ABSTRACT: Opencast mining is highly mechanized technological process which, due to low manpower, high production outputs and engagement of heavy-duty mining mechanization requires a very high consumption of power, spares and materials. Those facts indicate that rationalization of the consumption of power and materials requires specific attention in scientific senses.

SUMMERY:This essay systematizes all factors which may contribute to harmonization between functional dependence of the development of technology and consumption of power. A separate model is also proposed for analysis and monitoring of consumption of power which enables, to a maximum possible extent, adaptation of opencast mining of mineral materials to request of the 21st Century, which will be particularly rigorous from the aspects of consumption of power.

General prognosis that deals with the development of surface exploitation of coal in Yugoslavia, along with ecological issues also covers large energy and materials consumption in this field as a strong limiting factor. Such estimation is based on the ever increasing requirements for energy. spare parts and various materials that in surface exploitation of coal are growing with increase of the physical volume of production.

The complex analysis of the factors influencing consumption of energy and materials in the surface exploitation recognizes three groups of main factors such as natural. technological and organizational. The group of natural factors covers separation of deposits, relief of terrain, coefficient of overburden, physic-mechanical properties of the deposit, depth of mining, mineral materials quality and length of transportation roads. Technological factors include structural equipment design, project designs. installed power, method of excavation, loading and transportation, method of piling, development of excavated faces, useful value of mined materials and mineral processing. Quality mineral materials and the length of transportation roads can also be listed among the technological factors. The organizational factors are represented by: managing of process, qualification of stuff, maintenance of mechanization and monitoring the energy as well as material consumption.

Evaluation of the existing position of energy and material consumption at open pit mines in Yugoslavia under the stated influential factors, indicates that the possibilities for consumption are present. The consumption could be realized if the whole problem is thoroughly studied and if systematic monitoring, analyzing and planning all the standards as concerns the conditions characteristic for the open pit is provided for. The existing Yugoslav practice applied in the surface exploitation, the principles of planning and monitoring the energy and material consumption have not been regulated by the unique methodology. The principles of planning the material consumption have mainly been grounded on monitoring the empirical indicators. The data from previous years arc mostly taken and the consumption used is divided into the realized production and in a such a way the value of consumption per production unit is obtained. Such a way of planning the consumption permitted a constant struggle for achieving better results than during the previous year but it lacked professionally and scientifically defined methodology of real planning. Thus similarly the monitoring of energy consumption is carried out. While monitoring electric power consumption the data used refer to periodical control of such energy consumption and a comparison with the planned quantities was accordingly made, having in most cases quite a negative effect, as the adequate interventions failed when a large consumption was in question. Somewhat less complex system of evidencing was applied when monitoring fuel consumption, particularly in case of open pits having their own pump stations. Rarely, complex factors influencing the consumption of energy and material were analyzed such as the efficient technological processes and efficient organization of labor. Since recently, consumption of energy and material at open pits in Yugoslavia has become more actual.

Certain open pit mines initiate the study of a series of mutually interlinked issues concerning technology, efficiency and organization of production, thus overpassing the accepted principle that the planning standards are only based on the previously achieved consumption standards. Defining the modem methods of monitoring energy and material consumption might be considered as the general scientific-research direction in surface exploitation for the purpose of decrease in overall costs and better productivity.