The EU funded PROSUM research project looks at ‘Prospecting Secondary raw materials in the Urban mine and Mining wastes’. The more than 15 institutions participating in the project have recently published their findings in a final report.

The report has some interesting Sankey diagrams on market input, stocks, waste generation and waste flows for product groups such as vehicles, batteries, precious materials and selected critical raw materials (CRMs) contained in batteries, electrical and electronic equipment (EEE) and vehicles.

Here is the diagram for vehicles in the EU28+2 (=EU28 plus Switzerland and Norway) market. Data relates to the year 2015.

Flows are in tons and ktons, blending two scales in one diagram. This merits its own post, I think. (read it here)

The electric vehicles currently driving on the roads are shown as “Stock”, meaning that the materials are in use and that they could eventually be recovered at the end of the life of the vehicle. This is the large stackd bar between “POM” (placed on market) and “De-reg Vehicles”. Again this stacked bar uses two different scales (tons and ktons).

Official report citation: Jaco Huisman, Pascal Leroy, François Tertre, Maria Ljunggren Söderman, Perrine Chancerel, Daniel Cassard, Amund N. Løvik, Patrick Wäger, Duncan Kushnir, Vera Susanne Rotter, Paul Mählitz, Lucía Herreras, Johanna Emmerich, Anders Hallberg, Hina Habib, Michelle Wagner, Sarah Downes. Prospecting Secondary Raw Materials in the Urban Mine and mining wastes (ProSUM) – Final Report, ISBN: 978-92-808-9060-0 (print), 978-92-808-9061-7 (electronic), December 21, 2017, Brussels, Belgium

A study on key raw materials and their flows “through the EU economy, as raw materials or as parts of basic materials, components or products” has been produced by BIO Intelligence Service for the European Commission, DG GROW (BIO by Deloitte (2015) Study on Data for a Raw Material System Analysis: Roadmap and Test of the Fully Operational MSA for Raw Materials. Prepared for the European Commission, DG GROW).

It contains Sankey diagrams for 28 materials considered critical or important to European economy, such as cobalt, lithium, or tungsten.

The flows of these materials into the EU-28 geographical area (imports) as well as out of the EU-28 (exports) are displayed for all substances in the same way. Recycling of the substance within Europe is represented as a loop, leading to a kind of see-saw-ish diagram. Additions to in-use (e.g. the substance being part of a product in use) and a certain amount of the substance being disposed off (e.g. as waste) are also shown as arrows to the right. Below is the diagram for cobalt. Flows are in tonnes for the year 2012 (t/y).

All Sankey diagrams are color-coded the same-way, providing additional information whether the material (in the case above: cobalt) is imported as raw material or as part of a product, and whether it is exported as processed material, waste, or also as part of a product.

The study can be downloaded from this page or directly here (PDF, 6 MB)

Digging through some long untouched folders on my hard disk, I found this schematic Sankey diagram of iron and steel flows.


Schematic? Well, no quantities or units given, no time reference, no source of data. And no idea as to who the author is. Just take it as another miscellaneous Sankey diagram.

This presentation from 2015 by Alicia Valero of the Spanish Research Centre for Energy Resources and Consumption (CIRCE, Zaragoza) is on critical materials, minerals scarcity, recycling and a “thermodynamic cradle-to-cradle approach”.

It features two Sankey-style diagrams depicting the mineral balance of the European Union (UE).

This first one is a Sankey diagram for the mineral balance without fossil fuels (‘Diagrama de Sankey para el balance mineral de la UE sin combustibles fósiles’).

Data is for the year 2011, Flows are shown in tons. Iron and limestone dominate the picture with 77% of the input. Limestone is produced (extracted) mainly within Europe, while iron is mostly imported.

The second Sankey diagram is a scarcity diagram (‘Diagrama de rareza para el balance mineral de la UE sin combustibles fósiles’) and takes into account thermodynamic exergy to obtain (mine) the minerals. Although it depicts aluminium, gold, ion, nickel and the likes, flows are shown in an en(x)ergy unit (Mtoe).

Iron and limestone which seemed to be the most important mass-wise only constitute some 10% of the input. Aluminium and potash seem to be much more difficult to produce. Rare earth elements (REE) are not included in this diagram.

The author points out that it is important to not only look at materials from a mass perspective. Looking at materials availability taking into account thermodynamic exergy paints a different picture of the real cost and scarcity.

For those interested, please check out the presentation (in Spanish) here.

The Australasian Institute of Mining and Metallurgy (AusIMM) is an association of the minerals industry. In this AusIMM Bulletin article titled ‘From Waste to Wealth’ they talk about metal recovery and recycling in Australia.

This Sankey diagram (actually two Sankey diagrams) from the article visualizes metal flows in Australia in 2012/2013 based on data from Golev & Corder (2014).

The smaller yellow diagram section on the left actually just shows mining activities in Australia and the fact that the largest portion of mining output (ores) are exported. Only 7.5 Mt are processed within Australia. This Sankey arrow is then blown up and corresponds to the yellow input stream into the second diagram [a similar solution to decouple diagrams with different scales was presented in yesterday’s post].

In the metal production process there are losses, and material is being exported and imported. The annual increase to the Australian ‘in use stocks’ (i.e. metals being used infrastructure, buildings and products) is 12 Mt, possible only thanks to 7 Mt metals imports. Some 7 Mt of metals are also released annually from ‘in use stocks’.

The dotted lines signal that there are possible routes, but either outside the scope of the Australian market or no reliable data is available (new scrap from the manufacturing step being fed back to the smelting).

Happy New Year to all followers! Kicking off with a distribution diagram (aka ‘alluvial diagram’) for cobalt (chemical element ‘Co’) by the Geospatial Engineering Research Group at the University of Newcastle, taken from the article ‘Sankey diagram of cobalt life-cycle’ on their blog.

This shows the mining, refining, manufacturing and use stages for cobalt broken down by continent.

Not sure what the orange and green arrows stand for, or what the unit is. Also, there seems to be a mismatch between the input and the output quantitites at some nodes (check, for example, cobalt flows received from mining countries for refining in Europe compared to the deliveries to the manufacturing stage).
This could be due to mismatches in data from the different sources, or caused by changes in cobalt stocks (i.e. Europe mining and importing less but reducing stocks from previous year, thus being able to ship more to manufacturing in the same period). Maybe one of the authors wishes to comment?

Checking further on the authorship of the Sankey diagram I presented in this post, I came to the LCMP website at the University of Cambridge. LCMP? Yes … Low Carbon and Metals Processing. The engineering research group around Julian Allwood and Jonathan Cullen have three large research themes: WellFormed, WellMet2050, and WellMade.

The below Sankey diagrams are from the report ‘Going on a metal diet’ by Allwood, Cullen et.al. published within the WellMet2050 research theme.

The first Sankey diagram shows the global steel flows in 2007

the other the global aluminium flows in 2007:

One page 7 of the report the authors explain

“In our maps, the width of each line is proportional to the mass flow of metal. Values for the major flows are given in Mt (million tonnes). Steel flows less than 1 Mt and aluminium flows less than 0.05 Mt are not shown. Each major process step is shown as a vertical black line, with three possible outputs: useful metal (colored), process scrap (grey) and metal losses (black). Useful metal continues to flow to the next process step, while scrap loops back to the appropriate melting stage where it is recycled. Internal recycling loops, for example from the continuous casting processes for steel are shown small oval loops. (…)The working papers … give more detail about creating the Sankey diagrams

Unfortunately these two mentioned working papers are not (yet?) available on the website. These really fantastic Sankey diagrams have been compiled from different data sources. I thought I’d share them with you. Please visit the LCMP website and read about their other exciting projects.

Found the Sankey diagram below in an article on ‘Exergetic efficiency analysis of pyrometallurgical processes’. It is from a master thesis by Bart Klaasen (PDF file), that contains several Sankey diagrams.

The main diagram is titled ‘Exergetic Sankey diagram for a zinc recycling process’. Input streams are in blue, emission streams are in red. Internal flows are colored green, while yellow represents the actual product.

The flows don’t show arrow heads, but a general left-to-right direction can be assumed. No values in the above overall Sankey diagram, but for each process step individual input/output Sankey digrams can be found that feature exergy data in KJ. They look like this one:

In contrast to Sankey diagrams that represent energy flows, the input output flows into a process node don’t have to have the same magnitude. Exergy is synonymously called “available energy”.

“Energy is never destroyed during a process; it changes from one form to another (see First Law of Thermodynamics). In contrast, exergy accounts for the irreversibility of a process due to increase in entropy (see Second Law of Thermodynamics). Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings.” (Wikipedia)

So it is understandable that the exergy represented by the flow magnitude at the output of the process is less than the one of the flows on the input side.

NB: Bart’s article reminded me of some bookmarks to exergy diagrams I have, will try to post these in the near future too.