Determining the optimal orientation of ultimate pits for mines using fully mobile in-pit crushing and conveying systems

Ultimate pit limit determination provides the outline of the optimal pit for use in the mine design process. Ultimate pit limit determination for truck and shovel haulage systems can be completed with proven mathematical optimality. For fully mobile in-pit crushing and conveying systems, a new ultimate pit limit determination method must be developed that includes the additional constraints of a straight wall for the pit exit conveyor and regularly flat pit floors. One of the major steps in the new method is determining the orientation of the straight wall. A proposed method of achieving this using the mathematical concepts of convex hulls and bounding boxes is presented, with an explanation as to how it could be implemented in an ultimate pit limit determination algorithm. This method allows the determination of ultimate pit limits for fully mobile in-pit crushing and conveying with a straight wall oriented to provide the most value to the project.