In three-phase agitated contactors, the dispersion of gas and the suspension of solid particles are required simultaneously to promote both gas-liquid mass transfer and solid-liquid mass transfer. A new type of mechanically agitated three-phase contactor with a large ring sparger and a downflow pitched blade turbine was proposed, and its solid-liquid mass transfer performance was investigated experimentally with 4.75 vol% solids in comparison with the conventional types. The new type of contactor prevents the concentration of inflow gas around the impeller. resulting in efficient discharge flow from the impeller and efficient suspension of solid particles. The solid-liquid mass transfer coefficients under the regime of complete suspension of particles were correlated with the agitation power input to gassed liquid, independently of the types of contactor and the conditions of gassing. Under the regime of partial suspension of particles, the mass transfer coefficients depended strongly on the fraction of solid particles suspended.