Reverse flotation experiment of the phosphate ore from Zhijin,Guizhou was made with a homemade collector(WF 02).The effects of several parameters including the dosages of collector and depressor,grinding size,slurry concentration and floatation time on the grade and recovery of P2O5 were investigated by adopting the staged addition of the collector in experiment floatation.The results of experiment showed that when the dosage of collector WF-02 is 1.0 kg/t ore,the dosage of phosphoric acid is 10 kg/t ore,slurry concentration is 35%,grinding fineness of-200 mesh is 89% and flotation time is 9 min better flotation result can be obtained.Under these conditions,P2O5 grade of concentrate was increased from 21.90%(P2O5 content of raw ore) to 33.19%,and recovery rate of P2O5 reached to 89.89%.