Abstract: In order to realize the low-temperature (10～12 ℃) positive flotation of phosphate ore， low-temperature flotation tests were carried out with twelve kinds of phosphate-ester surfactants for gravity separation tailings in Houping Mining Section of Shukongping Mining Area in Hubei Province. The results showed that AEO-3P，APE-4P，and EB-10P could be served as low-temperature flotation synergists， and the synergistic effect of AEO-3P is better than APE-4P and EB-10P. The synergistic effect of MAP-K and ODEP-K were weak，and the other phosphate-ester had no synergistic effect. It indicated that polyoxyethylene ether phosphate containing alcohol，phenolic group，with low polymerization and suitable carbon chain has good low-temperature synergistic effect. While Phosphate-ester without polyoxyethylene or salt (PBTCA，HEDP-2Na) play an inhibitory effect. The synergistic effect of phosphate-ester with short carbon chain and larger polymerization is not obvious，may be caused by the strong hydrophilic of such agents.

Key words: phosphate-ester surfactants, low-temperature flotation, synergistic effect