Abstract: In order to achieve the high-efficiency recovery of titanium component in the titanium-blast furnace slag,the slag had been modified in terms of its chemical compositions and treated through the process of high temperature selective precipitation. The maximum crystal size and quantity of the resulted pervoskte was 63.17 μm and 30.62%,respectively. Based on the previous results,the study on the flotation of the modified slag had been carried out,including the effect of OHA dosage and sodium silicate dosage. It is found out that the OHA dosage and sodium silicate dosage do not affect the flotation obviously.SEM and EDX analysis show that the CaSO₄ micro-precipitate covers the surfaces of the minerals,which decreases the effect of OHA and sodium silicate. Therefore,the effective surface treatment agents should be developed to preprocess the modified slag prior to flotation separation.