The characteristics of the mass transfer between powder particles and liquid steel in the Ruhrstahl Heraeus process injection(RH-IJ)refining were simulatively investigated by the use of a 1/4 scale water model of a 150 t Ruhrstahl Heraeus(RH)degasser.The influences of the lifting gas flow rate,the up-snorkel and down-snorkel inner diameters and the size of powder particles on the characteristics of the mass transfer were examined.The results show that under the condition that the inner diameters of both the up-snorkel and the down-snorkel are the same,the mass transfer coefficient in the liquid,k increases with the increase of the inner diameter of the up-snorkel,the particle size and the lifting gas flow rate(Qg).However,the increase of Qg should not result in a saturated circulation rate.Under the current working condition,k ranges from 3.392×10-5 m/s to 2.661×10-4 m/s.On the other hand,with a given lifting gas flow rate and up-snorkel inner diameters,the mass transfer weakens with the increase of the down-snorkel inner diameter.An inherently nonlinear relationship between the circulation rate(Ql)of molten steel in the RH degasser and k,which increases with the increase of Ql,was found.Under the condition of other parameters being the same,k increases with the increase of the powder particle size.In order to enhance the mass transfer,it is better not to use extremely fine powder. The characteristics of the mass transfer between powder particles and liquid steel in the Ruhrstahl Heraeus process injection (RH-IJ) refining were simulatively investigated by the use of a 1/4 scale water model of a 150 t Ruhrstahl Heraeus (RH) degasser. influences of the lifting gas flow rate, the up-snorkel and down-snorkel inner diameters and the size of powder particles on the characteristics of the mass transfer were examined.The results show that under the condition that the inner diameters of both the up- snorkel and the down-snorkel are the same, the mass transfer coefficient in the liquid, k increases with the increase of the inner diameter of the up-snorkel, the particle size and the lifting gas flow rate (Qg) .However, the increase of Qg should not result in a full flow rate. Under the current working condition, k ranges from 3.392 × 10-5 m / s to 2.661 × 10-4 m / s. On the other hand, with a given lifting gas flow rate and up-snorkel inner diameters, the mass transfer weakens with the increase of the down-snorkel inner diameter. An inherently nonlinear relationship between the circulation rate (Ql) of molten steel in the RH degasser and k, which increases with the increase of Ql, was found. Under the condition of other parameters being the same, k increases with the increase of the powder particle size. In order to enhance the mass transfer, it is better not to use extremely fine powder.