Stereo Satellite Surveying: Volumetrics at Penasquito Gold Mine, Mexico

Satellite elevation surveying measurements of the volume of rock and overburden mined at Penasquito Gold Mine in one month

PhotoSat measured the volume changes over the entire site of the Penasquito Gold Mine over a period of one month. Stereo WorldView-2 satellite photos were taken of the Penasquito mine site on January 31 and again on February 27. Using its proprietary geophysical stereo satellite elevation processing system, PhotoSat produced surveyed elevation surfaces of the mine site for the two dates. The volume changes in the pit, the waste dumps, the leach pad and the ore stockpiles were then calculated from the differences between the February 27 and January 31 elevation surfaces.

Figure 1: Penasquito pit January 31 and February 27

The mine site volume changes are shown in Figure 2 and Figure 3 below. Volume additions in the leach pad are shown in Figure 4.

Figure 2: Volume decreases January 31 to February 27. The estimated volume of rock and overburden removed from the pit is 5,542,400 m3 of unblasted rock or 6,928,100m3 of blasted rock (assuming a 125% expansion factor for blasted rock). Some of the material mined will have been overburden with a lower expansion factor.

Figure 3: Volume additions January 31 to February 27. The volume additions to the Penasquito waste dumps, ore stockpiles and leach pad total 6,091,000 m3 for the period of January 31 to February 27.

Figure 4: Volume additions, Penasquito leach pad, January 31 to February 27, 2010