The key issue associated with the industries is the transportation and dumping of solids particulates in the form of slurry at the desired place using long length pipelines. In this perspective, numerical simulation of three-dimensional horizontal slurry pipeline of 0.0549 m diameter using Eulerian two-phase model with RNG kɛ turbulence closure is carried out. The glass - beads solid particulates having density (  = 2470 kg/m3) and slurry concentration varies as 10% to 50% (by volume) for velocity ranges of 3-5 ms-1. The computational modeling is done using available commercial software ANSYS Fluent for 125μm and 440 μm particulate size at different velocity and concentration range to know their effect on slurry flow characteristics. It is observed that for chosen particulate size pressure drop increases with increase in velocity at all solid concentration range. The pressure drop in slurry for 440 μm solid particulates is found higher as compared to the pressure drop of 125 μm solid particulates slurry. The percentage change in pressure drop is also reported in the paper due to particulate size effect at all velocity and solid concentration. The obtained results of predicted pressure drop are analytically compared with the available experimental results of literature and are in synchronism with that. A parametric study is carried out with the aim of visualizing and understanding the solid particulate size effect on slurry flow characteristics. Finally, the results of settling solid concentration contour, velocity contour, concentration profiles, velocity profiles and vector representation of concentration/velocity were also predicted for chosen particulates sized slurry.