Mechanical screening, often just called screening, is the practice of taking granulated ore material and separating it into multiple grades by particle size. This practice occurs in a variety of industries such as mining and mineral processing, agriculture, . A screening machine consist of a drive that induces vibration, a screen.
High frequency vibrating screens are the most important screening machines primarily utilised in the mineral processing industry. They are used to separate feeds containing solid and crushed ores down to . A rotary sifter uses a screen which rotates in a circular motion and the finer particles are sifted through the apertures.