This is one of the best equipments employed to obtain clean gold concentrates. They consist of a ruffled deck on some type of support. A motor placed on one side drives a small arm that shakes the table along its length. The table has riffles that are not more than one inch high and cover almost half table. Varied riffle designs are available in the market and each manufacturer has a special according to its use. The table oscillates horizontally and concentrates the heavy particles due to inertia differences created by the brisk, reciprocating motion of the inclined deck of the table. Coarse particles feed need long strokes at lower speeds and fine particles need shorter strokes at faster speed.
Deck sizes range from 18 by 40 inches for laboratory tests to by 15 feet for industrial applications. Tables can treat 175 t/d. The equipment is fabricated with two basic deck types, rectangular and diagonal. The first one is roughly rectangle shaped with riffles parallel to the long dimension. The second group is irregular rectangles with riffles at an angle. In both types the shaking motion is parallel to the riffle pattern. The diagonal decks are usually constructed of wood and metal, and are lined with rubber or plastic. These materials have a high coefficient of friction that aids gold recovery.
Shaking table products
When the equipment is working abed of particles experiences a horizontal movement oriented to create segregation according to the specific gravity and size. Under this concept, particles with high specific gravity will sink and the lighter particles will rise to the top of the riffles. In order to get an appropriate shaking, the movement must be enough to expand the bed. This movement must let a particle to particle contact. If small particles of light minerals and large particles of heavy minerals segregate to the same position, the separation will be difficult. A practical way to judge the process is to observe the stream color formed on the deck.
Shaking table concentrate with free gold particles