The way out for recycling non-renewable metal values D. Monteiro de Oliveira & L. Sobral RIPREXS...

URBAN MINING

The way out for recycling

non-renewable metal values

D. Monteiro de Oliveira & L. Sobral

RIPREXS Meeting(Mexico/2012)

INTRODUCTION

The future availability of metals is a complex topic, and one which depends on a mix of geological knowledge, industrial potential, and economics. We are limited to informed guesswork as to growth of personal incomes, changing cultural preferences, future technological advances, and the like.

What we can be certain of is that improved rates of recycling will be vital to any sustainable future, and that knowing where we stand today provides a most useful perspective, and one of the foundations upon which we can build a more sustainable world.

The recycling of metals is widely reviewed as a fruitful sustainability strategy. However, how such recycling is actually taking place?

Electronic Scrap

INTRODUCTION

Metals play an important part in modern societies and have,

historically, been linked with industrial development and

improved living standards. Society can draw on metal

resources from Earth’s crust as well as from metal discarded

after use in the economy. Inefficient recovery of metals

from the economy increases reliance on primary resources

and can impact nature by increasing the dispersion of

metals in ecosystems.

INTRODUCTION

The recycling of non-renewable resources is often advocated as the solution to potentially restricted supplies. It is indeed true that every kilogram of resources that is successfully recycled obviates the need to locate and mine that kilogram from virgin ores.

Unfortunately, however, notwithstanding their potential values, industrial and consumer products containing these resources have often been regarded as waste material rather than as “Surface Mines” waiting to be exploited.

As the planet’s mineral deposits become less able to respond to demand, environmental challenges, or geopolitical decisions, we limit our technological future by using these resources once and then discarding them through neglect, poor product design, or poor planning.

INTRODUCTION

Metals are uniquely useful materials by virtue of their fracture toughness, thermal and electrical conductivity, and performance at high temperatures, among other properties. For these reasons they are used in a wide range of applications in areas such as machinery, energy, transportation, building and construction, information technology, and appliances. Additionally, of the different resources seeing wide use in modern technology, metals are different from other materials in that they are inherently recyclable. This means that, in theory, they can be used over and over again, minimizing the need to mine and process virgin materials and thus saving substantial amount of energy and water while minimizing environmental degradation in the process.

INTRODUCTION

Recycling data have the potential to demonstrate how efficiently metals are being reused, and can thereby serve some of the following purposes:

Determine the influence of recycling on resources sustainability;

Provide information for research on improving recycling efficiency;

Provide information for life-cycle assessment analysis;

Stimulate informed recycling policies.

Scope of Study

Scope of Study

Ferrous Metals: V, Cr, Fe, Mn, Ni, Nb, MoNon-ferrous Metals: Mg, Al, Ti, Co, Cu, Zn, Sn, Pb

Specialty Metals: Li, Be, B, Ga,As, Se, Sr, Y, Zr, Cd, In, Sb, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Hg,Tl, Bi.

Simplified metal and product life cycle

The cycle is initiated byChoices in product design;Which material are goingTo be used, how they willBe joined, and which processare used for manufacturing.

Scope of Study

Metal Recycling Considerations

Metal Recycling ConsiderationsRare earths rosterHere's a closer look at some of the ways each rare earth element is used:

Scandium: Added to mercury vapor lamps to make their light look more like sunlight. Also used in certain types of athletic equipment — including aluminum baseball bats, bicycle frames and lacrosse sticks — as well as fuel cells.

Yttrium: Produces color in many TV picture tubes. Also conducts microwaves and acoustic energy, simulates diamond gemstones, and strengthens ceramics, glass, aluminum alloys and magnesium alloys, among other uses.

Lanthanum: One of several rare earths used to make carbon arc lamps, which the film and TV industry use for studio and projector lights. Also found in batteries, cigarette-lighter flints and specialized types of glass, like camera lenses.

http://education.jlab.org/itselemental/ele021.html



Cerium: The most widespread of all rare earth metals. Used in catalytic converters and diesel fuels to reduce vehicles' carbon monoxide emissions. Also used in carbon arc lights, lighter flints, glass polishers and self-cleaning ovens.

Praseodymium: Primarily used as an alloying agent with magnesium to make high-strength metals for aircraft engines. Also may be used as a signal amplifier in fiber-optic cables, and to create the hard glass of welder's goggles.

Neodymium: Mainly used to make powerful neodymium magnets for computer hard disks, wind turbines, hybrid cars, earbud headphones and microphones. Also used to color glass and to make lighter flints and welder's goggles.





Promethium: Does not occur naturally on Earth; must be artificially produced via uranium fission. Added to some kinds of luminous paint and nuclear-powered microbatteries, with potential use in portable X-ray devices.

Samarium: Mixed with cobalt to create a permanent magnet with the highest demagnetization resistance of any known material. Crucial for building "smart" missiles; also used in carbon arc lamps, lighter flints and some types of glass.

Europium: The most reactive of all rare earth metals. Used for decades as a red phosphor in TV sets — and more recently in computer monitors, fluorescent lamps and some types of lasers — but otherwise has few commercial applications.

Gadolinium: Used in some control rods at nuclear power plants. Also used in medical applications such as magnetic resonance imaging (MRI), and industrially to improve the workability of iron, chromium and various other metals.






Terbium: Used in some solid-state technology, from advanced sonar systems to small electronic sensors, as well as fuel cells designed to operate at high temperatures. Also produces laser light and green phosphors in TV tubes. Dysprosium: Used in some control rods at nuclear power plants. Also used in certain kinds of lasers, high-intensity lighting, and to raise the coercivity of high-powered permanent magnets, such as those found in hybrid vehicles.

Holmium: Has the highest magnetic strength of any known element, making it useful in industrial magnets as well as some nuclear control rods. Also used in solid-state lasers and to help color cubic zirconia and certain types of glass.

Erbium: Used as a photographic filter and as a signal amplifier (aka "doping agent") in fiber-optic cables. Also used in some nuclear control rods, metallic alloys, and to color specialized glass and porcelain in sunglasses and cheap jewelry.






Thulium: The rarest of all naturally occurring rare earth metals. Has few commercial applications, although it is used in some surgical lasers. After being exposed to radiation in nuclear reactors, it's also used in portable X-ray technology.

Ytterbium: Used in some portable X-ray devices, but otherwise has limited commercial uses. Among its specialty applications, it's used in certain types of lasers, stress gauges for earthquakes, and as a doping agent in fiber-optic cables.

Lutetium: Mainly restricted to specialty uses, such as calculating the age of meteorites or performing positron emission tomography (PET) scans. Has also been used as a catalyst for the process of "cracking" petroleum products at oil refineries.





Metal Recycling ConsiderationsRecycling rates reported for the 60 elements studied:More than 50 per cent recycling: 18 elements

Element Main Uses Element Main Uses

Pb Batteries Au jewelry, electronics

Ag electronics, industrial applications

Al in construction and transportation

Sn cans and solders Cu conducting electricity and heat

Cr stainless steels Ni stainless steels and super-alloys

Nb high strength / low alloy steels and super-alloys

Mn Steel

Zn coating steel - galvanizing Fe the basis and chief constituent of all ferrous metals

Co super-alloys, catalysts, batteries

Re gas turbines (perhaps 60% ofuse), and catalysts

Ti paint, transportation Pd, Pt, Rh

auto catalysts

Recycling rates reported for the 60 elements studied:25 to 50 per cent recycling: 3 elements


Mg construction and transportation

Mo high-performance stainless steels

Ir electro-chemistry, crucibles for mono-crystal growing, sparkplugs


W carbide cutting tools Ru electronics (hard disk drives), process catalysts /electrochemistry

Cd batteries (85%), pigments (10%)

10 to 25 per cent recycling: 3 elements


Recycling rates reported for the 60 elements studied:1 to 10 per cent recycling: 2 elements


Hg largely being phased out; main remaining uses: chlorine / caustic sodaproduction

Sb flame retardant (65% of use), lead acid batteries (23%)


Be electronics Ga electronics: ICs, LEDs, diodes, solar cells

In as a coating in flat-panel displays

Se manufacturing glass, manganese production, LEDs,photovoltaics, infrared optics

Less than 1 per cent recycling: 34 elements


Recycling rates reported for the 60 elements studied:Element Main Uses Element Main Uses

Sr pyrotechnics, ferrite ceramic magnets for electronics

Ta in capacitors in electronics

Ge in night vision (infrared) lenses (30%), PET catalysts(30%), solar cell concentrators, fiber optics

Er fiber-optics

Te steel additives, solar cells, thermo-electronics

Hf in nuclear reactors, and to a small degree in electronics

Zr in nuclear reactors Tl occasional use in medical equipment

V high strength-low alloy steels As Arsenic metal is used in semiconductors (electronics, photovoltaics) andas an alloying element; Arsenic oxide is used in wood preservatives and glassmanufacture


Recycling rates reported for the 60 elements studied:Element Main Uses Element Main Uses

Ba drilling fluid (perhaps 80% of use); as a filler in plastic, paintand rubber (about 20%)

Bi metallurgical additive and alloy constituent

Li in batteries La in batteries

Sc in aluminium alloys Y as a phosphor

Eu as a phosphor Yb as a phosphor

Lu a scintillator in computerized tomography

Ce as a catalyst

Os (occasionally used as a catalyst, but has little industrial importance

Tm no significant uses

Pr glass manufacturing and magnets

Gd in ceramics and magnets

B in glass, ceramics, magnets Nd, Sm, Tb, Dy, Ho

main use for all five: in magnets


Metal Stocks in Society


Electoleaching of Electronic Scraps

eClCl 22 2

OHHeOH 222 22

ClHHClOOHCl 22

HClOHClO

OHOHH 2

ClHClOClOHClO 222 3

eOClHClOOHClO 62/346236 232


Recycling Aluminium from Water Treatment Sludge


Recycling Metals from Brass Scraps

Cu , Zn 2+ 2+ ,Cd2+

Brass Scraps(Cu, Zn, Cd, Pb & Fe)

Fe3+ PbSO4

FeOOH

NaOH up to pH 3.8 blowing air

Cu , Zn e Cd 2+2+ 2+

NaOH up to pH 6.5

Cu(OH) + Zn(OH) & Cd(OH)2 2 2

Na ZnO2 2 Cu(OH) + Cd(OH)2 2

H SO up to pH 7

Zn(OH)2

2 4

H SO up to pH 32 4

ZnSO4

H SO até pH 32 4

CuSO + CdSO4 4

H S (or Na S) 2 2

CuS + CdS

CdSO

H SO2 4 diluted

CuS4

CuSO4H SO 2 4

H O 2 2

H SO + H O2 2 24

Na CO2 3 + C

Pbo

(800 C)o

OHClHOHCl 2222 222

OHNaClClHClNaClO 22 222


Recycling Metals from Automotive Catalyst

OHClHOHCl 2222 222

OHNaClClHClNaClO 22 222

Automotive Catalyst (Exhausted)

Cominution

TP<150#

Thermal Treatment(Roasting)

CO2O2 (350 C)o

Acid Leaching(HCl Concentrated)

or

Ceramic Substrate(Aumina - Al O )2 3

Pd , Pt , Rh (Acid Solution)

2+ 4+ 3+

Cementation(Zn Precipitation)

Pd, Pt & Rh(Metal powder)

H O2 2

NaClO


Recycling Metals from Steelworks Dust

Zn , Cd , Fe2+

Steelworks Dust(Zn, Cd, Pb & Fe)

3+PbSO4

FeOOH

NaOHup to pH 3.8Blowing air

Zn e Cd 2+ 2+

Na ZnO2 2 2

H SO up to pH 7

Zn(OH)2

2 4

H SO up to pH 32 4

ZnSO4

H SO up to pH 32 4

CdSO4

2+

H SO + H O2 4 2 2

NaOH up to pH 9

Cd(OH)2


Recycling Metals from Galvanic EffluentGalvanic Effluent

Cr , Zn , Ni , Cu , Fe6+ 2+ 2+ 2+ 3+

Fe(OH)3 Cr , Zn , Ni , Cu 6+ 2+ 2+ 2+

pH = 3 (NaOH)

pH = 5.5 (NaOH)

Cu(OH)2Cr , Zn , Ni 6+ 2+ 2+

Ni(OH)2

pH = 10 (NaOH)

Cr , ZnO 6+22-

Zn(OH)2

pH = 7.5 (H SO 0.1M) 2 4

Cr 6+

NaHSO3

Cr(OH)3


Aluminium Recycling from Tetra pak

Tetra pak packings

Before the disintegration

After the disintegration

Al + H2SO4 Al2(SO4)3 + H2

Flocculant AgentMelting

Dissolution

LDPE after cleaningoperation


Final Remarks

The recycling of non-renewable metal values out of secondary sources is of paramount Importance for the sustainable use of natural metal resources. Therefore, some key points have to be taken into consideration:

The definition of cost effective metal extraction processes, in terms of energy savings, and, in addition, bearing in mind the environment preservation;

To wave for the final use of the metal values extracted either as metal, back as final use as raw material to the mechanical industrial sector or as chemicals, such as CuSO4, CuCN, NiSO4, ZnSO4 etc., to be used in the plating and agricultural sectors;

Taking into consideration the huge variety of metals being used nowadays in sophisticated electronic devices, which are quickly obsolete due to the ever increasing technological advances, it is necessary to find out how much of those elements are being recycled as an attempt to drive the attention of our Central Government, in particular the Ministry of Mine and Energy, to consider, while issuing the ore prospecting directives for the Brazilian mining sector to go for recycling metals, in order to obviate the need to locate and mine virgin ores.

Débora Monteiro de Oliveira M.Sc.Service of the Metallurgical and Biotechnological Processes

[email protected]

Luiz Gonzaga Santos Sobral Ph.DHead of the Metallurgical and Biotechnological Processes Division

[email protected]

Centre for Mineral Technology CETEM/MCTAv. Pedro Calmon, 900

Cidade UniversitáriaRio de Janeiro - RJ

CEP: 21941-908Tel: 55 21 3865-7246

Fax: 55 21 3865-7232

The way out for recycling non-renewable metal values D. Monteiro de Oliveira & L. Sobral RIPREXS...

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