Technologies

Extraction of sea-sand is performed from the deposits located in the water area of the Gulf of Finland in the Baltic Sea with the help of sea dredge ships of the type of “Leningradskiy”, which are custom-made ships especially built for extraction of sea-sand from a depth of more than 30 metres. The “Leningradskiy” dredge ship is capable of loading within an hour more than 2.3 thousand cubic metres of sand. The design of the ship allows loading at both the boards to be performed simultaneously.

Transportation of sand is performed by motor vessels of the type of “Nevskiy”, related to decantation type vessels. A motor vessel transports 3.0 thousand tons of sand at a speed of 10 knots and has a draught of less than 3.8 m, which also allows the cargo to be delivered to on-shore objects of construction.

Processing of the produced sea-sand is performed at three extraction sites located in various districts of Saint-Petersburg. Unloading of the sea-sand into warehouses is performed via slurry pipelines with the help of hydraulic loaders, which also allows its.

Extraction of sand for construction is performed by two methods. After removing the overburden with the help of powerful mining engineering, excavation of mountain sand is performed, and the sand is widely used in all kinds of construction. Extraction of sand from irrigated layers of deposits is carried out with the help of a hydraulic mechanised method, using powerful mine pump dredges. This technology not only allows extraction to be performed efficiently, but also allows the sand to be cleaned to remove natural inherent admixtures, which enhances its qualitative characteristics substantially.

In 2005, for the first time in the history of hydromechanization of the North-West of Russia, the process of winter-time alluvion of sand was performed. For the purpose of organisation of the production of winter-time alluvion, a number of new engineering solutions were adopted: in the field of mine formation, optimisation of the operation of slurry pipelines and drainage systems, and formation of lagoons. Winter-time alluvion allowed an increase in the volume of extraction of pit aggradational sand and additionally allows an uninterrupted supply of aggradational sand to be delivered in the volumes required by the consumer