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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Underneath Norrköping : An Urban Mine of Hibernating Infrastructure

Wallsten, Björn January 2013 (has links)
This study examines the subsurface infrastructure in the Swedish city of Norrköping from an urban mining perspective. Urban mining is a broadly defined term for different strategies that regard the built environment as a resource base for materials. In this study, the focus is on three base metals that exist in large quantities in infrastructure parts: iron, copper and aluminium. A special focus is given to the parts of Norrköping’s infrastructure that are not in-use and thus constitute a ”hibernating stock” that contains recyclable metals. The main results of this study are twofold. First, a quantitative assessment of the hibernating stocks of urban infrastructure gives answers to how large the stocks are and where in Norrköping they are located. This was performed using a spatially informed Material Flow Analysis to arrive at a recycling potential in terms of weight and spatial concentration. Second, a qualitative assessment was made regarding how these hibernating stocks of urban infrastructure come into existence. An infrastructure studies perspective was used to outline three patterns with their own sets of ”hibernation” logics. These logics give rise to different prerequisites for the implementation of urban mining in practice. A main argument of this study’s cover essay is that both of the above outlined kinds of knowledge are needed to engage in urban mining with confidence. Thus, the main focus of the cover essay text is to describe how the two different perspectives of Material Flow Analysis and infrastructure studies were combined into a coherent research approach.
12

Urban Mining in Malmö - An Investigative Study to Identify the Potential of Urban Mining

Anesie, Laura Noemi January 2018 (has links)
This master thesis depicts the topic of urban mining and its possibilities and challenges in the city of Malmö. Because of present day’s high consumption and construction our resources are becoming scarcer. In order to continue to build and consume the way we do, we need to look at other alternatives to obtain these resources. One sustainable alternative is urban mining which is based on society as a resource base where material accumulating over time is a metal storage that can be used through reuse or recycling. This thesis is limited to one type of urban mining which refers to unused cables and pipes that lie underground, so called hibernating cables. The purpose of this thesis is to explore the possibilities and challenges with urban mining in the city of Malmö and to research the Kabel-x urban mining method and its implementation possibilities. To successfully understand the challenges and possibilities a qualitative approach was taken where semi-structured interviews were conducted to see attitudes towards urban mining as well as to identify stakeholders who would work with an urban mining project in the future. The qualitative approach was complemented by a literary research which built the theoretical framework with theories like urban mining, urban metabolism and material flow analysis and sustainability assessments. The empirical discoveries depict topics such as ownership, knowledge-gap or skepticism when it comes to urban mining as well as methods of extractions, but also point to high interest and economic incentives with are in concordance with sustainability aspects. This lead to the conclusion that urban mining shows both possibilities and challenges in Malmö, which proves a challenging but worth implementation. Regarding Kabel-x method, its sustainability aspects and challenges with its implementation, it was concluded that on account of mostly skepticism and knowledge-gap stakeholders proved its implementation challenging but also interesting for urban development.
13

Construction industry market segmentation: Foresight of needs and priorities of the urban mining segment

Ha, Simon January 2015 (has links)
Context: Current unsustainable practices have resulted in the depletion of natural resources and a prevailing material scarcity. Urban Mining has emerged in this context and suggests the “mining” of cities or other sources in urban areas to retrieve valuable resources. It raises the topic of how urban mining as a market segment of the construction industry is like today and in the future.  Objective: The thesis sets out to study what firms in the urban mining market segment desires in terms of needs and priorities. Furthermore, what could be prioritized in the future (2030), what future scenarios could be expected and what implications these can have on organizations within the segment and on the construction industry.  Method: A foresight methodology was applied as a framework for the research design. Interview with representatives from 10 firms, including observations of their operations, resulted in a number of mutual needs shared across the urban mining segment. These were prioritized in relative importance based on a questionnaire of 67 respondents representing 44 different firms in Sweden. A combination of these studies and a review of technology trends further enabled the extrapolation of future scenarios.  Results: The findings shows that firms within the urban mining market segment prioritizes and emphasizes needs related concerns in optimization, cost control, safety, environmental and social care today. Needs related to safety, environmental and social care are indicated to remain top prioritized as a result of the future market circumstances. A holistic and lifecycle approach in urban mining practices was deemed of low priority today but was indicated to grow significantly in relative importance in the future.  Conclusion: Technology, urbanization and globalization indicates stricter and more competitive market circumstances in the future. Especially related to safety, lifecycle consideration, environmental, and social care. The research suggests that firms concerned and those operating within the urban mining segment may need to undergo transformational changes in their organization to meet what the market segment expects in the future. Moreover, the findings opens up the possibility for actors and stakeholders concerned with the construction industry to proactively go into a desired future by knowing how the future market could unfold. / Stanford University, ME310: Urban Mining
14

The Urk World : Hibernating Infrastructures and the Quest for Urban Mining / Urkarnas Värld : Infrastrukturer i dvala och staden som resursbas

Wallsten, Björn January 2015 (has links)
This PhD thesis concerns urban mining, an umbrella term for different recycling strategies aimed to recover materials from the built environment. More specifically, it focuses on hibernating urban infrastructures, that is: cables and pipes that have been left behind in their subsurface location after they were disconnected. I term this subsurface urban realm of system rejects the “Urk World”. “Urk” is short for “urkopplad”, the Swedish word for “disconnected”, an abbreviation often found on old infrastructure maps denoting discarded system parts. Since urks contain high concentrations of copper, my normative stance is that the Urk World should be “mined” as a contribution towards diminishing the persistently wasteful handling of mineral resources in society. The thesis has three focus areas. The first of these discusses how the Urk World has emerged, that is: how the creation of urks is sustained in sociotechnical processes related to infrastructure’s provision. The second concerns the potential of urk mining, how much copper the Urk World contains, where these quantities are located and by which implications they could be recovered. The third focus area is devoted to the politics of urks, and is concerned with the political embeddedness of infrastructure and where politics might intervene for the sake of increased urk recovery. Five papers complete the thesis. The first paper investigates how much copper, aluminium and steel there is in the Urk World of the Swedish city of Norrköping, and how these quantities are spatially dispersed in the urban environment. The second paper is based on interviews with system owners and repair crews, and investigates how urks come into existence in relation to three different infrastructural processes: maintenance, larger installation projects and shutdown. The third paper describes how environmental systems analysis can be beneficially coupled with theories and methods from the social sciences to create knowledge useful to aid the development of urk recycling schemes. The fourth article makes use of the inherent ambiguities of urks to investigate a spectrum of locations where politics aimed for increased urk recovery can intervene as well as what is at stake there. The fifth and final paper investigates urks in Linköping’s power grid in spatial and weight terms, and analyses the implications of urk recovery from several different viewpoints. In overall terms, the major contribution of the thesis is how it improves the knowledge of societal stocks of materials, thereby giving an increased recognition of the built environment as a resource base. In overall scientific terms, it sets an example of how a coherent interdisciplinary research design can provide knowledge useful for the implementation of urk recycling schemes as well as for political decision–making for increased urk recovery.
15

Product-Service System Innovation in Urban Mining-A case study with Volvo CE

Chai, Yi, Gao, Zhenqing January 2014 (has links)
Volvo Construction Equipment (Volvo CE) is one of the world's largest manufacturers of construction machines. Now they want to access a sustainability-focused mining field – urban mining. This study is to find a solution helping Volvo CE quickly access to urban mining with a Product-Service System (PSS) development concept. To do this, the authors completed surveys and several interviews with construction companies, to understand the user and customer needs. The authors also go through a functional analysis on a new prototype of their collaboration partner - Stanford University. The result of this thesis is a PSS concept for urban mining, developed with machine selection guidelines combined with Life Cycle Assessment, and Quality Function Deployment. Recommendations include: 1) Improve the communication between Volvo CE and their Customers. 2) Adding more visible services. 3) Adding multiple business solutions provide to customers. 4) Understanding relevant stakeholders in urban mining 5) Expand research on urban mining.
16

[pt] AVALIAÇÃO TECNOLÓGICA E ECONÔMICA DE UMA ROTA DE PROCESSAMENTO PARA RECICLAGEM DE SUCATAS ELETRÔNICAS / [en] TECHNOLOGICAL AND ECONOMIC ASSESSMENT OF A PROCESSING ROUTE FOR ELECTRONIC WASTE RECYCLING

FELIPE SEABRA D ALMEIDA 07 June 2022 (has links)
[pt] O Brasil é o segundo maior produtor de lixo eletrônico das Américas, com uma produção que cresce a cada ano e apenas 10 por cento dela sendo tratada de forma apropriada. Adicionalmente, o Brasil não possui tecnologia própria para tratamento de placas de circuito impresso, componente chave presente neste tipo de resíduo. Atualmente, o Brasil não possui uma planta industrial voltada para essa atividade extrativista a partir de resíduos eletrônicos, sendo a maior parte do seu tratamento realizado no exterior. A hipótese de pesquisa deste manuscrito é que as universidades e suas comunidades poderiam desenvolver fontes de matéria-prima para tais processos de extração e, portanto, merecem atenção para a criação de pontos de coleta e parcerias. Nesse contexto, é necessário entender o comportamento dessa comunidade em relação à aquisição, armazenamento e descarte de equipamentos eletrônicos, bem como informações sobre temas relacionados ao gerenciamento e reciclagem de resíduos eletrônicos. Adicionalmente, criou-se uma rota conceitual de tratamento, a partir da integração de tecnologias descritas na literatura. Após a criação do design da rota, foi realizado um balanço de massa e energia, considerando dois casos base de fonte de placas de circuito impresso como matéria prima matéria prima: A) Lixo eletrônico em geral; B) utilizando somente celulares. Para ambos os casos, foi considerado o tratamento de 2 t/h. Determinou-se que o grupo estudado possui mais de 16,96 milhões de telefones celulares em hibernação, além de outros equipamentos, com valor de estoque estimado em 67,45 milhões de dólares para o grupo estudado na região metropolitana do Rio de Janeiro. Se extrapolado para todo o Brasil, pode chegar a 797,50 milhões de dólares para o grupo estudado. uma taxa interna de retorno de 141,6 por cento e 3990,7 por cento para o caso A e B, respectivamente e valor presente líquido de USD 44,834,616 e USD 3,215,300,083 para o caso A e B, respectivamente. Adicionalmente, foi determinado que o caso A possui uma grande sensibilidade a variação da taxa de ocupação. Neste contexto, a presente pesquisa tem o potencial de ajudar na criação da primeira planta industrial brasileira voltada para a reciclagem de placas de circuito impresso, assim como entender quais são as variáveis chaves para o processamento destes componentes. Adicionalmente, o projeto apresenta o investimento necessário para a criação da planta, sendo uma informação crucial para potenciais investidores. / [en] Brazil is the second largest producer of electronic waste in the Americas, with a production that grows each year and only 10 percent of it is properly treated. Additionally, Brazil does not have its own technology for treating printed circuit boards, a key component present in this type of waste. Currently, Brazil does not have an industrial plant dedicated to this extractive activity from electronic waste, with most of its treatment carried out abroad. The research hypothesis of this manuscript is that universities and their communities could develop raw material sources for such extraction processes and, therefore, deserve attention for the creation of collection points and partnerships. In this context, it is necessary to understand the behavior of this community in relation to the acquisition, storage and disposal of electronic equipment, as well as information on issues related to the management and recycling of electronic waste. Additionally, a conceptual treatment route was created based on the integration of technologies described in the literature. After creating the route design, a mass and energy balance was carried out, considering two base cases of printed circuit boards as raw material: A) Electronic waste in general; B) using cell phones only. For both cases, the treatment of 2 t/h was considered. It was determined that the studied group has more than 16.96 million cell phones in hibernation, in addition to other equipment, with an estimated inventory value of 67.45 million dollars for the studied group in the metropolitan region of Rio de Janeiro. If extrapolated to all of Brazil, it could reach 797.50 million dollars for the studied group. an internal rate of return of 141.6 percent and 3990.7 percent for case A and B, respectively, and net present value of USD 44,834,616 and USD 3,215,300,083 for case A and B, respectively. Additionally, it was determined that case A is highly sensitive to occupancy rate variation. In this context, this research has the potential to help in the creation of the first Brazilian industrial plant dedicated to the recycling of printed circuit boards, as well as to understand the key variables for the processing of these components. Additionally, the project presents the investment necessary for the creation of the plant, being crucial information for potential investors.
17

Chunk Metabolism : Exploring how to plan for reuse of structural elements / Chunk Metabolism : Hur man kan planera bättre för återbruk av tunga stomdelar

Nilsson, Isabella January 2022 (has links)
With a major share of the negative environmental impacts deriving from construction and its waste, ways to reduce the material and energy use in this sector have been the focus of studies for decades. Reuse of building elements and materials is gaining traction with researchers, architects, developers and real estate owners. However, it is rarely used in practice in Sweden. Barriers include fear of fluctuating supply, quality warranties, logistics, lack of experience in the design process and unknown availability. While many research projects are underway, a process of how to locate materials is still missing. Additionally, there is currently little connection between research and practice, and a lack of investigation into the long-term consequences that reuse will have on the design process and the role of the architect. Therefore, the aim of this study is to discover what heavy structural elements will be available for reuse in the Stockholm region and to explore which implications reuse will on the design process and the role of the architect. The study evaluated a new method for short-term mapping of available elements using demolition permits. It also intended to map available elements medium- term through detailed development plans, and long-term using comprehensive plans.  The results showed that the medium-term span mapping was not plausible as there are too many detailed development plans and no feasible way to review them due to how they are accessible to the public. The long-term mapping showed potential in identifying characteristics of different areas and indicating where demolitions or transformations might occur. Given there might be a paradigm shift in the way the industry manages resource, as policy and industry goals indicate, the areas where demolition is planned today might be transformed tomorrow. The short-term mapping was the most promising method developed. It showed that significant amounts of heavy structural elements will be available within two years. The buildings with heavy structural elements that are now up for demolition are mostly from the 1960-1980s and are principally all non-residential. 16 different structural typologies were identified and evaluated for reuse potential. Four typologies were highlighted as especially valuable for reuse: 1) cast in-situ reinforced concrete structure 2) prefabricated reinforced concrete elements structure 3) brick structure from before 1960 and 4) steel structure. The dominant structural material was concrete, which was the core material in 93% of the total area found. To test the method’s usefulness and reveal implications on the design process, it was used for an ongoing residential project by developer NREP and architects Tengbom and Lendager Group. The case study showed that suitable structural elements could be sourced for the project with the short-term mapping. A new design proposal for the structure was made with elements from the mapping, which was estimated to avoid significant environmental impact compared to a new structure. According to international studies on this type of reuse, over 90% of CO2-equiv. emissions for new buildings can be saved reusing prefabricated concrete panels. For the design process, the implication of reuse is often an elongated introductory phase. The case study showed that studying grids and proportions of the existing system was essential to transform it into a new one, allowing the process to be more material-driven. Considerations on how to use the elements to minimise waste and environmental impact from preparing the elements for reuse are imperative when designing the system.  It could be argued that waste is a design error, highlighting the need to educate new cohorts of architects and designers in designing for reuse. Potentials for reuse lie in maintaining the value of the structural elements, instead of paying to get rid of them, and to avoid large negative environmental impacts for raw material extraction and production. Projects realised today have shown large savings in CO2-equivalent and costs alike. Nevertheless, it requires innovative and non- conventional organisation and roles. Cooperation and trust amongst stakeholders is key. The design process needs to become more collaborative and iterative with higher frequency of information exchange. This requires designers, architects and engineers to look both backward, to understand the existing buildings and materials that we can use, and forward, in how to use them going forward with innovative strategies for project plausibility, the environment and great (longstanding) architecture. / Byggande och avfall står för en stor del av all negativ miljöpåverkan i världen. Sätt att minska material- och energianvändningen inom byggsektorn har därför varit i fokus för studier i årtionden. Återbruk av byggnadselement och material har ökat i intresse hos forskare, arkitekter, utvecklare och fastighetsägare senaste åren. Trots det implementeras det sällan i praktiken i Sverige. Barriärer för återbruk inkluderar rädsla för fluktuerande utbud, kvalitetsgarantier, logistik, bristande erfarenhet i designprocessen och brist på tillgänglighet. Många forskningsprojekt pågår men det saknas en process för hur man identifierar och lokaliserar material. Dessutom finns det för närvarande lite samband mellan forskning och praktik, och liten insikt i de långsiktiga konsekvenserna som återbruk kommer att ha på designprocessen och arkitektens roll. Därför är syftet med denna studie att ta reda på vilka tunga stomelement som kommer att finnas tillgängliga för återbruk i Stockholmsregionen och att undersöka konsekvenser för hur återbruk kommer att påverka designprocessen och arkitektens roll. Studien utvärderade en ny metod för kortsiktig kartläggning av tillgängliga stomelement med hjälp av rivningslov, samt utforskade kartläggning av tillgängliga stomelement på medellång sikt genom detaljplaner och på lång sikt med översiktsplaner.  Resultaten visade att kartläggningen på medellång sikt inte var möjlig eftersom det finns för många detaljplaner och inget genomförbart sätt att granska dem på grund av hur de är tillgängliga för allmänheten. Den långsiktiga kartläggningen visade potential för att identifiera egenskaper hos olika områden i Stockholm och indikera var rivningar eller omvandlingar kan inträffa. Med tanke på att det kan komma ett paradigmskifte i hur industrin hanterar resurser, som policy och branschmål indikerar, kan de områden där rivning planeras idag komma att transformeras i morgon. Den kortsiktiga kartläggningen var den mest lovande metoden som utvecklats. Den visade att betydande mängder tunga stomelement kommer att finnas tillgängliga inom två år. De byggnader med tunga stomelement som nu ska rivas är till största delen från 1960-1980-talet och är generellt kontor och industribyggnader. 16 olika stomtypologier identifierades och utvärderades för återbrukspotential. Fyra typologier lyftes fram som särskilt värdefulla för återanvändning 1) platsgjuten armerad betongkonstruktion 2) prefabricerad armerad betongelementkonstruktion 3) Tegelkonstruktion från före 1960 och 4) stålkonstruktion. Det dominerande konstruktionsmaterialet var betong som var kärnmaterialet i 93 % av den totala ytan som hittades. För att testa användbarheten av metoden och identifiera implikationer på designprocessen användes den i ett pågående bostadsprojekt av utvecklaren NREP och arkitekterna Tengbom och Lendager Group. Fallstudien visade att lämpliga stomelement kunde identifieras för projektet med den kortsiktiga kartläggningen. Ett nytt förslag för stommen gjordes med element från kartläggningen, vilket bedömdes undvika betydande miljöpåverkan jämfört med en ny stomme. Enligt en tysk studie kan denna typ av återbruk undvika 90 % av CO2-ekv. utsläpp under produktion och byggande genom att återanvända prefabricerade betongpaneler. Implikationen av återbruk på designprocessen är ofta en utdragen introduktionsfas. Fallstudien visade att det var viktigt att studera måttkedjor och proportioner i det befintliga systemet för att omvandla det till ett nytt, vilket gör att processen kan bli mer materialdriven. Överväganden om hur man använder elementen för att minimera avfall och miljöpåverkan från att förbereda elementen för återanvändning är absolut nödvändiga vid utformningen av systemet.  Avfall skulle kunna hävdas vara ett designfel, vilket understryker behovet av att utbilda nya arkitekter och designers i att designa för återbruk. Potential för återanvändning ligger i att bibehålla värdet på stomelementen, istället för att betala för att bli av med dem, och att undvika stora negativa miljöpåverkan för råvaruutvinning och produktion. Projekt som genomförs idag har visat på stora besparingar i både CO2-ekvivalenter och kostnader. Men det kräver et innovativ och icke-konventionell organisation och roller. Samarbete och förtroende mellan intressenter är centralt. Designprocessen måste bli mer kollaborativ och iterativ med högre frekvens av informationsutbyte. Detta kräver att konsulter ser både bakåt, förstår de befintliga byggnaderna och materialen som vi kan använda, och framåt, i hur man kan använda dem framåt med innovativa strategier för både genomförbarhet, miljö, bestående arkitektur.
18

End-Of-Life Wind Turbines in the EU : An Estimation of the NdFeB-Magnets and Containing Rare Earth Elements in the Anthropogenic Stock of Germany and Denmark / Uttjänta vindturbiner i EU: En uppskattning av tillgången på sällsynta jordartsmetaller i NdFeB-magneter i vindturbinsbeståndet i Tyskland och Danmark

Welzel, Lisa January 2019 (has links)
Securing rare earth elements (REE) for a stable supply require sustainable management strategies in Europe due to a missing local primary production and a dependence on China as the main producer of REE. These elements, like neodymium (Nd) and dysprosium (Dy), are contained in permanent magnets (PM) (mostly NdFeB-magnets) in wind turbines. Addressing the question whether PM-material, Nd- and Dy-contents from wind turbines could help to meet future demands of REE in Europe while reducing simultaneously the import dependence, the purpose of the present work was to analyze the urban mining opportunities, recovery - and recycling potentials for REE from end-of-life (EoL) wind turbines. This thesis aimed to identify current and upcoming stocks as well as material flows of the PM and their containing REE in the wind energy sector. Two European countries, Germany and Denmark, were chosen as case studies to be compared based on created future scenarios and the modeling of the theoretical recycling potential of Nd and Dy in both countries. It could have been identified that the German anthropogenic stock contains greater amounts of NdFeB-magnets and REE compared to the Danish stock. Overall it could be concluded that the countries’ demand could partly be met by using secondary Nd and Dy from the EoL-wind turbines. Although future scenarios were used, the results realistically illustrate the German and Danish anthropogenic stock until 2035 by relying on data of already installed turbines up to 2018, which makes an evaluation of capacities and EoL-turbines, which need to be decommissioned by 2035, achievable. The provided information is valuable for further investigations regarding recovery strategies, feasibility analysis, and future decision-making processes. / För att säkra tillgången på jordartsmetaller (REE) i Europa krävs hållbara beslutsstrategier. Detta på grund av avsaknaden av en inhemsk primärproduktion samt ett beroende av Kina som en huvudprodu-cent av REE. Jordartsmetaller som neodymium (Nd) och dysprosium (Dy), finns kvar i permanenta magneter (PM) (mestadels NdFeB-magneter) i vindturbiner. För att ta itu med frågan om huruvida Nd- och Dy-innehållet i PM-material, från vindturbiner skulle kunna bidra till att uppfylla framtida efter-frågan på REE i Europa samtidigt som importberoendet skulle minskas, var syftet med detta arbete att analysera möjligheterna till urban utvininng, återvinning och materialutnyttjande av REE från vindtur-biner i uttjänt tillstånd (EoL).Syftet med denna uppsats var att identifiera nuvarande och kommande tillgångar samt materialflöden av PM och därav följande REE inom vindkraftsektorn. Två europeiska länder, Tyskland och Danmark, valdes ut som fallstudier och jämfördes i framtida scenarier och mo-dellering av Nd -och Dy teoretiska återvinningspotential i båda länderna. Det kunde konstaterats att det tyska antropogena beståndet innehåller större mängder NdFeB-magneter och REE än det danska beståndet. Sammanfattningsvis kan man dra slutsatsen att ländernas efterfrågan delvis kunde tillgodo-ses genom att man använde sekundär Nd och Dy från EoL-vindturbiner. Även om framtida scenarier användes illustreras resultatet på ett realistiskt sätt det det antropogena lagret i Tyskland och Danmark fram till 2035 genom att man förlitar sig på uppgifter om redan installerade turbiner fram till 2018, vilket gör det möjligt att göra en utvärdering av kapaciteten och antal EoL-turbiner, som måste av-vecklas senast 2035. Informationen är värdefull för ytterligare utredningar om återvinningsstrategier, genomförbarhetsanalys och framtida beslutsprocesser.
19

Staden som gruva : I fäders spår för framtids segrar / Urban mining : Past, present and future of recycling of disconnected underground infrasystems

Gustafsson, Marcus January 2012 (has links)
Naturens mineralresurser är till viss del utnyttjade och uttömda, och framtiden är osäker och omdebatterad. Ingen vet säkert exakt hur mycket metall som finns kvar i jordskorpan, hur mycket som går att utvinna eller hur länge resurserna kommer att räcka. Samtidigt har vi byggt in rena metallådror i våra städer i form av elkablar, telekablar och fjärrvärmerör. Många av dem används givetvis, men många är också uttjänta och urkopplade, och därmed tillgängliga för återvinning.Syftet med denna studie är att klarlägga hinder, drivkrafter och möjligheter för metallåtervinning av urkopplade infrasystem i mark inom lokala el-, tele- och fjärrvärmenät i Sverige. För att uppnå detta tillfrågades Sveriges tio största ägare av underjordiska lokala elnät om bl.a. sina rutiner för urkopplade ledningar och genomförda projekt där ledningar tagits upp. Samma bolag frågades även om sina respektive fjärrvärmenät. Utöver dessa ingick telenätägaren Skanova, kommuner med anknytning till de tillfrågade nätägarna, metallåtervinningsföretag, entreprenörer och myndigheter i studien. Dessutom gjordes en litteraturstudie på området metallåtervinning.De viktigaste drivkrafterna för upptagning och återvinning av urkopplade infrasystem i mark visade sig vara ekonomi, utrymmeskonflikt i ledningsgatorna, krav i form av lagar, avtal eller egen policy, samt risk för miljöpåverkan. Alla förutom utrymmeskonflikt kan dessutom, beroende på omständigheterna, vara hinder för återvinning. En viktig möjliggörande faktor är att ledningens läge är känt och att den inte riskerar att förväxlas med andra ledningar.I dag är det vanligt att ledningar ligger kvar i marken en tid efter att de tagits ur bruk. I de fall de tas upp sker det ofta i samband med andra grävarbeten längs ledningen. Miljörisker, utrymmeskonflikter och krav kan tvinga fram upptagning av en ledning, medan ekonomi, med nuvarande metallpriser, är mer av ett hinder. Om återvinning av ledningar i mark ska bli norm krävs det att lönsamheten ökar. Detta kan ske genom ökade metallpriser, användande av alternativa metoder för upptagning, ett bredare synsätt som tar hänsyn till att återvinning kan minska behovet av primära metallresurser, eller kanske subventionering av återvunnen metall. Hårdare lagstiftning skulle kunna tvinga fram ökad återvinning, men för att alla inblandade ska vara med på det är det bättre att låta marknadskrafterna styra och att det baseras på frivillighet.Om återvinningen av infrasystem i mark ska ökas måste det göras insatser på flera nivåer. Nya metoder, som utvecklas av fristående entreprenörer, kan göra återvinning mer lönsam. Nationella mål och riktlinjer bör tas fram av Naturvårdsverket för att vägleda nätägare och markägare. Om ekonomiska styrmedel behövs måste det beslutas om av Riksdagen. Branschorganisationer och länsstyrelser kan samordna arbetet bland sina medlemmar och inom sina regioner. Markägarna måste sedan komma överens med nätägarna om vad som är lämpligt och vad som fungerar för just deras områden. / Earth’s natural mineral resources have, to some extent, already been used and depleted, and the future is both uncertain and debated. No one knows for certain exactly how much metal there is left in Earth’s crust, how much we can extract or for how long the resources are going to last. Meanwhile, we have installed ores of metal in our cities, in the form of electric cables, telecom cables and district heating pipes. Many of these are of course in use, but many have also reached end of life and been disconnected, and are thus available for recycling.The purpose of this study is to clarify barriers, drivers and enablers for metal recycling of disconnected underground infrasystems within the local electricity, telecom and district heating networks in Sweden. In order to do this, ten of Sweden’s largest owners of local underground electricity networks were asked e.g. about their routines and about projects where cables were taken up. The same companies were also asked about their district heating networks. Apart from these, the study included the telecom network owner Skanova, municipalities with connections to the ten electricity network companies, metal recycling companies, contractors and authorities. Furthermore, a literature study on metal recycling was conducted.The main drivers for taking up and recycling disconnected underground infrasystems proved to be economy, conflicts of space in the ground, rules and regulations in terms of legislations, contracts or company policies, and environmental impact risks. All of these, except for conflicts of space, could also, depending on the circumstances, be barriers for recycling. One important enabler is to know the exact position of the cables or pipes and that they don’t risk being confused with other cables or pipes.Presently, cables and pipes are commonly left in the ground for some time after they have been taken out of service. When they are eventually taken up, it is often done simultaneously with other digging operations along the cable or pipe. Environmental risks, conflicts of space and rules and regulations can force the excavation of cables and pipes, while economy, with current metal prices, is more of a barrier. If recycling of underground infrasystems is to become norm, the profitability needs to increase. This can occur through increased metal prices, use of alternative excavation methods, a wider view that takes into account that increased recycling can decrease the need for primary metal resources, or perhaps through subsidization of recycled metals. Tougher legislations could force a higher recycling rate, but in order to include all involved parts and not upset anyone, it is better to let the market drive and base it all on free will.If the recycling of underground infrasystems is to increase, efforts must be made on several different levels. New methods, developed by independent entrepreneurs, could make recycling more profitable. National goals and guidelines should be presented by the Swedish EPA, to guide and direct network owners and landlords. If financial instruments are needed, these must be decided upon by the parliament. Business associations and county administrations can coordinate the work among their members and within their regions. The landlords and the network owners must then agree on what is appropriate and applicable for their specific areas.
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Prvková analýza plochých zobrazovacích zařízení pro urban mining / Elemental analysis of the flat display devices for urban mining

Štípek, Radek January 2016 (has links)
aaaaaRare earth elements (Sc, Y and group 15 lanthanides) and their compounds currently have significant practical use in metallurgy, glass industry, as highly active catalysts for the production of so-called. NiMH batteries, alloys for the manufacture of permanent magnets and e.g. moderators rods in the nuclear energy, but above all they have an irreplaceable role in modern electronics for phosphors TV screens, CRT earlier today, PDP and LCD monitors and displays, tablets, mobile phones etc., which give them a high-quality picture and sound. Unlike most base and precious metals are concentrated in the conquerable ore deposits, occur in the form of compounds as part of mixed minerals in the rarely economically exploitable concentrations, a mining and processing is costly and negative impacts on the environment, paradoxically towards the title but their overall content in the crust is relatively high, the average concentration in the range of about 150 to 220 ppm. The main world producer of REE, China, in 2010, significantly reduced exports by 40 %, making prices of some REE increased up to 1500 % during the month. Demand for REE is growing, so often talks about the recycling of valuable materials back into production, as called. "Urban mining", ie "urban mining", thereby reducing the amount of...

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