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nickel (Ni), zinc (Zn), and others, while hitchhiker metals are geologically rare and
chemically related with one of the attractor elements.
Due to their exclusive properties, rare earth elements are used in electronics,
especially as doping agents in semiconductors, printed circuit boards, catalyzers,
photovoltaic cells, and other applications, which lists hitchhiker metals and respective applications (Ayres and Peiró 2013; Loureiro 2013). China is responsible for
97% of the 125,000 tons of rare earth elements produced every year in the world,
and new deposits are constantly sought (Loureiro 2013). Nevertheless, recent studies have discussed the potential of urban mining to mitigate the scarcity of resources
in the country.
10.3.2.3 Recycling and Urban Mining
Urban mining is a new approach to the flow of materials, which allows recovering
compounds from various anthropogenic processes (Baccini and Brunner 2012;
Lederer et al. 2014). Recovered materials present concentrations of valuable components that are similar to the values observed in the natural environment and may
represent a significant supply of resources (Cossu and William 2015).
For Krook and Bass (2013), “urban” means within the boundaries of a city environment, while “mining” is understood as the extraction of secondary metal
resources from the obsolete material. The concept of urban mining includes all
activities and processes used to recover compounds, energy, and elements from
manufactured goods, buildings, and waste generated from urban catabolism
(Di Maria et al. 2013; Wen et al. 2015).
According to the US Environmental Protection Agency (USEPA), recycling
involves the minimization of solid waste based on the recovery and reprocessing of
products that would otherwise be disposed of such as aluminum cans, paper, and
bottles. Another definition says that recycling is the process of transforming solid
waste based on changing its physical, physicochemical, and biological properties
with a view to the generation of production materials or conversion into new products (Brasil 2010).
Currently, the terms “recycling,” “resource recovery,” “urban mining,” “waste
minimization,” “circular economy,” and “material recovery” are being increasingly
used in business and industrial environments (Cossu and William 2015).
Independently of terminology choices, recycling is important not only from the
economic aspect but also from concern with the increasing scarcity of primary raw
materials in the effort to ensure supplies to future generations. The flow of materials
based on extraction from natural environments is finite, while recycling and urban
mining will be the most common approaches in the future.
The use of urban mining to obtain rare earth elements is directly associated with
the recovery of precious metals based on the recycling of devices. Nicolai (2016)
claims that more appropriate and economically feasible methods have to be considered in this form of recycling. For example, Umicore uses a combination of pyroT. A. da Silveira et al.
nickel (Ni), zinc (Zn), and others, while hitchhiker metals are geologically rare and
chemically related with one of the attractor elements.
Due to their exclusive properties, rare earth elements are used in electronics,
especially as doping agents in semiconductors, printed circuit boards, catalyzers,
photovoltaic cells, and other applications, which lists hitchhiker metals and respective applications (Ayres and Peiró 2013; Loureiro 2013). China is responsible for
97% of the 125,000 tons of rare earth elements produced every year in the world,
and new deposits are constantly sought (Loureiro 2013). Nevertheless, recent studies have discussed the potential of urban mining to mitigate the scarcity of resources
in the country.
10.3.2.3 Recycling and Urban Mining
Urban mining is a new approach to the flow of materials, which allows recovering
compounds from various anthropogenic processes (Baccini and Brunner 2012;
Lederer et al. 2014). Recovered materials present concentrations of valuable components that are similar to the values observed in the natural environment and may
represent a significant supply of resources (Cossu and William 2015).
For Krook and Bass (2013), “urban” means within the boundaries of a city environment, while “mining” is understood as the extraction of secondary metal
resources from the obsolete material. The concept of urban mining includes all
activities and processes used to recover compounds, energy, and elements from
manufactured goods, buildings, and waste generated from urban catabolism
(Di Maria et al. 2013; Wen et al. 2015).
According to the US Environmental Protection Agency (USEPA), recycling
involves the minimization of solid waste based on the recovery and reprocessing of
products that would otherwise be disposed of such as aluminum cans, paper, and
bottles. Another definition says that recycling is the process of transforming solid
waste based on changing its physical, physicochemical, and biological properties
with a view to the generation of production materials or conversion into new products (Brasil 2010).
Currently, the terms “recycling,” “resource recovery,” “urban mining,” “waste
minimization,” “circular economy,” and “material recovery” are being increasingly
used in business and industrial environments (Cossu and William 2015).
Independently of terminology choices, recycling is important not only from the
economic aspect but also from concern with the increasing scarcity of primary raw
materials in the effort to ensure supplies to future generations. The flow of materials
based on extraction from natural environments is finite, while recycling and urban
mining will be the most common approaches in the future.
The use of urban mining to obtain rare earth elements is directly associated with
the recovery of precious metals based on the recycling of devices. Nicolai (2016)
claims that more appropriate and economically feasible methods have to be considered in this form of recycling. For example, Umicore uses a combination of pyroT. A. da Silveira et al.