cement purdah

But it is easy to cause accidents for coal pillars destroy in the big fault. This paper introduced the technique of using cement purdah to prevent water burst firstly in the big colliery based on practice.
本文在理論研究和生産實踐的基礎上,系統縂結了肥城國家莊煤鑛採用帷幕截流技術治理大水鑛井突水的技術和工程經騐。