Overview of the Hydrometallurgical Processes for the Recovery of

Metals from WEEE

HIGH TECH RECYCLING

INTER-UNIVERSITY RESEARCH CENTER

I. de Michelis, F. Ferella, B. Bianco, P. Macolino, V. Innocenzi – University ofL’Aquila, Italy

F. Beolchini, L. Rocchetti – Università Politecnica delle Marche, Ancona, Italy

F. Pagnanelli, G. Granata, E.Moscardini – ‘’Sapienza’’ University of Rome, ItalyF. Vegliò - EcoRecycling, ItalyB. Kopacek - Austrian Society for Systems Engineering and Automation, Austria

Outline

• input material

• hydrometallurgical process

� block diagram� leaching� metal recovery

• What metal? What WEEE?

what metal? what waste?

• yttrium from fluorescentpowders of spent lamps

• indium from waste LCD

• yttrium and zinc fromfluorescent powders of wasteCRT

• lithium and cobalt from wasteLi-ion accumulator

Input material (1/6) - Lamps

• Fluorescent powder produced from the recyclingprocess of spent lamps (Relight, Milano)

Element %

Ca 25

Y 1.5-7

Ba 3

Mg 1.5

Mn 1

Fe 0.7

Pb 0.5

XRD:Y2O3, Ca5(PO4)3(OH), Ca5(PO4)2(SiO4)6 ,

BaSi2O5, Ca4P2O9

Input material (2/6) - CRT

• Fluorescent powder produced fromthe recycling process of waste CRT (Relight)

Element %

Al 8

S 12

K 4

Zn 14-35

Y 7.8-20

Cd 0.1-1

Ba 4

Pb 1-2 XRD:Y2O2S, Si, SiO2, ZnS, BaO, KFeS2,

Na3MnO4, Al(OH)3

Input material (3/6) - LCD

• shredded panel of LCD

SAMPLE

Al

(ppm)

Cu

(ppm)

Fe

(ppm)

In

(ppm)

Sn

(ppm)

Zn

(ppm)

Sr

(ppm)

1 N.D. 91 72 960 303 30 N.D.

2 2106 42 21 156 19 18 N.D.

3 762 2982 27 153 103 26 N.D.

4 573 6427 29 125 225 24 N.D.

5 321 N.S. 25 128 20 N.D. 109

6 289 N.S. 35 154 24 N.D. 97

(acid digestion of LCD panel pieces of about 1 cm)

Sample composition is variable.

Samples heterogeneity is probably due to particle dimensions (around 1cm), e.g. presence of part of PCB

on some pieces of LCD panel .

Input material (4/6) -LCD

Fine fraction is about 10% of initial weight

grinding and granulometric separation

� Leaching pre-treatments

Input material (5/6) - LCD

• Powder from the pre-treatmentof LCD

Samples are still heterogeneous

Sample Indium (ppm)

A 587

B 260

C 354

D 902

E 920

F 105

MIX 200

Input material (6/6) – Li ion batteries• Electrodic powder

Merceological analysis of Li-ion accumulator (% w/w)

hydrometallurgicalprocess

hydrometallurgy vs. pirometallurgy

� environmental sustainability

� feasibility for SMEs

hydrometallurgicalprocess

� block diagram

� leaching

� metal recovery

hydrometallurgicalprocess – lamps (1/3)� block diagram

block diagram ofthe processinvestigated in the larger scale

� leaching

-sulphuric acid-solid/liquid ratio: 20%;-acid concentration: 4N;-temperature: 70-80°C-time of treatment 3h.

Under these conditions yttrium extraction yields around 85% are observed. Sulfuric acid reduces

calcium dissolution

hydrometallurgicalprocess – lamps (2/3)

� yttrium recovery

-oxalic acid stoichiometric2Y3+ + 3H2C2O4 → Y2(C2O4)3 + 6H+

Ca2+ + H2C2O4 → CaC2O4 + 2H+

Under these conditions precipitation yield >90% and purity of yttrium oxalate > 95% are observed in the lab

-natural pH-room temperature-time of treatment 1h

Yttrium Oxalate:

precipitate recovered by centrifugation

hydrometallurgicalprocess – lamps (3/3)

hydrometallurgicalprocess – CRT (1/4)� block diagram

block diagram ofthe processinvestigated in the larger scale

� leaching

hydrometallurgicalprocess – CRT (2/4)

-sulphuric acid-solid/liquid ratio: 10%;-acid concentration: 4N;-temperature: 80°C-time of treatment 4h.

CRT

Solid waste after leaching

Under these conditions yttrium and zinc extraction yields are:

Y Zn

no-roasted ~ 80-90% <10%

roasted >90% ~ 100%

� yttrium and zinc recovery

hydrometallurgicalprocess – CRT (3/4)

- sodium hydroxide up to pH 4

- sodium sulfide stoichiometric(taking into account the reactions)Zn2+ + Na2S = ZnS + 2Na+

- oxalic acid stoichiometric(taking into account the reactions)2Y3+ + 3H2C2O4 → Y2(C2O4)3 + 6H+

Under these conditions Y and Zn precipitation yield obtained are>90% and > 95%, respectively, in the lab experiments.

Na2S

� yttrium and zinc recovery

hydrometallurgicalprocess – CRT (4/4)

Zinc sulphide

Yttrium oxalate

Production: Zn= ~0.3 g/g of CRT powder leached

Y= ~0.2 g/g of CRT powder leached

hydrometallurgical process – LCD (1/5)

block diagram and draft material balances

hydrometallurgicalprocess – LCD (2/5)

WASHING WITH WATER

Test N° H2O2 g/L FeSO4 g/L H2O2 / FeSO4

1 5 2,00 20

2 10 2,00 413 7,5 3,00 20

Concentration (mg/L)

Al In Sn Zn

Washing 1 0,02 0,01 0,21 0,10

Washing 2 0,46 0,03 0,20 0,00

Test N° COD in. COD fin. COD rem.

(mg/L) (mg/L) (%)1 1326 838 382 1307 664 49

3 1292 522 60

Test Tens. in. Tens. fin. Tens. rem.(mg/L) (mg/L) (%)

1 2,02 0,10 952 1,99 0,06 973 1,97 0,15 92

WASTEWATER TREATMENT BY FENTON PROCESS

COD reduction around 50%

Surfactant reduction >95%

no indium significant loss in wastewater

� Leaching pre-treatments

hydrometallurgicalprocess – LCD (3/5)

� LeachingPreliminary experiments: effect of the acid

the leached samples

HCl H2SO4 HNO3

Cu (mg/kg) 100 108 71

Fe (mg/kg) 59 144 72

In (mg/kg) 996 1029 928

Sn (mg/kg) 330 339 274

Zn (mg/kg) 36 38 31

temperature 80°C, 5% S/L ratio

extracted metals

In extraction >95%

hydrometallurgicalprocess – LCD (4/5)

� Leaching

indium extraction yields >95% are observed.

WASHED SAMPLES

-sulphuric acid-s/l ratio: 30%;-acid 1M;-temperature: 80°C-time 3h.

hydrometallurgicalprocess – LCD (5/5)

� Indium recovery

0

100

200

300

400

500

0 2 4 6 8

Indio mg/L

pH

indium precipitation complete with NaOH at pH>4.5

indium precipitate

hydrometallurgical process – Li ion batteries (1/3)

� block diagram

block diagram ofthe processinvestigated in the larger scale

� leaching

hydrometallurgical process – Li ion batteries (2/3)

-sulphuric acid-solid/liquid ratio: 10%;-acid concentration: 2M;-water peroxide 15% volume;temperature: 85°C-time of treatment 3h.

Under these conditions lithium and cobalt extraction yields are:

Li Co

96% 97%

� Lithium and cobalt recovery

hydrometallurgical process – Li ion batteries (3/3)

What’s on?

MOBILE-PLANT EXPERIMENTS

� Treatment of a bigger sample would reduce any problem related to heterogeneity

� Scale up validation

� Tailings and wastewater characterisation

Overview of the Hydrometallurgical Processes for the Recovery of Metals from WEEE

HIGH TECH RECYCLING

INTER-UNIVERSITY RESEARCH CENTER

I. de Michelis, F. Ferella, B. Bianco, P. Macolino, V. Innocenzi – University ofL’Aquila, Italy

F. Beolchini, L. Rocchetti – Università Politecnica delle Marche, Ancona, Italy

F. Pagnanelli, G. Granata, E.Moscardini – ‘’Sapienza’’ University of Rome, ItalyF. Vegliò - EcoRecycling, ItalyB. Kopacek - Austrian Society for Systems Engineering and Automation, Austria

Thank you