copper recycling

ENGR5187 – Solid Waste Processing and Recycling

(Term Paper)

Copper Recycling

Alberto Rui Frutuoso Barroso

March 24, 2010

Laurentian University

II

ABSTRACT

This document provides a general description of how copper is produced from ore

and scrap, and a more detailed synopsis of the equipment, processes and logistics

of the copper recycling industry. A list of the latest technologies in smelting,

converting, and melting furnaces is given, along with equipment capabilities in

primary and secondary copper production. The current status of secondary copper

production in the United States is compared to that of Canada and Europe, and the

transference of primary and secondary copper processing for countries with the

biggest growing economies in the world is referred. The techniques to recycle

copper from general mechanical and electrical scrap are analyzed, and a special

focus is given to the recycling methods of electronic equipments, because of the

recent recycling pressure that these copper products receive due to an extremely

ephemeral utilization rate.

III

Contents

1. INTRODUCTION ............................................................................................................................................... 1

1.1 THE COPPER INDUSTRY ........................................................................................................................... 1

1.2 COPPER PRODUCTION AND USAGE .................................................................................................................. 2

2. METALLURGY OF COPPER .......................................................................................................................... 4

2.1 INTRODUCTION ............................................................................................................................................... 4

2.2 COPPER COMMINUTION ................................................................................................................................... 5

2.3 COPPER FROTH FLOTATION ............................................................................................................................. 5

2.4 FURNACES USED IN COPPER PRODUCTION ........................................................................................ 7

2.4.1 Outokumpu flash furnace ....................................................................................................................... 8

2.4.1 ValeInco flash furnace ........................................................................................................................... 9

2.4.2 Noranda and El-Teniente bath smelting furnace ................................................................................. 10

2.4.3 AUSMELT and ISAMELT furnace ....................................................................................................... 11

2.4.4 Kivcet flash furnace ............................................................................................................................. 15

2.4.5 Contop furnace .................................................................................................................................... 15

2.4.6 QSL Process......................................................................................................................................... 16

2.4.7 Mitsubishi Process ............................................................................................................................... 16

2.4.1 Reverbatory Furnace ........................................................................................................................... 17

2.4.1 ASARCO Anode Furnace ..................................................................................................................... 17

2.4.2 Crucible Furnace ................................................................................................................................. 18

2.4.3 Blast Furnace ....................................................................................................................................... 18

2.5 CONVERTING OF COPPER MATTE ....................................................................................................... 19

2.5.1 Peirce-Smith Converter ....................................................................................................................... 19

2.5.1 Hoboken Converter .............................................................................................................................. 20

2.5.1 Inco Oxygen Top Blown Nitrogen Stirred Converter .......................................................................... 20

2.5.2 Solid Matte Outokumpu Flash Converter ............................................................................................ 21

2.6 FIRE REFINING AND CASTING OF COPPER ANODES ....................................................................... 22

2.7 CAPTURE OF SULFUR GAS FROM SEMELTING AND CONVERTING ............................................. 23

3. SECONDARY COPPER PRODUCTION ...................................................................................................... 24

3.1 INTRODUCTION ............................................................................................................................................. 24

3.2 UTILIZATION CYCLE OF COPPER CONTAINING MATERIALS ....................................................... 24

3.3 CATEGORIES OF COPPER SCRAP .................................................................................................................... 25

3.3.1 Types of copper alloys present in new scrap (Mike Laney, 2006): ...................................................... 26

3.4 COPPER SCRAP SORTING, PROCESSING AND BENEFICIATION ......................................................................... 27

3.4.1 Copper wire processing ....................................................................................................................... 27

3.4.2 Copper recovery from automotive scrap ............................................................................................. 29

3.4.3 Copper recycling from Electronic Scrap (E-scrap) ............................................................................. 30

3.5 SECONDARY COPPER PROCESSING PLANTS .................................................................................................... 33

3.5.1 New technologies in secondary copper smelting ................................................................................. 35

3.6 ISAMELT SECONDARY COPPER PROCESSING PLANTS .................................................................................. 37

3.6.1 UMICORE in Hoboken (Belgium) ....................................................................................................... 37

3.6.2 AURUBIS (Hüttenwerke Kayser) in Lunen (Germany) ....................................................................... 38

4. REFERENCES .................................................................................................................................................. 39

5. GLOSSARY OF TERMS .................................................................................................................................. 40

IV

List of Figures

Figure 1 : Global refined copper demand in thousands of metric tons (Eurocopper, 2010) .......................................... 1

Figure 2 : Production of refined copper worldwide (thousands of metric tons) (Eurocopper, 2010) ............................ 2

Figure 3 : Pyrometallurgy of copper (Biswas, 2002) ..................................................................................................... 4

Figure 4 : Hydrometallurgy of copper (Biswas, 2002) .................................................................................................. 5

Figure 5 : Floating circuit for copper sulfide (Biswas, 2002) ........................................................................................ 6

Figure 6 : Effects of collector concentration and pH on the floatability (Biswas, 2002) ............................................... 6

Figure 7 : Control system for an Outokumpu flash furnace (Biswas, 2002) ................................................................. 8

Figure 8 : ValeInco flash furnace (Biswas, 2002) ......................................................................................................... 9

Figure 9 : Noranda furnace (Biswas, 2002) ................................................................................................................. 10

Figure 10 : El Teniente furnace (Biswas, 2002) .......................................................................................................... 10

Figure 11 : Schematic of a Ausmelt furnace (Ausmelt, 2010) ..................................................................................... 12

Figure 12 : Market acceptance of TSL technology (Ausmelt, 2010) ........................................................................... 12

Figure 13 : Integrated smelting and converting (Ausmelt, 2010) ................................................................................ 13

Figure 14 : Mount ISA copper ISAMELT smelter (ISAMELT, 2010) ....................................................................... 14

Figure 15 : Kivcet Flash Smelter (MetSoc, 2010) ....................................................................................................... 15

Figure 16 : Mitsubishi Process (Biswas, 2002) ........................................................................................................... 16

Figure 17 : Reverbatory Furnace (Biswas, 2002) ........................................................................................................ 17

Figure 18 : ASARCO Anode Furnace (Biswas, 2002) ................................................................................................ 17

Figure 19 : Crucible tilting furnace (Majoreng, 2010)................................................................................................. 18

Figure 20 : Blast furnace (Majoreng, 2010)................................................................................................................. 18

Figure 21 : Peirce-Smith Converter (Biswas, 2002) .................................................................................................... 19

Figure 22 : The Hoboken cconverter (Biswas, 2002) .................................................................................................. 20

Figure 23 : Nickel-Copper extraction at Copper Cliff (TMS, 2010) ........................................................................... 20

Figure 24 : Oxygen Top Blown Nitrogen Stirred Converter (TMS, 2010) .................................................................. 21

Figure 25 : Outokumpu Flash Converter at Kennecott Utah (TMS, 2010) .................................................................. 21

Figure 26 : Anode furnace casting wheel (Biswas, 2002) ........................................................................................... 22

Figure 27 : Producing sulfuric acid from smelting and converting gases (Biswas, 2002) ........................................... 23

Figure 28 : Diagram showing the flow of copper-containing materials (Goonan, 2010) ............................................ 24

Figure 29 : Process flow chart for copper scrap (Goonan, 2010) ................................................................................ 27

Figure 30 : Electrical cable grinder-separator - mod. RC (cogelme, 2010) ................................................................. 28

Figure 31 : Eddy current separator (Dings, 2010) ....................................................................................................... 28

Figure 32 : Flow sheet for recovering metals from scrap automobiles (Biswas, 2002) ............................................... 29

Figure 33 : Printed circuit board (PCB) recycling equipment (hnsxjx, 2010) ............................................................. 31

Figure 34 : Low-grade copper recovery (Biswas, 2002) ............................................................................................. 32

Figure 35 : Spectramet Alloy Sorter System (WTE, 2010) ......................................................................................... 32

Figure 36 : High-grade brass and bronze alloying (Biswas, 2002) .............................................................................. 33

Figure 37 : Umicore recycling smelter (Umicore, 2010) ............................................................................................. 37

Figure 38 : Kayser Recycling System (Aurubis, 2010) ............................................................................................... 38

V

List of Tables

Table 1: Estimated distribution of impurities in flash furnace smelting (Biswas, 2002) ............................................... 7

Table 2: Energy consumption comparison (ISAMELT, 2010) .................................................................................... 14

Table 3: Old copper scrap generation and disposition in Japan (Biswas, 2002) .......................................................... 25

Table 4: 2006 metal demands for electronics equipments (Christian Hageluken, 2008) ............................................. 30

Table 5: Typical Types of Copper Scrap Processed to Produce Secondary Copper .................................................... 34

Table 6: Major U.S. Scrap Copper User Categories (Mike Laney, 2006) ................................................................... 35

Table 7: IPPC-BAT for Secondary Copper Smelters (IPPC, 2010) ............................................................................ 36

Table 8: Recent copper smelters .................................................................................................................................. 36

TERM PAPER ENGR 5187 – Solid Waste Processing and Recycling

Copper Recycling

Date: March 24, 2010

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1. INTRODUCTION

Mankind has been using copper for more than 10,000 years. 6,000 years ago the

discovery of Bronze (copper-tin alloy) revolutionized the manufacturing of metal

artifacts. The “Bronze age” is characterized by advanced metalworking, and

intensive copper recycling with the metal from damaged weapons and tools being

reused. The village of Titelberg, Luxembourg (Wikipedia, Titelberg, 2010) had one

of the first bronze recycling smelters of Europe (SHAW, 2007). Nowadays copper

continue to have a leading role in various industrial applications. For instance, it

recently replaced aluminum in Integrated Circuits (Wikipedia, 2010), and in Europe

was chosen as the best metal for the new Euro currency; in the first phase of coins

implementation (2002), 180.000 tons of copper were used in the coinage process

(Eurocopper, 2010).

1.1 THE COPPER INDUSTRY

This red metal is an essential resource in both the developed and developing

economies, with a global demand for refined copper growing continuously, from

500 thousand tons in 1900 to more than 18 million tons in 2007, with an average

annual growth rate of 4% since the 1990’s (Fig. 1).

Figure 1 : Global refined copper demand in thousands of metric tons (Eurocopper, 2010)

In 2007 the worldwide copper usage, including the direct reuse of scrap, was 22.8

million tons. Coppers main physical and mechanical properties (best electrical and

thermal conductor, malleable, durable and antimicrobial) make it irreplaceable in

the current human civilization. Copper is used in renewable energy production,

improving energy efficiency, in sustainable construction, in transport and hospital

equipment, and in various new technologies.

The world mine capacity has risen, from 9.6 million in 1980 to 17.9 million tons

in 2007, but copper recycling continue to have a very important role in the

production of this metal.


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1.2 COPPER PRODUCTION AND USAGE

The total production of refined copper is obtained with the sum of primary

production (metal from extraction) and secondary production (recycling of copper

scrap). The primary copper production worldwide reached 15.3 million tons in

2007. With an additional 2.8 million tons of secondary copper production, the

total refined production is 18.1 million metric tons.

Asia’s represents enormous copper production (figure 2), and in 2006, China

alone accounted for 17.5% of global production. The refining capacity (2.3

million tons) is exceeding the mine output in 0.7 million tons. Most European

copper producing countries, with the exceptions of Russia and Poland, import

copper in the form of concentrates from countries such as Chile, Mexico and

Indonesia.

Figure 2 : Production of refined copper worldwide (thousands of metric tons) (Eurocopper,

2010)

The current overcapacity of copper smelting is causing some problems in the

copper industry, some companies are on red ink (Aurubis, 2010) and others are

acting to avoid financial problems.


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In a recent announcement, Xstrata Canada (Xstrata, 2010) revealed that they plan

to close the Kidd Metallurgical operations in May of 2010; Claude Ferron, Chief

Operating Officer for Xstrata Copper Canada, commented about the Timmins

smelter shutdown as follows:

“Global smelting overcapacity is driving treatment and refining charges to

record lows while the costs to operate and maintain these facilities continue to

increase. Our situation in Canada is exacerbated by a strengthening Canadian

dollar. The requirement for further capital investment in these plants and lower

sale prices for some by-products including sulphuric acid have also negatively

impacted the viability of these operations. We have investigated options to

improve the situation and after careful consideration have made this difficult

decision to permanently shut down the Kidd zinc and copper plant”.

Global copper usage currently stands at 22.8 million tons (Eurocopper, 2010), of

which 63% is refined primary copper, 11% refined secondary copper (scrap and

end of life products requiring a refining stage) and 26% directly re-melted scrap

(scrap from throughout the copper value chain); this gives an overall recycling

rate of 37%. The main copper using countries and regions are the European Union

(EU) with 5.1 million tons, China (4.8), USA (3.1), Japan (1.9) and South Korea

(1.3). In 2002, China became the largest national market for refined copper (up

from 10% in 1996, to 21% of global demand in 2006). In 2009, refined copper use

per inhabitant remains much higher in the more developed economies, such as the

former EU15, the USA and Japan, where usage is around 9 kg/capita per year,

compared with many of the developing countries, where the usage is 1-2 kg/capita

per year.

In Europe, the use of refined copper has the following distribution:

� 58% in the electricity and energy sectors (cables, generators, motors,

transformers, etc)

� 26% in the construction area (façades, cladding, pipes, window and canopy

uprights, roofs)

� 10% in Mechanical engineering (machine tools, coins, etc)

� 5% in the transportation industry

� 1% in other activities.

Copper can be alloyed with other elements (zinc, tin, lead, nickel and aluminum)

to be used in a wide range of industrial applications. It has high resistance to

corrosion (the roof of the Hildersheim Cathedral remains intact from 1280),

possesses antimicrobial properties (pure or in alloy forms), and is a 100%

recyclable material.


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2. METALLURGY OF COPPER

This chapter describes the processing of copper from various ores and scrap.

2.1 INTRODUCTION

The presence of copper in Earth crust is made in copper-iron-sulfide and

copper sulfide. Minerals like chalcopyrite (CuFeS2), bornite (CusFeS4) and

chalcocite (Cu2S) are the most common ones, and the copper concentration in

these minerals in an ore body is low, with a typical 0.5% Cu in open pit mines,

and 1 to 2% Cu in underground mines. Copper with 99.99% purity is produced

from these ores using pyrometallurgy and refining (Fig. 3).

Figure 3 : Pyrometallurgy of copper (Biswas, 2002)

Copper present in oxidized minerals (Malachite, Azurite, Cuprite, Chrysocolla)

and Covellite (CuS) is usually extracted using hydrometallurgy (Fig. 4).


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Figure 4 : Hydrometallurgy of copper (Biswas, 2002)

2.2 COPPER COMMINUTION

Copper comminution is done typically in three stages: blasting, crushing and wet

grinding. The blasting can be minimized in block caving mine operations, but the

presence of rock-breakers and grinders in the comminution phase is constant.

Grinding is usually done with one semi-autogenous or autogenous mill, and one

or two ball mills, using a solid-liquid mixture (80% solids).

2.3 COPPER FROTH FLOTATION

Grinded particles must be fine enough to allow an efficient flotation, and that size

control is normally done using hydrocyclones (BISWAS, 2002) feeding the

flotation units with the overflow outputs (Fig. 5).


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Figure 5 : Floating circuit for copper sulfide (Biswas, 2002)

In the flotation units, sulfide minerals are hydrophilic. With a hydrophobic

treatment for copper, the mechanism to separate it from gangue minerals is

created. A standard copper ore froth flotation cell is designed with heteropolar

molecules as pulp reagents, making the selected mineral water repellent for a

determined pH and concentration in the pulp (Fig. 6). Air bubbles streams are

normally added to the floatation cells to facilitate the flotation process.

Figure 6 : Effects of collector concentration and pH on the floatability (Biswas, 2002)


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2.4 FURNACES USED IN COPPER PRODUCTION

The concentrate from the flotation cells consist mostly of sulfide minerals with

some residues of gangue oxides (Al, Ca, Mg, Si, etc). Oxidizing these sulfides

gives a sulfide-rich melt (matte) and an oxide-rich melt (slag).

In the following equation we can see the existence of a balance in the oxygen to

be given in the smelt process, having the main objective of generating a higher

grade matte (CuFeS) without over oxidizing the copper:

CuFeS2 + O2 → CuFeS + FeO +SO2

That trade-off can be solved adding some silica to the smelting process, with the

negative impact of additional energy needed to melt the silica and the increased

complexity in the control of the reaction (matte settling time).

The offgas from the smelting process contains SO2 that can be captured in gas

scrubbers to produce sulfuric acid (acid plant), and the dust particles can be

captured in bag-houses or electrostatic precipitators.

The estimated distribution of impurities during flash furnace production of a 55%

Cu matte is presented in table 1.

Table 1: Estimated distribution of impurities in flash furnace smelting (Biswas, 2002)

Metal Matte Slag Volatilized

Copper 99 1 0

Alkali, Al, Ti 0 100 0

Ag, Au, Pt group 99 1 0

Antimony 30 30 40

Arsenic 10 10 80

Bismuth 15 5 80

Cobalt 40 55 5

Lead 20 10 70

Nickel 50 45 5

Selenium 75 5 20

Zinc 15 45 40


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2.4.1 Outokumpu flash furnace

Outokumpu flash furnaces (Fig. 7) may vary in size and shape, but normally they

have the following particular characteristics:

� Concentrate burners (1 to 4) to add dry particulate feeds with O2 bearing blast

and blow them downward into the furnace.

� Reaction shaft for O2 and Cu-Fe-S feed particles.

� Molten matte and slag droplets settler to form separate layers.

� Removal of the molten matte and slag thru water-cooled copper block tap

holes.

� One uptake for removing hot SO2-bearing offgas.

Outokumpu flash smelters are responsible for more than half of Worlds Cu matte

smelting. Outokumpu smelters are also used for direct-to-copper smelting and for

continuous converting. The wide adoption of Outokumpu flash smelting is due to

its efficient capture of SO2, rapid production rate and its small energy

requirement. Outokumpu smelters have an important handicap: the inability to

smelt scrap.

Figure 7 : Control system for an Outokumpu flash furnace (Biswas, 2002)


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2.4.1 ValeInco flash furnace

The Inco flash furnace (Fig. 8) uses industrial oxygen blast to smelt Cu-Fe-S and

Ni-Cu-Co-Fe-S concentrates, producing high Cu and high Ni-Cu-Co mattes. It

uses an input of concentrate dry feed and industrial oxygen through four

horizontal burners. The SO2 offgas is removed through a central gas exhaust, and

after a water-quenched treatment, is processed in the sulfuric acid plant.

Very little nitrogen enters the Inco furnace so its blast and offgas handling

Systems are small. Also, the offgas is strong in SO2, 60-75 volume%, ideal for

SO2 capture. The slag phase can contain less than 1% Cu so it can be discarded

without Cu-recovery treatment. This gives it a cost advantage over most other

modem smelting techniques. Also, converter slag can be recycled through the

furnace for Cu recovery, but this procedure will cause disturbances in a very

stable smelting process.

Figure 8 : ValeInco flash furnace (Biswas, 2002)

ValeInco flash smelting process has some disadvantages when compared with the

Outokumpu flash smelting:

� more burners

� less efficient thermal design

� lack of offgas heat removal.


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2.4.2 Noranda and El-Teniente bath smelting furnace

The Noranda and El-Teniente smelting furnaces use a large (5 m x 20 m long)

cylindrical shape barrel (Fig. 9 and 10), and they always contain layers of molten

matte (72-75% Cu) and slag. The concentrate oxidation is done blowing oxygen-

enriched air through tuyeres into the furnace's molten matte layer.

Figure 9 : Noranda furnace (Biswas, 2002)

The Cu-Fe-S input is dried and blown into the furnace using 3 to 10 submerged

dedicated tuyeres. Moist (8% Water), flux, scrap and recycle materials and scrap

are inserted using an end wall.

The furnace output products are:

� high-grade molten matte (72 to 75% Cu)

� slag (typically with 6% of copper)

� SO2 offgas.

Figure 10 : El Teniente furnace (Biswas, 2002)


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These furnaces can rotate to remove the liquids from the tuyeres, to unclog them

when the blowing is defective. The submerged blast blowing method causes

violent stirring of the matte-slag bath, resulting in a very fast melting and

oxidation of the furnace content, and preventing the excessive deposition of solid

magnetite in the furnace walls during highly oxidizing conditions.

This violent stirring also permits extensive smelting of scrap and reverts. Noranda

and Teniente furnaces are vastly used in Chile and account for 15 to 20% of world

copper smelting.

2.4.3 AUSMELT and ISAMELT furnace

The biggest disadvantage of flash smelting is the use of fine particles that

generate problematic quantities of dust, requiring large settling areas to be built

into the furnace. To address this problem, in 1971, researchers at the CSIRO

(Commonwealth Scientific and Industrial Research Organization) in Australia

began investigating the use of top-lancing technology for injecting coal into tin

slags with the objective of improving the reduction kinetics. This research led to

the development of a technology suitable for a variety of pyrometallurgical

applications, including the smelting and converting of sulfide concentrates. This

technology is now sold by two dominant organizations in smelting technology:

AUSMELT (AUSMELT, 2010) and ISAMELT from Xstrata (ISAMELT, 2010).

When compared with other smelting systems, the use of this type of smelting

furnaces will result in a low cost, smaller and less complex gas handling system.

The acid and sulphur fixation plants for these furnaces are more efficient, with

optimized fuel and air-oxygen delivery systems, materials handling and feeding

systems. The input feeding uses standard equipments with no need for drying or

grinding of furnace input materials.

2.4.3.1 AUSMELT furnace

This technology uses a proprietary top submerged lance (ATSL), and is based on

reactions between the sulphidic and metallic components of the feed material and

contained oxygen and ferric oxide in the bath. Critical process phenomena

including feed material dissolution, energy transfer, reaction and primary

combustion all take place in the slag layer. The intense agitation in the vessel

ensures that reactions occur rapidly and residence times are low, because of the

use of a vertically suspended lance, submerged in the molten slag bath. Process

gases (air & oxygen) and fuel are injected through this lance, and the fuel is

combusted at the lance tip to provide heat to the furnace. The slag is mixed by the

pressure generated with injection of the process gases, and a controlled swirling of

the process air in the lance, cools the exterior of the lance and allows the

solidification of a slag layer on it. This solid slag layer protects the lance (Fig. 11)

against the highly aggressive environment inside the furnace.


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The AUSMELT lance is similar to tuyeres, and is designed to deliver precise

quantities of process gas to the reaction medium (the slag), with the advantage of

not suffering blockages or tuyere line refractory wear out. The degree of process

oxidation and reduction is controlled by adjusting the fuel to oxygen ratio supply

to the lance, and the proportion of reducing coal feed. This enables the furnace to

be operated through a range of extreme oxidising to extremes reducing states.

Figure 11 : Schematic of a Ausmelt furnace (Ausmelt, 2010)

AUSMELT currently have the status “Technology of Choice”, with more than 34

commissioned furnaces, 14 in copper production. The comparatively low capital

and operating costs, and excellent environmental performance, is causing the

abandonment of other smelting technologies in new projects.

Figure 12 : Market acceptance of TSL technology (Ausmelt, 2010)


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AUSMELT furnaces can be integrated in a smelting and converting circuit (Fig. 13),

producing blister copper from primary and secondary copper materials.

Figure 13 : Integrated smelting and converting (Ausmelt, 2010)

The choice of furnace depends on the least expensive energy available (natural gas,

fuel oil, electricity, etc). Choosing electric furnaces for the metal settling will allow a

better control of the operating oxygen potential. An electric settling furnace allows

the launder to be connected to the furnaces, with the relative heights of the furnaces

adjusted, allowing the molten converter slag to flow from the converter to the settler.

In this layout granulated or crushed matte is fed directly to the converter. The key

advantage of this circuit is the reuse of the contained heat in the recycled converter

slag, lowering the overall energy consumption of this integrated solution.

AUSMELT Technology also processes a range of high and low-grade copper bearing

secondary materials to produce black copper, converter grade copper or copper

alloys. The range of secondary materials includes metallic scrap, alloys, reverts,

residues, dusts and other recyclable copper-bearing materials such as electronic and

computer scrap (Matusewic R W, 2010). The Ausmelt furnace system can handle

coarse and fine-sized secondary materials. Solids fed to the furnace are shredded or

crushed, while fine feeds can be agglomerated to prevent entrainment by offgases

before reaching the slag bath. Organic and/or halide compounds present in some

scrap are broken down during processing to benign compounds in the slag bath.


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2.4.3.2 Xstrata ISAMELT smelting technology

Using the same patented lance technology (J.Floyd, 1993) present in AUSMELT, the

ISAMELT process provides a separated path solving some of the operational

problems of this type of furnaces (Fig. 14).

The three major breakthroughs from ISAMELT are:

� Low pressure drop operation.

� Accretion minimization with a redesigned sealed offgas circuit.

� The major refractory wear out mechanism was identified and minimized.

Table 2: Energy consumption comparison (ISAMELT, 2010)

Comparison of copper ISAMELT energy consumption with the original roaster-

reverbatory furnaces

Roaster-reverb

furnaces

Copper ISAMELT

plant

Concentrate treated (ktpa) 650 1,070

Coal used (tpa) 85,000 6,300

Natural gas used (kN�� 0 6,120

Oil used (kL/year) 2,400 1,980

Energy consumption per tonne of

concentrate (GJ/t)

4.12 0.47

The energy savings using ISAMELT/AUSMELT are well known (Table 2), and more

than 50% of new projects plan to use this technology.

Figure 14 : Mount ISA copper ISAMELT smelter (ISAMELT, 2010)


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2.4.4 Kivcet flash furnace

The Kivcet Furnace (Fig.15) was developed in the USSR for smelting complex

copper concentrates containing lead, zinc and other impurities. Dried concentrate is

introduced tangentially into a small water-cooled cyclone where it is autogenously

flash smelted with technical oxygen. The products pass into a partition chamber

where they melt and off-gases are separated. The liquid metal flows into a settling

kernel by passing below a vertical water cooled partition wall, immersed in the melt.

The partition wall prevents reactor gases from entering the settling kernel from the

partition chamber. The settling kernel is direct resistance heated. Settling of matte

and slag takes place under a reducing atmosphere which is maintained by adding coke

fines. The Kivcet process has the potential to be developed into a continuous or

single step smelting process for treating complex concentrates.

Figure 15 : Kivcet Flash Smelter (MetSoc, 2010)

This furnace has various benefits associated with it, and when compared to the old

sintering and blast furnaces, the Kivcet smelter can reduce particulates (smoke) in the

environment by 90% and the metals emissions by 70% to 90%.

2.4.5 Contop furnace

The German company KHD Humboldt Wedag AG developed this furnace type in

1979. Using this furnace, this process combines autogenous oxygen flash smelting in

a water-cooled cyclone with top blowing of the resulting high-grade matte (up to 80%

Cu) and slag in separate, interconnected chambers.

CONTOP means Continuous smelting and TOP blowing.


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2.4.6 QSL Process

In Queneau-Schumann-Lurgi (QSL) smelting process, the copper concentrate, the

recycled flue, and a fluxing agent are wet, mixed and compacted to pellets before

being fed to this furnace. Like the Kivcet furnace, the oxidation and blast furnace

(reduction) are combined into one autogenous direct reduction unit.

2.4.7 Mitsubishi Process

This continuous system merges the smelting and converting furnaces with an

intermediate electric slag cleaning furnace (Fig. 16). It produces two continuous, high

SO2 strength offgas streams for high volume sulphuric acid production.

The main advantages over other copper furnaces is the simplicity of the copper

recovery from slag, the flexibility in treating a wide range and grade of concentrates

and secondary materials such as refinery anode scrap and copper scrap.

It has the disadvantage (compared to single-furnace) of having has two offgas streams

rather than one. With system improvements, the productivity of the Mitsubishi

process was increased with:

� Increased oxygen-enrichment of smelting and converting furnace 'blasts'.

� Increased core life due to better refractory insulation, increased water cooling

and improved lance tip positioning.

� Improved process control with the use of a real time temperature measurement

system, and an expert system assisting the plant control.

Figure 16 : Mitsubishi Process (Biswas, 2002)


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2.4.1 Reverbatory Furnace

All reverbatory (roof radiating) furnaces were decommissioned in the USA, because

of a high cost of operation and environmental issues. Old units can be upgraded with

oxy-fuel burners (Fig. 17) and be used to recycle low-grade copper scrap.

Figure 17 : Reverbatory Furnace (Biswas, 2002)

2.4.1 ASARCO Anode Furnace

ASARCO anode furnaces are fed with blister copper with purity of more than 98%,

but containing too much sulphur and oxygen. This anode furnace uses a tuyere to

blow natural gas into the copper melt to burn off the oxygen. Initially in this process,

a tall yellow flame billows from the top of the anode furnace, and when the oxygen

present in the copper is gone, the flame becomes blue-green (Fig. 18).

Figure 18 : ASARCO Anode Furnace (Biswas, 2002)


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2.4.2 Crucible Furnace

Crucible furnaces are used for large amount of secondary copper production, using

hydrocarbon gases and oils as the combustible. Normally used in foundries to melt

clean (and well segregated) scrap. This furnaces can be stationary or tilting (Fig. 19).

Figure 19 : Crucible tilting furnace (Majoreng, 2010)

2.4.3 Blast Furnace

Blast furnaces are used with low-grade copper and brass scrap, refinery slags,

drosses, and skimmings. If this furnace is used exclusively to melt scrap, and has no

chemical reduction involved, it is called a cupola furnace. The product of the blast

furnace is normally called black copper.

Figure 20 : Blast furnace (Majoreng, 2010)


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2.5 CONVERTING OF COPPER MATTE

The objective of the converting phase in the metallurgy of copper is the oxidation of

molten Cu-Fe-S matte, and the creation of the more pure 'blister' copper (99% Cu).

A large number of copper smelters use old and inefficient copper smelting

technology, and in the smelting of primary copper, a low to medium grade matte is

produced.

In a converting phase, oxidation must remove between 30 to 80% of the sulphur

present in the mined concentrate. Old converter technologies like the Pierce-Smith,

the Hoboken and the inspiration converter, use the traditional two-cycle batch process

with some operational problems:

� Intermittent gas flows of variable SO2 strength and gas flow rate.

� Ingress of air around the off-gas collection hood which dilutes the gas.

� Slow ladle transfers and repetitive handling of matte and slag, always with a

handling danger and sulphur (gas) fugitive emissions.

� The thermal cycling and the bath composition will reduce the refractory life

Because of these problems, alternative continuous converting processes have been

studied with some field implementations:

� Downward lance Mitsubishi converting.

� Solid matte Outokumpu flash converting.

� Submerged tuyere Noranda continuous converting.

2.5.1 Peirce-Smith Converter

The mature side-blown Peirce-Smith converter (Fig. 21) is widely used in the

metallurgic industry, and after more than 80 years the Peirce-Smith type continues

to dominate the copper industry that still use converters. Through many decades of

usage, many mechanical and metallurgical improvements have been introduced, but

the original concept remains the same.

Figure 21 : Peirce-Smith Converter (Biswas, 2002)


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2.5.1 Hoboken Converter

The Hoboken converter (Fig. 22) is designed with an inverted u-shaped side flue at

one end to siphon gases from the interior of the converter directly to an offgas

collection system. The siphon results in a slight vacuum at the converter mouth.

Figure 22 : The Hoboken cconverter (Biswas, 2002)

2.5.1 Inco Oxygen Top Blown Nitrogen Stirred Converter

This converter is used in the Copper Cliff plant (Fig. 23), and uses a combination of

top blowing and bottom stirring with a simplified feeding technique. The

application of nitrogen through porous plugs to facilitate stirring has been

introduced. Input feeding is accomplished by gravity introduction of dry,

nonagglomerated concentrate (90% -44 µm) through a water-cooled pipe (Fig. 24)

onto the "eye" created by the nitrogen. Supplemental heat is provided in the area to

promote melting. Feeding zones and converting zones are separated so that gas

velocity around the feed stream is minimal, minimizing the dusting rate to 1.5-2%.

Figure 23 : Nickel-Copper extraction at Copper Cliff (TMS, 2010)


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The gentle bottom stirring with nitrogen promotes desulfurization of the molten

blister and enhances the approach to chemical equilibrium.

Figure 24 : Oxygen Top Blown Nitrogen Stirred Converter (TMS, 2010)

2.5.2 Solid Matte Outokumpu Flash Converter

This converter (Fig. 25) is an efficient matte oxidation system, with an excellent

recollection of the offgas and dust. The extra energy needed to process the matte feed,

and the inefficient operation melting scrap copper are the principal disadvantages.

Figure 25 : Outokumpu Flash Converter at Kennecott Utah (TMS, 2010)


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2.6 FIRE REFINING AND CASTING OF COPPER ANODES

The final step of the pyrometallurgical copper production is electrorefining.

In the electrorefining process, thin and strong smooth anodes are needed for

interleaving with cathodes in the electrorefining cells.

The formation of surface blisters is prevented by removing sulphur and oxygen from

the converter molten copper by air oxidation and hydrocarbon reduction.

The air (S removal) and hydrocarbons (O removal) are usually injected into the

molten copper via one or two submerged tuyeres in a rotary 'anode' furnace (Fig. 18).

Anodes are usually cast in open molds on a large rotating wheel (Fig. 26).

Uniformity of anode mass is critical for efficient electrorefining so most smelters

automatically weigh the amount of copper poured into each anode mold.

Figure 26 : Anode furnace casting wheel (Biswas, 2002)

The cast anodes are often straightened and flattened in automated anode preparation

machines. Their lugs are normally machined to a knife-edge. Straight, flat, vertically

hung anodes are required to give pure cathodes and high current efficiencies in the

electrorefinery process.

Smelters and refineries can reject 2 or 3% of their new anodes because of physical

defects or incorrect masses. They also produce 15 to 20% un-dissolved anode

scrap after a completed electrorefining cycle. These two primary scrap materials

return to the rotary 'anode' furnace to be re-melted and cast into new anodes, going in

a new feed to another electrorefinery cycle.


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2.7 CAPTURE OF SULFUR GAS FROM SEMELTING AND CONVERTING

The smelting and converting of sulphide copper ore (85% of the world copper ores

offering) involves the extraction of the sulphur present in the concentrates. In that

extraction process a dangerous and environmental destructive gas (SO2) is produced,

requiring a SO2 gas processing unit; the smelter acid plant (Fig. 27).

Figure 27 : Producing sulfuric acid from smelting and converting gases (Biswas, 2002)

The current smelting techniques used to process sulphide copper concentrates are

typically producing 2.5 to 4.0 tonnes of sulphuric acid per tonne of produced copper.

High sell prices and stable production of the sulphuric acid byproduct, will help the

profitability and a fast return of the investment (ROI) in copper production plants.


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3. SECONDARY COPPER PRODUCTION

The previous sections gave a description of some of the equipments and processes

used in the primary and secondary copper production. This chapter will give a

detailed description of the secondary copper production, with emphasis in the latest

technologies used in the copper recycling industry.

3.1 INTRODUCTION

The production of copper from scrap can be justified with following reasons:

� Price, it is cheaper to recycle copper than to extract new copper.

� Limited resources, 12-13% of all known reserves have been mined.

� Energy efficiency, recycling a ton of copper saves 85% of the energy that

would be used to mine and extract the same ton of copper.

� Landfill costs, waste from household and industry is usually dumped in holes

in the ground (landfill), that are rapidly getting filled up and becoming a very

expensive away to dispose waste.

� Environment, less gases and dust are released in the recycling of copper.

3.2 UTILIZATION CYCLE OF COPPER CONTAINING MATERIALS

Copper is one of the metals that is present in all types of electrical equipment, and it

has a strong presence in non-electrical equipment.

The U.S. geological survey circular 1196-x, summarizes the flow (figure 28) of

copper containing materials in our actual human civilization.

Figure 28 : Diagram showing the flow of copper-containing materials (Goonan, 2010)


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Figure 28 shows that the semi and finished product fabricators generate an

impressive 735,000 metric tons of new scrap copper, when compared with the

1,920,000 of old scrap.

This reinforces the idea that the recycling of old scrap needs to be more efficient, to

lower the segregation and processing costs.

Some of the viability problems that exists in the processing of old scrap are well

known:

� Segregation problems, old copper scrap mixed with other materials.

� Unpredictability, irregular day to day flow of scrap to be recycled, causing

storage or underproduction operational costs.

� Logistics, old copper scrap is scattered through multiple locations.

As a result, old scrap will stay in warehouses, junkyards and landfills (table 3), if the

price is not competitive to recycle the copper.

Table 3: Old copper scrap generation and disposition in Japan (Biswas, 2002)

Source of Scrap Disposed Collected Landfilled %Recycled

Power cables, Analog cables 197 197 0 100

Electric Appliances, Machinery 142 29 113 20

Automotive 79 38 41 48

Industrial machines, ships, cars 62 51 11 82

Buildings 118 81 37 69

Totals 598 396 202 66

3.3 CATEGORIES OF COPPER SCRAP

The most common categories of copper scrap are:

� Number 1 scrap, with a minimum copper content of 99% and a minimum

thickness of 1.6 mm.

� Number 2 scrap, with a minimum copper content of 96%, in the form of wire,

heavy scrap, or nodules

� Light copper, with a minimum copper content of 92% (gutters, downspouts,

boilers, kettles), generally containing minimal levels of alloyed copper.

� Refinery brass, scrap from various copper alloys with a minimal copper

content of 61.3%.

� Copper-bearing scrap, all low-grade materials such as skimmings, sludges,

slags, reverts, grindings and other residues.

Copper wastes are a special category of scrap, and are characterized by a poor

copper content and high processing costs (PCB etchants, copper mixed with

radioactive materials, etc).


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3.3.1 Types of copper alloys present in new scrap (Mike Laney, 2006):

Copper is intensively used in the electrical industries in pure form (>99%) because

of the excellent electrical and thermal conductivity, but to obtain extra mechanical

properties is alloyed with a myriad of metals, the most common alloys of copper

are:

� Beryllium-copper, with the addition of beryllium (0.5–2.0 percent by

weight) this copper alloy will exhibit high electrical and thermal

conductivity, good corrosion and fatigue resistance, high strength and

hardness, and nonmagnetic properties.

� Cadmium-copper, with the addition of cadmium (0.8–1.2 percent by weight)

this copper alloy will exhibit a double mechanical strength and wear

resistance of pure copper, will retaining 90 percent of its conductivity; this

alloy is widely used in contact wire and catenary strand.

� Chromium-copper, with the addition of chromium (0.6–1.2 percent

chromium by weight) this copper alloy will exhibit twice the mechanical

strength of pure copper, while retaining 85 percent of its conductivity, and

obtaining an excellent corrosion protection.

� Aluminum-copper and copper-aluminum, the copper content of copper-

aluminum alloys ranges from about 70 to 90 percent copper (average copper

content is about 85 percent by weight), the balance being aluminum and

perhaps small amounts of other elements. Bolts, bushings, cams, and gears

made from these materials are corrosion resistant with good strength.

Aluminum bronze is a type of bronze in which aluminum is the main

alloying element added to copper. Aluminum bronzes are most valued for

their higher strength and corrosion resistance compared with other bronze

alloys. They have low oxidation rates at high temperatures and low

reactivity to sulfurous compounds and other exhaust products of

combustion. They are also resistant to sea water corrosion. Aluminum

bronze castings have exceptional corrosion resistance; high strength,

toughness, and wear resistance; and good casting and welding

characteristics.

� Nickel-copper and copper-nickel alloys include cupronickels (68–88 percent

copper and 10–30 percent nickel) and nickel silvers (55–65 percent copper,

12–25 percent nickel, and 3–27 percent zinc). Because copper-nickel alloys

are corrosion and oxidation resistant and thermally stable, they are used in

marine and powerplant applications, such as condenser tubes, valves, pumps

and fittings.

� Bronze, the copper-tin alloys or tin bronzes (70–90 percent copper, 5–12

percent tin, balance other metal) have good corrosion resistance and are

stronger and more ductile than brass. Additions of lead (6–12 percent)

diminish alloy strength but enhance machineability.

� Brass, a copper-zinc alloy with 10 to 40% of zinc and other elements (lead,

tin, etc); Brass is used in decorative and artistic applications, hardware,

munitions, and plumbing.


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3.4 COPPER SCRAP SORTING, PROCESSING AND BENEFICIATION

After the collecting of copper scrap, some processing paths need to be taken to get a

recoverable copper, pure or in an alloy form (Fig. 29).

Figure 29 : Process flow chart for copper scrap (Goonan, 2010)

3.4.1 Copper wire processing

Copper scrap wire and cable can be classified in three types:

� Aerial cables, predominantly high-voltage power cable, mainly copper with

little insulation, and easy to recycle.

� Surface indoor/outdoor cables, various insulations and sections. Due to the

lower sections of the conductor, the cost of processing per kg of recovered

copper is higher than thicker cables. The mixing with other hardware (steel

brackets, tie raps, etc) will require additional processing steps; the

automotive harnesses is one example.

� Underground and submarine cables, characterized with a strong and

complex construction, and multiple layers of metal and insulation. The

recycling process of these cables can be complex and create environmental

hazards.

Standard cables can be chopped and sorted using compact cable grinders (Fig. 30).

Special cables will require special equipments and recycling processes.


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Figure 30 : Electrical cable grinder-separator - mod. RC (cogelme, 2010)

In cables with aluminum and copper conductors, Eddy-current separators can be

used after the shredding of the cable to segregate metal from plastic (Fig. 31).

Figure 31 : Eddy current separator (Dings, 2010)


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3.4.2 Copper recovery from automotive scrap

With the massive implementation of electronic technology in the automotive

industry, more copper (and other metals) are present for the electrical system.

Other components (Fig. 32) made of copper (radiators, tubes, etc) may need distinct

segregation procedures.

Figure 32 : Flow sheet for recovering metals from scrap automobiles (Biswas, 2002)

Copper electrical cabling present in automobiles, is characterized with thicker

insulations to ensure mechanical and thermal protection for the conductors. This

insulation can be removed from the wire with very fine chopping, producing a

fine-particle mixture of insulation and wire, which can be segregated using a

fluidized bed, separating the insulation (overflow) from the wire (underflow).

Another copper-insulator separation process is the automated cable stripping, where

the cable is passed slowly through a machine that separates the insulation from

single strands of copper wire.


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3.4.3 Copper recycling from Electronic Scrap (E-scrap)

With the astonishing technological advances of microelectronics, electronic

appliances are having a premature end of life. Nowadays the end of life can be 6

months for a cell phone, 2 years for a note book, 3 years for a desktop PC, 4 years

for some TV appliances, etc. The VHS video recording system took 30 years to

reach the end of life (Wikipedia, Wikipedia, 2010), and was replaced by the DVD

system.

The DVD system, needed only 10 years of operational usage to become obsolete,

and is currently being replaced by the high definition blue ray disc system. This

“premature” end of life of the DVD system, is also sending to the scrap yard, tons

of displays (low resolution CRT, LCD, Plasmas, etc), making even worse the

scenario of the recycling the giant inventory of E-scrap waiting to be recycled.

With a large number of different materials (metals, plastics, polymers, etc) present

in E-scrap, copper continues to be the most used (Table 4).

Table 4: 2006 metal demands for electronics equipments (Christian Hageluken, 2008)

3.4.3.1 European Community WEEE Directive

The European Community created in 2002 a directive (2002/96/EC), trying to

attenuate the environmental problem caused by the E-scrap. The Waste Electrical

and Electronic Equipment Directive (WEEE Directive) put some rules on the

handling of the waste created by electrical and electronic equipment.


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In February of 2003, the WEEE directive and the RoHS Directive (Restriction of Hazardous

Substances Directive) was added to the European legislation, defining very restrictive rules in the

collection, recycling and recovery targets for all types of electrical goods. The WEEE directive

imposes the responsibility for the disposal of waste electrical and electronic equipment on the

manufacturers of such equipment. Those companies should establish an infrastructure for

collecting WEEE, in such a way that "Users of electrical and electronic equipment from private

households should have the possibility of returning WEEE at least free of charge". Also, the

companies are compelled to use the collected waste in an ecologically-friendly manner, either by

ecological disposal or by reuse/refurbishment of the collected WEEE.

3.4.3.2 Equipments used in E-scrap recycling

Recycling E-scrap is a challenging task, because of the complexity of the scrap.

Manual removal of the electronic content from the metallic (steel, aluminum) cases

of VCRs, computers, LCDs, etc, is the first segregation operation.

After the initial segregation, inspection and stockpiling is needed to bin out the

waste to the proper recycling procedures.

The printed circuits boards are normally shredded, and processed using automatic

equipments (Fig. 33).

Figure 33 : Printed circuit board (PCB) recycling equipment (hnsxjx, 2010)

The grinded particles present at the output of this equipment can be additionally

segregated using x-rays automated technologies (Fig. 35).


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Figure 34 : Low-grade copper recovery (Biswas, 2002)

Burning, sweating and drying (Fig. 36) steps may be applied to the segregated

particles; these extra processing steps add environmental issues with the possible

emissions of toxic gases (Fig. 34). These problems, in combination with the

associated extra costs incurred to the recycling operation, make single step recycling

processes the most wanted technology for new recycling plants.

Figure 35 : Spectramet Alloy Sorter System (WTE, 2010)


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Figure 36 : High-grade brass and bronze alloying (Biswas, 2002)

3.5 SECONDARY COPPER PROCESSING PLANTS

Copper scrap (Table 5) can be processed in primary or secondary smelters.

Primary smelters normally smelt copper concentrates, but some smelting designs are

adapted to smelt all grades of scrap. The designs from Isasmelt, Mitsubishi, Noranda,

reverberatory and top blown rotary converter smelting furnaces are some of the

existing examples. Some copper scrap is also recycled in the converters of primary

smelting plants. Standard secondary smelters (Table 6) use blast furnaces, top blown

rotary converters and electric furnaces for smelting low-Cu grade scrap. In these old

plants, the normal smelting output product is black copper (80% Cu), subsequently

converted into rough copper (96% Cu), and then fire refined and casted into anodes

(98.5% Cu). Because these processes cannot completely remove other metals (Ni, Sn,

etc) from the recycled copper, the final step of electrorefining is required.

Electrorefining also recovers silver and gold and other group metals, with the

subsequent slime processing.


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Table 5: Typical Types of Copper Scrap Processed to Produce Secondary Copper

The secondary copper refining is “more dirty” than primary copper refining because

of impurities present in the copper scrap. Therefore, bigger facilities are needed to

house larger electrolyte purification tanks and slimes treatment units. Copper scrap

recycling will slow down the process of the depletion of the copper present in earth's

crust, and reduce energy costs associated with copper mining and mineral processing.


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Table 6: Major U.S. Scrap Copper User Categories (Mike Laney, 2006)

3.5.1 New technologies in secondary copper smelting

The future of secondary copper smelting in the world is experiencing a big revolution

with the Ausmelt and Isasmelt top lance technologies.

The United States is shutting down all old technology secondary smelters because of

environmental and economical reasons.

European Community under the IPPC directive (Integrated Pollution Prevention and

Control) defined a set of best available techniques (BAT) with the objective of

emissions reductions and environmental improvements.

In the IPPC directive (IPPC, 2010) a comprehensive review of copper smelting and

converting technologies for producing primary and secondary copper is presented.


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Table 7: IPPC-BAT for Secondary Copper Smelters (IPPC, 2010)

Top lance smelting (bath smelting) is present in the majority of new and projected

secondary smelters (Table 8).

Table 8: Recent copper smelters


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3.6 ISAMELT SECONDARY COPPER PROCESSING PLANTS

3.6.1 UMICORE in Hoboken (Belgium)

The fuel savings and emissions control of the top lance technologies, compensate for

the downtime that this system has in the periodical replacement of the top lance (30

to 60 minutes in a 10 day period). A state of the art recycling plant is present in

Hoboken (Belgium) using the ISAMELT furnace as the core component of the

pyrometallurgical process (Fig. 37).

Figure 37 : Umicore recycling smelter (Umicore, 2010)


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3.6.2 AURUBIS (Hüttenwerke Kayser) in Lunen (Germany)

The same technology is labelled with the name Kaiser Recycling System (KRS) in

the Hüttenwerke Kayser AG (Aurubis, 2010) plant in Lunen (Germany).

Figure 38 : Kayser Recycling System (Aurubis, 2010)

The KRS recycling plant was implemented using ISASMELT furnaces, replacing

three blast furnaces and one Peirce Smith converter used for smelting residues and

scrap copper. The benefits of using this technology can be summarized as follows:

� Improved overall copper recovery with a less copper present in the slag phase.

� Less furnaces in operation

� Decrease in offgas volume

� Production capacity exceeds the original design by 40%

� Energy consumption is down by more than 50%

� CO2 emissions down by more than 64%

� Overall emissions are 10% of the old plant.


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4. REFERENCES

Aurubis. (2010). Aurubis. (Aurubis) Retrieved from Aurubis: http://www.aurubis.com/en/home/

Ausmelt. (2010). Ausmelt. Retrieved from Ausmelt:

http://www.ausmelt.com.au/PDF/Capability%20Statements/Ausmelt%20Copper%20Capability%2020

05%20%28LR%29.pdf

Biswas, W. D. (2002). Extractive Metallurgy of Copper (4th edition). Oxford: Pergamon.

Christian Hageluken, C. M. (2008). Mining our Computers. Stuttgart: EGG.

cogelme. (2010). cogelme. Retrieved from cogelme: http://www.cogelme.com/eng/cable-weee-

recycling-wire-stripper.htm

Dings. (2010). Dings. Retrieved from Dings: http://www.dingsmagnets.com/industrial-magnet-

industries/recycling.html

Eurocopper. (2010). Eurocopper. Retrieved from Eurocopper: www.eurocopper.org

Goonan, T. G. (2010). Copper Recycling in the United Sates in 2004. Virginia: US Department of the

interior.

hnsxjx. (2010). hnsxjx. (hnsxjx) Retrieved from hnsxjx: http://english.hnsxjx.cn/393.shtml

IPPC. (2010). EU. (EU) Retrieved from EU:

http://ec.europa.eu/environment/air/pollutants/stationary/ippc/index.htm

ISAMELT. (2010). ISAMELT. Retrieved from ISAMELT: http://www.isasmelt.com/

J.Floyd. (1993). freepatentsonline. Retrieved from freepatentsonline:

http://www.freepatentsonline.com/5251879.pdf

Majoreng. (2010). majoreng. Retrieved from majoreng:

http://www.majoreng.com.au/metals.tilting_crucible.php

Matusewic R W, B. B. (2010). Ausmelt Technology for Recycling of Computer Board and Other High

Value Materials. Retrieved from Ausmelt:

http://ausmelt.com.au/PDF/Papers/Ausmelt%20Technology%20-

%20Recycling%20of%20Computer%20Boards.pdf

MetSoc. (2010). MetSoc. Retrieved from MetSoc: http://www.metsoc.org/virtualtour/processes/zinc-

lead/kivcetlarge.asp

Mike Laney, P. P. (2006). Current Status of Secondary Copper Production in the United States. NC:

RTI International.

SHAW, M. L. (2007). THE NORTH SMELTER AT TITELBERG: POST-IMPERIAL BRONZE

RECYCLING IN BELGIC GAUL. Columbia: University of Missouri.

TMS. (2010). TMS. Retrieved from TMS: http://www.tms.org/pubs/journals/JOM/9601/Queneau-

9601.html#ToC6

Umicore. (2010). Umicore. (Umicore) Retrieved from Umicore: http://www.umicore.com/en/

Wikipedia. (2010). Retrieved from http://en.wikipedia.org/wiki/Copper_interconnect

Wikipedia. (2010). Retrieved from : http://en.wikipedia.org/wiki/VHS

Wikipedia. (2010). Titelberg. Retrieved from Wikipedia: http://en.wikipedia.org/wiki/Titelberg

Wikipedia. (2010). Wikipedia. (wikipedia) Retrieved from Wikipedia:

http://en.wikipedia.org/wiki/VHS

WTE. (2010). Spectramet. (WTE) Retrieved from WTE:

http://www.wte.com/html/new_technologies.html

Xstrata. (2010). Xstrata. Retrieved from Xstrata:

http://www.xstrata.com/media/news/2009/12/08/0702CET/200912080702.en.pdf


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5. GLOSSARY OF TERMS

CCR - Canadian Copper Refinery (Montréal), is an Xstrata plant that refines anode

copper from the Horne and Altonorte smelters.

Matte - Is an intermediate, more concentrated (with respect to the desired metal)

material than concentrate, from which it is made, and is usually transferred to another

furnace for further concentration. Copper mattes contain between 50 and 70 percent

copper, depending on the process parameters.

Slag – partially vitreous by-product of smelting.

Tuyere – Tube, nozzle or pipe used to blow air into the furnace.

Black copper – Impure (ex:80%) copper obtained in a blast-furnace.

Blister copper – The product of a converting furnace. It is an intermediate, more

concentrated (with respect to the desired metal) material than matte, from which it is

made, and is usually transferred to another furnace for further concentration. Blister

copper contains about 98 percent copper, the exact percentage depending on the

process parameters. Blister copper is sometimes cast into ingot forms and placed into

worldwide trade. Most often it is fire-refined onsite. The name origin derives from the

blistered surface caused by the SO2 escape.

New scrap (prompt scrap) – generated in manufacturing processes (residues).

Old scrap – collected copper present in the final products or applications.

No1 copper – purity greater than 99%.

No2 copper – product with 94 to 98% of purity.

Light copper – 88 to 94% copper.

Irony scrap – small electric motors, shredded automobile copper fractions.

Anode – The positive terminal in an electrolytic cell where electrons leave a device to

enter the external circuit. A copper anode at 99 percent purity will dissolve.

Cathode – The negative terminal in an electrolytic cell where copper is plated during

electrowinning or electrolytic refining. Copper so plated is referred to as “cathode”

and is generally about 99.99 percent pure.

Anode slimes – A mixture of metals and some insoluble compounds that originate in

and dissolve from the anode during electrolysis and precipitate from the electrolyte

onto the cell floor. These are processed for the metal content. In copper electrolysis,

gold, silver, selenium, tellurium, and other metals are recovered.

OFC - Oxygen-free copper

OFHC - Oxygen-free high thermal conductivity copper.

Copper concentrate - A product of flotation milling. It composes sulfide minerals

and entrained material and contains one-third each copper, iron, and sulfur. It can be

processed pyrometallurgically in a smelter to produce matte or hydrometallurgically

(pressure leaching) to produce pregnant leach solution, both products requiring

further processing to obtain copper metal. Copper concentrate may participate in

worldwide trade or be smelted domestically in its country of origin.


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Electrolyte - An acidic solution containing copper ions. In electrorefining, the

concentration of copper ions remains relatively constant, in balance with copper

dissolution at the anode and copper precipitation at the cathode. In electrowinning,

the copper concentration is more variable but in relative equilibrium with new copper

ions introduced by rich (copper-loaded) electrolyte from the solvent extraction facility

and with the copper precipitation at the cathode.

PCB – Printed Circuit Board (or PWB for Printed Wire Board).

Electrorefining - An electrolytic refining process where less pure copper anodes are

dissolved, and high-purity copper is plated at the cathode.

Electrowinning - An electrolytic refining process where the anode is inert, and rich

(copper-loaded) electrolyte continually replaces lean (copper-depleted) electrolyte as

copper is plated at the cathode.

Flash smelting - Smelting process for sulfur-containing ores (chalcopyrite, etc)

developed by Outokumpu in Finland, used for the first time in 1949 at the Harjavalta

plant for smelting copper ore. It can be adapted for nickel and lead smelting.

The flash process uses the autogenic principle of using the energy contained in the

sulfur and iron (exothermic oxidation) for melting the ore.

Fire-refined copper - The product of a fire-refining furnace. It is an intermediate,

more concentrated (with respect to the desired metal) material than blister, from

which it is made. Because oxygen is added in the processing to upgrade the copper

content by oxidizing the impurities in the furnace charge materials, the resulting

copper must be deoxidized, usually by stirring it with natural gas, with the carbon in

the natural gas reacting with the excess oxygen. Fire-refined copper contains about 99

percent copper, the exact percentage depending on the process parameters. Fire-

refined copper is sometimes cast into ingot forms and placed into worldwide trade.

Often it is transferred to another same-company electrorefining facility for processing

into 99.99 percent copper cathode. Fire-refining is also used to purify high-grade

copper scrap consumed at brass mills in the production of tube and sheet products.

Flotation - A method of mineral separation in which air and a variety of reagents are

injected to create a froth in water. Some finely crushed minerals float and other

minerals sink. The preferential flotation of sulfide minerals and sinking of the gangue

materials is used to concentrate the copper for economic smelting. The resulting

product is called “concentrate.”

Flux - Slag-making materials, such as sand, lime, limestone, that are added to high-

temperature metal and metal-oxide emulsions to fuse the oxides into a relatively low

melting-point material that can be readily separated from the molten metal.

Pregnant leach solution - The metal-loaded acidic solution collected in a lined pond

following percolation of acid through leachable ore piles. It is the feedstock for

solvent-extraction operations.

Primary copper - Copper extracted from ores and recovered as copper metal or

copper-bearing chemicals.

Secondary copper - Copper recovered from scrap and waste. Scrap types include

clippings, cuttings, grindings, turnings, flue dust, slag, filter cakes, and spent

electrolyte solutions.


Copper Recycling


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ISRI – Institute of Scrap Recycling Industries, Inc

WEEE - Waste Electrical and Electronic Equipment Directive

ROHS - Restriction of Hazardous Substances Directive

Pyrometallurgy - A process of separating desired metals from materials under

conditions of high heat.

Hydrometallurgy - A process of separating desired metals from aqueous solutions.

Sweating - heating below the melting point of copper and copper alloys scrap types

that contain low-melting lead alloys.

Raffinate - The copper-depleted flow back to the heap leach after the copper-rich

pregnant leach solution has been stripped of its copper load through solvent

extraction.

copper recycling

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