Applications of Seismic Tomography to in Situ Leach Mining.
tweeton-8; Cumerlato-DR; Hanson-CL; Kuhlman-JCHL
Minerals and Geotechnical Logging Soc 1989 :747-764
The U.S. Bureau of Mines is conducting research to develop improved methods for predicting and monitoring the flow of leach solution during in situ mining. Potential benefits include higher metal recovery through better leach solution distribution as well as enhanced environmental monitoring. Seismic velocity decreases with fracturing, and laboratory experiments have shown that p-wave velocity increases with saturation. Therefore, the ability of crosshole seismic tomography to detect fractured zones and wetted regions above the water table was tested for applications in predicting flow patterns and in monitoring leach solution injected above the water table. The tomographic analysis program BoMtom (Bureau of Mines tomography) has special options for crosshole geophysical applications. BoMtom provides a test for the uniqueness of reconstructions and optional mathematical constraints to help obtain unique reconstructions. The Fortran program is available from the authors. During field tests at a Wisconsin limestone quarry, seismic refraction tomography located fractured zones resulting from the intersection of major joint sets with a shallow refracting rock layer. A crosshole field test at an Iowa limestone quarry located a wetted region created by injecting water between source and receiver boreholes 20 m apart. Field tests were also conducted at the San Xavier Experimental Mine near Tucson, Arizona, with a borehole spacing of 40 m. Tomograms were consistent with known geologic features and with a borehole sonic log.
Minerals and Geotechnical Logging Soc., 1989, PP. 747-764