Long-Range Mine Planning At Gibraltar Mines Limited

CIM Bulletin, Vol. 70, No. 786, 1977

T. E. Milner, (at time of writing) — Senior Mine Engineer, Gibraltar Mines Limited, McLeese Lake, B.C.

The optimum design and sequencing of interior-stage pits and the selection of operating parameters, such as the mining rate, cut-off grade, metal price, etc., are interdependent factors that must be considered to achieve a maximum-profit mine plan. Long-range mine planning at Gibraltar is further complicated in that the property consists of four separate orebodies. This paper discusses the package of computer programs implemented at Gibraltar for the development of long-range mine plans. A Lerch-Grossman three-dimensional pit design program is used for pit design and sequencing of interior-stage pits. A mine simulation program is used to produce production schedules and open-pit mining equipment requirements. Discounted-cash-flow techniques are used to evaluate alternate mine plan schedules. Areas under consideration for further expansion of the computer mine design package will also be discussed.

Keywords: Open-pit mining, Gibraltar Mines Ltd., Mine planning, Computers, Pit design, Bench plans, Simulation.