Paste filling is a structural flow filling method in which the filling material slurry is in a paste like form. Specifically, paste filling refers to a mining method in which filling materials such as coal gangue, fly ash, industrial slag, and municipal solid waste are mixed with water in a certain proportion to form a paste like slurry with "no critical flow rate and no need for dehydration". The slurry is transported through pipelines using a filling pump or gravity pressure to the goaf of the longwall working face underground, partially or completely filling the goaf to control overlying rock and surface subsidence.

Paste filling has the following technical advantages:

The water leakage rate of the filling material is low, and the quality of the filling joint is high.
The compactness of the solidified body is high, and the strength of the filling body is high.
Good control effect on rock movement and surface subsidence.
High resource extraction rate and low filling cost.
Suitable for various mining conditions.
In addition, paste filling can also achieve green mining and quality upgrading. For example, by adopting efficient filling pumps and advanced ERP management systems, the efficiency of filling operations can be improved, environmental pollution can be reduced, and the coal industry can achieve sustainable development.

Overall, paste filling is an efficient, environmentally friendly, and suitable mining method for various mining conditions.