Abstract
A fundamental component of the Definition Standards for Mineral Resources is the requirement that the material have “Reasonable Prospects for Eventual Economic Extraction” (RPEEE).
The first adoption of the RPEEE requirement by a widespread group was in 1997 as part of the Denver Accord meeting and has since become an international standard.
Mineral Resource statements are prepared for mineral properties that are at various stages in the mining cycle, ranging from the discovery stage, through to the production stage. Depending upon the stage of the mineral property, the level of certainty of information available for the development of the input parameters for the technical and economic components of RPEEE varies greatly; consequently, the RPEEE assumptions may evolve with the stage of the mineral property.
The economic aspects of RPEEE are commonly achieved by the selection of appropriate input parameters for the establishment of a cut-off grade. The technical aspects can include consideration of such items as minimum widths, spatial continuity, and the application of appropriate constraining surfaces and volumes.
This presentation shares some of the authors’ thoughts and experiences regarding how the RPEEE requirements can be achieved when preparing Mineral Resource estimates and statements using current computer assisted estimation work flows.