Development of a Fly Ash-cement Mine Sealing System.
Maser-KR; Wallhagen-RE; Dieckmann-JT
NTIS: PB 250 611 Available for Reference At Bureau Libraries :113 pages
This report describes the development of a system which modifies an existing fly ash-foam remote mine sealing technique to make it capable of impounding water in a fire zone. Laboratory-scale determinations were made of the capillarity, permeability, and cement. Leakage tests (1/4-scale) indicated that shrinkage in fly ash-cement mixtures always result in leakage, whereas fly ash- bentonite mixtures were impervious to water. Large-scale leakage tests with a 15-foot water head showed that a 1:1 fly ash-bentonite bulk seal with a 2-inch top layer of 1:1 fly ash-huron cement is the optimum combination for a water-tight seal; a froth foam topping is suitable for providing an air-tight seal. A water leakage rate of about 1.5 Gpm is predicted for the optimum combination of the above sealants in a typical mine with a 15-foot water head. Guidelines are given for determining the quantities of materials required for constructing a mine seal.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB 250 611 Available for Reference At Bureau Libraries