Sand is a very important element used in the construction of any structures. As a building material, sand is formed under natural conditions and due to the influence of many natural factors. The conditions for its extraction directly depend on the conditions under which sand deposits are formed.
Sand is the smallest rock particles. It can be located both on the bottom of water bodies and on land, which makes up a considerable part of the surface. And for its extraction using completely different methods.
What is needed for mining
But in order to get sand from the bowels of the earth, you need not only trucks, dump trucks, a special dredger for sand extraction, but also a license for such activities in a certain place, since without it it is illegal. The license is needed for all miners, except for landowners in garden and household plots, as well as for enterprises that have launched mining in places on the border of the allotment of mountain and geological lands.
Sand mining methods
For each method of sand production, specialized equipment and methods are used.
The first method is dry mining. With this approach, sand is mined from the quarry. Here, characteristic methods and techniques are used for the open mining of any mineral resources. To begin with, wells are drilled, then loosened with explosives, and then loaded onto trucks and transported to combines and enterprises.
The second method involves the extraction of sand from the bottom of a reservoir (lake, river, shallow sea). In this case, a special design is used - a dredger for sand extraction. Also, as an option, you can use long-arm excavators, excavators with a pop-up bucket. However, such equipment is expensive, which affects the final price of the material.
Mining can also occur in wet conditions when using an alluvium hydraulically. This method does not require blasting and drilling. It has an advantage over competitive methods - the extracted sand is free from impurities.
Sand mining in shallow water
As noted above, a dredger is used to extract sand on rivers, lakes and shallow seas. The principle of operation is as follows: a device with pumping equipment sucks in sand, which is located at the bottom of a reservoir. Then it is loaded into the hold of the ship or on the barge. The most convenient for this method of extraction are dry ponds.
The sand dredger has a complex structure, which depends on the conditions of use. In particular, a scoop-type dredger is used if the soil at the site is harder. The extracted sand is immersed and transported to the place where it undergoes final cleaning of impurities.
Dredger construction
Sand dredger contains a mandatory list of structural elements:
- The case is a necessary part for fastening all the necessary mechanisms, it is also equipped with pontoons.
- Pile apparatus - an important component that ensures the movement of the dredger during the extraction of sand and soil.
- Deck superstructure - located in the central pontoon, has a cabin with the necessary equipment.
- The ripper is the main part of the soil-mining complex.
- Installation for transportation of soil. It consists of several elements, usually located in the hold. Main parts: soil pump, suction wire, drive, as a power plant and pressure wire. As a drive, a diesel, electric or diesel-electric drive is usually used.
- Arrow. It helps the mechanic control the depth of development as well as move the ripper. Thanks to the winch included in its base, the boom is raised and lowered.
- Water supply equipment. It has an auxiliary role in cooling, flushing and sealing pump parts.
As can be seen from the description, a sand dredger, the photo of which clearly confirms the complex design of the mechanism, is a whole complex of interconnected systems, the interaction of which greatly facilitates human labor and simplifies the production of material.
Dredger Features
Dredgers during operation should have some characteristics that allow you to perform work as efficiently as possible. For example, installation and dismantling of a dredger should be short-lived and simple. For quick movement, the machine must have a floating base, which can be quickly removed if necessary.
When choosing equipment, it is necessary to pay attention to the dredging coefficient of the dredger during the extraction of sand, the type of soil, the method of extraction and the capabilities of the mechanism. The main characteristic of a dredger is its productivity. This is a device in which many different functions are combined. With the coordinated work of the functions, maximum performance will be obtained.
Dredger Classification
These mechanisms are divided by the method of loading and transportation into:
- Dredging projectile - loading and moving is carried out due to pulp.
- Rock crushing - used to loosen rocky soils of various strengths.
- Scoop - this is a type of excavator machines that move and immerse the soil due to the scoop.
According to the method of transportation are divided into:
- Refuller. The clearance factor of a refractory dredger during sand mining is an important characteristic that affects the performance of a dredger. Transportation is carried out using the pulp line afloat.
- Shalandovy. Transportation with the help of scows - specialized ships that load soil into the hold and transport it to the port.
- Longucular. A long tray is used to move the soil, which sends it ashore or to a cargo ship.
- Self-transporting. Based on the name, the dredger loads the soil into its hold and takes it.
- With the ejection of pulp hydromonitor effect. It is used if work is carried out on river mouths, as well as on sea waters during hydro-washing.
By the method of working movement:
- Anchor - move due to built-in anchors.
- Self-propelled - movement due to the built-in engine.
- Pile - moving on piles.
- Pile-anchor - they use both anchors and piles.
According to the method of work are divided:
- Trench - the dredger forms sand trenches during sand mining, moving along the site.
- Papillonage - the dredger moves across it when developing a site.