GEOVIA PCBC Mine Sequence Optimization for block caving Part 3

LL 2021-09-03

The generation of a mine sequence for a block caving mine is challenging given it represents the direction for opening draw points. In this new series we will present a new option for optimizing mine sequences using the concept of ‘best and worst case’ adopted from open pit mines. In our previous post, we provided an example of this concept in real footprint at the Regal deposit. Today, we will show the results of the mine sequence applied in two zones.

MINE SEQUENCE APPLIED IN TWO ZONES (EAST AND WEST)

Because of the orebody shape and grade distribution, the footprint was divided into two zones as shown in Figure 12.

Figure 12: Footprint divisions into two zones.

SEQUENCE EVALUATION FOR WEST ZONE

Using the same procedure described before, a new set of sequences were modeled for the West zone. Due to the size of this zone only one center sequence was created starting at the highest economic value. The result of 38 sequences evaluated for this portion of the footprint is shown in Figure 13.

Figure 14 outlines three of the best alternative sequences for this zone, with the start of the sequence shown in warmer colors. In this zone, it is clear that the best alternative is to start in the center or using a V-shape with 280 deg. of azimuth. The economic value of both options is very similar determining the best alternative should be the V-shape to avoid operational complexities.

Figure 14: Sequences shapes for West Zone.

SEQUENCE EVALUATION FOR EAST ZONE

The same process was repeated for the East zone, but in this case more sequences were completed starting at the center of the footprint due to its size and the different locations of high grade. The result of 45 sequences evaluated for this zone of the footprint is shown in Figure 15.

Figure 16 shows four of the best alternative sequences for this zone, with the start of the sequence shown in warmer colors. In this zone, the results using a flat or V-shape are very similar. Surprisingly the option to start in the center was not better than the others. This is an indication that any of the best shape options could be used. Taking into consideration the complexity of the operation the best sequence is using a V-shape with an azimuth of 80 deg.

Figure 16: Sequences shapes for East Zone.

▶ In our next post, we will present the final results for the sequence selection. Stay tuned!

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