Sand is a very important element used in the construction of any structures. As a building material, sand is formed in natural conditions and due to the influence of many natural factors. The conditions under which sand deposits are formed directly affect the methods of its extraction.
Sand is the smallest particles of rock. It can be located both at the bottom of reservoirs and on land, which makes up a large part of the surface. And they use completely different methods to extract it.
What is needed for mining
But in order to extract sand from the bowels of the earth, not only trucks, dump trucks, a special dredger for sand extraction are needed, but also a license for such activities in a certain place, since without it it is illegal. All miners need a license, except for landowners of garden and household plots, as well as enterprises that have launched mining in places on the border of mining and geological land allotment.
Methods of extracting sand
Specialized equipment and methods are used for each sand extraction method.
The first method is dry mining. In this approach, sand is extracted from a quarry. It uses characteristic methods and techniques for open-pit mining of any minerals. To begin with, they drill wells, then loosen them with explosives, and only then they are loaded onto trucks and transported to factories and enterprises.
The second method involves the extraction of sand from the bottom of a reservoir (lake, river, shallow seas). In this case, a special design is used - a dredger for sand extraction. Also, as an option, you can use long-arrow excavators, excavators with a throw-out bucket. However, such equipment is expensive, which affects the final price of the material.
Also mining can take place in wet conditions using alluvial hydraulics. This method does not require blasting and drilling. It has an advantage over competitive methods - the extracted sand is free of impurities.
Shoal sand mining
As noted above, on rivers, lakes and shallow seas, a dredger is used to extract sand. The principle of operation is as follows: a device with pumping equipment sucks in the sand that is at the bottom of the reservoir. Then it is loaded into the hold of a ship or onto a barge. The most convenient for this method of extraction are dried-up reservoirs.
The sand dredger has a complexdesign, depending on the conditions of use. In particular, a bucket-type dredger is used if the ground on the site is harder. The extracted sand is loaded and transported to a place where it undergoes final cleaning from impurities.
Dredger design
The sand dredger contains a mandatory list of structural elements:
- The hull is a necessary part for attaching all the necessary mechanisms, it is also equipped with pontoons.
- The pile machine is an important component that ensures the movement of the dredger when extracting sand and soil.
- Deck superstructure - located in the central pontoon, has a wheelhouse with the necessary equipment.
- The cultivator is the main part of the tillage complex.
- Installation for soil transportation. Consists of several elements, is placed, as a rule, in the hold. Main parts: soil pump, suction wire, drive, as a power plant and pressure wire. The drive is usually diesel, electric or diesel-electric drive.
- Arrow. It helps the mechanic to control the depth of development, as well as move the ripper. Thanks to the winch, which is its basis, the boom is raised and lowered.
- Water supply equipment. Has a supporting role in cooling, flushing and sealing pump parts.
As you can see from the description, sand dredger, photowhich is clearly confirmed by the complex design of the mechanism, is a whole complex of interconnected systems, the interaction of which greatly facilitates the work of a person and simplifies the receipt of material.
Dredger Specifications
Dredgers during operation must have some characteristics that allow them to work as efficiently as possible. For example, the installation and dismantling of a dredger should be short and simple. To move quickly, 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 dredge clearance coefficient when extracting sand, the type of soil, the method of extraction and the capabilities of the mechanism. The main characteristic of a dredger is its performance. This is a device that combines many different functions. With the coordinated work of the functions, maximum performance will be obtained.
Dredger classification
These mechanisms are divided according to the method of loading and transportation into:
- Dredging projectile - loading and moving is done by pulp.
- Rock crushers - used for loosening rocky soils of various strengths.
- Scooter is a kind of excavator machines, they move and immerse the soil due to the scoop.
According to the method of transportation, they are divided into:
- Refull. The coefficient of clearance of the refuller dredger in the extraction of sand is an important characteristic,affecting the productivity of the dredger. Transportation is carried out with the help of slurry afloat.
- Scow. Transportation with the help of scows - specialized vessels that load the soil into the hold and take it to the port.
- Longcucular. Used to move the soil a long tray that sends it to the shore or to a cargo ship.
- Self-propelled. As the name implies, the dredger loads the soil into its hold and transports it.
- With pulp jet effect. It is used if the work is carried out at the mouths of rivers, as well as on sea waters with hydraulic reclamation.
By the way of working movement:
- Anchor - move due to built-in anchors.
- Self-propelled - movement due to the built-in engine.
- Pile - moving occurs on piles.
- Pile-anchor - they use both anchors and piles.
Divided according to the method of work:
- Trench - when extracting sand, the dredger forms trenches, moving along the site.
- Papillon - the dredger moves across it when developing the site.
