Why Dry-Discharged Tailings Are Replacing Wet Discharge?

In the "last mile" of mine production, the choice of tailings treatment technology directly affects the balance of safety, environmental protection, and economy. Although the traditional wet discharge process once dominated, it hides many hidden dangers: wet discharge tailings ponds are like 高悬 "artificial lakes" with high phreatic lines and poor dam stability. Once a dam breaks, it will trigger mudslides, causing devastating blows to downstream lives and properties. A large amount of tailings water accumulated for a long time not only leads to the penetration of harmful substances and pollutes groundwater but also may cause tailings liquefaction due to vibration, sharply reducing the safety level of the reservoir area. In addition, wet discharge requires a large amount of land, and the cost of land expropriation is increasing year by year. The later maintenance, closure, and environmental governance costs are even heavier burdens, and the electricity expenses for long-distance transportation also keep operating costs high.

The emergence of tailings dry discharge technology is precisely a targeted solution to these pain points. Through processes such as pressure filtration and vacuum filtration, efficient separation of tailings sand and water is achieved. The dry-discharged tailings sand has extremely low water content and can be directly stored in abandoned mines or barren slopes without the need to build large wet discharge tailings ponds, fundamentally eliminating the risk of dam breaks and overtopping. Dry-stacked tailings sand is in an unsaturated state, with high shear strength and strong earthquake resistance. Even if an accident occurs, it will not form long-distance flowing disasters, greatly reducing the scope of impact. At the same time, the water resource recovery rate is significantly improved, and tailings sand can be reused for construction sand or goaf filling, saving resources and creating additional value.

In the long run, although dry discharge requires high initial equipment investment, it can reduce land expropriation costs and operating costs. Under the same storage capacity, the service life of the tailings pond can be extended by more than 30%. After closure, the reclamation cycle is short, and the environmental restoration cost is lower. In today's era of increasingly strict environmental protection requirements and increasingly scarce land resources, tailings dry discharge is not only a "safety valve" to ensure mine safety but also a "must-choice" to achieve green and sustainable development.