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3 Extracting Metals :Introduction An ore is any naturally-occurring source of a metal that you can economically extract the metal from. Aluminum, for example, is the most common metal in the Earth's crust, occurring in all sorts of minerals. However, it isn't economically worthwhile to extract it from most of these minerals. Instead, the usual ore of aluminum is bauxite - which contains from 50 - 70% of aluminum oxide. Ores can often be an oxide for example bauxite or a sulphide like pyrite. But before reducing the metal compound to the metal you must concentrate it. Basically concentrating the ore means getting rid of as much of unwanted rocky material as possible before the ore is converted into the metal. Only then is it ready for reduction changing it into an extracted metal state. There are many ways of this kind of process but it is really long and costly economically. Reducing the metal compound into a metal: At its simplest, where you are starting from metal oxides, the ore is being abridged because oxygen is being removed. However, if you are opening with a sulphide ore, for instance, that's not a lot of help! It is much more obliging to use the meaning of reduction in conditions of gaining electrons. ...read more.
Throughout electrolysis, electrons are being added straightforwardly to the metal ions at the cathode (the negative electrode). The disadvantage (predominantly in the aluminum case) is the price of the electricity. A benefit is that it can produce very pure metals. This procedure would be really efficient in terms of extracting aluminum and gold but not iron due to the ore properties. Conversion of the aluminum oxide into aluminum by electrolysis The aluminum oxide is electrolyzed in solution in molten cryolite, Na3AlF6. Cryolite is another kind of aluminum ore (bauxite), but is rare and costly, and most is now manufactured chemically. The electrolysis cell The diagram shows a very simplified version of an electrolysis cell. Although the carbon lining of the cell is labeled as the cathode, the effectual cathode is chiefly the molten aluminum that forms on the base of the cell. Molten aluminum is siphoned out of the cell from time to time, and fresh aluminum oxide supplemented at the peak. The cell operates at a low voltage of about 5 - 6 volts, however at vast currents of 100,000 amps or more. The heating outcome of these large currents maintains the cell at a temperature of about 1000°C. ...read more.
In conclusion redox and displacement reactions could be severe and dangerous. In some cases they aren't efficient and reliable. They waste resources and it is a lengthy process. The process might not be recommended in terms of extracting iron, aluminum or gold. Conclusion: Summing up all the ways and methods you could extract aluminum, gold and iron; electrolysis would be the best and most efficiently reliable method which does not waste resources, fuel or much money. It may be costly in some situations and in some terms but it is worth the payment. Out of all the methods listed above electrolysis would be the most quickest and fast paced way of extracting these metals. Basically it is the most dominant procedure compared to the rest and only has one disadvantage which would be the electrical price. Electrolysis is the separating of a compound into its constituent elements by passing an electrical current through it when in a molten or aqueous state. The word electrolysis means the process of breaking molecules to smaller parts by using an electric current. Positive and negative poles of an electric source, such as a battery, can absorb opposite ions of an electrolyte, causing separation of ions and creation of a new substance. Electrolysis is a chemical change. Ergo it is in overall the superlative technique. ...read more.
This student written piece of work is one of many that can be found in our GCSE Changing Materials - The Earth and its Atmosphere section.
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