Abstract:China is endowed with abundant phosphate ore resources，with proven reserves ranking among the top in the world. However，these resources are unevenly distributed，characterized by a scarcity of rich ores and an abundance of lean ores，as well as a relatively low average grade. The commonly encountered difficult-to-select sedimentary siliceous and calcareous phosphate rocks generally exhibit fine dissemination size，complex mineral composition，and close intergrowths，which make it challenging for traditional single positive or reverse flotation processes to achieve satisfactory mineral processing results. Against this backdrop，the double reverse flotation process， with its unique technical approach，has enabled the efficient separation of silicate and carbonate gangue minerals through selective depression and differential collection. It has now become the core sorting technology for treating medium- and low-grade collophane ores. This paper reviews the research progress of the double reverse flotation process in terms of the principles of action of collectors and depressants，the development of new collector agents，and the selection of different process flows. Particular emphasis is placed on the mineral processing technologies of phosphate ores in Yunnan，Guizhou，and Hubei provinces. In response to the characteristics of ores from different regions，a differentiated sorting scheme combining double reverse flotation with other processes has been adopted. Case applications have demonstrated that through continuous optimization and innovative combinations of the double reverse flotation process，stable high-quality phosphate concentrates can ultimately be obtained to meet the needs of downstream production. The main developments and research directions of the double reverse flotation process are summarized，with the development of new environmentally friendly agents， optimization and control of processes，and integration with intelligent systems identified as important technological supports for resolving the supply and demand contradictions of phosphate resources and achieving sustainable development in the industry. This provides a practical and feasible technical pathway for the efficient utilization of medium- and low-grade collophane ore resources in China.