Froth flotation is the process of using physicochemical methods to separate valuable minerals from gangue. It is one of the most important methods in mineral processing. Previous studies have found that using cavitation bubbles can widen flotation particle size-range, increase the probability of bubble particle attachment, and reduce the probability of bubble particle detachment; all of which improve flotation recovery. Collector and frother dosages can also be reduced with cavitation-generated bubbles. Therefore, this technology reduces both energy consumption and operating costs. Hydrodynamic cavitation is the most economical method used for creating tiny bubbles for flotation. It is the development and growth of a gas and/or vapor filled void in a liquid. Cavitation bubbles are generated at the throat of devices, when liquid passes through a constricted area, such as a valve, orifice, venturi, or nozzle. Liquid velocity increases at the throat or vena-contracta. As the velocity increases, the kinetic energy associated with the liquid increases, and the pressure decreases. Once the local pressure falls below the vapor pressure of the liquid, hydrodynamic cavitation happens. The efficiency of cavitation bubble generating devices and their geometry design is analyzed using computational fluid dynamics (CFD) in this study. CFD is used to analyze multiple interacting phases, understand complex physical changes, and test all possible parameters without consuming a large amount of resources. Different geometries, venturi tubes, nozzles, and orifices from literature were used. Mathematical models were validated through comparison with experimental results. Critical cavitation velocities and volume fractions of venturi and orifices with different geometries, circular, square, and slot, were compared. Circular venturi tubes were found to be the best design for cavitation bubble generation. To optimize the geometric design of the venturi tube, six parameters were modified. These include the inlet diameter, throat and inlet diameter ratio, convergent angle, divergent angle, throat length, and entrance length. A response surface method central composite design was conducted for evaluating the effect of these six parameters affecting the efficiency of the Venturi tube. The response of the model is called critical velocity for cavitation, which means the minimum required velocity for cavitation is generated by each geometry. Because flotation column eliminates rotor and stator, the only energy supply is mixing and pumping prepared feed. The smaller critical cavitation velocity means the easier for cavitation to happen. Therefore the lower energy required, the better the design for hydrodynamic cavitation design is. 48 venturi tubes with designed geometry were created using ANSYS ICEM. Vapor volume fractions of each