The Exergy Evolution of Mineral Wealth - Thanatia: The Destiny of the Earth's Mineral Resources - page 407

Zirconium
Zinc
Wolfram
Vanadium
Uranium
Titanium-rutile
Titanium-ilmenite
Tin
Tantalum
Silver
Silicon
Rhenium
REE
Phosphate rock
Nickel - sulfides
Nickel - laterites
Molybdenum
Mercury
Manganese
Lithium
Lead
Gypsum
Gold
Fluorspar
Copper
Cobalt
Chromium
Cadmium
Bismuth
Beryllium
Arsenic
Antimony

300,000

250,000

200,000

150,000

Gypsum

100,000

Gold

Fluorspar

50,000

Copper

Cobalt

0

Fig. 13.34 Natural bonus loss associated with the extraction of the main non-fuel mineral com-
modities on Earth throughout the 20th century, excluding iron ore, potash and aluminium

of renewable energy or telecommunication technologies, for instance, has radically
increased the use of REE, PGM, cobalt and tantalum.
It should be stressed that all the above percentages are estimations, based on
the assumption that no further deposits are to be found and that production is
to remain constant. Such figures thus constitute a static vision of the state of
mineral resources. It is a well-known fact that reserves tend to increase when
demand increases and prices rise. This incentivises exploration efforts and certain
deposits which were classified as uneconomic, start to become profitable again.
Furthermore, technological improvements may also decrease extraction costs leading
to a re-classification of reserves. In fact, in the short period elapsed in the writing
of this topic, reserve figures reported by the USGS have changed (more often than
not they have increased) year on year and have even suffered a series of revisions
within the same year.
Combining world resources with the variation of production over time would
therefore provide a more realistic picture. This is accomplished now through the
application of Hubbert Peak models to the analysed minerals where data is available.
However, world resources figures are rather speculative, since they are very di cult
to assess. With both figures one does however obtain a range of the probable peaks;
the lower limit corresponds to data based on available reserves, whilst the upper
relates to world resources. Since unit exergy replacement costs are assumed to be