Sieving

Sieving is a separation technique in which unwanted particles are separated from the desired product on the basis of difference in the particle size of the two components of the mixture.
Common example is separating flour from unwanted material by passing it through a sieve. 

Sieve is the device which has small holes in it. Fine particles can easily pass through it, leaving behind coarse bigger particles.

A sieve can be operated by hands, as in our homes, and also can be used with the help of machines. In latter case, a large-sized sieve is connected to a machine which help in vibrating or moving the sieve. 

A strainer is a form of sieve used to separate a solid from a liquid. For example, separating tea leaves from tea.

Advantages:

1. It can be used to separate large amount of mixture when operated using a machine.
2. Easy handling
3. Saves time
4. Results are accurate and reproducible.

Disadvantages:

1. Consumes large amount of electrical energy, when operated using machine. Otherwise, it is a cheaper process.
2. It works only with dried mixture.