| The determination of mine design variables such as mine shaft locations, mine field dimensions, mine design capacity, and mine service life under various mining conditions is of primary importance to the economics of developing and subsequently operating an underground coal mine. However, the problem has received little academic attention in the United States. Solutions to the problem tend to be subjective and based upon personal experience and managerial judgment rather than objective and based upon some quantitative criteria.;In formulating the problem, relationships among mining costs, main shafts location, section production per shift, number of production sections in mines, mine output, and mine field dimensions were analyzed. Thereby, the unit cost of coal was expressed as a function of mine field dimensions, mine design capacity, and mine service life. The problem was then formulated as a nonlinear optimization model in terms of minimizing the unit cost of coal subject to certain constraints, and solved analytically for flat seams and numerically for inclined seams. Possible extensions of the formulation were also discussed.;The methodology developed in the research was intended to be an important step toward the increased application of quantitative methods in designing underground coal mines. The results obtained from the study are expected to serve as useful aids in establishing logical mining units (LMU) or dividing a deposit into blocks for development, locating mine shafts within a mine field, planning annual mine production rates, and projecting the lifetime of an underground coal mine.;The purpose of this research was to conduct a quantitative study on the problem of evaluating these mine design variables and to develop a mathematical modeling approach that permits a quantitative determination of the design variables and facilitates the analysis of effects of input parameters such as seam angle, seam thickness, seam depth, underground traveling speed of men, mine recovery, plant recovery, average productivity, and interest rate on the size of underground coal mine operations and the unit cost of coal. |
