In the Creston Pit at Lluvia, we are operating with a long-term trial of Selective Mining, with the intent of up-grading the ore we will feed to the heaps, and reducing the total volume of material that will be heap leached. This is NOT a high-grading method, we leave no ore behind in favor of the high-grade. Instead, this program is focused on elimination of Internal Waste, which would otherwise dilute the actual ore.

From extensive sampling of the old Lluvia heaps, we know that very significant dilution of the ore occurred with the mining methods employed by previous operators of the Creston Pit, during 1995-98. We have prioritized the development of this new Selective Mining method because of the high Capital Cost of new Leach Pad construction. We expect to reduce the demand for leach pad volume, by eliminating waste rock that should not be delivered to the heaps.

There are 2 key aspects of this Selective Mining Program; (a) closely-spaced drilling of the blast holes, and (b) small-scale, flexible, and fast mining equipment.

In the Creston Pit at Lluvia, we are operating with a long-term trial of Selective Mining, with the intent of up-grading the ore we will feed to the heaps, and reducing the total volume of material that will be heap leached. This is NOT a high-grading method, we leave no ore behind in favor of the high-grade. Instead, this program is focused on elimination of Internal Waste, which would otherwise dilute the actual ore.

On the map of Bench 902.5 N above, the green and orange blocks were predicted to be Ore by the NI 43-101 Reserves Model of 8 July 2010. The closely-spaced drilling yielded assays which showed ore in each of the red polygons, and those polygons are exactly what was mined as Ore and sent to the Heaps for leaching. All of the remaining green and orange blocks were sent to the Waste Dumps. This blast, on Bench 902.5 N, was the greatest success of the Selective Mining Program to date, achieving a significant improvement in ore grade.

The key equipment for the Selective Mining program is the Cat 345 back excavator. With its 1.2 meter wide bucket, this unit enables mining of waste or ore zones as small as 2 meters in width. As shown in the photo below, we mine with this machine sitting on top of the already-blasted material, and feeding a truck parked on the floor below the blasted material. We use 40-ton articulated trucks for ore haulage, because they are narrower, faster, and much more flexible than rigid-frame haul trucks. The articulated trucks can also climb steeper ramp gradients, lowering costs for access roads within the pit.

The results of the first two months of Selective Mining at Lluvia are significant, and will be released soon, in a general news release to the public.