Environmental Engineering Reference
In-Depth Information
Import/Export
Scrap
23
Ore and
concentrate
107
Tungsten
carbide
powder
10
Finished
products
5
Other
7
APT
20
Ore and
concentrate
Production
Use
F & M
Wa ste
management
130
242
220
(EUSM)
159
(FPM)
19
Phantom low
Ore
29
156
(EUSM)
78
(FPM)
Tailings
3
34
22
9
Stock (industrial
and governmental)
Processing
waste
Secontary production
(prompt and obsolute scrap)
Ore
Environment
Tungsten: 1975 to 2000
All values in Gg W
510
11-50
51-100
101-125
125+
All values in Og W
FIGURE 6.78 Overall cycle and material flows for tungsten. (Reprinted with permission
from Harpu, E.M. and Graedel, T.E. 2008. Euvironmental Science and Technology , 42, 3839.
Copyright (2008) American Chemical Society.)
opportunity to reuse the product several times if recovered from the disposal process.
From the disposed material, some fraction of the metal can be recovered in its original
form and used to remanufacture the product. Finally, the recovered metal may also be
used as a raw material in the production chain. During any of the product life cycle
processes, some fraction of the metal (in any oxidized, reduced, or native form) may
be released to the environment (air, soil, or water).A material flow analysis during the
entire life cycle of the metal can be done to ascertain the overall fate of the metal in
any manufacturing process. The overall cycle and material flow analysis for tungsten
in the United States during the years 1975-2000 is given in Figure 6.78. Once the rate
of input into the environment is obtained, a fugacity model can be used to ascertain
the overall environmental fate of the metal in various compartments.
PROBLEMS
6.1 2 Consider a lake with a total capacity of 10 10 m 3 with an average volu-
metric water flow rate of 10 3 m 3 /d. The lake receives a wastewater pulse
of pesticide A inadvertently released into it by a local industry due to an
 
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