Open pit to underground mine transition - no simple recipe!

摘要

Mine projects are complex businesses that demand a constant assessment of risk. This is because the value of a mine project is typically influenced by many underlying economic and physical uncertainties, such as metal prices, metal grades, costs, schedules, quantities and environmental issues, among others, which are not known with absolute certainty. For a given deposit, the selection of particular working method is done based on the site-specific geo~ mining parameters and the prevailing techno-economic environment. Generally, the shallow deposit developed into surface mines and deep deposits are worked by underground mining methods. Today, the open pit mining operations take place in a continually changing environment and presently, there are many deposits that have the potential to be mined by a combined method of open pit and underground. Particularly, the present global demand for base metals, combined with diminishing near surface resources, has influenced a number of deep, open pit mining operations to consider the transition to underground mass mining operations to recover the deeper reaches of an ore body extending the life of the operation. Here, the author discusses the parameters which influences the expansion of any operating deep open pit mine and also to highlight the difficulties, constraints and considerations associated with transition which can be used to generate a discussion on this very important subject of the future for the general education of one and all.