Shaking tables, also known as wet tables, consist of a sloping deck with a riffled surface. A motor drives a small arm that shakes the table along its length, parallel to the riffle and rifle pattern. This longitudinal shaking motion consists of a slow forward stroke followed by rapid return strike. The riffles are arranged in such a manner that heavy material is trapped and conveyed parallel to the direction of the oscillation. Water is added to the top of the table perpendicular to the table motion. The heaviest and coarsest particles move to one end of the table while the lightest and finest particles tend to wash over the riffles and to the bottom edge. Intermediate points between these extremes provides recovery of the middling (intermediate size and density) particles.
Shaking tables find extensive use in concentrating gold but are also used in the recovery of tin and tungsten minerals. These devices are often used downstream of other gravity concentration equipment such as spirals, reicherts, jigs and centrifugal gravity concentrators for final cleaning prior to refining or sale of product.