Sand and gravel can be seen everywhere in our production and life. It is a precious natural resource and plays an important role in engineering construction. With the growing demand for sand and gravel, natural sand and gravel are beginning to face the pressure of resource reduction and environmental protection. Since natural river sand and sea sand are no longer available resources, in order to achieve sustainable development and environmental protection, it is inevitable that machine-made sand will replace natural sand as construction sand in the future. How to deal with a large amount of mud and sewage after sand washing?
The traditional mud treatment process uses a sedimentation tank to treat the mud, pouring it into the sedimentation tank for natural air drying. The natural air drying method through this sedimentation tank is easily affected by the weather, and it takes a long time to complete the air drying process. This is time-consuming and space-consuming. If the terrain does not allow, it will cause secondary pollution to the surrounding environment, and it cannot fully meet the standards for recycling or discharge. And the large amount of sludge that has settled needs to be cleaned regularly, because the sludge is fluid, and it will cause environmental pollution to the production site when it is cleaned with a loader.
In the entire sand washing process, sand washing machines, fine sand recovery machines, and vibrating dewatering screens have become indispensable equipment for each sand field. However, many sand fields often do not pay enough attention to the treatment of muddy sewage after sand washing. The muddy sewage from sand washing is discharged without treatment or directly discharged into the nearby river, causing water pollution, disrupting the natural balance of water around the river, aggravating the collapse of the coastline, and posing a major hidden danger. This also makes the river shallower, increasing flood disasters during the rainy season. So how to deal with the large amount of muddy sewage after sand washing?
Most of the current sand field sewage treatment equipment uses filter presses, concentration tanks, dosing systems, and clean water recovery pools. The common filter presses in sand washing fields are mostly plate and frame filter presses, which are suitable for the dehydration of tailings mud such as iron ore, copper ore, lead-zinc ore, fluorite ore, bauxite or rare earth ore. Ceramics, petroleum, medicine, food, smelting and other industries are also suitable for industrial filtration sewage slurry treatment, etc. Through plate and frame extrusion, the material is intercepted by the filter medium to form a filter cake and discharged from the filter chamber, so that the water in the sludge is discharged through the filter cloth to achieve the purpose of dehydration. The mud cake squeezed out by the plate and frame filter press has a low moisture content, which is convenient for later transportation and treatment.
The concentration tank is used in conjunction with the dosing system. When using polyacrylamide flocculants in sand washing plants, users cannot directly add them to sewage. They must be dissolved in water before use and use their aqueous solution to treat sewage. The water used to dissolve polyacrylamide flocculants and polyaluminium chloride coagulants should be clean water (such as tap water) and not sewage. Water at room temperature is sufficient. Generally, heating is not required. Water temperatures below 5 degrees dissolve very slowly. The dissolution rate increases with increasing water temperatures, but temperatures above 40 degrees will accelerate the degradation of the polymer, affecting the use effect. Once the temperature exceeds 60 degrees, it will become ineffective.
Production practice in recent years has proved that the filter press and concentration tank produced by Heside Environmental Protection Equipment have a good effect on the treatment of sand washing sludge sewage. The filter press can make the sludge into cakes. The flocculant added to the concentration tank can accelerate the sedimentation of the sediment in the water, and help the filter press production of the subsequent filter press equipment, ensuring that qualified return water is used for circulating production, so that the production is stable and economical. Based on past experience, a specific implementation plan for treating the large amount of sludge and wastewater after sand washing has also been summarized.
