This article focused on the factor of time in separation process of rare earth elements (REEs) between solid phase and leaching sample of Iran Saghand's uranium mine. First, sufficient amount of samples were been collected from the region and analyzed. Then the acid leaching process was used for the selected sample. In this method, separating REEs from the minerals can be done easily and selectivity. As a result of this separation the obtained amounts include 500 ppm Yttrium, 580 ppm Cerium and 940 ppm Lanthanum. However, ion exchange method with fixed bed is an appropriate technique to separate REEs. Therefore, 0.5 cc Dowex 5owx8 (H⁺) solid phase have been brought in to 50cc of leaching solution for 10 to 60 minutes. This experiment includes two stages, absorption and efficiency stage, only absorption stage has to be used. The sample analysis showed that maximum of absorption amount obtained for 475 ppm Yttrium, 290 ppm Cerium and 658 ppm Lanthanum in 30 minutes.