The traditional tailings storage method is no longer suitable for today's environmental requirements, and it occupies a large area and has high operating costs. The commonly used tailings treatment method nowadays is tailings dry stacking, and the core of tailings dry stacking technology is to use different combinations of dewatering equipment for tailings dewatering. Today we will introduce a high-frequency screening technology for mineral processing, which corresponds to an high-frequency dewatering screen .
1. Equipment composition: high-frequency dewatering screen +high-efficiency concentration cyclone group+tailings pump tank+slurry pump.
2. Workflow: Low concentration tailings enter the tailings pump tank, and are pressurized by the slurry pump to be supplied to the cyclone group for pre concentration. High concentration tailings enter the dewatering screen for dewatering, and dry tailings are stacking from the screen. Water is stacking from the screen into the tailings pump tank for circulating filtration, and the overflow water from the cyclone enters the thickener.
3. Operating data: Taking Xinhai equipment as an example, the dry stacking rate of tailings reaches over 80%, and the moisture content on the screen is less than 18.5%, meeting the design requirements.
4. Operating cost: Taking Xinhai VD9 dewatering screen as an example, the unit price per ton of operating cost is 1.13 yuan/t, which is lower than the cost of long-distance tailings transportation and tailings pond operation management.
5. Efficient Thickener: To treat the overflow water from the cyclone, a deep cone high-efficiency thickener is generally selected, and chemicals are added to improve the sedimentation effect. The bottom flow is used for the next stage of treatment, and the effluent is recovered to the clean water tank as water for mineral processing production.
6. Mud dewatering system: deals with tailings carried by the bottom flow of the thickener. The equipment composition is similar to that of the tailings dewatering system, but the sieve holes are finer. The cyclone structure is designed with a double cone angle, and the cutting point is set at around 37 μ m. The slurry concentration discharged from the bottom flow outlet is>50%, and the moisture content of the dry tailings stacking from the dewatering screen is about 10% -20%. The tailings recovery rate is about 70%, and the effluent from the cyclone overflow outlet contains about 6% of the total tailings, which is supplied to the filter press for treatment.
7. Filter press: To process the overflow liquid from the cyclone of the mud dewatering system, only a small filter press needs to be selected to meet production requirements. The filtrate is recovered to the clean water tank for reuse, and the filter cake is transported to the storage yard for processing.
8. Dry tailings storage yard: Choose valleys or flat areas that are closer to the beneficiation plant and have less impact on the environment for stacking or landfilling, and try to choose belt transportation for dry tailings transportation.
After applying high-frequency screening technology in mineral processing, some mineral processing enterprises no longer need to build large thickeners and tailings dams. Tailings can be transported by conveyor belts nearby for landfilling, followed by greening or secondary utilization through external transportation, saving a lot of investment for the enterprise.
Through this technology, tailings can be stacking dry, and the utilization rate of return water has increased from around 70% -75% to over 95%, achieving zero stacking in production, reducing environmental damage, and achieving significant economic and social benefits.
The tailings dry stacking system with dewatering screen as the main dewatering equipment can achieve the dry stacking of all tailings, increase the utilization rate of return water to over 95%, and achieve zero discharge of enterprise sewage. It has huge economic and social benefits and is worth promoting and applying.
