Urban Mining of e-Waste and the Role of Consumers

This chapter adds to the body of literature on the Circular Economy (CE), urban mining, and their intersection with consumer behaviour, by first providing a review of existing and emergent EU regulations aimed towards enhancing the collection rate of household WEEE. The fast growth of the EEE waste stream and its potential for Urban Mining as well as the inability of WEEE collection to keep up with the growth of the EEE industry is showcased with statistical data. The final section critically analyses the literature the intersection between consumer behaviour and closed-loop supply chains for EEE, identified through a systematic keyword search to ensure replicability. The findings point at a lack of theoretical, methodological and product-case heterogeneity among the identified sources, with most of them employing the Theory of Planned Behaviour and survey methods and focusing on mobile phones or general WEEE. While the literature suggests important behavioural differences across EEE categories, this was not representatively explored. The final section contributes to filling this gap by developing a taxonomy of EEE categories based on characteristics that may predispose consumer behaviour. The identified dimensions are: size, involvement, long-term reliability expectations, value type, internet access, multifunctionality, the quality of being outdated and social meaning.

Desafios da reciclagem de lixo eletrônico e as cooperativas de mineração urbana / Challenges of e-waste recycling and urban mining cooperatives

A expansão da população, atrelada à elevação dos níveis de produção e consumo de bens, vem intensificando a geração de resíduos sólidos em áreas urbanas. Estima-se que no Brasil são gerados anualmente 2 milhões de toneladas de resíduos de equipamentos eletroeletrônicos (REEE). Se não for tratado adequadamente, essa categoria de resíduos pode causar impactos negativos ao meio ambiente em razão do potencial de contaminação. Os depósitos de REEE localizados nas áreas urbanas são conhecidos também como minas urbanas, uma vez que os REEE apresentam uma quantidade expressiva de matérias-primas críticas e metais valiosos. Aliado à Política Nacional de Gestão de Resíduos Sólidos (PNRS), o presente trabalho apresenta uma discussão sobre os desafios para o funcionamento eficiente das cooperativas de reciclagem de REEE, as quais também podem contribuir para o desenvolvimento da mineração urbana como uma maneira de auxiliar na mitigação do impacto negativo da crescente geração destes tipos de resíduos e gerar renda.

Urban mining by flash Joule heating

Precious metal recovery from electronic waste, termed urban mining, is important for a circular economy. Present methods for urban mining, mainly smelting and leaching, suffer from lengthy purification processes and negative environmental impacts. Here, a solvent-free and sustainable process by flash Joule heating is disclosed to recover precious metals and remove hazardous heavy metals in electronic waste within one second. The sample temperature ramps to ~3400 K in milliseconds by the ultrafast electrical thermal process. Such a high temperature enables the evaporative separation of precious metals from the supporting matrices, with the recovery yields >80% for Rh, Pd, Ag, and >60% for Au. The heavy metals in electronic waste, some of which are highly toxic including Cr, As, Cd, Hg, and Pb, are also removed, leaving a final waste with minimal metal content, acceptable even for agriculture soil levels. Urban mining by flash Joule heating would be 80× to 500× less energy consumptive than using traditional smelting furnaces for metal-component recovery and more environmentally friendly.

Mining the Built Environment: Telling the Story of Urban Mining

Materials are continuously accumulating in the human-built environment since massive amounts of materials are required for building, developing, and maintaining cities. At the end of their life cycles, these materials are considered valuable sources of secondary materials. The increasing construction and demolition waste released from aging stock each year make up the heaviest, most voluminous waste outflow, presenting challenges and opportunities. These material stocks should be utilized and exploited since the reuse and recycling of construction materials would positively impact the natural environment and resource efficiency, leading to sustainable cities within a grander scheme of a circular economy. The exploitation of material stock is known as urban mining. In order to make these materials accessible for future mining, material quantities need to be estimated and extrapolated to regional levels. This demanding task requires a vast knowledge of the existing building stock, which can only be obtained through labor-intensive, time-consuming methodologies or new technologies, such as building information modeling (BIM), geographic information systems (GISs), artificial intelligence (AI), and machine learning. This review paper gives a general overview of the literature body and tracks the evolution of this research field.