According to the different forms of medium movement and the purpose of the operation, gravity separation can be divided into six types of operations.
(1) Heavy media separation. Gravity separation must be carried out in a medium, which can be air, water, heavy liquid, or heavy suspension. Water is the most commonly used medium. When air is used, it is called pneumatic separation; when heavy liquid or heavy suspension with a density greater than water is used, it is called heavy media separation. Heavy media separation is a method of strictly separating minerals according to their density.
(2) Classification. When loose materials settle in air or water, particles of different sizes and shapes have different settling velocities due to different resistance from the medium. They can then be separated according to particle size. This type of gravity separation is called classification.
(3) Washing. When ore is cemented by clay and interferes with subsequent operations, washing is required. It is an operation that uses the force of water flow and mechanical force to separate the clay from the ore.
(4) Jigging. Jigging is a gravity separation process that utilizes a periodic, vertically variable-speed medium flow to repeatedly loosen, densify, and stratify mineral particles according to density.
(5) Shaking table separation. This method utilizes the inertial force generated by the asymmetrical reciprocating motion of the shaking table surface and the washing effect of water flow to loosen, stratify, and transport particles on the table surface, thereby achieving separation.
(6) Sluice box separation. This method uses water flow in an inclined sluice box for mineral separation.