Extraction is the pillar phase the amount of pillar recovery possible for a given stope is highly dependent upon ore grade and the as-mined configuration of the stope. In areas the highest ore grade, it is possible to extract nearly 100% of the pillars with the aid of backfill. While it is not economic to backfill areas of average grade, 20% to 75% extraction of the pillars is possible, depending upon geometry (Figure 7.8).