To the best of authors’ knowledge, although the first patent on the hydrocyclone is about 128 years old, to date, there are just a few re- views on hydrocyclones (Table 1), and marginal effort has been at- tempted to comprehensively review and summarize enhanced-separa- tion hydrocyclone technologies developed by optimizing operating parameters and conditions. For example, Sheng published a review on the separation of liquids in a conventional hydrocyclone, which mainly demonstrated the definition of the separation efficiency of a two-phase, liquid system in the presence of a solid. Chakraborti et al. Svarovsky and Narasimha et al.presented reviews on hydrocyclone models. Bergström and Vomhoff reviewed the experimental studies about the flow field of hydrocyclones. Holtham focused on dense medium cyclones for coal washing, while Kharoua et al. and Liu et al. on de-oiling hydrocyclones and three-phase hydrocyclones, respectively. Wang et al. presented the researches and developments of the hydrocyclonic separation technol- ogies, including the fish-hook phenomenon, separation of molecules,