BCE

1
The ages of civilization and Metal Consumption
Stone Age
Bronze age
Iron Age
2000
0
2000
4000
Time (years)
CE
BCE
2
Mineral Resource Consumption
Iron
Copper
Lead
Aluminium
Zinc
3
Metal consumption resources
4
Life expectancies of resources of selected
commodities based on crustal abundance
5
Metal Recycling
6
Metal Recycling (Continued)
Salient U.S. Recycling Statistics for Selected
Metals
7
Metallic Mineral Exploration Looking for the
proverbial needle in the haystack
8
Black Smokers and Massive Sulphide Ore Deposits
PbCl2
ZnCl2
CuCl
350 oC
Chalcopyrite
(CuFeS2)
Pyrite
(FeS2)
Sphalerite
(ZnS)
9
Hydrothermal vein deposits
Hg-bearing quartz vein
Cinnabar (HgS)
Hot water dissolves metals as complex molecules,
e.g. H2WO4 or Hg(HS)2. Quartz and metallic
minerals precipitate in fractures in response to
cooling or changes in water chemistry
1 cm
Wolframite (Fe,Mn)WO4)
Fluid inclusion
10 cm
10 mm
10
Porphyry Copper deposits
Brine (NaCl-H2O) exsolves from cooling diorite
intrusion
Porphyry ore
Cu dissolved as CuCl2, Fe as FeCl2
Reaction with H2S on cooling to form chalcopyrite
(CuFeS2)
1 cm
Open pit mine
11
Formation of an epithermal gold deposit
Gold-bearing quartz veins
Au(HS)2- H 0.5 H2O Au 0.25O2 2H2S
Removed by boiling
Native gold
Native gold
12
Gold panning
Alluvial deposits
Gold nugget
13
Witwatersrand Goldfields
(Produces 35 of worlds gold)
Gold- bearing conglomerate
14
Understanding Planet Earth
The Earth as a System