Abstract
In practice, blocks are selected according to their estimated value and not according to their true unknown value. In order to avoid serious errors in calculating a grade-tonnage curve, we must be able to define clearly the relationships existing between estimates and the corresponding true values. This leads to study in details the following distributions:
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— the in situ distribution of true block grades.
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— the distribution of estimated block grades.
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— the joint distribution of true and estimated grades.
It is shown that to forecast correctly the average grade of the selected ore, conditionnally unbiased estimators should be used. However, since we work on estimates, some losses in profitability will necessarily occur. Finally the paper indicates briefly how to forecast grade-tonnage curves at an early stage of the mine development when complete information is not yet available.
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References
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© 1976 D. Reidel Publishing Company, Dordrecht—Holland
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Huijbregts, C. (1976). Selection and Grade-Tonnage Relationships. In: Guarascio, M., David, M., Huijbregts, C. (eds) Advanced Geostatistics in the Mining Industry. NATO Advanced Study Institutes Series, vol 24. Springer, Dordrecht. https://doi.org/10.1007/978-94-010-1470-0_8
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DOI: https://doi.org/10.1007/978-94-010-1470-0_8
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