Recycling of Secondary Rear Earth Metal

8/10/2019 Recycling of Secondary Rear Earth Metal

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Recycling of Secondary Rare

Earth and Precious Metals

in China

Hao Du

Institute of Process Engineering

Chinese Academy of Sciences


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Outline

Rear Earth Metal Resources

Recovery of Secondary Rare Earth Metals

Recovery of Precious Metal from PCBs

Closing Remark

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1. Rare Earth Metal Resources-Overview

Position of rear earth metal andprecious metal on the periodic table

La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, andYtotally 17 elements. 3


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Rare Earth Metal Resources-Application

Rare earth metals (REMs) have

unique electric, magnetic, optical,and biological properties, and

are important materials for

information, biology, and energy

technologies-Vitaminsformodern industries.

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La Atomic number:57

High refractive index glass, hydrogen storage materials, battery-

electrodes, camera lenses, cracking catalysts

Application of REMs -Lanthanum

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Ce Atomic number:58

Application of REMs - Cerium

Glass additives, high temperature alloys, catalysts, laser materials6
http://en.wikipedia.org/wiki/File:Cerium2.jpg


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Pr Atomic number:59

Magnets, laser materials, carbon arc lighting, glasses additives, alloys

Application of REMs - Praseodymium

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http://en.wikipedia.org/wiki/File:Praseodymium.jpg


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Nd Atomic number:60

Rare-earth magnets, laser materials, glass and ceramics

Application of REMs - Neodymium

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http://en.wikipedia.org/wiki/File:Neodymium2.jpg


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Application of REMs Summary

Application Area REM Used Products

Magnetic material Nd, Pr, Dy, Tb, SmHard discs, Permanent magnet,

Electronic Driving device

hydrogen storage

material

La, Ce, Pr, Nd Battery

Automobile emission

purification material Ce, La, Nd Catalysts

Petrochemical Area La, Ce, Pr, Nd Catalysts

Luminescent materialEu, Gd,Tb, Dy, La, Ce, Pr,

GdLCD Panel, Monitor, Lamps

Polishing powder Ce, La, Pr, mixed metals LCD Panel, Silicon Chips

Glass additives Ce, La, Nd, Gd, Yb, Er Optical glass, Optical Fibers

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Advanced Materials

Agriculture andlight industry

Glass and

ceramics

Petrochemical

industry

Metallurgical and

Mechanical industry

Application of REMs -Trend

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Current application:

Japan: 90% for high technology application

U.S.A: 70% for high technology application

China: In 2008, 54.8% for advanced material application.

Application of REMs - Current and Future

China, Japan, and the USA are three of major countries for REM

consumption, accounting for 85% of consumption globally

Future application:

Traditional area: Metallurgy, Catalysts, Polishing Powder,

Ceramics5.3% increase annually

High technology area: Magnetic materials, Hydrogen Storage

Materials, Optical Materials, Catalysts28% increase annually.

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Rare Earth Mineral Distribution - Global

China, Australia, Russia, America, Brazil, and Canada12


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China

AmericaRussia

Australia

Brazil

IndonesiaIndia

Rest

China: 36 million tons, Russia: 19 million tons, America: 13 million tons

22.83%

5.48%5.48%

13.19%

19.27%

36.52%

Rare Earth Mineral Distribution - Global

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ChinaAmerica

India

Rest

94.23%

2.56%

1.97%1.24%

Rare Earth Mineral Production - Global

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Rare Earth Mineral Distribution - China

Largest countryin terms of REMs reserves, production amount, sales

volume, and consumption amount.Only countrythat can provides all category of RE products.

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Baotou

Shandong

Sichuan

Southern China

Rest83%

8%

3%3%

3%

Baotou

Shandong

Sichuan

Southern China

Rest83%

8%

3%3%

3%

83%

8%

3%3%

3%

Baiyunerbo RE minerals are mainly located in northern China, total reserve

43.5 million tons, accounting for 83%percent of total reserve in China.

RE minerals in southern China is mainly ionic medium and heavy RE minerals,which is only foundin China.

RE minerals in China - Characteristics

(Ce,La)PO4

(Ce,Na,Ca)(Ti,Nb)O3

Light REM

ores

Loparite

MonaziteBastnasite

(Ce,La,Y)CO3F(Ce,La)PO4

(Ce,Na,Ca)(Ti,Nb)O3

Light REM

ores

Loparite

MonaziteBastnasite

(Ce,La,Y)CO3F

Heavy REM

ores

Ion

adsorption

type

Xenotime

YPO4

Heavy REM

ores

Ion

adsorption

type

Xenotime

YPO4

RE2O3

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2 R f REM f S d R


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2. Recovery of REMs from Secondary Resources

1. RE permanent magnet materials;

2. Hydrogen storage materials

3. Catalysts

4. luminescent materials

5. Polishing powders

Secondary REMs resources include:

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R f REM f d


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Species

Waste utilization rate during production

and application

Secondary material recovery

rate

Permanent magnets > 80% < 20%

Nickel-hydrogen battery 2050%Ni >5080% < 20%

Luminescent powder 2050% 2050%

catalysts < 20%Precious metal >80% < 20%

Recovery of REMs in Japan

Species

Waste utilization rate during production

and application

Secondary material recovery

rate

Permanent magnets > 90% < 20%

Nickel-hydrogen battery 80% < 10%

Recovery of REMs in China

Recovery of REMs from secondary resources

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R f REM P t M t


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Globally, 68 kilo tons of Nd-Fe-B permanent magnetic materials annually

and50 kilo tons in China.Total REMs recovery >90%.

Recovery of REMs -Permanent Magnets

Acid

Treatment

Alkaline

Treatment

RE

Hydroxides

Spent NdFeB

Materials

H2SO4

NaOH

Acid

Treatment

HCl

Solvent

Extraction

Sedimentation

& calcination

Nd2O3, Dy2O3

H2

C2

O2

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Recovery of REMs Hydrogen Storage Materials


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Dissemble

Leaching

Alkalization

Acidification

Leaching Cake

RECl3

Leaching liquor

Solvent

Extraction

Zn, Mn, Fe

Solvent

Extraction II

CoSO4

Ni(OH)2

Recovery of REMs -Hydrogen Storage Materials

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Reco er of REMs Catal sts


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Flocculation and

Sedimentation

S/L

Acidification

Extraction

Liquor

Strip Liquor with

Concentrated REMs

Filtrate of

Molecular Sieves

Flocculants

HCl

Striping

Recovery of REMs - Catalysts

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Recovery of REMs Luminescent Materials


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Recovery of REMs - Luminescent Materials

Recovery of REMs from fluorescent lamp

Supercritical fluid extraction of rare earth elements from luminescent material in waste fluorescent lampsJ.

of Supercritical fluid, 332005 235-241

Schematic diagram of the fluorescent lamp and

photograph of the luminescent material

Schematic diagram of SFE experimental system

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3 Recovery of Precious Metals from PCBs


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3. Recovery of Precious Metals from PCBs

Where are the E-wastes from?

Internally: 350 million TVs, 13 million refrigerators, 17 million

washing machines, 18 million PCs, 19 million cell phones

Externally: Around 4000 tons of electronic wastes are produc

ed every hour, and about 70% of them are imported into China

through different channels

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Properties of E-wastes


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Cons

Contains heavy metals including Pb, Cd, Hg, Cr (VI) .

Contains organic pollutants including PBB and PBDE.

A pollution of one Ni-H battery to the soil will last 50 years.

Properties of E-wastes

Pros

Contains precious metals including: Au, Ag, Cu, Pt.

For each tonnage of PCBs, 450 grams of Au can be recovered

For each tonnage of wasted PCs treated, 128 kg Cu, 58 kg Pb,

and 40 kg Sn can be recovered.

Why to recycle them?

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Recovery of E wastes: Existing Condition


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Recovery of E-wastes: Existing Condition

Collect Dissemble Recycle

How to recycle them?

Heavy Pollution !!!25

Recovery of Precious Metal from PCB: Example


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Recovery of Precious Metal from PCB: Example

90% of the value of the PCBs is from Au and Pd

Element

Weight Percent Value

Value from

PCBs

Value from

PCBs

/kg /kg

Au 0.025 6500 1.63 59.4

Pd 0.010 8000 0.8 29.2

Ag 0.1 70 0.07

Cu 16 0.8 0.13

Sn 3 3 0.01

Pb 2 0.3

Ni 1 5 0.05

Al 5 0.9 0.05

Fe 5 0.1

Zn 1 0.8

Total 2.74

Composition and valuable elements of PCBs

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Recovery of Precious Metal from PCB- Methods


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Thermal technologies

Pyrometallurgical method

Serious environmental pollution,

thus it was abandoned

gradually

thermolysis method

Low recovery of metals

Mechanical methods

Simple

Little secondary pollution

Complete liberation of

metals could not be

achieves

Biological technologies

Low cost

Clean process

Low leaching rate

Hydrometallurgical technologies

High recovery of metals Large consumption of

chemical solvents

Eroding the equipment

Bright future of commercial

scale application

Recovery of Precious Metal from PCB Methods

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Recovery of Precious Metal from PCB-Physical Separation


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A CrashingMagnetic SeparationElectrostatic Separation

Daimler Benz Ulm Research Centre (Germany) process

CrashingMagnetic

separationCrashing

Nitrogen

freezing

Electrostatic

separation

calcinaitionPrecious metalextraction

Plastics andprecious metal

mixture

Metals

Recovery of Precious Metal from PCB Physical Separation

B CrashingFluidized Bed Separation Ray Chapman (USA) process

Course

CrashingFine

CrashingPCBs

Fluidized

Bed

Separation

Metal

Concentrate

Plastics

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Recovery of Precious Metal from PCB - Physical Separation


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Course

Crashing

Fine

Crashing

Sieving

Flotation

Separation

Shaking Bed

Separation

PCBs

Fine

Particles

Coarse

Particles

Precious

Metal

Concentrate

y y p

C. CrashingShaking

bedFlotationseparation process

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Recovery of Precious Metal from PCB - Chemical Separation


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A Acid Leaching

PCBsStrong

acid

xidant

Precious

metal

precipitateSelective

Reduction

Precious

Metals

liquidRecover Cu

B Dissolution

C Electrolysis

y p

PCBs

Cl containingsolution

dissovlingprecious metal

containing slag

Furthertreatment

precious

metal

l

e

r

o

y

s

i

s

u

o

n

w

i

th

a

d

PCBs

various

metals

Recovery of Precious Metal from PCB - New Technologies


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Manual dissembleUtilization of pneumatic and electric tools

Automatic dissemble

SAT( Australia) Automatic scanning, double laser de-

soldering, and separation under vacuum. 400 kilotons of PCBs

are expected to be dissembled in Europe.

NEC (Japan)utilize infraredto heat and chop PCBs,

advanced thermo shockequipments, and automatic polishing

to remove residue solders.

Advanced dissemble technology is the key for the efficient

recycling of PCBs

y g

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Recovery of Precious Metal from PCB - New Technologies


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Waste PCBs

Separation of metals and nonmetalsby intensified chemical

swelling under extra-fields

Selective metals digestion underchemical catalysis

Poly-metallic

Cu Recovery by SX

Cu SnPb

Polymer based plates

Base plates modification

produced flame-retardantPolyurethane

Flame-retardant

Polyurethane

Separation of

Precious Metals

Ag Au Pd

Medium Cycle

Wastewater

Treatment

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Recovery of E-wastes: Comparison


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China

Physical separation: collect

metal concentrate, followed

by smelting and electrolysis

to recovery precious metals

Chemical leaching: dissolve

precious metals using

strong acid, followed by

reduction to recovery

precious metals

Advanced Countries

Deep bury: Leave the waste

for future treatment

Waste transfer: transfer the

pollution to other countries

Physical separation

Efficient concentrate

previous metals, avoiding

further chemical treatments

Production line transfer:produce electronic products

in other countries

y p

Environmental pollutions Pollution Transfer33

Recovery of E-wastes: Comparison


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Resource of E-waste

No collection system

No stable collection source

Large trading expense

High transportation expense

Stable collection source

Low raw material costs

No trading expense

Low transportation expense

y p

China

Advanced

countries

In China, less than 10% of the E-wastes are collected throughformal channels (with government licenses)34


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Final Exam


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Write a 20 page review about all the metallurgicaltreatment processes discussed in the class.

Inculding Fe Al Ti V Cr Au and Cu.

Review should include main resource main

treatment process and main pollution resource.

Flow sheet for each process is highly suggested.

Major reaction in the process should be clarified.

The review paper is due 15th

Nov.

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Recycling of Secondary Rear Earth Metal