Flow regimes and particle degradation in pneumatic transport depend on the operating conditions, granular material properties, and dynamic behavior of the system in a very complex way. In this work, an experimental study was carried out using a blow tank system, which was operated under several phase regimes with the help of a secondary air line. Flow maps were constructed to predict horizontal flow patterns under conditions that ranged from plug to dilute phase flow, using two test materials: sodium and potassium nitrate prills. They have identical particle size distributions, but very different strength properties, allowing a comparative study of the particle degradation (breakage and dusting) of soft and hard materials in a wide range of flow conditions, identified as plug-, slug-, dune-, and dilute-phase regimes. The results demonstrated clear advantages in dust reduction for dense-phase conveying compared to dilute phase; however, particle breakage rates were similar in both types of systems. Dusting and breakage were the dominant wear processes for the softer material (sodium nitrate), while breakage, to a lesser extent, prevailed for the case of the brittle material (potassium nitrate).