Uses of Metals and Alloys
Properties of Metals
Metals are often shiny, malleable, ductile and have a range of melting points. They also conduct electricity.
They can conduct electricity because some of their electrons are free to move through the metal . We say they are delocalised electrons.
Alloys
Most of the elements in the Periodic Table are metals. Some are extremely reactive, whereas other barely react at all. However, sometimes a pure metal just isn't quite suited for a job. So we can melt two or more metals together, let them solidify and form an Alloy.
An alloy is a mixture of metals. They have superior properties to the pure metals they are made from. They might be stronger, lighter or better at conducting electricity or heat than pure metals.
The table below shows some examples of common alloys:-
The videos below give more information on two alloys; Bronze and Steel, and then an example of alloy use in Veterinary Medicine:-
Bronze : The first Alloy
Steel : How is it made ?
Medical Alloys
Extraction of Metals
Some precious metals are like Gold can be found uncombined in the environment. This is because they are very unreactive.
Most Metals are found in the environment in the form of ores; rocks made out of metal compounds.
In order to extract the metal for the surrounding material, two methods can be used :-
Heating ( sometimes with a reducing agent).
Electrolysis
Extraction of Metals using Heat
Some metals can be extracted by heating alone. For example, if you heat the rock cinnabar then liquid Mercury is released.
More reactive metals require heating with a reducing agent. A reducing agent is a chemical that can remove Oxygen from a metal.
An example of this is the extraction of Copper and Iron from their Ores:
In both of the above reactions, the Carbon binds with the Oxygen in the ore to form Carbon Dioxide, leaving pure metal behind.
The video below shows how pure Copper is extracted from its ore on an industrial scale:-
Extraction of Iron - Blast Furnace
Iron is one of the most common elements in the Earth's crust. We turn it into the alloy steel and use it for construction, cars, cutlery, surgical instruments and more...
In order to extract the Iron from its ore, a Blast furnace is used . The blast furnace combines the iron ore with lime and coke (carbon) to extract the pure iron:-
The video below shows the process of the extraction of Iron from its ore:-
Electrolysis
Some Elements are so reactive that not even carbon can extract them from their ores. In order to extract the most reactive metals, we must use Electricity to extract them. This process is known as Electrolysis.
The following table shows the extraction process for a range of metals:-
