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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.
1

Manufacturing processes and materials selection for a sustainable future

Kågesson, Gustav, Tahir, Zainalabidin January 2015 (has links)
This study focuses on different manufacturing processes and material choices for products that are designed to help the future to be more sustainable. These products were developed in a global project that explored the field and subfields of urban mining. This thesis is a part of that project and is meant to come with valuable input to the results. In this urban mining project two products were developed. The two different products that has been developed during this project is the NIX and the UM Factory. They work together with keeping material on the construction site when space is limited in order to reduce the transportation, both for the environmental benefit and also from a cost perspective. Together they will not only keep the material on the site but also refine them so they can be used again. This thesis will look into how these two products can be manufactured and what materials is a suitable choice for the products. These two factors were also thought about during the development of the products, both how to make it as simple design that was easy to produce while still fulfilling the requirements set. Also what materials might be a suitable choice for different parts of the products is considered, in order to be reliable, easy to work with, and relatively cheap. The study also explored some methods and materials that might be worth looking into in a few years. Methods and materials that today are undeveloped or not economically viable.
2

Urban Mining potential in local power grids: Hibernating copper and aluminium in Linköping

Andersson, Simon January 2013 (has links)
Power grids have a high content of metal, mainly copper and aluminium. When old cables reach their end-of-life, or in some way lose their intended purpose, they are usually left lying in their subsurface position. Material no longer used, but not yet discarded as waste, is in a state known as hibernation. Over time there is an accumulation of hibernating cables under ground that potentially could be recovered or “mined”. The aim of this study is to examine the total hibernating metal content of an urban, subsurface power grid, how it is distributed and also what reasons for disconnection are the most common. The focus of the study is the power grid of Linköping. Using a GIS based variant of material flow analysis the hibernating metal stock is examined both in terms of size and spatial distribution. The results of the study show a significant amount of hibernating copper and aluminium; in total 240 tons of metal were identified. By comparing the results with previous studies both similar and differing patterns appear. The main differences lie in the distribution of the stock within the city which is affected by the characteristics of the cities. When examining the reasons for disconnection continuous repair and maintenance work seems to be the most common reason for disconnection of cables. Further studies on how the characteristics of a city affects the formation of hibernating metal stocks in the infrastructure are suggested.
3

Urban mining i praktiken : Hur kan återvinning av markförlagda kablar integreras i infrastrukturs-planeringen och vilka kostnadsposter kan användas vid projektbererdning

Granberg Lomyr, Mikaela January 2017 (has links)
För att hantera den ökande befolkningen i världen behöver jordens resurser användas mer effekt vilket till exempel kan göras genom att återvinna material som inte längre fyller någon funktion. Området Urban mining handlar om att frigöra material som inte längre används i den urbana miljön och göra dem tillgängliga för nya produkter. I Sverige förläggs olika typer av infrastruktursystem i marken och när de inte längre används får de vanligtvis ligga kvar. Resursbasen som bland annat urkopplade elkablar utgör har identifierats i tidigare studier som intressant att ta upp i samband med markingrepp, då de innehåller värdefulla metaller. Att förädla malm till ren metall är dessutom mer kostsamt, ur både ekonomiskt och miljömässigt perspektiv, än att återvinna produkter som inte längre används.Studien har omfattat intervjuer med elnätsägaren i Linköping om hur beslut fattas kring elnätets förvaltning samt en praktisk pilotstudie i utvecklingsorten Vikingstad. Personer på olika strategisk nivå intervjuades och styrande dokument som ägardirektiv för verksamheten granskades. Därefter identifierades möjligheter och hinder för att kabelupptagning ska ske i större utsträckning än idag samt vart i den strategiska processen frågan behöver integreras. I Vikingstad var planen att både förnya och förstärka elnätet på sträckor där kablar som skulle kopplas ur låg. Under pilotstudien undersöktes vilka extra moment som upptagningen krävde, vad momenten innebar för kostnader, vilken tid de tog samt vilka intäkter som kabelskrotet genererade.Elnätsägarna regleras av energimarknasinspektionens intäktsram och branchorganisationen Svensk energi har en central roll för ökad och spridd kunskap hos Sveriges elnätsägare. Dessa två intressenter har därför viktiga roller i ställningstagandet om huruvida urkopplade elnätskablar ska tas upp eller ej. Hos elnätsägaren i Linköping är det när beslut tas om vilka förstärknings- eller förnyelseprojekt som ska genomföras som möjligheten till integrering av upptagning av urkopplade kablar bör undersökas. Detta då fallspecifika parametrar som fördelaktig ny sträckning och omkopplingsmöjligheter är avgörande för genomförbarheten. Resultatet från pilotstudien visar att fyra typer av moment är nödvändiga för att ta upp urkopplade kablar: ”schaktning och friläggning”, ”lyfta upp kabel ur schakt”, ”samla ihop kabel och kabelband” samt ”återställning”. Av dessa moment påverkar ”schaktning och friläggning” kostnaderna mest om extra djup krävs och ”lyfta upp kabel ur schakt” är mest kostsamt om det finns många andra system kring kabeln som ska tas upp. Det ekonomiska resultatet visar att tre procent av kostnaderna på sträckorna där kablar togs upp kan allokeras till upptagningen.Slutligen konstateras att fördelar som ökad miljöprestanda och frigjord plats för nya system i marken bör beaktas i större utsträckning hos elnätsägaren. Kostnader och intäkter kan också styras om för att motivera elnätsägarna mer, då upptagningen i dagsläget medför ökade kostnader för dem. För att underlätta budgetering av förstärknings- eller förnyelseprojekt med integrerad kabelupptagning presenteras kostnadsposter för de sammanslagna momenten upptagningen innebär, baserade på olika grundförutsättningar. Exempel på framtida studier för att öka kunskapen om och möjligheterna att ta upp urkopplade kablar är fler pilotstudier för att erhålla ett mer generaliserbart dataunderlag samt att undersöka hur ekonomiska värden av kabelupptagning kan fördelas mer fördelaktigt för elnätsägarna. / Städer som gruvor II
4

Recovery and Separation of Rare-earth Metals from Mobile Phones

Alkhater, Ali M. 04 1900 (has links)
Production and purification of rare-earth elements (REE) is among the most demanding separation practices. In general, extracting REE from natural ores requires a large amount of chemicals and energy. Separating the ores contents is also a complex process which needs a tremendous amount of organic solvent mixtures to produce high purity lanthanides. Partial mitigation to this issue lies in urban mining. Recycling old, discarded electronics is an important step in implementing the circular economy concept, making electronics more sustainable. In this work, specific components of old mobile phones were selected for targeted metal recovery. The main focus was on treating permanent magnets containing Nd, Pr and Dy as REE. These magnets were dissolved with nitric acid and the dissolutions were used to measure multicomponent adsorption in different polymeric commercial cationic resins. The adsorption of lanthanides on Amberlite IR-120 and DOWEX 50WX8 resins is found to reach equilibrium within 60 minutes. Across all the metals and lanthanides, Amberlite IR-120 has shown a greater adsorption. Generally, it is observed that more metals are adsorbed at higher pH values. This behavior seems to be consistent for both metals and lanthanides. The experimental data of the three lanthanides (Pr+3 , Nd+3 , and Dy+3) was fitted with diverse models and Sips rendered the best results. Freundlich and Langmuir models also provide satisfactory correlation coefficients
5

Designing for the Unknown : Exploring Urban Mining as a case study

Erlingsson, Oskar, Dahlqvist, Karin January 2015 (has links)
The earth’s resources are limited; with the speed that humanity are using earth’s resources today, we would need 1.5 times of the earth’s regenerative capacity to compensate for what we use. Raw materials has since a long time ago been mined from the bedrock, which affects the earth in a negative way. If we could use materials and products that are circulating in our society, but are not being used and thereby considered as waste, traditional mining could be replaced with urban mining. Imagine what would happen if earth’s resources would be limited by laws and regulations in the future; mining as it is known today would not be allowed and there would be a need of resources that is gathered in another way, an unknown way. The world is constantly changing and this results in the fact that there will always be unexplored areas that needs to be defined and developed to be able to handle the changes in the future. Considering the fact that urban mining is such an unexplored field, there is a need of creating a process to define the segment in order to develop product/services within it. The outcome of this thesis is therefore recommendations for how a generic design process can be tailored and implemented for innovation development in undefined areas. The result is reached through investigating a development project, which focuses in the research area urban mining, as a case study and also by studying design processes in theory. The investigation is conducted with an explorative approach by observing the field and sub-fields of urban mining. This thesis shows that drivers and trends for urban mining exist, and that there is a future need to capitalize this market. The result also shows that the most important characteristics of the design process when designing for the unknown, is the fact that defining the research area requires even more effort when dealing with an initially unknown field, compared with known research areas. / Jordens resurser är begränsade; med den hastighet som mänskligheten använder jordens resurser idag, skulle vi behöva 1,5 gånger jordens återhämtningsförmåga för att kompensera för det vi använder. Råmaterial har sedan länge brutits från berggrunden, vilket påverkar jorden på ett negativt sätt. Om vi istället skulle kunna använda material och produkter som cirkulerar i vårt samhälle, men inte används och därmed betraktas som avfall, skulle traditionell materialutvinning kunna ersättas med urban mining. Tänk vad som skulle hända om jordens resurser i framtiden begränsas genom lagar och regler; materialutvinning som det är känt idag inte skulle tillåtas och det då skulle finnas ett behov att samla resurser på ett annat sätt, ett idag okänt sätt. Världen förändras ständigt vilket resulterar i det faktum att det alltid kommer att finnas outforskade områden som måste definieras och utvecklas för att kunna hantera dessa förändringar i framtiden. Urban mining är ett sådant outforskat område och därför finns det ett behov av att skapa en process för att definiera segmentet och på så vis kunna utveckla produkter och tjänster inom området. Resultatet av denna uppsats är därför rekommendationer för hur en allmän design process kan skräddarsys och implementeras för innovativ utveckling i odefinierade områden. Resultatet uppnås genom att analysera ett utvecklingsprojekt, som fokuserar på forskningsområdet urban mining, som en fallstudie, samt att studera designprocesser i teorin. Undersökningen genomförs med ett explorativt tillvägagångssätt genom att utföra observationer inom ämnet urban mining. Arbetet visar att drivfaktorer och trender för urban mining existerar och att det finns ett framtida behov att utforska och dra fördel av denna marknad. Resultatet visar också att de viktigaste egenskaperna hos design processen vid utveckling inom okända områden är det faktum att forskningsområdet kräver ännu större fokus på att definiera området, jämfört med kända forskningsområden.
6

[en] EVOLUTION OF MOBILE PHONES TECHNOLOGY AND THE IMPACT ON THE WASTE OF ELECTRICAL AND ELECTRONIC EQUIPMENT / [pt] EVOLUÇÃO DA TECNOLOGIA MÓVEL CELULAR E O IMPACTO NOS RESÍDUOS DE ELETROELETRÔNICOS

FABRICIO ROBERTO SENA 06 November 2013 (has links)
[pt] Os produtos da indústria de eletroeletrônicos possuem alta empregabilidade no dia a dia. No entanto, por terem um ciclo de vida curto impactam na demanda por recursos naturais não renováveis. Dentro do universo de equipamentos eletroeletrônicos, os telefones celulares estão entre os mais complexos e os que empregam maior quantidade de elementos químicos diferentes. Apesar de pequenos, são vendidos aos milhares, em parte devido a sua curta vida útil. Esses fatores aliados indicam a existência de riscos à saúde e ao meio ambiente, o que faz repensar como destinar corretamente esses aparelhos no pós-consumo. A proposta do trabalho é fazer uma análise de como os telefones celulares impactam no volume e na complexidade dos Resíduos de Equipamentos Eletroeletrônicos, explicar a razão desse bem essencial ter uma vida útil tão curta e expor os motivos que tornam a sua reciclagem absolutamente necessária para continuar o seu desenvolvimento tecnológico, atender a demanda dos consumidores e reduzir o impacto ambiental da produção ao descarte. / [en] In the last century, through new production processes, the industry has increased the variety and availability of products offered to the population, providing better quality of life. This has happened because the inception of series production has offered a greater supply of consumer goods, including the Electrical and Electronic Equipment (EEE). The evolution of electronics technology has provided, and will continue to provide a better quality of life than the one we used to have. However, the technology of these products is continuously evolving, and this brings advantages and disadvantages.
7

Potential for Urban Mining in Norrköping : a Static Quantification of Metal in Subterranean Infrasystems

Andersson, Simon, Petersson, Johan January 2011 (has links)
As the society’s demand for metal increases, the rate of mineral extraction will do the same. This contributes to environmental implications in the form of emissions and depletion of finite natural resources. Conventional recycling is a common practice used to reduce the need for extraction of metal ore and in turn reduce the environmental impact. Recycling is an important source to satisfy the metal demand; as much of 30 % of the metal demand is covered by recycling in some markets. Another form of recycling is the practice of urban mining. A practice which includes recycling of society’s stocks of unused but not discarded metal, these unused amounts metal is part of a so called hibernating stock. An example of a very large stock is the infrasystems in the shape of power cables and pipes. The objective of this thesis is to quantify the metal stocks of copper, aluminium and iron in subterranean infrasystems in the city district of Södra Butängen in Norrköping. Also, a quantification for Norrköping as a whole is performed but on slightly different infrasystems. An economical valuation of these stocks is also performed. The Municipality of Norrköping has the ambition to transform this small industrial area, that Södra Butängen is today, into to a sustainability profiled residential and commercial area which opens up an opportunity to recycle the infrasystems when all buildings are removed and the ground is dug up. To fulfil the objective of the thesis, and quantify the metal stocks, so called static quantification was used. The infrasystems to be included in this study were chosen and the data describing these systems was collected from the respective owner of the systems. The gathered data consists of maps which were digitalized with GIS-software using ArcMap 10 where the stocks then were quantified. The results show that the infrasystems in Södra Butängen holds almost 600 tons of metal with an economical value of 4.67 million SEK. For the Norrköping quantification the results shows that the stock contains about 30,000 tons of metal. The economical value is a little over 70 million SEK. The hibernating stocks in Norrköping equals to 5,100 tons of metal and a value of 9.5 million SEK. There is a potential for urban mining in Södra Butängen that should be considered. However, there are some issues that also must be considered, like cost of extraction. There are large stocks of metal that not have been possible to identify in this thesis. This includes the power grid for Norrköping; a valuable stock due to its large copper content.
8

Laptops and smartphones - a gold mine? : A material flow analysis of small electronics in a Swedish organisation with focus on metal resources

Karlsson, Daniella January 2021 (has links)
The aim of this study is to contribute to today´s knowledge about stocks of electronic products on the organisational level. This is done by using a bottom-up MFA on laptops and smartphones in a chosen organisation, the data collected for this study is done by both semi-structured interviews and literature searches. Investigating the associated metals in the laptops and smartphones is also an aim of this study. Having knowledge of the existing stocks and flows of materials is important for the prospects of urban mining. This study takes a circular economy aspect of the current state of stocks and flows of materials. Circulation of materials within society is an effective approach to saving resources rather than just recycling the materials since not all materials can be retrieved through recycling processes. The results show that there is a significant stock of metals embedded in the laptops and smartphones in the organisation. Metals found include Aluminium, Magnesium, Copper, Iron, Nickel, Tin, Gold, Silver, Palladium, Zinc, Lead, Cobalt, Barium and Neodymium. The results also indicates that some of the laptop stock is in hibernation and so is the associated metals in these laptops. These stocks could be of big importance for future sources of metal resources, but more studies are needed to fully understand the stocks of metals in society and how much of these stocks that are in hibernation. / Gruvan i garderoben
9

Urban mining - Återvinning av byggnadsmaterial i främre Boländerna

Ekholm, Disa, Hallberg, Alice, Stenlund, Ellen, Wallsten, Johan, Westerström, Sara January 2020 (has links)
Boländerna är ett äldre industriområde i sydöstra Uppsala som ska omvandlas till en ny stadsdel. Med detta har frågan om utnyttjande av redan befintliga byggnadsmaterial i området uppmärksammats. Denna rapport har tagits fram på Uppsala kommuns och STUNS energi:s begäran för att ge förslag på åtgärder för en hög återvinningsgrad vid byggandet av främre Boländerna.  Med hjälp av tekniska beskrivningar bestämdes materialvolymerna av byggmaterialen betong, gips, tegel, trä och stål i fem byggnader i det blivande rivningsområdet. Litteraturstudier gav information om materialen och dagens återvinningsprocesser samt data från livscykelanalyser för de fem olika byggnadsmaterialen. En hållbarhetsmodell konstruerades med kriterier för att kunna jämföra de olika materialen. Denna modell användes som underlag vid bedömningen av huruvida återvinning och återanvändning av de olika materialen var miljömässigt lönsamt och hållbart. I hållbarhetsmodellen ingick även kostnader som ett kriterium. Resultatet visade att återvinning av samtliga material kan leda till miljöbesparingar. Stål visade sig ha hög klimatpåverkan både vid nyproduktion och återvinning, men enligt modellen var återvinning av materialet ändå fördelaktigt utifrån ett miljöperspektiv. Återvinning av trä respektive återanvändning av tegel visade mest hållbara resultat för alla kriterier i modellen utom kostnaden. I rapporten presenteras också ett urval av studier som kan bli relevanta för att i framtiden ytterligare öka återvinnings- eller återanvändningsgraden av materialen. Exempelvis en ny återvinningsteknik för betong som kan användas på rivningsplatsen vid namn Concrete to Cement and Aggregate (C2CA). I studien undersöktes även åtgärder för att minska klimatpåverkan vid bygg- och rivningsprojekt i Uppsala kommun. Det framkom att materialinventering, noggrann planering av avfallshantering och transport samt tydliga styrmedel och miljöcertifieringar kan bidra till ett ökat fokus på hållbarhet inom byggbranschen och därmed minska dess klimatpåverkan.
10

Exploring the potential for local end-processing of e-waste in South Africa

Sadan, Zaynab 29 January 2020 (has links)
E-waste is one of the fastest-growing waste streams in the world, and South Africa (SA) is no exception. This is driven by increased consumer demand and access to electrical and electronic equipment, in addition to perceived equipment obsolescence, and rapid advancements in technology. E-waste recycling presents an opportunity in providing a source of secondary resources such as metals, plastics and glass, as well as employment and economic opportunities in both developed and developing countries. Furthermore, the diversion of this waste stream from landfills or dumps prevents additional land use and the potential negative impacts on human health and the environment. E-waste collection and upgrading is a relatively small-scale but growing industry in SA. Only 12% of e-waste generated was estimated to be recycled in 2015. Most of SA’s ewaste volumes are inaccessible due to lack of formal take-back schemes, lack of consumer awareness, as well as e-waste being kept in storage or disposed of in landfills. E-waste recyclers in SA generally carry out collection, dismantling and sorting, refurbishing, as well as pre-processing of value fractions. There is currently limited local end-processing capacity, therefore partially upgraded value fractions are prepared for export, while non-viable fractions are stockpiled or disposed of in local landfills. The business case for local end-processing of e-waste value fractions, particularly metals, does not seem feasible due to the inconsistent and insufficient volumes available. Furthermore, SA faces unique socio-economic challenges such as an unregulated yet well-established informal sector. Additionally, the legal framework presents many inhibitors for e-waste recyclers. This research study builds upon the knowledge that there is a limited understanding of the feasibility of existing e-waste end-processing technologies for implementation in the South African socio-economic and legislative context. Therefore, this research intends to find out what are the key barriers and enablers to implementing e-waste end-processing technologies in SA. Qualitative research methods were used to uncover the current challenges faced by local recyclers and other stakeholders in the value chain. The data collection thus took the form of interviews, site visits and desktop research. The findings show that the e-waste recycling industry in SA is undergoing many new developments in terms of research and investment interest, as well as the anticipated outcomes from the recent submissions of Industry Waste Management Plans (IndWMP). The industry shows potential as an emerging secondary resource economy, however, the extent to which it will mature is dependent on the organisation of its collection network as well as the development of local end-processing and manufacturing capacity. The collection network and infrastructure are currently supported by both informal and formal recyclers who provide a diversity of collection strategies and a wide network of ewaste sources. However, efforts to increase recycling rates by accessing volumes in storage and increasing consumer awareness and engagement is necessary. Besides the economies of scale required to support the development of local end-processing, alternative technologies to large-scale smelting should be considered for the SA context. While this is seen through initiatives by SA Precious Metals, end-processing technologies is still inaccessible to small and medium recyclers due to cash flow issues as well as cherry-picking of high-grade materials. Therefore, recyclers require further support in terms of dealing with non-viable fractions. This includes research and investments into technologies and business models for the recycling of low-value materials including plastics, as well as subsidies for the cost of safe disposal or treatment of these fractions. Additionally, acquisition of product markets and an increase in manufacturing capacity is necessary to accelerate industry development. The legislative framework also poses limitations on recyclers in the e-waste value chain, stemming from the legal definition of e-waste as a liability as opposed to a resource. While the legislation is unlikely to change, provisions to relieve any legal barriers should be implemented. This includes permissions for pilot projects to test new technologies, as well as legal support for smaller recyclers in the form of consultancy as well as guidelines for sustainable waste management practices should be provided. Finally, while there are many challenges present in the e-waste recycling industry today, the IndWMP offers an opportunity for collaboration between key stakeholders, including the relevant government bodies. Plans have been submitted and the outcomes of approved plans will be revealed at the beginning of 2019. The plans offer solutions for recycling subsidies, increasing the collection and recycling rates, as well as investment into technology, research and enterprise development. However, successful implementation of these plans will only occur if integration and collaboration of the local e-waste community prevail over greed and the struggle for power.

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