Turbulence and Bifurcation in the Motion of an Hydrocyclone

The hydrocyclone is a tool used in different fields but mostly in mining industries to separate minerals. The minerals are put in a liquid or in a stable suspension of a chosen density which must be less than the density of the heavier minerals and greater than that of the lighter minerals [1,2,3]. Nowadays there is a strong interest for such tools, mostly in the processes where is possible to eliminate or reduce a lot the operation of grinding. This allows to reduce the cost of production and simplify the separation of minerals [4,5,6,7]. The modes of separation are two. One is the static mode, where the basis of the separation process is the gravitational force. The other is the dynamic mode, which operates by using a centrifugal force. The static mode can be applied when is valid the relation Fg > FD, where Fg is the gravitational force and FD is the resistance force to the motion of mineral particles into the dense fluid. The relation is strictly related to the mass and dimension of the particles. As a consequence, the static separation can be used only with dimensions of the particles greater than 4–6 mm. Instead the dynamic separation can be used with a dimension of the particles less than 0.2–0.3 mm. The hydrocyclone can be classified as: i) conic hydrocyclone (DMS); ii) cylindric hydrocyclone (DWP); iii) multi–stage hydrocyclone (TRI–FLOW).