This talk will present recent work investigating the use of elasto-plastic continuum models for predicting the flow behavior of particulate materials. Several constitutive relations have been implemented in a commercial finite element method (FEM) software package to predict flow and stress fields in hoppers and tumbling blenders. The stress and velocity fields and mass flow rates match well with other widely accepted models and correlations. Particle mixing and segregation are incorporated by coupling the FEM-predicted continuum flow field with an advection-diffusion-segregation equation, which includes correlations derived from experiments and discrete element method simulations. The blending and segregation results match experimental results well. These models hold the promise of modeling particulate flows at industrial scales.