Gyratory Screen Separators impart a combined gyratory and vertical motion and arc used for fine-screening applications, wet or dry, down to 40 pm, including laboratory use. The basic components consist of a nest of sieves up to around 2.7 m in diameter supported on a table that is mounted on springs on a base. Suspended from beneath the table is a motor with double-shaft extensions, which drives eccentric weights and in doing so effects horizontal gyratory motion. Vertical motion is imparled by the bottom weights, which swing the mobile mass about its center of gravity, producing a circular tipping motion to the screen, the lop weights producing the horizontal gyratory motion. Ball trays and ultrasonic devices may be fitted below the screen surfaces to reduce blinding. Circular screens are often configured to produce multiple size fractions. These types of screens are typically used in low-capacity applications, one example being the dewatering of carbon in gold plants.