Abstract: The content of binding phase in Cr-bearing vanadium and titanium magnetite is insufficient， which makes the sintering strength and low temperature reduction degradation index (RDI) bad. The sintering basic characteristics， i.e.， crystal intensity， self-intensity of adhere phase， fluidity of liquid phase， assimilation temperature， were studied in four kinds of Cr-bearing vanadium and titanium magnetites， which were compared with the single burning test results of four kinds of iron ore concentrate， to explore the effect of the sintering basic characteristics on RDI_+3.15. The results showed that the RDI_+3.15 of sinter decreases with increasing the assimilation temperature， and increases with increasing the strength of binding phase， but the fluidity of liquid phase and crystal intensity have little influence on it.

Key words: Cr-bearing vanadium and titanium magnetite, sinter, basic characteristics, RDI(reduction degradation index)； optimization ore matching