Following steps are used to separate a mixture of
saw dust and sugar :
(i) Add water to the mixture 
(ii) Sugar present in the mixture dissolves in water but saw dust does not.
(iii) The solution is then filtered through filter paper.
(iv) We will get sugar solution as filtrate and saw dust will remain on the filter paper.
(v) Then the solution is heated and when water evaporates completely, sugar is left behind

Sea water is allowed to stand in shallow pits. Due to solar heat, water in the pits get evaporated. After some days, the water evaporates completely and the solid salts remain in the pits. These salts are further purified to get pure common salt

Sieving is a process used for separating solid components of mixtutres varying in size.
It allows the fine particles to pass through the holes of the .sieve while the bigger particles remain on the sieve. It is used to separate pebbles and stones from the sand

When a mixture is allowed to stand for some time, the heavier components in the mixture settle at the bottom and the process is called sedimentation. For example, when mixture of sand and water is allowed to stand for some time, the particles of sand settle down at the bottom of vessel. The settling down of sand particles is called sedimentation.

The source of salt is sea water. When sea water is allowed to stand in shallow pits, water gets heated by sunlight and evaporates leaving behind the solid saIts. Common salt is obtained from this mixture of salts by further purification

We need to separate harmful or non-useful substances that may be mixed with the substance used. Sometimes, we separate even useful components if we need to use them separately.
For example: To separate stones from rice, churning milk to obtain butter etc.

Since, clothes may have small holes but filter papers do not have any holes, in fact it has very fine pores in it, hence sand particles settle down on the filter paper while water after very neat pouring reached to vessel.

When no more substance X can be dissolved in the solution at a given temperature then the solution is saturated.
When a hot saturated solution of a substance is allowed to cool, crystals of substance separate out from the solution.

We should add ice to lemonade after dissolving sugar. Without ice, sugar dissolves easily in lemon of juice because solubility depends on the temperature.
When the temperature is high, then more sugar can be dissolved. After mixing ice, it gets cool and less sugar will dissolve in it.

We will obtain clear water from a sample of muddy water by the process of filtration.
In this process, we use a piece of cloth for filtering muddy water. Because in a piece of cloth, small holes or pores remain in between the woven threads. These pores in a cloth can be used as a filter.
If the water is still muddy, impurities can be separated by a filter paper that has even smaller pores. A filter paper is one such filter that has very fine pores in it. A filter paper folded in the form of a cone is fixed onto a funnel. The mixture is then poured on the filter paper.
Solid particles in the mixture do not pass through it and remain on the filter paper and finally, the clear water is obtained.

Yes, it is possible to separate sugar mixed with wheat flour by sieving.
Size of sugar particles is more than that of the wheat flour. So, sugar will stay on sieve and wheat flour will pass through the holes of the sieve.

Sieving is a method by which fine particles are separated from bigger particles by using a sieve. It is used in a flour mill, our homes and at construction sites.
In a flour mill, impurities like husk and stones are removed from wheat before grinding. At construction sites, pebbles and stones are removed from sand by sieving.

We can separate husk or dirt particles from a given sample of pulses by winnowing. Being lighter, husk particles will fly away from pulses. We can also separate these by handpicking method.

Winnowing is used to separate heavier and lighter components of a mixture by wind or by blowing air, e.g. wheat grains and husk are different in weight, husk being lighter than wheat.
When this mixture is allowed to fall down from a height. the wind carries the lighter husk with it and the heavy grains fall vertically down on the ground. This process is used by farmers to separate lighter husk particles from grain.

A mixture is made by mixing two or more substances, which can be easily separated. We need to separate different components of a mixture for the following reasons:
(i) To separate two different but useful components.
(ii) To remove non-useful components.
(iii) To remove impurities or harmful components.
Two examples are as follows:
(i) Separation of stones from rice. Here, stones are non-useful component.
(ii) Churning milk to obtain butter. Here, both components are useful.