FURTHER EXTRACTION OF ORE DEPOSITS BY UNDERGROUND MINING IN THE PIT INFLUENCE ZONE

摘要

The rational utilization and comprehensive exploitation of the mineral deposits is the basis for the growth of the mining industry and for the expansion of the economic potential of any country. But the present economic crisis that is affecting the East European countries, including the countries newly formed after the collapse of the USSR, is forcing us to include in the processing cycle the reserves of only the richest segments of the mineral deposit. This makes it possible for the mining enterprises to survive in the present difficult economic conditions. However, the selective exploitation of the segments of the deposit that are rich with regard to the content of the useful components leads to change of the stress-strain state of the undermined rock mass, which must be considered in the further extraction of the remaining ore reserves. Therefore the main task at the present time in planning the working of the deposits of the useful minerals is the rational utilization of the deposit ore reserves with subsequent further mining when the economic crisis eases. These questions were considered in preparing the working plan for the further mining by the underground technique of the reserves of the Alpys (Kazakhstan) deposit.The Alpys deposit has been mined by the surface technique since 1979. At the present time because of the large lag in the overburden operations (about 4.7 million m~3 from the planned contour), and also in connection with the current economic situation of the enterprise, operations in the pit have essentially been stopped at the 190 m level. On the basis of the data of a survey made of the AO "Maikainzoloto" enterprises by the specialists of Giprotsvetmet (State Institute for the Planning of Nonferrous Metallurgy Establishments) in September of 1997 under contract with the firm "East Point Holdings", the preliminary Technical/Economic Calculations were performed, on the basis of which the feasibility was determined of further mining of the remaining reserves of the deposit by the combined (surface and underground) technique. It was proposed to work the upper part of the remaining reserves by the surface mining technique, and the lower part by the underground technique.