melnourne. pp. 207–214.
Pan G. 1998: Smoothing effect, conditional bias and recoverable reserves. CIM Bull., 91, 81–86.
Ravenscrof P.J. and Armstrong M. 1990: Kriging of block models-the dangers re-emphasized. In: Proc.
22nd APCOM, Berlin, Germany, vol. II, pp. 577–587.
Rivoirard J. Introduction to Disjunctive Kriging and Non-Linear Geostatistics. Oxford, 1994.
Vann, J., Jackson, S., Bertoli, O., 2003. Quantitative kriging neighbourhood analysis for the mining
geologist—a description of the method with worked case examples. In: Dominy, S. (Ed.), Proceedings
of the 5th International Mining Geology Conference. Australasian Institute of Mining and Metallurgy, Melbourne, Australia, pp. 215–223.
Wackernagel H. 2002: Multivariate Geostatistics: an introduction with applications. Springer Verlag,
Berlin, Germany, 388 pp.
the uncertainty related to grades, contained metal and tonnage and thus provides a better
understanding of the geological and financial risks associated with the deposit.
ACKNOWLEDGEMENTS
The authors are grateful to CMOC for their support to this paper based on a case study at
the Niobium Boa Vista Mine. We also thank the Geovariances Latin America technical support, specially Artur Saldanha e Silvia Misk for their comments and suggestions to improve
this case study and the quality of the paper. Finally, the first author expresses his gratitude to
Dr. Michael Harley, from Anglo American, who first applied non-linear techniques in Niobium Deposits in Brazil.
REFERENCES
Abzalov, M.Z. 2006. Localised uniform conditioning (LUC): a new approach for direct block modelling. Mathematical Geology, vol. 38, no. 4. pp. 393–411.
Abzalov, M.Z. “Localized uniform conditioing (LUC): Method and application case studies”. In: The
journal fo the South African Institute of Mining and Metallurgy 114 (2014), pp. 205–211.
Armstrong M. and Champigny N. 1989: A study on kriging small blocks. CIM Bull., 82, 128–133.
Deraisme, J., Rivoirard, J., and Carrasco Castelli, P. 2008. Multivariate uniform conditioning and block
simulations with discrete gaussian model: Application to the Chuquicamata deposit, Proceedings of
the VIII International Geostatistics Congress (Geostats 2008), Santiago, Chile, 1–5 December 2008.
Gecamin, Santiago. pp. 69–78.
Deraisme, J. and Assibey-Bonsu, W. 2011. Localised uniform conditioning in the multivariate case—An
application to a porphyry copper gold deposit. Proceedings of the 35th International Symposium
on Application of Computers and Operations Research in the Minerals Industry (APCOM), Wollongong, Australia, 24–30 September 2011. Baafi, E.Y., Kininmonth, R.J., and Porter, I. (eds.). Australasian Institute of Mining and Metallurgy, Melbourne.
De-Vitry, C., Vann, J., and Arvidson, H. 2007. A guide to selecting the optimal method of resource
estimation for multivariate iron deposits. Proceedings of Iron Ore2007, Perth, Australia. Australasian
Institute of Mining and Metallurgy, Melbourne. pp. 67–77.
Hansmann, K. When should uniform conditioning be applied?. J. S. Afr. Inst. Min. Metall, Johannesburg, v. 116, n. 7, p. 645–654, July 2016.
Harley, M. and Assibey-Bonsu, W. 2007. Localised uniform conditioning: How good are the local estimates? Proceedings of the 33rd International Symposium on Application of Computers and Operations Research in the Minerals Industry (APCOM), Santiago, Chile, 24–27 April 2007. Magri, E.J.
(ed.). Gecamin, Santiago. pp. 105–112.
Lantuéjoul, CH. 1994. Non conditional simulation of stationary isotropic multigaussian random functions. In: Armstrong, M., Dowd, P.A. (Eds.), Geostatistical simulations. Kluwer, Dordrecht, The
Netherlands, pp. 147–177.
Lantuéjoul, CH. Geostatistical Simulations. Models and Algorithms. Springer-Verlag Print, 2002.
Berlin. ISBN 3-540-42202-1.
Leuangthong, O., McLennan, J.A., Deutsch, C.V., 2004. Minimum acceptance criteria for geostatistical
realizations. Natural Resour. Res. 13 (3), 131–141.
Millad, M.G. and Zammit, K.M. 2014. Implementation of localised uniform conditioning for recoverable
resource estimation at the Kipoi Copper Project, DRC. Proceedings of the Ninth International Mining
Geology Conference. Australasian Institute of Mining and Metallurgy, Melnourne. pp. 207–214.
Pan G. 1998: Smoothing effect, conditional bias and recoverable reserves. CIM Bull., 91, 81–86.
Ravenscrof P.J. and Armstrong M. 1990: Kriging of block models-the dangers re-emphasized. In: Proc.
22nd APCOM, Berlin, Germany, vol. II, pp. 577–587.
Rivoirard J. Introduction to Disjunctive Kriging and Non-Linear Geostatistics. Oxford, 1994.
Vann, J., Jackson, S., Bertoli, O., 2003. Quantitative kriging neighbourhood analysis for the mining
geologist—a description of the method with worked case examples. In: Dominy, S. (Ed.), Proceedings
of the 5th International Mining Geology Conference. Australasian Institute of Mining and Metallurgy, Melbourne, Australia, pp. 215–223.
Wackernagel H. 2002: Multivariate Geostatistics: an introduction with applications. Springer Verlag,
Berlin, Germany, 388 pp.