Some mineral processing problems are not yet satisfactorily solved by the current technology, especially those based on the use of mechanical energy for comminution and separation. The use of mechanical energy has certain inherent drawbacks such as wear of machinery components and limitation in the speed of moving parts to avoid risk of failure under the severe working conditions encountered in the industrial processes. Waterjet can contribute to overcoming such disadvantages since it allows to transfer energy without contacts between solid materials (no wear) and it is suitable for generating high velocity streams in air or in water even at relatively low pressures. The potential benefits of waterjet technology are particularly interesting in flotation where the size and speed of the air bubbles, that depend on the shear velocity induced by agitation, are a critical aspect for the optimization of the separation results (recovery and selectivity) and the reduction of the running cost items (wear and energy consumption).