Influence of the amount of fine particles on rheological properties of uranium dioxide powders

Autor: Madian, A., Saleh, K., Ablitzer, C., Matheron, P., Leturia, M., Bernard-Granger, G.
Přispěvatelé: CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Technologie de Compiègne (UTC), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Transformation Intégrée de la Matière Renouvelable (TIMR), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Nuclear Engineering and Design
Nuclear Engineering and Design, Elsevier, In press, ⟨10.1016/j.net.2020.01.012⟩
Nuclear Engineering and Design, In press, ⟨10.1016/j.net.2020.01.012⟩
ISSN: 0029-5493
1872-759X
Popis: International audience; In industry, the use of powders is very common. Understanding granular flow in silos, hoppers orpneumatic conduits is necessary. This study investigates the characterization of the rheologicalproperties of uranium oxide powders in the context of a powder metallurgy process for nuclear fuelpellets manufacturing. The flow and arrangement properties of these powders must be compatiblewith a reproducible feed of press moulds. This may require a modification of the physicalcharacteristics of the powders. In particular, particle size is known to have a great impact on therheological properties and a significant effect of fine particles (less than 100 µm) is suspected. In thisstudy, we have quantified this influence of particle size distribution on rheological properties of UO2powders, especially the influence of the amount of fine particles. Two complementary approacheshave been used. The first approach is to characterize the powder in a static state: the density,compressibility and shear measurements make it possible to understand the behaviour of thepowder when it is moved from static state to dynamic state. The second approach is to characterizethe behaviour of the powder in the dynamic state. It allows understanding the flow capacity of apowder in the process. To answer the problem of reproducible filling of the press moulds, it isessential to characterize the two regimes, that is to say the flow of the powder from a hopper or ashoe, then the behaviour in the dynamic state. The amount of fine particles has been more especiallyvaried because the cohesive forces are considered predominant with respect to gravitational forcesfor particles smaller than 100 μm. A threshold of the rate of fines has been demonstrated in bothtypes of measurements. Beyond this threshold, the behaviour of the powder is approximatively thesame.
Databáze: OpenAIRE
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