Three-dimensional numerical simulations of a particle-laden jet have been carried out with an Euler-Euler approach and compared with experimental data obtained by Hadinoto et al. 2005. The particles transport and dispersion occurs in many industrial applications as chemical, pharmaceutical, agricultural and risk management. A better understanding of particles flow behaviour has significant convenience for process control, productivity and safety in industrial application. Nowadays, the numerical simulation is a powerful tool for the prediction of particle-laden flow even for industrial scale. However the numerical tools still need to be evaluated by the comparisons with experimental data, the so-called the test cases. The present one is the discharge of particles in a confined environment. In the experiments several solid mass loading and particle diameters have been used in order to investigate the effect of the polydispersion on the expansion of the granular jet. The three-dimensional numerical simulations have been carried out by using the Euler-Euler solver NEPTUNE_CFD. NEPTUNE CFD is a multiphase flow software developed in the framework of the NEPTUNE project, financially supported by CEA (Commissariat à l’Energie Atomique), EDF (Electricité de France), IRSN (Institut de Radioprotection et de Sûreté Nucléaire) and AREVA-NP. NEPTUNE_CFD is based on an unsteady multi-fluid Eulerian approach for dilute and dense particle-laden flows. The theoretical approach is based on PDF (probability density function) approach (Simonin 1991, Simonin et al. 1993) allowing to derive the continuum transport equations for the mass, momentum, and agitation of the particulate phase.