The Exergy Evolution of Mineral Wealth - Thanatia: The Destiny of the Earth's Mineral Resources - page 383

Fig.13.10TheHubbertPeakappliedtoAustraliansilverreserves

800 0.9

Exergy cost Ore grade

0.8

700

0.7

600

0.6

500

0.5

400

0.4

300

0.3

200

0.2

100

0.1

0 0

Year

Fig. 13.11 Ore grade and exergy replacement cost of Australian lead mines

Fig. 13.12 shows the Hubbert Peak Model applied to lead. The theoretical peak
year is reached in 1994, considering that the economic demonstrated reserves are
R 1859 = 57:9 Mtoe. The regression factor is RF = 0:84. It should be noted that
the production points for the latest years (1998 - 2007) do not fall under the curve.
According to production data, the real peak might have been reached in 2002 which