Abstract: To make the worked-out section of an iron ore have no back water equipment and can not leak out slurry，we should ensure the backfilling pulp emulsify timely.This study by using the method of adding the water glass to the slurry and changing it’s emulsion time, and also by the mortar rheological test and injection-mold test, we can know the mobility and compressive strength in different concentrations and different cement-sand ratio.Finally, we identified the slurry concentration of 50%，cement-sand ratio of 1∶8 and water glass ratio of 1∶116 as the best ratio according to three factors of rheological properties, compressive strength and emulsifying time.

Key words: Tailings backfilling, Ratio of backfilling pulp, Rheological properties, Emulsification