Methods of separating mixtures and compounds vary according to the physical properties such as solubility and magnetic attraction. For example, a mixture of sulphur and iron filings can be separated using a magnet as the magnet will attract the iron filings and leave sulphur behind. Various methods can be used to separate iron and sulphur.
The separation of sulphur and iron can only occur if the two compounds have not chemically reacted. It is thus important to note that if the mixture between the iron fillings and sulphur is heated, a chemical compound called iron sulphide is formed. To separate iron and sulphur that have not chemically reacted, two methods are magnetism and the use of carbon disulfide.
During the process of separating iron and sulphur, in case of an iron ore, the finely crashed iron ore is washed in a stream of water. During this period, the other particles other than iron are washed away while the iron material sinks. These materials are then dried and separated using a magnet, since iron is magnetic.
If it is a mixture of iron fillings and sulphur, a magnet is used to separate the Iron fillings from sulphur particles since the sulphur particles are not attracted by the magnet. To make sure the magnet picks all the pieces of iron fillings, you can stir the container using the magnetic bar, and the iron fillings will stick on the magnetic bar. Swirling the mixture with the magnet under the container is also another method that can be used, since the Iron filings will fall towards the place where the magnet is.
Whereas sulphur is insoluble in water, it dissolves when mixed with carbon disulfide. Because of this, carbon disulfide is used to separate iron from sulphur. The mixture of sulphur and iron is put in a carbon disulfide solution. After shaking well, the sulphur component dissolves in the carbon disulfide solution while iron does not. The new formed solution is then filtered and iron particles are left behind. To separate sulphur from carbon disulfide, the solvent is evaporated, which leaves a residue of pure sulphur.