Copper ore mining

The low content of copper and other non-ferrous metals in the ore (on average from 0.5% to 10%) determines the need for the extraction and processing of large volumes of rock mass.

For example, to smelt 1 ton of cast iron, it is necessary to extract on average 2-3 tons of ore, and to obtain 1 ton of copper, mining and processing plants need to process more than 200 tons of ore. Therefore, to ensure the specified production volumes, it is difficult to imagine the figure representing the amount of ore processed per year. However, despite the difficulties associated with large volumes of processed rock mass, the rate of copper mining and production is constantly increasing, which subsequently entails new trends in the exploration and development of new copper deposits.

Ore deposits located relatively close to the earth's surface are developed by open-pit mining; deposits located at considerable depths are developed by underground mining. The depth of open-pit mines reaches 150-300 m, individual mines have a working depth of about 600 m. Ore is mined underground at a depth of 500 m, and at individual mines the working depth reaches 800-1500 m. However, there are certain standards regulating the advisability of further deepening of quarries or shafts to continue mining. This is due to the fact that the conditions of mining operations become much more complicated, and the productivity of equipment decreases as quarries and shafts deepen.

In non-ferrous metallurgy, the open-pit method of mining ore raw materials has received preferential development, which is characterized by lower losses as the depth of the mined ore increases. But despite the advantages of the open-pit method of mining, the absolute volume of production in underground mines is also continuously increasing due to the need to involve deposits located at great depths in the operation.

Fig. 2. Kirovsky mine (Murmansk region)

Due to the different conditions of ore extraction, three main technological development systems are distinguished:

• using self-propelled equipment;
• with continuous work flow (use of continuous-action vibration mechanism complexes);
• with a hardening backfill of the mined-out space.

The technology with self-propelled equipment has found wide application in various versions of the room-and-pillar system at the mines of the Dzhezkazgan, Achisai and Norilsk plants.

For the development of powerful and medium-power ore bodies, a mining technology has been created that allows for the continuous release of ores from blocks using vibration equipment complexes with forced floor and sub-floor caving systems. This system provides the best indicators for the release of ore from a block (Zyryanovsky, Tekelisky and other plants).

The system with hardening and hydraulic backfilling ensures continuous extraction of reserves of powerful deposits with minimal losses. The use of such systems reduces losses and dilution by 3-4 times, which compensates for the costs of backfilling operations.

In order to more fully utilize the reserves of the subsoil, Russia, the USA, Canada, Australia and South Africa use a highly effective method of extracting ore in horizontal layers. When filling the mined-out space (in underground mines) with hardening mixtures, rubber-lined or basalt-lined pipelines are used, the service life of which is 50-100 times longer than that of ordinary steel ones.

In modern production, to increase labor productivity in deep quarries, it is necessary to switch to a cyclic-flow technology of mining operations, including selective extraction of ore on mining benches. The best results are achieved by taking into account the stratigraphic features of the occurrence of ore bodies, the optimal content of gas-forming components in the explosive, the appropriate location of blast holes and the consumption of explosives. A mine or quarry is an integral part of a unified ore quality management system of the complex: mining shop - processing plant.