step webinar “the crt challenge”

Step Webinar “The CRT Challenge”

Rolf Widmer, Empa

What? CRTs are still alive?

ca. 1900

ca. 2000

Widmer "The CRT Challenge", Step Webinar June 2016 2

CRT issues

CRTs are replaced by new screen technologies: the world is confronted with large stranded CRT stocks.

Developing countries are at risk to become the final sink of CRTs because they are the last users and producers of CRTs.

They urgently need feasible options for alternative recycling and disposal routes.

Pb-free CRT glass has found a stable market in the container glass industry (Europe).

Pb-containing CRT glass is the issue - should be recycled or disposed to carefully selected applications.

Cathode Ray Tube (CRT) screens contain 1 to 1.5 kg of Pb per screen. Pb is both toxic and (geochemically) rare. If available recycling options are not acceptable, an interim storage

should be considered where Pb-containing CRT glass remains under control and accessible.


CRT components


cathode

cone glass

shields

frit glass (solder)

front glass fluorescent screen

deflecting unit

electron beams

neck glass

shadow mask

35% of glass is funnel, neck and frit 10 to 25% of funnel is PbO

up to 85% of display is glass

up to 65% of glass is Pb-free panel

Comparison of CRT glass demand vs. supply


Global supply and demand (for production of new CRTs) of CRT glass cullet Source: Gregory et al., 2009

Evolution of CRT globally [t]


-

500 000

1000 000

1500 000

2000 000

2500 000

3000 000

3500 000

4000 000

2009 2014 2017

Evolution CRT glass in globally WEEE generated

Non-Pb GlassPb Glass

-

200 000

400 000

600 000

800 000

1000 000

1200 000

1400 000

2009 2014 2017

Pb-glass regional generation

Oceania

Europe

Asia

Americas

Africa

Evolution of CRT in Europe


0

200000

400000

600000

800000

1000000

1200000

2011 2013 2015 2017 2019 2021 2023

Tota

l Mas

s /

t

Evolution CRT glass in WEEE generated

Non-Pb Glass

Pb Glass

-

200 000

400 000

600 000

800 000

1000 000

1200 000

1400 000

2011 2013 2015 2017 2019 2021 2023

Tota

l Mas

s /

t

Evolution of CRT-TV & PC Waste Generated in EU28 ++ (35 countries)

Simulation and measured CH-Data (2015) average lifetime: CRT-TV 10 Jahre, CRT-PC 7 Jahre (Gaussverteilung)


CH CRT-Glas forecast 2016 - 25


CRT treatment in CH


CRT treatment in CH and EU


Eliette Restrepo, Rolf Widmer, Mathias Schluep

StEP review till end of 2015: Federico Magallini, Jaco Huisman, Colton Bangs, Patricia Whiting, ... Outsider: Jhoanna Rosales, Andriana Kotovrakis, ...

Recycling and Disposal Options for Leaded Glass from CRTs

Questions we wanted to answer

1. What are alternative recycling and disposal options for CRT leaded glass, especially for developing countries? (Literature review *)

2. Which recycling or disposal option is better technically, environmentally and economically? (Multiple Criteria Decision Analysis (MCDA) **)

3. What are the consequences of implementing a recycling option in the demand and supply of raw materials replaced? (Comparison of demand and supply of CRT leaded glass for each option worldwide)


* approx. 100 references ** V. Belton, and T. J. Stewart, Multiple Criteria Decision Analysis: An Integrated Approach, 2nd ed. Norwell, Massachusetts USA: Kluwer Academic Publishers, 2003.

Smelting flux (e.g. for Cu smelting) Crystal glass

Alternative recycling: 8 options

Clay bodies Foam glass Concrete

Recycling CRT to CRT (close-loop)

Hazardous waste landfill

Disposal/Storage: 3 options

Backfilling old mines

Lead metal (e.g. for batteries)

Ceramic glazes

Waste vitrification glass

Interim storage of glass cullet

No longer possible

Feasibility scale

High Medium Low

Results (1/2)


Application Pb glass demand/Mt Lead metal for batteries 139.66 Waste-vitrification glass n.i. Smelting flux 0.12 Clay bricks 26.25 Ceramic glaze 0.09 Concrete 3'470.92 Crystal glass 0.02 Foam glass n.i.

Results (2/2)


Application # CRT supply / demand Concrete 200 000 000 000 0.0003 Lead metal for batteries 8 200 000 000 0.007 Clay bricks 5 100 000 000 0.01 Smelting flux 6 900 000 8.5 Ceramic glaze 5 300 000 11.2 Crystal glass 1 100 000 53.0

Themes Technology Health and

Environment Economy

Criteria Material

replacement Global

demand Indispensability

of Pb Pb

leaching

Retrievability

from application

Price of material replaced

Importance Medium Medium High High Medium Medium

Scoring method A A C B A B

Scoring methods

A

B

C

Ranking and assigning score equal to ranking position [1,2,3…n] ; n = number of options evaluated

Binary score [0,1] ; 0 = properties of lead are not required / does not comply with permitted levels 1 = properties of lead indispensable / complies with permitted levels

Ternary score [1,2,3] ; 1 = irretrievable 2 = moderate retrievability 3 = retrievable

Assessment method


Multi-Criteria Decision Analysis (MCDA *)

Score Table (sorted according total score)

Options Evaluation criteria overall score

(geom. average)

Product main application

Technology Health & Enironment Economy Material

replacement Global

demand Indispensa-bility of Pb

Pb leaching Retrievability

from application

Price of material replaced

Options for Open-loop Recycling metal. lead car batteries 11 6 1 1 3 9 1.97 Flux Cu- & Pb-

smelter 3 4 1 1 2 6 1.57

Vitrification Nuclear wastes 11 1 1 1 1 7 1.48 Glaze floor tiles 4 3 0 1 1 6 - Bricks above ground 5 5 0 0 1 5 - Concrete above & under 2 7 0 0 1 4 - Cristall glass stem ware 11 2 1 0 1 8 - Foam glass therm. insul. 1 1 0 0 1 6 -

Options for Disposal Interim storage 11 1 1 1 3 1 1.37 Landfill 11 1 1 1 2 1 1.32 Backfill 11 1 1 1 1 1 1.24


overall score: geometric mean (based on Cobb–Douglas and mariginal utilities)

𝑆 = 𝑠𝑖

𝑛

𝑖

𝑛

Swicos' Bildröhrenmanagement bis 2020

Stand Ende 2015

R. Widmer

An interim storage for Swiss CRT-cullets

max. storage amount decreases sharply with a later AD failure

the destocking depends on the runoff (here 600 t/a as flux in Cu Pb smelter)

costs depend on the requirements for pre-processing of CRT (cleaning & sorting of cullets prior to storing)

cumulative Siwss CRT glass stocks, if AD fails and MC stays (lines for year of AD failure)


Conclusion

Pb is both toxic and rare: recycling options to "dilute" the lead contained in CRT glass should not be a solution!

Currenly best open-loop recycling options: 1. Use leaded glass to extract the lead for lead-acid battery production

(however, Pb batteries may decline together with ICE-car production) 2. Use leaded glass as smelting flux in Cu and Pb smelters (however, current

demand is 8x lower than potential supply) 3. Use leaded glass to vitrify waste (e.g. nuclear waste, however, this is not

widely tested yet) Interim storage is the most attractive disposal option. Future

applications of Pb are in sight (e.g. solar pv cells) None of the options are profitable, a financing strategy/scheme for

attractive options (e.g. smelter, storage) needs to be defined/implemented


Webinar discussion points

The assessment results depend on the scoring scheme. Ours has 2 'killer indicators' (yes/no) (based on legal requirements) Pb techn. required and possible Pb leaching. Is this biased? how to improve?

If an interim storage option is pursued what are the implications (technical, financial, legal, ...) in particular for developing countries?

...


Thank you!


Indicators, e.g. demand for CRT glass For glass replacements

𝐷𝑖 = 𝑤𝑥𝑖 × 𝑤𝐶𝐶𝐶𝑥 × 𝐺𝑖 Where: Di = Demand of CRT glass for recycling option i worldwide; in mass units wxi = Mass fraction of material x (to be replaced by CRT glass) in product i wCRTx= Mass fraction replacement of material x by CRT glass in product i Gi = Global production of product i

For lead metal replacements

𝐷𝑖 = 𝐷𝑓𝑓𝑤𝑓

; 𝐷𝑓𝑖 = 𝐺𝑃𝑃𝑓𝜀𝑃𝑃

× 𝑀𝑟𝑃𝑃𝑟𝑀𝑟𝑃𝑃

Where: Dfi = Demand of CRT leaded glass for production of product i wf = Mass fraction of CRT leaded glass in CRT glass GPbi = Global demand of Pb for production of product i εPb = Efficiency in Pb recovery from CRT leaded glass MrPbO = Molecular weight of PbO MrPb = Molecular weight of Pb


Indicators of open-loop recycling and disposal options


Optionen Bewertungskriterien potenzieller CRT

Jahres-bedarf

Quellen Produkte Hauptanwendung Technologie Gesundheit + Umwelt Wirtschaft

möglicher Rohstoffersatz durch Bleiglas

weltweite Bleiglasnachfrage

Unerlässlichkeit von Blei

Blei-Auslaugung in Wasser, Boden

und Lebensmittel

Rückgewinnbarkeit von

Blei

Marktreis der er-setzten Rohstoffe

kg/kg Mt ja/nein mg/l hoch/mittel/ tief

USD/t Millionen

Optionen für Open-loop Recycling metallisches Blei Starterbatterien 1 48.88 ja n.i hoch 1'994 8'000 [50], [51],

[53]–[56], [58], [59]

Flussmittel Cu- & Pb-Hütten 0.1* 1.18*** ja 0.01 tief 44.78 6 [58], [66] Beton Hoch- & Tiefbau 10% volume of

fine aggregates 1 214 nein 1.42 tief 7.65 204'000 [58], [74],

[101] Tonziegel Hochbau 0.03 26.24 nein 1 tief 10 5'000 [64], [65] Schaumglas Wärmeisolation 1** n.i. nein 0.1 tief 44.78 n.i. [51], [58],

[79], [102] Keramikglasur Bodenfliessen 0.5* 0.03 nein n.i. tief 44.78 5 [41], [58],

[72] Kristallglas Trinkgläser 1 0.01 ja 0.6 tief 97.8 1 [58], [80],

[81], [85] Vitrifikation Nuklearabfälle 1 n.i. ja n.i. tief 87 n.i. [58], [90]

Optionen für die Beseitigung Reststoffdeponie 1 n.a n.a n.i. tief n.a n.a [15], [93],

[94] Bergbauversatz 1 n.a n.a n.i. tief n.a n.a [95], [96] Zwischenlager 1 n.a n.a n.i. tief n.a n.a -

World's prim. and sec. Pb production

International Lead Association, http://www.ila-lead.org, 07.12.2014 International Lead & Zinc Study Group, http://www.ilzsg.org/static/, 07.12.2014


Pb batteries absorb 85% of the lead demand

International Lead Association, http://www.ila-lead.org, 07.12.2014


addendum

Perovskite solar cells

perovskite

some links: solar technology Empa news (tandem cells)


A perovskite is any material with the same type of crystal structure as calcium titanium oxide (CaTiO3), known as the perovskite structure ... Perovskites take their name from the mineral, which was first discovered in the Ural mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist L. A. Perovski (1792–1856). (wikipedia)

http://www.omagdigital.com/publication/index.php?i=-288779&m=23867&l=1&p=10&pre=#%22page%22:10,%22issue_id%22:288779

https://www.empa.ch/web/s604/tandem-solar-cells

http://www.nrel.gov/ncpv/images/efficiency_chart.jpg

https://en.wikipedia.org/wiki/Perovskite_(structure)

https://en.wikipedia.org/wiki/Perovskite_solar_cell

Legal requirement CENELEC Norm 50625

The handling of intact CRT devices must not damage to the tube. The necessary measures have to be documented i.e. collection, logistics / transport operators as well as dismantlers must document and possibly prove their effectiveness

Contaminated CRT cullets (phosphor and Pb-glass dust), but probably also vented CRTs must be considered hazardous waste and handled accordingly i.e. it requires "*" waste codes and probably bilateral notifications

The release of pollutants (phosphors and Pb-glass dust) to air and water must be prevented. i.e. explicit evidence is required; it is questionable if current bulk transport is conform

Smashing the CRT and the removal of the phosphor at two distant places is not explicitly prohibited, thus probably tolerable; however, phosphor and Pb-glass dust must be removed prior to any use of the cullets. Thus a future interim storage would require the cullets to be cleaned.


Legal requirement CENELEC Norm 50625

Phosphors should be recycled. Since phosphors and other coatings are already removed from CRTs in wet or dry processes and thus can easily be obtained in a concentrated form, a mandatory recovery of rare earth metals such as europium and yttrium is possible given commodity prices are attractive.

Storage and transport containers for CRTs, which are likely to be contaminated with phosphor and Pb-glass dust, must be cleaned accordingly.

The effective removal of the CRT from the EoL devices and the separation of the leaded glass and the phosphor from the resulting fractions has to be verified in accordance with the future Technical Specification TS 50625-3-3, "Collection, logistics and treatment requirements for WEEE - Part 3-3: Specification for de-pollution - WEEE Containing CRTs and flat panel displays".


step webinar “the crt challenge”

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