Using the examples of 2 metals, discuss the advantages and disadvantages of recycling over extraction.

the energy involved. Aluminium is a light, strong, metal which is an excellent conductor of heat and electricity, reflects light and radiant heat and is also non-magnetic. The characteristics of aluminium above is what that makes it useful in the norm of life. Extraction of  aluminium by electrolysis was founded by a French chemist, Henri Etienne Sainte-Claire Deville by the electrolysis of sodium aluminium chloride. What are the advantages of extraction of aluminium from its ores? One of the advantages is that there are plentiful supplies of high grade ores and also because it can be extracted from its ores economically by electrolysis. The mineral bauxite is used as the source of the oxide. High grade oxide contain up to 70% aluminium oxide,                         along with the impurities iron(III) oxide and silicon(IV) oxide. Production of aluminium is costly due to the high cost needed for the electric power. Current is also used to maintain the temperature of the cell. Therefore, the electrolysis of aluminium is mainly done close to sources of cheap electrical power, like a hydroelectric power station. Recycling aluminium too has its advantages. Recycling aluminium uses just 5% of the energy for extracting  aluminium from the mineral. Potentially the mining and smelting of aluminium can have major environmental impact. The industry is very conscious of this and its efforts and achievements in rehabilitation of open cut sites and restoring flora and fauna have won awards from the United Nations Environment Programme. Red mud disposal areas are now successfully revegetated. Emissions from the pot line are passed through scrubbing systems to ensure that environmental requirements are met. The economic and environmental reasons for recycling most materials today are strong, but for aluminium they are absolutely compelling. It will progressively undermine the `aluminium is too expensive' philosophy as more and more aluminium is recycled. The reasons are simple, although it takes 14,000 KWH to produce 1 tonne of aluminium, it only takes 700 KWH, 5% of this, to remelt that same tonne when it is recycled. There is no difference in quality between virgin and recycled aluminium and its alloys. Beverage cans become new beverage cans on a 3 to 6 month cycle, cylinder head castings become new castings on a 10 to 20 year cycle and structures become new structures on perhaps a 50 year cycle. At the end of its life, whether 6 months or 50 years, the product needs to be located, collected, dismantled where necessary and fed back into the production system. At the time of writing it is estimated that 60% of the metal in use is being recycled, as new products are developed with recycling as an intrinsic design feature this will surely grow. Iron is the most common metal produced today with its many steel alloys – 19 million tonnes in the UK per year, and about 1.5 billion tonnes a year world-wide. Iron has been worked for thousands of years and, in the past, the nations that developed the most successful iron industries became the major industrial and imperial powers. The extraction of iron involves the blast furnace through the reduction of the mineral oxide in iron ore. The reducing agents in the blast furnace are coke and carbon monoxide. Extraction of iron form its ores requires a high temperature and great deal of energy therefore iron is operated as a continuous process non-stop and is only ever shut down for maintenance work. The extraction of iron through the blast furnace will cause many environmental problems. Extraction of iron will leave large areas of land with quarries and heaps of spoil and slag. Restoring  the appearance of the landscape can be very costly. Carbon monoxide which is produced from the blast furnace is also poisonous and toxic to all invertebrates. The sulphur impurities about 1.5% in UK ores produce sulphur dioxide which causes acid rain. Iron ores are a finite resource and the cost-effective mines will be exhausted one day. In the mean time, as deposits dwindle they become more expensive to mine, simply because we use the more readily available sources first. So as ores become scarcer, recycling becomes more economically favourable. Because of this, recycled iron and steel now accounts world-wide for 45% of all iron and steel produced. The recycling industry produces nearly 100% pure metal.