Theory:

Depends on the type of the material to be separated, we can use different separation method to separate the substances from the mixture. Now, let us learn a few methods of separation:
 
Methods of separation:
  
1. Handpicking
2. Winnowing
3. Threshing
4. Sieving
5. Sedimentation
6. Decantation
7. Filtration
8. Evaporation  
1. Handpicking
Handpicking is the process of removing the impurities or non-essential substances by using hand.
We can use this handpicking process to separate, slightly larger sized impurities like the pieces of dirt, stones, and husk from wheat, rice or pulses.
Example:
1. Handpicking the stones from grain.
 
2. Separating the stones and insects from rice.
 
bug-1204318_1280.jpg       
 
3. Extracting spoiled or rotten vegetables from a vegetable basket.
 
veg.jpg 
 
2. Winnowing
Winnowing is the process used to separate heavier and lighter components of a mixture by wind or by blowing air.
Winnoving.jpg
 
Winnowing method is most commonly used by farmers to separate lighter husk particles from grains.
 
When the husk particles introduced into the air, it goes carried away by the wind. Then the seeds of grain get separated and form a heap near the platform for winnowing.
3. Threshing
We can easily handpick or pluck the mangoes or tomatoes from the trees or plants. But, grain seeds are much smaller than vegetables and fruits. So, plucking them from their stalks would be difficult and tiresome.
 
And that is where we are using the method called threshing.
Applying the threshing process, we can separate the grains or seeds from the stalks by beating the stalks to free the seeds.
Threshing.jpg
Reference:
Image credits:
Vegetables: https://www.pxfuel.com/en/free-photo-xceix
insects in rice: https://www.needpix.com/photo/559164/bug-insect-animals-rice
Winnowing: https://www.flickr.com/photos/icrisat/6119489108
Threshing: https://commons.wikimedia.org/wiki/File:Threshing_harvest_Sangrur_Punjab_India.jpg