Question

why do we need to separate the components of a mixture

Answer 1

If we don't separate the components from the mixture then whatever the dust present in it will be as it is . When we separate the components then it would be easy to have or get the component back from the mixture.
Due to some technics like sublimation , distillation etc we can separate components to some extend from a mixture .

Answer 2

$<b><i>$
$\huge\red{Answer:}$

Different components of a mixture are separated in order to either separate the unrequired components from a mixture or sometimes, to separate more than one useful components from a mixture.

$\large\blue{Examples:}$

-Grain purchased from shops can contain several impurities such as pieces of stone, husk, broken grains, etc. Thus, grain is separated from these impurities to make it edible.

-Similarly, after preparing tea, we strain it to remove the used tea leaves from tea.

$\huge\pink{Keep\: It\: Mello}$

✌✌✌