Analysis of the Kovdorsky open pit operation over the last 5 years has shown that the volume of the blasted block varied widely (from 30 to 130 thousand m³), with its average value for rock decreasing by 22.4 thousand m³ (from 55.6 to 33.2 thousand m³) and for ore by 28 thousand m³ (from 51.5 to 23.5 thousand m³). Carry over reserves of blasted rock mass also fluctuated significantly; its maximum reserve in 1967 1968 reached 780 800 thousand m³, and in 1969 amounted to 840 thousand m³, while the minimum reserve in 1965 was 270 thousand m³, and in 1967 and 1968 it was 520 and 500 thousand m³, respectively.