21.8: Summary
- Page ID
- 43537
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Recycling is currently a ‘hot topic’ in the political sense, and a challenging one scientifically. As the Earth’s resources become more energy-intensive to extract, recycling will move towards the forefront of scientific research and development.
It would seem common sense that recycling is the way forward for development. Unfortunately, until the economics of recycling are more beneficial than the economics of primary production, it will not become the primary source of metal. Increased research into methods for recycling that minimise energy expenditure – and therefore increase the economic appeal of recycling - requires the expertise of materials scientists and metallurgists.
In this TLP you have:
- Learned how statistics quoted about recycling need to be critically analysed before making any conclusions.
- Used thermodynamic and electrochemical principles from materials science to actually calculate the energy saved by recycling Aluminium.
- Explored the varied methods by which metals are sorted prior to recycling from a scientific viewpoint, recognising the key role materials science plays in developing recycling technology.
- Looked at the reasons behind separating metals before remelting, using materials science concepts to explain why this is necessary.
- Learned a little about the recycling process of automobiles – acknowledging that recycling of metals in this scenario has been a success.
It was the aim of this TLP to provide a taster for the huge range of different branches of materials science that contribute to metals recycling technology.
Going further
References
[1] USGS Minerals Yearbook, 2003.
[2] British Metals Recycling Association.
[3] Part III Materials Science Lecture notes © Dr R.V. Kumar, University of Cambridge.
[4] WasteOnline website.
[5] Part 1A Materials Science Lecture notes © Dr J.L. Driscoll, University of Cambridge.
[6] Personal weblog of Haiko Hebig.
[7] Atlas of Electrochemical Equilibria in Aqueous Solutions, Pourbaix.
Websites
- An excellent website on aluminium can recycling, with information on starting recycling initiatives in your area:
http://www.alupro.org.uk/
- Recycling cars booklet by Toyota Motor Marketing Europe:
http://www.toyota.de/Images/Car_Recycling_Brochure_EN_tcm281-210236.pdf
- More information on electromagnetic induction
http://en.wikipedia.org/wiki/Electromagnetic_induction
- More information on eddy current generation
http://en.wikipedia.org/wiki/Eddy_currents
- More information on the production of magnesium by electrolysis – including more accurate technical data.
http://www.magnesium.com/w3/data-bank/article.php?mgw=81&magnesium=163