The passage from a linear to a circular approach has characterised waste management strategies over recent decades.
The linear traditional approach is based on the extraction of raw materials, production, use, wasting and landfilling (figure below, dotted line). In other words, there are no options for the raw materials except to be used and then discarded. However, with the constantly expanding populations, there is a shortage of raw materials to continue to support this linear path. The circular approach primarily arises from this increasing need for primary raw material. Attention is currently moving from the limited and fixed stocks of raw materials to the increasing anthropogenic stocks of materials. This creates the base for the development of the Urban Mining concept.
Urban Mining activities are undertaken in this context, comprising actions and technologies designed for the recovery of materials and energy from products of the urban catabolism. Therefore, Urban Mining provides a systematic management of anthropogenic resources stocks and waste (products and buildings), in the view of long term environmental protection, resource conservation and economic benefits.
An illustrative example is given by Waste from Electrical and Electronic Equipment (WEEE). Due to their short economic life, the amount of this waste stream is continuously increasing. Currently, their growth can be estimated as being three times faster than the average growth of municipal solid waste. Given that gold concentration in electric and electronic scraps is considerably higher than the amount of gold in gold mines, recovery of gold from WEEE may potentially become result in a more ecologically compatible mining activity.
Read the full introduction by Raffaello Cossu et al.
Figure 1. Role of Urban Mining in materials life cycle
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