Aluminium and sustainability Summary of the report ‘Sustainability aspects of aluminium’, commissioned by the Aluminium Centrum.

Niels Jonkers, Lieke Dreijerink

Amsterdam, April 2011

IVAM research and consultancy on sustainability Plantage Muidergracht 14 - 1018 TV Amsterdam - Postbus 18180 - 1001 ZB Amsterdam Tel. 020-525 5080, Fax 020-525 5850, internet: www.ivam.uva.nl, e-mail: [email protected]

Colofon

Title Authors

Aluminium and Sustainability N. Jonkers, L. Dreijerink

This report was commissioned by: Aluminium Centrum Contact person commissioner: Paul Bruinsma

For more information on this report, contact: Niels Jonkers, [email protected] or 020-525 5080 Data from this report may be used, under the condition that the source is properly referred to. IVAM UvA B.V. does not accept any responsibility for damage or harm resulting from the use or application of the results of this report.

Aluminium and sustainability Aluminium is present in our daily life in many ways. We use it as food packaging, in the form of foil and cans. In buildings we find aluminium window frames or roofs. Furniture, bicycles, trains and airplanes often have aluminium parts, and it is also present in e.g. mp3-players or mobile phones. Just like any other material, the production of aluminium has an impact on the environment. The environment (planet) in combination with social (people) and economic aspects (profit) form the concept of sustainability. But which are the main consequences of our use of aluminium in terms of sustainability? And what is being done to reduce the negative impacts, and to optimize the environmental benefits that the use of aluminium can offer? What is aluminium? Aluminium is, after oxygen and silicon, the most abundant chemical element in the earth’s crust. In contrast to some other metals, aluminium is not a scarce material. Aluminium in nature does not occur in metallic form, but is part of several mineral ores. The main raw material for aluminium production is bauxite ore, which contains the highest percentage of aluminium of all ores. Bauxite is mined in over 20 countries. The highest volumes are mined in Australia, Brazil, Guinea, Jamaica, China and India. Bauxite is first processed into an intermediary product called alumina. This is often done in the vicinity of the mine. Alumina is formed by adding sodium hydroxide to the bauxite and heating it. Alumina is then transformed into aluminium by an energy intensive process called electrolysis. This last process is also done in factories in the Netherlands. Alumina used in the Netherlands originates mainly from Jamaica and Guinea. Besides the production of new aluminium, many companies (also in the Netherlands) process aluminium scrap into recycled material. On average in Europe, aluminium contains 47% recycled and 53% new material. The aluminium is further processed into a product. Casting, extrusion (pressing the material through a mould) or rolling processes are used to form engine blocks, window frames or aluminium foil, or a large number of additional products.

Consequences of aluminium production for sustainability Aluminium production has, like all forms of industry, an impact on the environment. For bauxite mining, vegetation and top soil must be removed, access roads must be constructed. In a number of cases, forest must be cut down. Companies reduce these effects by relocating or conserving rare plants or animals, and returning areas to their original state as much as possible after closure of the mine. During bauxite processing, harmful substances are emitted, such as fine particulate matter and sulphur oxides (the second one mainly due to bunker oil used in the process). Bauxite residue (red mud) remains, which is stored ponds. These ponds are lined with a plastic layer which separates the residue from the soil, to prevent leaching into groundwater. After several years, the stored red mud is not harmful anymore. Alternative uses of the red mud are currently under investigation, such as application as brick material. In the Netherlands, no bauxite is mined or processed, so no red mud ponds are present.

Above is an example of rehabilitation of the landscape after bauxite mining. Background: original state; middle: during bauxite mining; foreground: recovered terrain.

Bauxite mining, besides the negative aspects like impact on the landscape and emission of substances, also has positive consequences for the local communities, such as employment opportunities. Finally, the transformation of alumina into aluminium requires a large amount of electricity. By building these factories close to power plants, losses due to energy transport are reduced. In addition, technical innovations have led to a reduction in energy consumption in this process. The use of aluminium products can have environmental benefits compared to other materials. For example, aluminium is a relatively light-weight material, so less fuel is needed during its transport. Aluminium car parts that replace heavier materials lead to lower fuel consumption. In addition, aluminium is a long-lasting material, so there is less need for maintenance or replacement than for less durable materials. Aluminium packaging materials extend the shelflife of food products (so less food needs to be thrown away) and aluminium insulation foils in construction lead to savings in energy use for heating or cooling in buildings.

Recycling of aluminium Recycling aluminium requires about 95% less energy than the production of new aluminium, because the processing steps from bauxite to alumina and from alumina to aluminium are not needed. The aluminium scrap only needs to be cleaned and remelted. The quality of recycled is equal to new aluminium. Aluminium recycling is therefore of high importance: it saves a lot of energy, and is cheaper than the production of new aluminium. As a consequence, aluminium is recycled quite efficiently in many sectors, with highest recycling percentages in the construction and transport sector of up to 95%. However, because the use of aluminium is increasing and aluminium products have a long life time, there is not enough aluminium scrap available to produce new products purely of recycled aluminium. To supply the increasing demand, new aluminium has to be produced as well. The average percentage of recycled aluminium in a product is therefore lower (around 47%) than the percentage that will be recycled after use (often more than 90%).

bauxite mining

alumina production

production new aluminium recycling

energy supply

transport

semifabrication

use phase product manufacture

environmental impact (LCA-points)

Calculation of environmental 2 impacts The overall impacts of 1,5 aluminium on the environment can be calculated with a 1 method called life cycle 0,5 assessment (LCA). For each step in the life cycle of a 0 product, a range of environmental impacts are -0,5 calculated and added up (e.g. land use, emission of -1 greenhouse gases, depletion of raw materials). In the graph, -1,5 an LCA example is shown for an aluminium façade panel. The graph shows that the highest environmental impact occurs during the production of new aluminium. This is mainly caused by the electrolytic conversion of alumina into aluminium. Other phases in the life cycle, such as recycling, the rolling process or transport have a much smaller environmental impact. The aluminium that, after recycling, will be available again for new products can be considered as an environmental benefit (a negative score in the graph): the next user will have less need for new aluminium, and therefore save a lot of energy consumption. This calculation clearly shows the large environmental importance of recycling. Sustainable improvements in the life cycle of aluminium The aluminium industry strives to further improve the sustainability of the whole aluminium life cycle. Progress in the efficiency and monitoring of industrial processes has led to considerable improvements in the reduction of energy consumption per ton aluminium, emission reductions of harmful substances, and safer treatment of solid waste. The use of renewable energy is increasing in the industry, mainly in the form of hydropower. In addition, older plants are being modernised, which reduces their energy consumption. Products like packaging materials are being redesigned to require less aluminium while maintaining their functional properties. Furthermore, in the design phase of new products, the possibilities for recycling are increasingly taken into account: ‘Design for Recycling’. Recycling processes are further developed as well. Techniques to separate aluminium from other municipal waste are still becoming more efficient. In car recycling as well (where very high recycling percentages have been achieved already) new techniques are being developed to retrieve the last remaining aluminum from shredder residues.

This publication is a summary of the report ‘Sustainability aspects of aluminium’, commissioned by the Aluminium Centrum and written by IVAM UvA B.V. Research and consultancy on sustainability; Amsterdam, 2011. Are you interested to know more? Then request the full report at the Aluminium Centrum, via www.aluminiumcentrum.nl.