The Process of Aluminium Recycling and the benefits thereof. Gary Munn Zimco Aluminium Company a Division of Zimco Group (Pty) LTD
Why is Aluminium so important as a recycled material? Aluminium has become globally the second most used metal and the recycling thereof does not need to be encouraged as it simply makes a lot of sustainable sense.
Background Aluminium is used in powder form in the manufacture of various explosives as an energy source. It is also used to manufacture chemical products in water treatment and deodorants. But unfortunately when it fulfils its purpose there will be very little Aluminium left to recycle. However, other than for the purpose of chemical reactions, recycling of used Aluminium components is a very feasible process.
The processing of the metal can be broadly divided into two categories: Primary Aluminium And Secondary Aluminium processes
Primary Aluminium is produced from the Bauxite ore via the Bayer and the Hall- Herhoult processes which was introduced in the 1880 s. Primary Al process
Secondary Aluminium is produced by recycling used Aluminium components as well as scrap produced from manufacturing processes such as the primary smelters, cables, automotive, extruders, mines, packaging etc.
The other main sources of Aluminium raw material (Scrap) is that collected by scrap merchants from smaller bucket shops through an organised network of collection and sorting, while discarded extrusions from building sites, recycled Beverage cans, Electrical motors and cabling as well as other redundant componentry from mines and other industry also contribute.
In 2012 South Africa exported 46 000 tons of recycled Aluminium Scrap, while the local secondary Smelters absorbed 17 000 tons Approximately 80% of the exported scrap went to the four main export markets. These being India, China, South Korea and Taiwan.
With the recent introduction of complete Aluminium Beverage cans to replace steel cans, recycling of Aluminium cans will create a niche cycle from the consumer to re-manufacturing process.
The scrap material which is classified as raw material in the secondary industry, falls in a number of classes related to the size, cleanliness, chemical composition as well as its previous product group before recovery, and is based on the International Scrap Recycling Institute (ISRI) specifications
The recovered metal scrap is converted in the secondary industry to alloys which are used mainly for the casting sector to produce parts for the Automotive industry, commercial products, components for electrical transmission lines, street lighting and many more.
Recycled Aluminium is also used for the production of chemical products such as powders, de-oxidants in steel manufacturing as well as for water treatment.
Sustainability of Aluminium recycling (Meeting the needs of the present, without compromising the ability of future generations to meet their own needs) Over 90 % of our energy is derived from coal, emitting sulphur dioxide into the atmosphere. The second dioxin, carbon dioxide, is also a global warming gas emitted by smelters.
Sustainability of Aluminium recycling (Meeting the needs of the present, without compromising the ability of future generations to meet their own needs) The emission of fluorides is a problem in the primary smelting process. It is this triple challenge of social responsibility, environment and prosperity, which we label sustainable conduct.
75% of all Aluminium produced is still in use today. This is due to the fact that Aluminium is infinitely recyclable, unlike other materials such as plastics which can only be recycled a limited number of times. Aluminium is in effect an energy bank that could be tapped over and over again.
Aluminium offers an excellent hope for energy conservation. Once the metal has been made it can be recycled using as little as 5% of the energy required to produce it from the ore.
The 95% saving in energy (Although in a practical sense a more realistic figure could be about 92%), also contributes to 95% fewer greenhouse gas emissions (GHG), than manufacturing primary Aluminium.
Today, the global aluminium recycling industry prevents close to 170 million tons of GHG from entering the environment every year. That is a GHG saving equivalent to taking 900,000 cars off the road for 12 months. Recycling 1 ton of Aluminium avoids the emission of about 9 ton of CO2 emissions just 1 ton of CO2 is equivalent to driving nearly 4500 kilometres by car.
With most manufacturing processes some waste product has to be generated. So, unfortunately in the Aluminium production, both Primary and Secondary generate Aluminium Dross. Aluminium dross is the waste product created during the oxidation of Aluminium and other metallic components during the smelting process. The upside of this is that this dross is used as an additive in the cement industry as well as in the refining of molten steel. The unusable dross which makes up approximately 0.15 % is disposed of to Landfill.
The role of Aluminium recycling has many advantages. This process saves natural resources : 4 tons of Bauxite produces 1 ton of Aluminium Reduces the need for landfill allocations Saves energy. The extension of these aspects into an energy life cycle is a global issue. Reduction of Green House Gasses.
The role of Aluminium recycling has many advantages. Reduction of Fluorides into the air and water resources. Waste products are used for other industrial processes. Creates Entrepreneurial opportunities in the recycling chain. The benefits obtained from aluminium recycling outweigh any other engineering or packaging material recycling gains.
By ensuring the effective recycling and reuse of Aluminium scrap we can contribute to a sustainable and greener future.