Yazar "Dalgic, Abdurrahman" seçeneğine göre listele

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    The optimization of cut-off grades by means of memetic algorithms
    (Polska Akad Nauk, Polish Acad Sciences, Miner & Energy Econ Res Inst Pas, 2022) Cetin, Erhan; Dalgic, Abdurrahman
    Cut-off grades optimization is a fundamental issue for mineral deposits. A cut-off grade is any grade that is used to separate two courses of action; to mine or not to mine, to process or to dump. In order to achieve the maximum discounted cash flow, generally a decreasing order of cut-off grades schedule takes place. Variable mining costs are applied to the extracted material, not to all of the depletion rate as some of the depletion can be left in-situ. Because of access constraints, some of the blocks that have an average grade less than the determined cut-off grade are left in-situ, some of them are excavated and dumped as waste material. The probability density function of an exponential distribution is used to find the portion of the material below the cut-off used that is left in situ. The parts of a mineral deposit that are excavated but will be dumped as waste material and tailings of ore incur some additional cost of rehabilitation. The method of memetic algorithms is a very robust optimization tool. It is a step further from the genetic algorithms. The crossover, mutation and natural selection behavior of the method ensures it escape from a local optimum point, and a further local search improves the optimum further. This paper describes the general problem of cut-off grades optimization, outlines the use of memetic algorithms in cut-off grades optimization and further extension of the method including partial depletion rates and variable rehabilitation cost. This paper is the first application of memetic algorithms to cut-off grades optimization in this context.
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    Öğe
    The use of dynamic programming in optimisation of cut-off grades and different depletion rates together with rehabilitation cost
    (Taylor & Francis Ltd, 2025) Cetin, Erhan; Dalgic, Abdurrahman
    Cut-off grade for a mineral deposit is a grade that is used to classify the material as ore or waste. In order to get maximum profit from a mineral deposit, an optimum schedule of cut-off grades must be used. This paper describes the use of dynamic programming in cut-off grades optimisation and further extension of the method regarding with depletion rates and rehabilitation cost. Partial depletion rates have been used for calculating mining and rehabilitation costs. The software developed in this work guarantees the global optimum for different depletion rates.