Research of Optimal Transition Depth in opencast-underground combined mining

An Uncertainty-based Transition from Open Pit to Underground Mining

There are some large scale orebodies that extend from surface to the extreme depths of the ground. Such orebodies should be extracted by a combination of surface and underground mining methods. Economically, it is highly important to know the limit of upper and lower mining activities. This concern leads the mine designers to the transition problem, which is one of the most complicated problems...

Optimizing the open pit-to-underground mining transition

A large number of metal deposits are initially extracted via surface methods, but then transition underground without necessarily ceasing to operate above ground. Currently, most mine operators schedule the open pit and underground operations independently and then merge the two, creating a myopic solution. We present a methodology to maximize the NPV for an entire metal deposit by determining ...

on the status of mixed methods research in applied linguistics

چکیده ندارد.

Underground Mining Transportation Systems

Living near opencast coal mining sites and children's respiratory health.

OBJECTIVES To answer the question whether living near opencast coal mining sites affects acute and chronic respiratory health. METHODS All 4860 children aged 1-11 from five socioeconomically matched pairs of communities close to active opencast sites and control sites away from them were selected. Exposure was assessed by concentrations of particulate matter with aerodynamic diameter < 10 mic...