The Increment Extraction Error during Exploration and Mining

Recovery problems when drilling during exploration programs is a well-known concern by geologists all around the world. Such problem is typical of an extraction problem when the drilling bit is selective on what it takes. The Increment Extraction Error IEE could have been called the Increment Recovery Error. When drilling orebodies, IEE is probably responsible for one of the most important sources of bias during geochemical exploration, ore reserve estimations, feasibility studies, and grade control at mining operations. This extraction error takes place every time a fragment with its center of gravity within the boundaries of the correctly delimitated core, is pushed outside these boundaries for some reason and not part of the actual fragmental core. The problem may also be reversed for fragments having their center of gravity outside the ideal boundaries but, for some reasons, are pushed inside, thus contaminating the actual fragmental core.