Clean Technologies for automotive Batteries Recycling: A case Study in Brazil

Dr. Ing. Heloisa Vasconcellos de Medina Centre for Mineral Technology / Ministry of Science and Technology Avenida Ipê 900, Cidade Universitária, Rio de Janeiro, 21941-590, BRAZIL hmedina@cetem.gov.br

Abstract This text aims to present an overview of the main aspects of lead recycling from car batteries illustrated by a six months case study in Brazil conducted, in 2003, under my supervision, by Vincent Gilles Trouche.1 Two lead recovery and recycling processes are going to be discussed and compared: the pyrometallurgical and the hydrometallurgical. Some technical and economical and environmental aspects of lead recovering from batteries are also highlighted. The strengths and the weakness for future development of lead recycling market in Brazil are pointed out as well as the best opportunities. It is important to mention that this material was picked out for its importance on Brazilian market, in terms of income and employment, and for the challenges that it poses to the environmental management and industrial organisation. In short it represents a group of materials that claims for new and clean technologies and sound recycling process management avoiding extra environmental impacts.

1. Introduction Clean recycling processes avoiding emissions and water contamination by heavy metals and other toxic elements is an ever-present challenge to metallurgical industry. Quoting Wernick and Themelis (1998) "The success of secondary metals markets depends on the cost of retrieving and processing metals embedded in abandoned structures, discarded products, and other waste streams, relative to the prices of primary metals." The economic viability of recycling processes is also a key issue for the emerging recycling industries that are often linked to complex waste streams from civil construction, and end of life products (ELP). In the words of Wernick and Themelis (1998): "Demand for scrap metals depends on industry structure and the availability of production technologies that accommodate scrap feeds to yield value added products. This complex market relies on the decisions of many independent actors, including scrap dealers, brokers, dismantlers, and smelters." For ELP the major contribution comes from automobile industry and electric and electronics products that are the largest materials intensive sectors. Besides that the economic viability of recycling for such ELP depends on materials separation, the first stage in the metal recycling chain. Materials treatment, chemical and metallurgical processes as well as lower concentrations of the 1 Trouche was a former scholarship in production engineering that developed at CETEM his Projet de Fin d’Etudes (PFE) en Génie Productique, to INSA, Lyon, France.

desired metal in the secondary source increase the difficulty of separation. On the other hand new technologies such as spectroscopic analysis using lasers introduced in shredding operations came to assure and to speed the technical evolution in this field. Anyway to get the best and the soundest methods on separation is nowadays the most important challenger for materials science and engineering. This is specially true for metals and their alloys since they often are contaminated by chemical treatments and assembly processes such as joining techniques, painting etc, which represents a risky situation for recycling. For automobile industry, according to European Automobile Manufacturers Association (ACEA) (http://www.acea.be) the factors that determine the recyclability of single materials and components include the purity of the recovered products, the market for the recovered products, the monetary value of the material, the cost of collection and transport, the cost of sorting, the cost of transformation into reusable material and the cost of disposing of any residual material. In fact, nowadays materials and products are being designed according to the strictest environmental regulations than ever. The European commission regulations on end of life products, for instances, are enhancing industrial companies social responsibility. In Europe, since October 2000, according to European Directive 2000/53/CE on End of Life Vehicles’ (ELV) recycling, cars makers are supposed to be responsible for their vehicles from cradle to grave. That means that they have to close automotive materials life cycle loop. From now on automobile is changing from a former essentially polluter product into an almost 100 % recyclable one and soon available in zero emission version. Nevertheless recycling does not intrinsically prevent environmental impacts. For instance, regarding toxic materials such as heavy metals, lead, mercury, chrome and cadmium, new and clean technologies and sound recycling processes management are required avoiding extra environmental impacts. In this sense materials are also being conceived to be less toxic and hazardous to environment as well as human health. These are exactly the case of lead-free solders and free-lead painting for automotive uses. So even though the composition of a typical car has not changed substantially in recent years, as we can see at the two charts below, lead most important use is in automotive batteries.

Car weight by materials - 1999

Non ferrous metals10%

Iron11%

Steel55%

Other Materials9% Plastics

8%Rubber

4%Glass

3%

For Renault in France in 2001 the average composition of a car was more or less the same one showed at the chart above. 67 % for ferrous metals (iron and steel), 9% non ferrous metals and 20 % for organic materials corresponding to plastics, rubber and other materials, and, finally, 4% of glass.

Source: DIMAT - Direction de l’Ingénierie des Matériaux , Technocentre Renault.

2. Lead Recycling from Lead-Acid Batteries Batteries are more than ever a feature of modern daily life. Besides the traditional lead acid starter car battery, they can supply energy to environmentally friendly forms of transportation such as electric cars, forklift trucks, electric buses, wheelchairs and even golf caddies. They guarantee safety while being used as back up power in security applications such as planes, trains, metros, tunnels and a number of industrial applications. Other areas of use are power plants, computer systems and in telecommunication. In terms of life cycle analysis we can say that at the consumption phase batteries have a friendly environmental profile, since they lead to storing renewable energy. But, on the other hand, at production and recycling phase batteries claim for extra care concerning environmental and human health aspects. To cope with environmental regulation Lead Acid Batteries - ordinary car batteries - recycling are claming for cleaner recycling processes and for technological innovation, such as rechargeable batteries, long lasting batteries for electric or hybrid vehicles. In short it demands new technological trails leading too much more efficient batteries. In between nickel, zinc oxide, titanium nitride, and lithium are in perspective for future developments for vehicle uses. In this context the design of new batteries and the materials selection are suppose to have a great impact on recycling process in medium-term and even short-term. Batteries are also a good example of practical R&D of the so-called eco-materials. “In the R&D of ecomaterials, the end application of the material is obviously of great importance. In the field of consumer materials, where great quantities are consumed daily, efforts focus mainly on finding substitutes for harmful substances to reduce the environmental burden during and after use, examples being materials for batteries, packing, soldering, painting.”

Nowadays scrap automotive batteries (lead-acid batteries) are the major source of secondary lead in Brazil as all over the world. And the main environmental issues concerning ULAB (usage lead acid batteries) are the risk of water, soil and air contamination. ULAB is a hazardous waste for recycling proposes as well as for final disposal. Additionally to lead, automotive batteries have also acids and other metals and minerals such as arsenic, antimony, tin, calcium - in suspension and solution. But the lead (oxide and metallic) represents around 70% in car batteries' weight. Car batteries are recycled all over the world at different rates such at 90 % in European Union and at 50 % in less developed countries. In Brazil we do not have official data or systematic studies on batteries recycling but a engineering student of INSA de Lyon Vincent Trouche made a 5 months case study under my supervision (from April to August 2003) and he estimated this rate on an interval from 65 to 80 %, varying from the north to the south of the country according to local the infrastructure and the legislation of the different Brazilian States.

The Recycling Loop of Vehicles Batteries in Brazil

Export Batteries

Import Pb metal

47000 Pb

Battery Production

24000 Pb 65000 Pb

End-User

Lost Batteries

20%

80%

Collection Network

Lost Acid

Recycling Plant

< 100

Pb

Slag. Effluents

33000 Pb

Source: Trouche V. (2003) As we can see the recycling loop of lead / acid batteries in Brazil is not yet perfect. The collection system as well as the recycling process itself can be improved to comply with the environmental management best practices of a end-of-life product that contains not only metallic lead (up to 90% in the grid) but also lead compounds with oxides and sulphuric acid (PbSO4, PbO2, Pb2O3), electrolyte liquid, polypropylene, and other. The chemical composition of a car battery is presented in table 1 (by Araujo R. V. V., Soares P. S. M., Trindade R.E 2001).

Table 1 - Automotive Battery

Elements % Pb 71.2

SO4 18.1 Sb 0.3 Ca 0.4

SiO2 0.14 As < 0.04 Sn < 0.1

The active ingredients, lead and sulphuric acid, are toxins in the environment, and for human health, that have to be handled with great respect. In addition to being a danger if it enters the water cycle, lead is a strategic metal, and has salvage value, so it should be recycled. Nowadays a great majority of the lead, acid, and plastic in new car batteries comes from recycled batteries. Improper disposal is becoming less of a problem as the dangers of lead poisoning become well known, but is still a significant problem in developing countries. (For more details see http://www.gaiam.com/)

2.1 Technical Aspects Concerning technical aspects pyrometallurgical refining (on blast furnace and rotary furnace) is traditionally the most used process worldwide for both primary and secondary lead productions. Wernick and Themelis (1998) resumed the pyrometallurgical ordinary recycling process “At a typical recycling plant, batteries are crushed or sliced and separated into streams: lead materials (about 60% lead, 15% PbO2 and 12% PbO4) polypropylene scrap, and sulphuric acid. The lead–containing materials are smelted to produce lead bullion and a molten silicate solution containing all of the lead oxides. This slag by-product is smelted and reduced with carbonaceous material and fluxing agents in a lead blast furnace, similar to those used in the primary smelting of lead oxides. The low-lead slag in such furnaces is environmentally inert and is disposed in industrial landfills”. Nevertheless monitoring and preventing the escape of dust and fume is crucial. In the recent years, pyrometallurgical process has been largely improved to cope with the environmental requirements as well as to face the challenger of hydrometallurgy alternative that avoids gas emissions. Wernick and Themelis (1998) also pointed out some of these innovations: “in another lead recycling process, used extensively in Europe; lead components are smelted at 1000° with coke breeze and sodium carbonate flux and iron filings, used to fix sulphur by forming an iron sulphide matte, in a short fuel-fired rotary furnace. It is reported that use of bulk oxygen and other innovations can increase the production capacity of such furnaces by 40%. The ISASMELT furnace process used in Australia and South Korea; introduces lead materials with lump coal into a vertical reactor containing a slag bath. Air and oxygen are injected in this reactor that similar to the top blown BOF furnace used for steel making. During smelting, metallic lead containing less than 0.01 of antimony settles in the bottom and is periodically tapped out of the furnace. When the upper slag layer in the reactor reaches a certain depth the slag is reduced from 40-60% lead and 5-6% antimony, to 2-4% lead and less then 1% antimony by continuous injection in the presence of coal. Most of the treated slag is then tapped out the reactor and the cycle repeats. Thus, the two-reactor process used in U.S. (reverbatory and blast furnace) is replaced by a two stage process in a single reactor.”

Hydrometallurgical methods are the newest and the soundest technology developed but its economic and industrial viability has to be proved. Hydrometallurgy is a chemical metal processing technology to dissolve a metal from its concentrate by using water, oxygen and other substances on a pressurised vessel. Usually there are a further series of chemical processes, involving a number of separation and purification steps, which result in the production of a high purity metal. Compared to the pyrometallurgy process it is technically more efficient (recovers a higher percentage of the metal concentrated), more environmentally friendly, and uses much less energy. On the other hand its industrial scale is over 10 times smaller than the conventional pyrometallurgical smelters plants. Nevertheless Engitec Technologies presents its CX Compact process that is able to treat 5t/h batteries as and advantage compared to their CX traditional system. US Bureau of Mines made the first step on this via by the end of the 70's and the first results were published in 1981. At industrial level Engitec Technologies provided the best initiatives in 1992 (CX-EW and CX Compact). The CX plants in operation are considered as state of art units for environmentally friendly design, for the quality of the recovered products and for the quality of design and manufacture of the equipment. As described by Engitec the CX systems plants were environmentally friendly designed, for the quality of the recovered products and for the quality of design and manufacture of the equipment. For instance in all pilot units operating around the world the process water is continuously recycled. The main advantages of the CX Compact according to Engitec are:

• Minimizing the requirements for civil works and costs (can be pre-assembled) • It can be easily transported • Long life are guaranteed by stainless steel equipment • As well as high performance and low maintenance costs • It can be expanded (even at a later stage)

Engitec Technologies SpA is a kind of engineering and contracting company, located in Milan, Italy, and active in the non-ferrous metals production. It is in charge of the design and construction of plants and complete facilities for the recycling of non-ferrous metal scraps and residues. (For detailed information see http://www.engitec.com or email info@engitec.com). In Brazil, since 1998, CETEM carried out a 5 five-year research on recycling domestic batteries and automotive batteries. The aim of the first project was to determine the level of contamination of final disposal of domestic batteries on proper conditions. The second one aimed to reduce the environmental impacts of the pyrometallurgical process by associating a hydrometallurgical phase for lead paste desulphurisation from car batteries. These research at CETEM were encourage by CONAMA's Resolutions on batteries final disposal and recycling, by the end of the ninths (228/97, 235/98, 257/99) inspired on the 1994 Basel Convention the ban of exports of hazardous waste (including ULAB) from developed to developing countries. Later on, in 2001, a study conducted by researchers at the Chemical Institute of UFRJ (Federal University of Rio de Janeiro) and at the FIOCRUZ (Oswaldo Cruz Foundation) provided indicators of environmental pollution in areas adjacent to a source of stationary lead emission based on dust

and air contamination. This study measured lead concentration in both the outdoor air and the household dust from houses located around a lead-acid battery repair shop. As a result over 50% of the air samples exceeded the standard limit (1.5 ug Pb.m-3) (for more details see http://www.scielo.br) The recycling industry for batteries to cope with environmental regulations have to deal with complex tasks such as handling with toxic materials from collecting to transportation up to dismantling and separation of a number of materials, avoiding extra contamination of soil, air or water throughout all these phases. In addition it is also a complex market that depends directly on many actors such as scrap dealers, brokers, dismantlers and smelters and indirectly has to deal with governmental and environmental agencies and so on and so forth....

2.2 Environmental aspects The milestone of environmental regulations concerning batteries where first established at international level by the Basel Convention in 1989. Basel Convention was developed by United Nations Environment Program and adopted on 22 March 1989. The Convention was first conceived to control the movements of hazardous waste and their final disposal and in 1994 it banned all exports and imports of hazardous waste for final disposal and recycling from developed to developing countries. The obligations for the convention members are:

• To minimize the movement and the generation of hazardous and other wastes, and ensure environmentally sound disposal, and more specifically,

• To control the export and import of hazardous and other wastes, to provide for notification and/or consent.

Brazilian Environmental Regulations followed the prescriptions of Basel Convention since July 1993. After backs and forwards, the main involved agencies such as CONAMA (National Council for the Environment), IBAMA (Brazilian Institute for the Environment and, NBR (Brazilian Technical Standard Bureau) set up the basis of the regulation for transporting and recycling used batteries. The photos below we got from one of the greatest Tires and Batteries Collection and Transportation Company - Mazola Pneus, show how Brazil is nowadays transporting and packing ULAB according to Basel convention recommendations. (See more details at http://mazolapneus.com.br)

Storage of used batteries

Storage before collecting

Weighting to be transported by Mazolla

Ready to be transported by road

In Europe even before the Council Directive concerning integrated pollution prevention and control (96/61/EC 24 September 1996) a Battery Directive from 1991 (91/157/EEC) set technical procedures and standards for collection and recycling used lead acid batteries. Latter on in November 2003 the European Commission will repeal this Battery Directive to all types of batteries and more stringent targets for Nickel-Cadmium ones. (See details at http://eippcb.jrc.es/pages/FAbout.htm). Resuming European legislation proposal is seeking for a closed loop system, resulting in the collection of all batteries in Europe to cope with Basel Convention. However EUROBAT, representing 85% of the battery manufacturers in Europe, from its practical experience states that this is quite difficult to achieve since there are only limited ways of determining the true collection rate of industrial and automotive batteries. Preliminary methods of calculation introduced in Germany, Italy and Sweden demonstrate that for example automotive batteries are collected at high rates in these Member States. For Automotive Batteries, the quantity of batteries sold in relation to batteries recollected can vary significantly, as the collection rate is influenced by the lifespan of automotive batteries from 3 (in Brazil) to 7 years (in Canada and west Europe), the percentage of cars that is exported and the variation of metal prices. Besides while the collection is well established across Europe, the infrastructure has to be installed in certain countries, especially the less developed countries. In consequence the implementation of a collection system has to consider an appropriate transition period that takes into account that diversity. (See more at http://www.eurobat.org/Eurobat/docs/Environment/index_html).

As international environmental regulation role is somehow to push the countries towards best practices in April 2001 the eighteenth session of Basel Convention a Technical Working Group, presented a Draft Guidelines on the Environmentally Sound Management of Lead-acid Battery Waste (report elaborated for the Basel Convention Secretariat). This Draft stands a board view of batteries recycling process from storing, collecting and transporting named pre-recycling phase. "Before reaching the recycle plant, used batteries must be collected, transported and stored with proper care, in order to avoid health and environmental contamination Since these procedures are not performed inside the recycling facility, they are denominated pre-recycling on this document". After this the recycling process itself are considered in this paper as ideally divided in three major processes: Battery opening (draining); lead reduction and lead refining. Specific recommendations on air, water and soil pollution prevention and effluent treatment are also provided. Two photos that we got from one of the greatest Tires and Batteries Collection and Transportation Company -Mazola Pneus - show how Brazil is transporting and packing ULAB. (See at http://mazolapneus.com.br)

3. Lead recycling market in Brazil The more restrict environmental regulations and the continuous falling down of international metallic lead prices through the lead-recycling sector in Brazil into the ever-present crisis. The sector is economically depressed and technically menaced by its traditional pyromettalurgical process that is in accordance to the new environmental paradigm requirements. Nevertheless scrap automotive batteries (lead-acid batteries) are the major source of secondary lead in Brazil as all over the world. For lead Brazil has no primary extraction since 1996 (1), in spite of a huge an increasing domestic's apparent consumption (the biggest of Latin America) as showed at Table 2 and Table 3.

Table 2: Recent Primary and Secondary Production of Lead in Brazil

Production

Specification

1995

1998

2001

Primary Metal

13 958

-

-

Lead

Secondary Metal

50 000

48 000

52 000

Source: DNPM, Mineral Summary 1996, 2000, 2002 Note: (-) Null

Table 3: Apparent Consumption of Metallic Lead Products in Brazil

Metallic Lead

1997

1998

1999

2000

2001

Secondary Production

53

48

52

52

52

Import

60,7

60

56

70,7

73,4

Consumption

113,7

108

108

122,7

125,4

Source: Trouche V. 2003 (estimate based on DNPM data)

Figure 1 International Metallic Lead Price 1997-2003

Source: London Metal Exchange. www.lme.co.uk Prices in dollar per tonnage.

Ten years from now most of lead recycler companies were shut down (a dozen of them in Rio de Janeiro) and the ones that still remains are operating at a very low production scale. Environmental Federal Authorities shut some of them down after 1995 under the pressure of the NGOs. Other were close down for financial and economic reasons such as over capacity and lack of suppliers such as Cobrac a primary lead producer, shut down in 1995 due to the depletion of mineral reserves. Among the most important ones we can mention: FAE and independent one that had 2 industrial plants (São Paulo and Rio Grande do Sul) with an annual capacity of 24.000 tons, and Saturnia - Microlite a vertically integrated Company with a capacity of 18000 tons per year. Since then the Brazilian Lead Recycling Market is passing through a risk situation in both senses economic and environmental. There are a number of informal lead smelters and even some big companies, which are operating under risky situations. Recent Greenpeace investigations revealed that Moura, the largest manufactures of car batteries in Brazil, is still importing ULAB.

Geographic Distribution of the Brazilian Recyclers

20.000

Extracted from Trouche V. 2003

12.000

12.000

10.000

The recyclers geographic distribution showed above are the following companies: • Tonolli for instance is an independent recycler in São Paulo State with a capacity of 36.000 t. /year but actually produced around 12.000 in the year of 2001. • Moura is an integrated company (batteries and lead recycle) is located in Pernambuco State Northeast of Brazil, with a capacity of 22.000 t. per year • Tamara Metais is an independent company for metals recycle located at The State of Parana producing 12.000 tons per year. • Sulina de Metais located at the State of Rio Grande do Sul with annual production of 11.000 tons. Considering internal and external market conditions we can say that, from the standpoint of a SWOT's analysis – Strengths, Weaknesses, Opportunities and Threat –, Lead Acid Batteries Recycling in Brazil faces more Threats than ever and has big challenges to overcome. The main threats are:

• Lack of a National Program to collecting spent batteries • Large number of irregular disposals (up to 90 % of the municipalities) • Lack of environmental legislation at local level and an effective application of pay-polluter

principle • Out-date recycling technologies (mainly pyrometallurgical) • Important informal recycling sector dealing with batteries • Well-established lobby of big batteries companies

And the Challenges, that could be turned into opportunities, are:

• To have a national policy for sound recycling activities • To settle up a collecting system at national level • To promote clean technologies development • To extend environmental legislation to local level, extending pay-polluter system • To encourage design for environment and design for recycling practices at industrial level

Overcoming the threats and facing these challenges, the risk situation that leads Brazilian Lead recycling market into the present crisis could be over turned this activity into good opportunities for employment and for new business. For instance Germany legislation enforced a successful a well-organized system of collecting getting almost 100% of lead batteries colleted and recycled. According to Varta (http://www.varta.com/eng/), today nearly all consumer batteries, especially primary batteries, are free of mercury and cadmium. On the other hand, heavy metals are still essential components in mercury batteries, rechargeable nickel-cadmium batteries and lead-acid accumulators. These metals may cause damage to the environment if disposed of improperly and in large quantities. All consumers in Germany must return their used batteries to the dealer or to local collection points. This is a requirement of the German Battery Regulation (Batterieverordnung), which came into force in April 1998. In accordance with this regulation, manufacturers and importers are required to take back, sort and dispose of used batteries. When purchasing a new starter battery in future, customers will have to pay a deposit of DM 15 if they are not returning an old battery. Besides Germany is also doing a great effort on R&D of new generation of batteries mercury, cadmium, and lead free. In this sense, Varta says that the battery industry is working to develop alternatives to

replace mercury, cadmium and lead wherever possible. Alternatives are already available for a large number of applications (e.g. nickel-metal-hydride and zinc-air systems). Other new technologies are already in an advanced stage of development.

4. Final Remarks In this scenario recycling is surely a great opportunity for the less developed countries’ producers of raw materials to get into the Research and Development of new materials and new products based on environmentally friendly technologies. That is also a means of get a national commitment and contribution to the sustainability materials’ and components for automobile industry. Working in network universities, research centres, and the industrial sector can share risks and profits and also get more innovative solutions to improve the recyclability of end of life vehicles and components on technical, economic and environmental bases. Based on our study we can conclude that to promote the development and the adaptation of clean technologies for recycling is a core task for Brazil to get into a sustainable path of development encompassing the new environmental paradigm, that will be for sure the main feature of production systems in the twenty first century.

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INTERNET SITES:

ENGITEC Technologies : http://www.engitec.com

Greenpeace : http://www.greenpeace.org

INFOMET : http://www.infomet.com.br

GAIAM http://www.gaiam.com/retail/gai_content/learn/gai_learnArticlePrint.asp?article_id=1400, “Large Storage Batteries”, Gaiam Staff.