Flows of particulate materials are ubiquitous in nature and industry. Predictions of flow rates and mixing times rely on an understanding of the rheological properties of the materials, which can differ considerably from that associated with a single-phase fluid. This presentation highlights some unique features of granular materials and inertial suspensions and includes recent experimental results. In addition, the seminar overviews new work related to the mixing and gaseous diffusion in cement. Cement production releases significant amount of carbon dioxide; carbon dioxide can be partially reabsorbed into cement by diffusion through the multiphase material. The ongoing research includes modeling of the carbon dioxide uptake and considers ways to accelerate the process, such as mixing with the cement paste.