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In-Depth Information
That said, MFA, LCA and IO analyses are complementary and can be used at
different scales ranging from the urban, regional, national, continental and even
global (MacLean et al., 2010). Thermoeconomics uses these methodologies with-
out superseding them but instead serving to improve their precision as and when
required. It applies to any physical system no matter how complex and should
be of paramount importance at both the BoL and EoL stages of metal recovery
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(see Sec. 14.5).
Unfortunately the knowledge and use of Thermoeconomics is not widely spread.
It is however exact and solid. It is also the only way to assign a true physical foot-
print, i.e. one that takes into account the energy, water, chemicals and pollutants
of any product, under any circumstance. In particular, it is important in multi-
output production processes, such as those used for mineral production and in the
metallurgy of recyclates. Regrettably, it is also time consuming and the method
whilst extensively used in power production has been scarcely used for minerals.
Provided that LCA databases continue to include more or less arbitrary but “rea-
sonable” assumptions rather than exergy allocations, the accuracy of the results and
the conclusions drawn will be doubtful. This is because metals and minerals are
always the root of any production chain with no unique-element-ores found in the
crust. Accordingly, energy and material value allocation is always needed in order
to obtain the cost of a particular element. Yet this procedure is so complex, that
in fact, LCA handbooks recommend an avoidance of allocation where possible
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.
The authors of this topic disagree with this stance and firmly believe that should
the Thermoeconomics of metal separation be intensively researched, more accurate
LCAs will be developed thus facilitating a more precise picture of the raw material
production processes and their global management.
9.8 Summary of the chapter
In this chapter an introduction to the thermodynamics associated with the micro
and macro formation processes of a mineral deposit and that linked to mining,
smelting and refining has been undertaken. The reader has seen that the Second Law
and its properties entropy and Gibbs free energy form the basis of understanding
the phenomena related to mining and metallurgy. Specifically, the focus has been
placed on the entropic vision of mineral extraction and the problem of scarcity.
Given that entropy is connected to probability and information, it can also provide
an interpretation as to the nature of the mixing of ions, atoms or molecules in a
solid solution.
The thermodynamic behaviour of smelting and refining is fundamentally ex-
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In both stages, the problem essentially consists of separating metals from a mixture and reducing
them to a metallic state using the least amount of fuels, water and chemicals possible.
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See ILCD handbook for LCA http : ==lct:jrc:ec:europa:eu=pdfdirectory=ILCDHandbook
GeneralguideforLCADETAILonline 12March2010:pdf. Accessed March 2013
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