An optimal determination of longwall panel dimensions

The optimal dimensions of a longwall panel are investigated using four different objectives of minimum average unit cost, internal rate of return, profitability index and present value of average unit cost. The two main variables, production and cost are analyzed into different parameters. Production and cost equations are developed and the four different objectives are expressed in the form of equations. These equations are solved and the plots of the results are included. A sensitivity analysis of the results is made by changing initial investment, project life, cycle time and cost of capital. If the objective of the decision maker is to minimize average unit cost, the optimum dimension of the longwall coal mining face in this study is in the range of 450 to 550 feet.