Mineral resource sensitivity tables: Getting it right

Mineral resource statements published publicly are often accompanied by sensitivity tables that examine the degree to which the mineral resources vary with changes to the values of selected input parameters, most commonly metal prices. National Instrument 43–101 requires that each case presented in a sensitivity table must meet the reasonable prospects of eventual economic extraction requirement. The evolution of various software packages has increased the ease of preparing sensitivity tables. However, the workflows applied to create these tables can result in materially inaccurate results. This paper examines the impact of various common workflows on the preparation of mineral resource grade-tonnage sensitivity tables using three case studies of hypothetical gold deposits in open-pit and underground settings. The anticipated audience for this paper is primarily those practitioners and qualified persons who prepare sensitivity tables in support of mineral resource statements disclosed to the public. We anticipate that the concepts discussed will also be of interest to other industry colleagues who may refer to these sensitivity tables.