OPTIMIZATION OF PRODUCTION PLANNING IN UNDERGROUND MINING A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF BACHELOR OF TECHNOLOGY IN MINING ENGINEERING BY KWANGWARE TAPIWA (R199302G) Under the guidance of DESIRE RUNGANGA DEPARTMENT OF MINING AND MINEAL PROCESSING ENGINEERING MANICALAND STATE UNIVESITY OF APPLIED SCIENCES Introduction Mine production scheduling is an important problem in mine planning (Gershon, 1983). Main objective of the production scheduling is to maximize cash flow and it is also the main objective of all the mining industries. Before the use of computers in planning, it was done manually and based on the sections and graph created by the persons, this work takes a lot of time and is bit tedious and efficiency also depends on the individuals. But now days, operation research techniques are used to define or optimize any process or activities (Newman et al., 2010). These techniques are faster and more work is being carried out to decrease the computational time. Solutions obtained from these techniques are close to the real . Notable constrains at Golden valley mine include, • The cost of development is increasing with depths • Inconsistent production schedules • Decreasing of mineral grades as we mine deeper • Increasing costs of ventilation • Unplanned dilution • Increasing costs of transportation and hoisting ores • Failure to meet production targets Problem statement The current underground stope, access layout optimization and production scheduling algorithms in practice at Golden Valley Mine lack the ability to deal with real world large scale complex underground mine planning problems. Algorithms and solvers available do not integrate production scheduling with stope layout optimization. This uncertainty has subsequently led to uncertainty in the LOM. Largely, there are discrepancies in planning projected values before extraction and actual values after milling, leading to disputes between the respective departments. Justification There is need to digitalize and compute mine planning optimisation because the existing planning strategy has become irrelevant in the following way: Nature and value of costs has changed from 2011. o According to Figure 1-5, gold price has been fluctuating significantly from 2011. Figure 1-5 Gold Price Trends 2011-2017 (Source: London Fix Historical Charts, 2017) To maximize the profitability of mining operations, an integrated optimized stope layout , access layouts and production schedule is required to coordinate underground mining activities such as development, extraction, haulage and processing. Aim This project sets to use mineable shape optimizer which can solve complex and nonlinear processes that would otherwise be difficult for empirical models to perform o o To have a schedule strategy to assist determine how and when to mine a designed stopes To generate non-linear programming used to maximise the overall economic value subject to the constraints of generating optimal stopes and access layout, which is solved by a Genetic Algorithm modified for computational efficiency , that is consistent with modern day operation and market parameters. Objectives • To assess the current empirical models used on stope layout design and production scheduling • To optimally design stopes for open stoping method based on constraints of stope extraction angle and stope height • To do production scheduling of the generated stopes by applying heuristic approaches . • to provide a feasible starting point for stope design. • to conduct a cost benefit analysis
