Main reason for exploration of mineral deposits is their disintegration from their natural environment by underground mining methods. Therefore, even initial, preliminary geological exploration entails the existence of a “project” for the construction of the mine. The first phase of a life cycle of the mine is feasibility. Feasibility study is an engineering study based on research and analysis, which gives enough information in order to make a decision to continue work on the "mine construction project". Feasibility study can have multiple levels of complexity and reliability of assessments made, according to the number and reliability of data used for its production. The first level of feasibility study, Conceptual study (scope study or order of magnitude) is based on assumptions and on the small number of research papers and information about the deposits, when there is not enough data yet to define a mineral resource. This study defines a rough general design of the future mine with rough estimate of capital and operating costs. Default error of this assessment is ±40%. Based on this study mineral resource cannot be translated into mineral reserves, but the decision about continuing or suspension the exploration can be made. Prefeasibility study is a inter-step in project evaluation. Usual default error of this assessment is ±25%. Main purpose of this study is to determine mining method and mineral processing technology, to estimate operating and capital costs as well as the influence on the environment. Often, several variants can be analyzed in order to have their comparison. Best variant is selected and will be developed in more detail in next phase. Geotechnical study for mine and tailing dams is often included in this study. Very important task of this study is to identify open problems in the project and to define additional research and exploration necessary for them to be resolved in the next phase. Very often, based on this study treated resources can be translated into reserves.
Minerals Council of Australia, 2014
Basically, Feasibility study is worked out prefeasibility study. Key components of this study are design of the mine, production plan, detail scheme of the processes, plan of the enterprise, resolving problems of environmental protection, detailed assessment of operating and capital costs, as well as a complete economic model of the project. This study produces enough data for the mineral resources to be translated into mineral reserves and based on it the decision about constructing the mine or suspension of the project can be made. Only few of the projects survive Conceptual study, about 50% are active after prefeasibility study and about 20% of the projects are dropped after detailed feasibility study. The second phase of a life cycle of the mine is detailed elaboration of the mine design project. In this phase main project of exploitation is made and it has all the necessary technical projects, such as: technical project of mine opening, excavation, servicing, transport, ventilation, dewatering, mineral processing, industrial and commercial buildings, etc. In this phase an assessment of the impact of exploitation on the environment is made as well as a re-cultivation project. Upon drafting listed and other technical, economic and legal documentation the conditions for acquiring the Exploitation Rights and the license for exploitation of the mineral deposit are met . The third phase includes the construction of the mine based on and in accordance with drafted project documentation. The objects of opening the mine are constructed (shafts, adits, ramps, workshops, storages, water collectors, etc.). Parallel to this industrial and business objects, processing plants with tailing dams are constructed, etc. Fourth phase is the exploitation of the mineral deposit in the way specified in the project. Prior to excavation, the development is carried out in accordance with the mining method. This is the longest phase and depending on the size of the deposits and annual capacity, it is often 10 years or several decades, sometimes more than 100 years. During this phase the exploration of the mineral deposit proceeds deeper and laterally. The fifth phase is mine closure, permanently or temporary, that can happen because of depletion of deposits or changes in market conditions that prevent profitable operations over a longer period of time.