ارزیابی اقتصادی پروژه های استخراج معدنی از زمین های مورد بهره برداری در طول دوره عملیاتی

The exploitation of minerals from fields of exploitation can be treated as a separate investment project. Three stages of such a project should be considered during the decision-making process, the preparation of a field for exploitation, the acquisition of raw materials and the liquidation of the field following mining activities. During the implementation of these various stages, the evaluation of the economic efficiency of static and dynamic methods are taken into account in each of the stages. An essential element is also the evaluation of risks connected with the investment, this is a quantitative measure of the uncertainty of achieving specific objectives. The bases for the correct calculation of economic efficiency include: proper input data, including economic and technological aspects. This article highlights the necessity of an economic evaluation concerning the exploitation of fields during operational periods due to their recognition in higher categories and the ever changing mining and economic conditions. Such changes are analysed with economic efficiency of exploitation systems. The initial value of the project takes into consideration the time value of money proposed as a criterion of economic evaluation. Income and expenditure, which correspond to the liquidity of the company, are assumed as a basis for calculation. Net present value is presented as a sum of values regarding preparation period, exploitation and field liquidation.