Reasonable Prospect of Economical Extraction: Tools for Underground Mineral Resource Classification
The JORC and NI43-101 codes impose that mineralized material has a reasonable prospect of economical extraction to be classified as Mineral Resource. For deposits close to surface and amenable to open pit mining, it is easy to show reasonable prospect of economic extraction running a Lerch-Grossman optimization. The Lerch-Grossman pit provides a transparent and repeatable way of separating the Mineral Resource (within the pit) from the remainder of the mineral inventory (outside the pit). Deposits amenable to underground mining are more challenging because of the variety of the underground methods. AMEC developed a stand-alone software package that outlines the material which has reasonable prospect of economic extraction for open stoping, block caving, sublevel caving and room and pillar. The software is based on an improved floating stope algorithm for open stoping, and more sophisticated algorithms for the other methods. It takes a block model file in ASCII and exports a 3D surface in dxf format outlining the part of the mineralization that has a reasonable prospect of economic extraction, and which the Qualified Person can smooth out manually if required. It also exports the dollar value of each block, and, in the block caving case, the upper dilution cap above the block caving resources.
Resources, Economical Extraction, Mineral Resource Classification, Reasonable Prospect, software