New Separation and Recovery Process of Platinum using … · 2009. 1. 15. · Pourbaix diagram for Pt-H 2O-Cl system 0 0.5 1.0 1.5 –2 0 4 8 10 Pt [PtCl 6]2– PtO 3 PtO 2 PtO pH

The 3rd Workshop on Reactive Metal Processing, March 2-3, 2007, MIT

New Separation and Recovery Process of Platinum using Chlorinating Agents

Chiyoko Horike and Toru H. Okabe

Institute of Industrial Science The University of Tokyo, Japan

2


Platinum group metals (PGMs)

• High electric conductivity• Corrosion resistance• Heat resistance• Catalytic properties

http://www.platinum.matthey.com/market_data/1147696728.html

Wor

ld d

eman

d, w

/ to

n

Year1975 1985 1995 20050

50

100

150

200

250

Total demand

Demand for automotive catalysts

Os Ir Pt

Ru Rh Pd44 45 46

76 77 78

Characteristics

The worldwide demand for Pt is increasing.

The development of an efficient recovery process of Pt is very important.

Worldwide demand for Pt

3


Previous research conducted by our group

New extraction process of PGMs from waste materials by using reactive metal vapor

Pt Mg-Pt Ca-Pt0

20

40

60

80

100

Mas

s% o

f dis

solv

ed P

t

Mass of samples: 0.05–0.1 g

Leaching time: 1–4 h

Temperature: RT

Solvent: Aqua regia

Alloying treatment of PGMs using reactive metals vapor

The dissolution efficiency of PGMs in aqua regia improved significantly.

T. H. Okabe et al., Journal of Materials Research, 18, No. 8 (2003), pp. 1960–1967. T. H. Okabe et al., Materials Transactions, JIM, 44, No. 7 (2003), pp. 1386–1393.

4


Pourbaix diagram for Pt-H2O-Cl system

0

0.5

1.0

1.5

–2 0 4 8 10

Pt

[PtCl6]2–PtO3

PtO2

PtO

pH

Pot

entia

l, E

/ V

vs.

SH

E

T = 298 KaCl

– = 0.48

Pt is dissolved in 1M HCl to form a chloro complex in the +4 oxidation state.

The chlorination of Pt is an effective pretreatment for dissolution.

2 6

5


Development of a new process for the effective recovery of PGMs from scrap

Purpose of this study

Chlorination

R-Pt-Cl

R-PtR: reactive metal

Compound formation under a highly reducing atmosphere• Pretreatment for selective and efficient dissolution of PGMs

pCl2

• Higher dissolution efficiency• Lesser amounts of acids required for dissolution• Fast dissolution

Che

mic

al p

oten

tial o

f ch

lorin

e [PtCl6]2–

Oxidation/DissolutionPt Processingtime, tprocess1 2

3

Short dissolution time required

6


(R’Clx: FeCl3, CuCl2, etc.)

Flowchart of the new processScraps containing PGMs (M)

Mg vapor treatment

Mg-M compounds

Mg-R’-M-Cl compounds

Dissolution

Solution containing PGMs

Pure PGMs

Chlorination

PGMs recovery

Reactive metal(Mg)

(M: Pt, etc.)

Chlorinating agent(Cl2 or R’Clx)

HCl aq. Waste solution

Residue

This study

7


Pure Pt was reacted with molten Mg at 1173 K for 12 h.Homogeneous Mg-Pt compounds were formed.(SEM, EDS, XRD)

Stainless steel reaction vessel

Ta crucible

Pt plate

Stainless steel plate

Ti sponge

TIG welding

Stainless steel cover

Mg block

Synthesis of Mg-Pt compounds

8


5 cm

Cl2: KMnO4: 10 gconc. HCl: 40 ml

Chlorination of Mg-Pt compounds and Pt

600

300

450

750

Tem

pera

ture

, T /

K

• Reaction at 673 K

Stainless steel crucible

Ar or Cl2/vacuum

Chlorinating agent (FeCl3 or CuCl2)

Quartz tube Stainless steel tubes Powder of Mg-Pt compounds

Heater Quartz crucibles

Pt powder(Condenser/Sample collector)

673 K

Feed samples were chlorinated by using a chlorinating agent (Cl2, FeCl3, or CuCl2 gas) at 673 or 873 K for 3 h.

Weight of the feed samples: 0.32–0.40 g

FeCl3: 3.68–4.05 g

CuCl2: 3.31–3.99 g

9


Compounds obtained after chlorination

Mg-Pt compound

powder

Pure Pt powder

673 K 873 K 673 K 873 K

After chlorination in CuCl2 at 673 K and 873 K for 3h

The morphologies and colors of the samples were different.

10


Weight measurementComparison of weight change100

Cl2 FeCl3 CuCl2

Mg-Pt Mg-Pt Mg-PtPt Pt Pt0

20

40

60

80

0

20

40

60

80

100

0

20

40

60

80

100

Rat

io o

f wei

ght i

ncre

ase,

R(%

)

Effective chlorinating condition:

R （%） = 100 × (wo,i – wf,i) / wf,i

wf,i: Weight of the feed sampleswo,i: Weight of the obtained samples

Ratio of weight increase, R （%）

(1) Mg-Pt compound(2) High temperature (873 K was more effective that 673 K)

(3) Chloride salts

: 673 K

: 873 K

: < 1%

11


XRD analysisIn

tens

ity, (

a.u.

)

(a) Feed Mg-Pt

(b) Sample obtained after chlorination

Angle, 2θ（degree, Cu-Kα）30 90

Chlorination agent: CuCl2Reaction temperature: 873 K

The sample obtained after chlorination was different from the feed Mg-Pt.

However, their phases were not identified.

50 70

12


––*08.705.245.609.2ICP-AES

51.521.304.015.305.8XRFObtainedSample

––*01.3<0.171.916.6ICP-AES

––*<0.1––*87.812.2XRFFeed Mg-Pt

ClFeCuPtMg

Composition of element i, Ci (mass%) AnalysisSample

Composition analysis


Cu of CuCl2 participated in this chlorination.

*Not detected

13


Summary

A fundamental technique that utilizes the selective alloying of PGMs using collector metals followed by chlorination/oxidation.

1. Pt was reacted with Mg at 1173 K and the obtained Mg-Pt compounds were “chlorinated” by using the vapors of a chlorinating agent (Cl2, FeCl3, or CuCl2) at 673 K and 873 K.

2. During chlorination, Pt was effectively reacted with chloride salts at 873 K after Mg alloying. After the experiment, Pt formed a complex compound.

Future work:

Integration of the proposed chlorination method with the conventional dissolution methods of chlorinated Pt in acid solution will be investigated.


New Separation and Recovery Process of Platinum using Chlorinating Agents

Chiyoko Horike and Toru H. Okabe

Institute of Industrial Science The University of Tokyo, Japan

15


16


The Price of PGMs

000,029.18Al

000,005.83Cu

000,449.52000.45Ag

021,543.41021.54Au

Os

027,974.28027.97Ru

014,791.00014.79Ir

192,926.05192.93Rh

011,061.09011.06Pd

039,003.22039.00Pt

US$ per kgUS$ per g

LME Official Price15 Feb 2007http://www.lme.co.uk/dataprices_daily_metal.asp

GFMS London Fixingsam 15 Feb 2007http://www.gfms.co.uk/spot_prices.htm

Johnson Matthey Base Prices

16 Feb 20078:30 (Hong Kong Time)http://www.platinum.matthey.com/index.html

17


Supply and Demand

http://www.platinum.matthey.com/market_data/1132069464.html

Pt209 t

Rh25 t

Auto catalyst:95 t (46%)

Jewelry:63 t (30%)

other: 30 t (14%)

Electrical:11 t (5%)


Jewelry:45 t (21%)

Electrical:30 t (14%)

Dental:28 t (12%)

Pd214 t


other: 0.5 t (2%)Demand Chemical: 1.4 t (6%)Chemical: 10 t (5%)

Chemical:10 t (5%)

Electrical:0.3 t (1%)

other: 9 t (4%)

Glass:1.6 t (7%)

Pt205 t

Pd235 t

Rh23 t

South Africa:159 t (78%)

South Africa:81 t (34%)

South Africa:19 t, 83%

Russia:116 t (50%)

North America:29 t (12%)

Russia:3 t (12%)

other: 8 t (4%) other: 9 t (4%)North America: 0.6 t (3%)

other: 0.5 t (2%)

Supply

Russia:27 t (13%)

North America:11 t (5%)

18


Typical recovery process for PGMs

Recovered PGMs

Scraps containing PGMs

Pre-treatment (Crushing, etc.)

Dissolution in acid

Separation and purification

Cu, Pb, Fe, etc.

Extraction by collector metals

Collector metal containing PGMs

Dire

ctly

dis

solv

ed in

ac

id

Pyrometallurgical process

○ High efficiency○ High speed

× High energy cost× Large-scale

facilities required

Hydrometallurgical process

○ Low energy cost○ Easy handling

× Long processing time

× Generation of a large amount ofwaste solution

19


Pt recovery process by precipitation of (NH4)2PtCl6

Chloride complex containing Pt

Dissolution

CrystallizationS L

(NH4)2PtCl6

Calcination / Reduction

Pt powder

Chlorination

R-Pt compounds or Pt

Solution containing Pt

NH4Cl aq. Waste solution

HCl, NH3, etc.

20


Rose process

Fig. PGMs recovery process from automotive catalyst scrap.

*Laid-open disclosure public patent bulletin H04-317423 (1992).

Crushing

Automotive catalyst scrap

PGMs

PGM recovery

Reductant

Smelting (1573 - 1673 K, 4 h)

FluxCu or Cu2O

Slag

Smelting

Cu metalAir or O2

Cu2O Cu metal

21


Ellingham diagram

0

-200

-400

-600

-800

-1000400 600 800 1000 1200

Sta

ndar

d G

ibbs

ene

rgy

of fo

rmat

ion,

ΔG

f゜/ k

J・(m

ol・C

l 2)-1

Reciprocal temperature, T / K

PtCl4 PtCl3

PtCl2

CuCl2

RhCl3

CuClFeCl2

FeCl3

ZnCl2 AlCl3

MgCl2

CaCl2

NaCl KCl

673 K 873 K

*I. Barin: Thermochemical Data of Pure Substances, 3rd edition (1995).

22


Vapor pressure of selected metals and chlorides

Reciprocal temperature, 1000 T-1 / K-1

0.8 1.0 1.2 1.4 1.6 1.8 2.0-20

-15

-10

-5

0

Vap

or p

ress

ure,

log

p i(a

tm)

Pt

Fe CuCuCl MgCl2

FeCl2

FeCl3

Mg

873 K 673 K

23


The predicted enthalpy of formation

Pt2Mg3

PtMg

Pt3Mg2

Pt2Zn3

PtZn

Pt3Fe5

Pt2Fe3

PtFe

Pt3Fe2

Pt3Cu5

Pt2Cu3

PtCu

Pt3Cu2

0 -10 -20 -30 -40 -50 -60 -70 -80ΔHcalc

for / kJ·mol-1

Mg-Pt

Zn-Pt

Fe-Pt

Cu-Pt

*F. R. deBoer, R. Boom, W. C. M. Matttens, A. R. Miedema, and A. K. Niessen: Cohesion in Metals (1995).

24


Phase diagram of Mg-Pt binary system

25


Chlorination using Cl2 gas

Powder of Mg-Pt compoundor Pt

Ar

KMnO4 aq.

Light-proofbubbler

Na2S2O3 aq.H2O

P2O5

H2Oconc. KMnO4 aq.

conc. HCl aq.

Cl2 gas generator

Chlorination reactor

Cl2 absorber

Cl2 gas inlet

Gas outlet

Dehydrator

Heater

26


XRD analysis

T = 673 K

10 40 70 100Angle, 2θ（degree、CuKα1）

Inte

nsity

, I(a

.u.)

The obtained sample from Mg-Pt compoundsChlorination by Cl2

27


XRD analysis

T = 673 K

10 40 70 100Angle, 2θ（degree、CuKα1）

Inte

nsity

, I(a

.u.)

The obtained sample from Mg-Pt compoundsChlorination by FeCl3

: Pt ＃04-0802

28


––*00.500.566.213.5ICP-AES

38.401.901.344.314.1XRFObtainedsample

––*01.3<0.171.916.6ICP-AES

––*<0.1––*70.529.4XRFFeed MgPt

ClFeCuPtMg




*Not detected

29


––*09.000.148.010.4ICP-AES

44.435.6––*17.202.7XRFObtainedsample

––*01.3<0.170.215.9ICP-AES

––*<0.1––*70.529.4XRFFeed MgPt

ClFeCuPtMg



Chlorination agent: FeCl3Reaction temperature: 673 K

*Not detected

30


––*13.200.260.312.4ICP-AES


––*01.3<0.172.615.2ICP-AES

––*<0.1––*89.310.7XRFFeed MgPt

ClFeCuPtMg



Chlorination agent: FeCl3Reaction temperature: 873 K

*Not detected

31


––*00.100.171.017.5ICP-AES


––*01.3<0.171.916.6ICP-AES

––*<0.1––*87.812.2XRFFeed MgPt

ClFeCuPtMg



Chlorination agent: Cl2Reaction temperature: 673 K

*Not detected

32


––*<0.100.166.014.8ICP-AES

00.7<0.1––*76.422.8XRFObtainedsample

––*01.3<0.172.615.2ICP-AES

––*<0.1––*89.310.7XRFFeed MgPt

ClFeCuPtMg



Chlorination agent: Cl2Reaction temperature: 873 K

*Not detected

Documents

New Separation and Recovery Process of Platinum using … · 2009. 1. 15. · Pourbaix diagram for Pt-H 2O-Cl system 0 0.5 1.0 1.5 –2 0 4 8 10 Pt [PtCl 6]2– PtO 3 PtO 2 PtO pH