Briefly Identify the Chemistry Issue and the relevant Social or Environmental Context.
Recycling can be considered as a mechanism intended to convert waste to reusable material. Waste will be converted into a useful material which will be in the previous forms of the cycle. Waste recycling has several benefits to the society in general, the technique will be quite cost effective and recycling procedures will result in benefits to the society like there will be immense impact on the environmental conditions. The total GHG emissions being emitted to the environment will get arrested as there it is going to have considerable reduction in the manufacturing process and there is going to have an associated decrease in the environmental degradation. Eventhough the relative benefits and environmental advantages of the recycling process will depend more on the actual material recycled and the actual process employed for recycling, definite benefits of recycling are assured. The current discussion is about aluminium recycling in the context of Australian social, economic and environmental conditions. There is going to have a discussion on the entire recycling process in chemical perspective (Schlesinger 2013).
Recycling in Australia:
From several years, Australia domestic resources are being recycled. As high as 51% of the total household waste in Australia will get typically recycled. When compared with most of the other countries in the world, Australia mean recycling rate is quite higher. It is not a puzzling issue to understand the commitment of the country towards aluminium recycling. The chief most factor responsible for aluminium recycling is the fact that the aluminium is 100% recyclable. Aluminum parts are extensive in use in Australia like in many other countries. The recycling procedures and the processes employed for aluminium recycling are really environmental friendly and generally the properties of the metal will not be lost during the recycling process. Also the quality of the product will not be impacted during the recycling process (Tenorio 2002). Another chief concern is that the chemical energy requirement for recycling aluminium components is only 5% of the actual energy requirement for making a new product. Also it is true that in Australia like in many other countries that 75% of the aluminium ever produced is actually in use in the country (Shintzato 2005).
Aluminum recycling statistics in Australia:
By recycling about six aluminium cans of aluminium it is possible that enough energy to offset carbon emissions from a 10km journey in an average-size car and 17km journey bus ride. Australians use over 3 billion aluminium cans annually with approximately 350,000 aluminium cans are being made very minute (Gaustad 2012).
Aluminum recycling process is very simple and the chemistry of aluminium recycling is quite easy to use. The entire recycling process of aluminium consist of six main processes. Firstly the process consist of mechanical collection of the aluminium cans and then sorting them into proper format for recycling. The first phase of the process consist of removing foreign material like steel specimens included in the samples collected using the magnets. The second phase of the recycling process consist of inducing eddy currents in the material and then picking the material using the magnetic effects. Once so collected aluminium cans will be subjected to the further baling using mechanical forces and this follows with shaling to remove any further presence of steel specimens in the samples. Once the process of baling and shaling is removed the paints and other organic substances presented in the aluminium cans will get removed using decoaster blasts of about 500 degree Celsius temperature. This process will be followed by heating the aluminium material at about 700 degree Celsius temperature. Then the molten aluminium formed at this stage of the process will be poured into the castings to make ingots and these ingots will be further moved to rolling mills to make the sheets and plates for diverse applications (Hatayama 2012).
Main stream Aluminum production process:
It is possible that the aluminium extraction can be further refined to eliminate to remove any impurities present in the molten aluminium. However usage of the refining process will actually depend on the final requirements of the process. Depending on the end requirements of the products, the degree of refining of the aluminium material will be employed. The following schematic indicates the basic refining process of the molten aluminium also the same procedure will be employed to extract aluminium from the bauxite ore. There will be mix up of ingredients to increase the flexibility of the material to become melted at low temperatures. Cryolite is generally employed to drastically bring down the temperature of melting of aluminium (Das 2010).
Electrolysis of the molten aluminium will work out to let the oxygen move towards the anode and aluminium will be moved towards the cathode, the casing. The entire process consists in liberating sufficient amount of carbon dioxide into the atmosphere, there will be sufficient amount of carbon monoxide also liberates into the environment(Green,2007).
Environmental benefits of Aluminum recycling:
The intense energy usage for making pure aluminium is maximum eliminated with the recycling of aluminium cans, When aluminium cans are recycled the energy consumed during the recycling process is quite less, it is only 5% of the total energy used for processing. Hence all the associated emissions during the energy production process like emission of greenhouse gases, energy and emissions associated with the mining of the ore, transportation of the ore to the processing zone etc. are completely eliminated. It is quite a big environmental benefits since number of environmental problems can be rooted first to the presence of GHG emissions in the atmosphere. It is also true that the recycling will contribute to the value addition to the economy of the country, since there is considerable saving in the form of cost effectiveness. Considering the bulk of aluminium cans and materials being recycled, there is considerable advantage to the countries in terms of environmental benefits and advantages.
It is true that the aluminium recycling process is quite toxic and it releases number of chemicals into the atmosphere. Further the process produces a waste called as dross, which is very toxic and requires to dump it into the landfills by burying. Generally sealed containers will be employed to bury the dross (Graziano 1996).
Typically for about every tonne of aluminum melted about 200 to 500 kilograms of salt cake will be produced (Gelles 2007). The salt cake contain several elements like aluminium oxides, metallic aluminium, carbines, nitrides, sulphides and phosphides. Also it is possible that there can be air pollution from recycling the aluminium. It will not just come from energy generating means, there will also be immense release of furans, dioxides, hydrogen chlorides and particulate matter during the process. Furans released during the recycling of aluminium do cause impact on the lever in human beings (Tenorio 2001).
When compared with several other recyclable materials, aluminium recycling do have a distinct significance owing to the potential advantage which the material recycling can offer to the society. Aluminum recycling is quite profitable as it has good potential to contribute to the cost effectiveness. Also it is easier when compared with other recycling processes. It is also true that aluminium cans and other products constitute maximum amount of wastage and hence it is very much required to appreciate the usage of aluminium recycling process. Australia being a proactive country in emissions reduction and ecological sustainability initiatives, encouraging aluminium recycling in all the possible means.
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Schlesinger, M.E., 2013. Aluminum recycling. CRC Press.
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Gelles, G.M., 2007. Aluminum recycling economics. Aluminum Recycling.
Green, J. A. (2007). Aluminum recycling and processing for energy conservation and sustainability. ASM International.