Question

What is hand picking? When is this method used?

Answer 1

Hand-picking is a method of separation by which impurities that are different from the useful material in a mixture are hand-picked and removed. For example, rice, wheat, pulses, etc., contain impurities such as small stones or unwanted grains. These impurities look different from the useful material and are easily hand-picked and removed.
This method is used when these following conditions are fulfilled.

1. The quantity of the mixture is small.
2. The unwanted material is present in smaller quantities.
3. The size, shape and colour of the impurities are different from those of the useful substance.