an open-cut operation for mining coal, ores, and nonmetallic materials. In the coal industry the quarry is called a pit, and in ore mining it is sometimes referred to as a mine. The word “quarry” is also used for the excavations created by open-cut operations.
In a quarry the work includes excavating, transporting, and unloading minerals, overburden, and covering and enclosing deposits. The aim of the mining is to fulfill the plan quotas for extracting minerals and to create mineral reserves ready for excavation. A notable feature of a quarry is the continually changing work area. Modern quarries are highly mechanized, with machines and equipment for breaking down, removing, transporting, and storing any rock. The basic production units of small quarries, which mine nonmetallic building materials, are the mining shop (section) and the mineral processing shop. In the large coal and ore open-cut mines, the units include territorial sections or specialized shops (for example, drilling, blasting, cutting-loading, and transport). In addition, the quarry or open-cut mine includes auxiliary and subsidiary shops and sections. In ore mining the open-cut mine itself is frequently a shop of the mining-concentrating or metallurgical combine (such as the NoriPsk Mining-Metallurgical Combine and the Krivoi Rog mining-concentrating combines).
A complex of mine excavations is involved in working the rock in benches. The rock cutting within the benches is carried out in sequential strips—that is, passes of the excavators along the faces of the benches. The upper benches are done before the lower. In working horizontal deposits, the depth of the quarry or mine is fixed, and the advance of the benches leads to an increase in the size of the quarry, with the overburden usually being returned to the dug-out area. Mining work in sloping or steeply tilted deposits necessitates the deepening of the quarry or mine and the creation (cutting) of new benches by digging cross section trenches. In this case the working of the above-lying benches must advance more rapidly. Sloping major trenches are made for providing transport between the surface and the faces in the mine. Planning the construction of the quarry or mine includes providing for the stripping and cutting of benches along the deposit, with the benches in the capping overburden being worked more rapidly than the benches below, and the construction of access transport arteries as well as production buildings and housing.
The depth of individual quarries and mines in the USSR (1970) reaches several hundred meters (for example, the Kor-kino Mine of 300 m), and the planned depth of a number of mines is 500-700 m. The productivity of the large quarries and mines in the USSR is tens of millions of tons of ore per year (for example, the open-cut mine of the southern mining-concentrating combine, or IuGOK, and the northern mining-concentrating combine, or SevGOK, in Krivoi Rog). In 1972 coal and ore mines were being designed to produce 40-50 million tons annu ally for the mineral and over 100 million tons for the overburden.
IU. I. ANISTRATOV