Metals and the Environment
EAEE E4001
Nickolas J. Themelis
1
METALS AND CIVILIZATION
From the dawn of civilization, metals have been
associated with economic development, prosperity,
and even art: “Native” gold, silver, and copper alloys
were the first form of currency and the second form
of art (after stone carvings).
The Bronze Age and the Iron Age were named
after metals.
METALS IN THE 21ST CENTURY
Many people think that today everything is done by
computers. But the computers are made of metal.
Also, all commercial and industrial buildings.
And all means of transportation.
And all generators of electricity and motors.
And the conveyors of 99.99% of the electricity
used by humanity (fiber optics do the rest).
In fact, the skeleton, muscles, and skin
of modern civilization are made of metals.
THE PRINCIPAL METALS AND THEIR
GLOBAL PRODUCTION IN 2000 in million
tons
Iron (Fe, 55.85) and steel (Fe+C/alloys): 833
Aluminum (Al, 26.98): 23.9
Copper (Cu, 63.55): 12.9
Zinc (Zn, 65.39): 8
Manganese (Mn, 54.94): 7.45
Lead (Pb, 207.2): 2.98
Nickel (Ni, 58.69): 1.23
Magnesium (Mg, 24.31): .284
Gold (Au, 196.97): .0025
Silver (Ag 107.87): .0179
(molecular weights g/mol)
source: USGS
Annual consumption of copper during
the 20th century
Copper is principally used in electrical and water conduits
Its per capita use is a good measure of the material standard
of living in a nation
• 10 kg/capita for the
highly developed nations
• 0.6 kg/capita in China
• 0.2 kg/capita in India
• More used in 20th
century than in all
millennia
Ore RESERVES are not infinite: Effect of
ore type on energy needed per ton of
production (H.H. Kellogg)
Energy (and CO2) savings from metal recycling
Estimated global anthropogenic emissions
in tons/year (after Nriagu &Pacyna 1998)
As
Cd
Cr
Cu
Hg
Ni
Pb
Zn
To atmosphere:
18800
7600
30500
35400
3600
55700
332400 131900
75%
% Contribution of global metal industry:
80% 50% 75% 1% 35% 10%
80%
To aquatic systems:
4100
9400
142000 112000
4600
113000 138000 226000
10%
% Contribution of global metal industry:
10% 20% 10% 2% 20% 5%
10%
Advantages of “continuous” over “batch”
smelting processes: Copper production from
virgin or recycled materials (Noranda process)
• Use of heat from sulfur combustion
• Production of sulfuric acid (instead of SO2 emissions)
• Can smelt any kind of copper scrap
Off-gases
Feeding
Port
Burner
Slag
Matte
concentrates
Slag exit
hole
Tuyeres
air+oxygen
Copper
exit hole
APPLICATION OF METAL PRODUCTION
TECHNOLOGIES TO 21th CENTURY PROBLEMS
Technology
Applied geophysics
For humanity


Mining
Exploration for
minerals and fuels
Extraction of
minerals
For Earth






Hydrometallurgy
Metal production and
refining



Pyrometallurgy
Metal production and
refining


Environmental assessment
and remediation
Brownfield/greenfield
Mine rehabilitation
Landfill engineering
Constructed wetlands
Water/soil
decontamination
Metal recovery
from wastes
Materials/energy
from wastes
Vitrification
Earth and Environmental Engineering :
A new discipline for materials and the
environment
Intelligent processing of combustible solid wastes for energy
and metal resource recovery at Waste-to-Energy plant at
Rochester, MA (developed by EAC)
INDUSTRIAL ECOLOGY LESSONS FOR METAL
PRODUCTION AND USE IN 21ST CENTURY
Production and use of metals and all
other materials must take into account
the needs of both Humanity and the
Earth.
INDUSTRIAL ECOLOGY LESSONS FOR METAL
PRODUCTION AND USE IN 21ST CENTURY
Metal extraction is one of the most
Earth-intrusive industrial activities.
Engineers need to be fully cognizant of
upstream (raw materials) and
downstream (products) effects of their
activities.
INDUSTRIAL ECOLOGY LESSONS FOR METAL
PRODUCTION AND USE IN 21ST CENTURY
Dispersive uses of metals must be phased
out and post-use material/energy recovery
increase: Advantage for processes that can
use as feedstock both “virgin” and recycled
materials, such as scrap and waste streams.
World steel production from ore (pig iron) and recycled steel