Sieving is a separation technique based on the difference in particle size. It is a method of using a sieve to distinguish small particles from bigger particles. A sieve is a device with a mesh or perforated bottom that separates particles of different sizes. The larger particles are retained by the sieve, while the smaller particles pass through the holes. Sieving is a traditional and easy method of separation that does not require much skill and is relatively cheap. It is commonly used in flour mills or building sites to remove impurities such as husks, stones, or pebbles from wheat or sand.

The principle of sieving is based on the fact that particles of different sizes will be separated by a sieve with holes of a specific size. The mesh size of the sieve can vary depending on the application. The factors that affect sieving include the size and shape of the particles, the size and shape of the sieve, and the amplitude and frequency of the vibration applied to the sieve.

Some advantages of sieving include that it is a simple and quick method of separation, and it does not require expensive equipment. However, some disadvantages of sieving include that it cannot separate two substances in a mixture that have the same size, and it may not be suitable for separating very small particles.