Patent attributes
A separation system is disclosed for separating selected particles from a mixture of particles in a fluid. The system includes a froth flotation vessel into which in use the mixture of particles and fluid are subjected to an upward flow of an introduced gas to form a froth layer which rises above an interface formed between the froth layer and the mixture of particles and fluid, such that a quantity of the selected particles is conveyed out of the vessel by the froth layer to become a first product of the system. The vessel also has a first outlet arranged in use for receiving a flow of some of the mixture of particles and fluid from the vessel, an entry to the first outlet being located in a region proximate to, but below, the interface. The vessel also has a second outlet arranged in use for receiving a flow of some of the mixture of particles and fluid from a region of the vessel which is located below the first outlet. In use the first outlet receives a quantity of the selected particles which were not conveyed out of the vessel by the froth layer, and the second outlet receives a quantity of the selected particles in a first by-product of the system. The first by-product comprises a relatively higher percentage of solids compared to the flow of particles and fluid in the first outlet. The flow of the mixture of particles and fluid from the vessel via the first outlet passes to a classification device, which separates the flow into two or more fractions on the basis of their size or density or a combination of the two.