51 efficient processes must be ensured. Model is most effective when recycling facilities are located in urban areas. The use of waste energy from various recycling processes can be used in various urban areas for various purposes, for example, for heating or cooling, electricity generation (waste-to-energy), etc, as you can see in Figure 2. Figure 2 - The concept of implementing Urban Mining for urban waste streams [6]. For the implementation of a comprehensive Urban Mining model, we also need to better understand the development and functioning of urban system "city". In particular, it is important to know and take into account the different stages of urban urban development. Most cities are developing and growing, some are in a state of hibernation, and some are in the phase of shrinking. In cities with growth, the import of solid materials, especially building materials, is significantly higher than the export of waste materials from cities. Today, this is especially true for fast growing Asian cities, where the input/output ratio for solid materials is greater than 10:1. For such sites, the processing of waste materials generated in urban areas can not significantly contribute to the satisfaction of demands. For example, recycling of construction waste is important for environmental protection, but it can not completely eliminate the needs to extraction of primary non-renewable raw materials. Knowledge of data on mass waste streams and material stocks in urban areas plays a very important role in introduction of the Urban Mining model. Today, researchers are still not aware of whether it is the largest potential source of urban stocks, municipal solid waste landfills and other landfill sites, or in tailings and mining waste. Urban mining also involves calculations with quantifying, valuing, and assessing the reusability of materials within the mining waste, construction waste, electronic waste (e-waste), etc. to promote a circular economy. Key methods include determining in-use stock, calculating the Urban Mining Index (UMI) for buildings, and evaluating the monetary value of other materials.
RkJQdWJsaXNoZXIy MTM0Mzk2