When using concepts such as "mine", "mine" and "mine", usually there is no difficulty in determining whether an object belongs to the extraction of a type of natural minerals. And what is a quarry? Is it also an artificial industrial facility or is it a natural deepening?
Definition
A quarry is an artificially formed excavation in the surface of the earth's crust for the extraction of an underlying layer of natural resources by the open sampling method. As a rule, it has a funnel shape, tapering downward. The territory is limited by educated planes. At the initial stage of development, the topsoil is removed and moved outside the production zone.
The concept of “quarry” arose from the word carriere borrowed from the French language, which was used to designate the places of extraction and processing of natural stone. It can also be used to highlight the specialization of an enterprise whose activities are related to open-pit mining of natural resources.
Varieties
Production in a closed way without removing the top layer is usually called a mine. In open pit mining, the term cut is used. In the development of minerals for the extraction of metal ores and crystals, the concept of a mine (a mine) is more common.
For all cases, it can be said that the quarry is an open-cast mining for industrial sampling of rock lying in depth. Depending on the deposit, it can be sand, clay, gravel, limestone. The extraction of fossil fuels is carried out in peat, shale, coal quarries. For the chemical industry, samples are made to extract phosphites, apatites, sulfur, arsenic and other salts from the bowels of the planet. From non-metallic materials, quarries for the extraction of alabaster, talc, and mica can be distinguished.
Metals are mined from ore. Its extraction is most often also carried out by the quarry method. This is how raw materials are produced for the production of ferrous metals (iron, manganese, chromium) and non-ferrous (copper, zinc, tin). The same principle is used to select ores of noble, radioactive and rare-earth metals. A mining and processing plant is usually built near such deposits.
Granite mining
The method of opening depends on the nature of the field. Usually use a vertical trench directed inside the mine. The peculiarity of the quarries is that the material goes to the production of facing stone and blocks. The main task is to maximize the safety of the monolith of the extracted blocks.
Granite has the property of cracking along the plane of occurrence of the rock. This feature is used for wedge mining. Apply several technological methods. The simplest is drilling a well with subsequent laying of explosives. During blasting, the rock is opened. Large pieces go on cutting plates. The disadvantage of this method is the large amount of waste that goes to rubble. In large parts, the likelihood of microcracks that occur during processing increases. A more gentle method is the injection of compressed air into a borehole, which leads to cracking of the formation.
Granite quarries at the preparation stage during field development are cheaper than marble ones. But in the process of development due to complex technology, the cost of production increases. The best results in terms of product quality are obtained by cutting the rock layer immediately into blocks. But this is the most expensive option.
Sand quarry
Intensive construction requires a lot of concrete. Sand is an indispensable component in its composition.The presence of deposits of this material at a shallow depth in the immediate vicinity of the city limits has a positive effect on the cost of construction. When evaluating the field, the chemical composition (SiO content) is taken into account2), the presence of impurities, refractoriness, rock structure, its physical and mechanical properties.
The shallow depth of the deposit makes it possible to open the field with wheeled vehicles: scraper, bulldozers. Sampling is carried out by draglines, bucket excavators, and transportation - by road. Sand quarry is a relatively shallow mine (up to 15 m). The peculiarity is that the material is bulk. It is not possible to ensure the stability of the front dumps because of the danger of collapses. Another feature is the likelihood of flooding by groundwater, which involves their diversion or the use of “wet” production technology.
