Abstract: Abstract: Low-density particles solid-liquid suspension characteristics are very critical problem in stirred vessels industrial process. Solid-liquid suspension characteristics for low-density particles in a dual six-blade-Rushton-turbine(6-DT) impeller stirred vessel was simulated numerically by using computational fluid dynamics (CFD).The multiple reference frame (MRF) and Euler-Euler two fluid model based on the kinetics of granular were used in the simulation. Flow field and solid holdup distribution in the stirred vessel were obtained and realized visualization. Furthermore, the influences of the operating condition on solid-liquid suspension were investigated. The simulated results are in good agreement with experimental data in the literature, which verified the feasibility of our numerical method. The research results show that the flow pattern in a dual-radial-impeller stirred vessel was closely related to the clearance of the two impellers. When the clearance is greater or equal to a half diameter of the vessel, parallel flow will form, since the effect among the circulation flows is less. A typical double circulation pattern is formed for every disc turbine, and there are four circulation loops in the stirred vessel. Liquid velocity decreases slightly with low-density particles adding to the vessel. On the whole, solid holdup increases along the axial height. The highest solid concentration is found in the center of the liquid surface region for low-density particles which easily accumulate there, while the lowest solid holdup is in the center of the bottom region. Solid holdup in the center of the circulation loops and behind the blades is relatively high. The phenomenon of solid holdup regional distribution is also observed in the dual-radial-impeller stirred vessel. Taking the height of h=0.5T as a boundary, the vessel can be subdivided into upper region and lower region, and solid holdup in upper region is obviously higher than that in lower region. With the increasing of impeller speed, solid holdup in the liquid surface region and upper region decreases significantly, while it increases in lower region of the stirred vessel. Solid suspension is even for very small size particles. The uniformity of solid suspension worsened with the increasing of particles size or the reducing of impeller speed. The effect of particles content on solid suspension is not very obvious. The study can provide helpful references for design, optimization, and scale-up of the stirred vessel for low-density particles suspension.