From exploration to commercial mining operation
The road from initial exploration to the production and sale of commercial products is long. Below is a description of the different elements of a project from prospecting to mining. The time from the selection of an exploration area and prospecting to mining production is estimated to be at least 10 years for a project that develops positively and undergoes all development steps according to the figure below.
The ore exploration process includes prospecting, followed by exploration, project studies, and a profitability analysis. The aim of the exploration is to identify the potential ore-rich areas and determine the resources contained therein.
Prospecting and selection of study areas
The prospecting phase targets areas with favorable geological conditions in which the possibilities of discovering ore deposits are estimated good. Prospecting work includes collecting geological, geochemical and geophysical data from the selected area. This information is then compiled and analyzed, and based on the achieved results it is estimated whether the area can be considered ore critical.
If the prospecting phase is successful, the exploration process continues to the next level. In the area estimated to be ore critical a geological mapping will be carried out, including boulder hunting and geophysical land surveys with various methods. Till and other rock samples are taken to assay.
These study methods act as a foundation for the first test drilling program. If the results of this initial study are positive, the most expensive phase of the exploration involving detailed and systematic core drilling may be carried out. This enables creating an estimate of the size and concentration of the mineralization and classifying the mineral resource as either measured or indicated according to the recognized standard.
On the basis of this study, if estimated that the resource is economically extractable, the ore will be examined mineralogically and metallurgically, and considering the beneficiation processing techniques in order to decide if a complete economic feasibility study is needed.
Classification of mineral resources and ore reserves
Endomines has decided to report the mineral resources in accordance with the Australian JORC code or the Canadian National Instrument (NI) 43-101. The Swedish and Finnish organizations in mining industry, SveMin and FinnMin, support these standards.
The classification rules in question are based on an entirely transparent sampling and assaying that can be repeated if necessary. The assays must also be carried out by an accredited, independent laboratory and the results controlled by another independent laboratory.
The drilling and sampling density must be appropriate to the ore type in question. For instance, massive sulphide ore or ilmenite ore can be considered as ore reserves with 50 meters’ section spacing with the help of geophysical survey. In principle, gold ore can never be considered as ore reserve if the drill hole or drill section spacing and sampling density exceed 20 meters because the shape of a gold ore occurrence is often irregular and its grade varies. Gold usually exists in irregular veins, and the continuity of the grade seldom follows geophysical surveys.