| 摘要 |
Cement and silicate are mixed and sprayed into the mine roadway or gallery to form a wall or stopping which is self-supporting and prevents passage of acid water from abandoned workings. Preferred ratio is 7 to 75% Portland cement to 25-93% water. The silicate is mixed in ratio of 6-100% sodium silicate to 0-94% water. Fly ash as setting retardant is mixed in ratio of 7-55% Portland cement, 10-65% fly ash and 25-45% water. Bentonite as thixotropic agent is mixed in ratio 12-70% silicate solution, 1-10% bentonite and 25-80% water. A mixer with twist pipe, control valve and outlet spray is used, controlled remotely. Cheap, simple, absence of moulds, shuttering etc. and remote control. |
