At the present, China has strictly prohibited river sand mining, so the only source is machine-made sand from stone and gravel. What is manufactured sand? Simply speaking, it refers to sand produced by machines. This sand is more regular and can be processed into different sizes to meet daily needs. Its sources are mainly mountain rocks, river pebbles and so on.
The typical production line is: crushing - ball milling - sand washing - sludge dewatering by plate frame filter press - fine sand recovery - finished sand. Finally the stones become construction sand with various particle sizes. This type sand has uniform particle size and high strength, so it can improve the quality of constructions. Under the trend of environmental protection, the sand gravel wastewater treatment is particularly important.
After physical flocculation and precipitation, sand washing waste water can be recovered and can realize taling's dry stack. In details, after the gravel wastewater flows out from sand washing machine, it directly flows into the thickener. At the same time, coagulant will be mixed with the sewage. Then solids quickly precipitate and form a high-concentration slurry. The supernatant will overflow away, and finally will be recycled or directly discharged. Then the thicken mud, at the bottom, is pumped into the chamber filter press by a filter press pump for sludge dewatering. In the end, the dry stack tailings (DST) is realized, and this is beneficial to the ecological environment.