Crystalline structures and preferential surfaces developed in the Al-Ni-O system

S.A. OBREGÓN; M.R ESQUIVEL

Bariloche

Congreso; XXIII Latin American Symposium on Solid State Physics; 2018

Universidad de Rio Negro-Comisión Nacional de Energía Atomica

The nuclear activity generates wastes that must betreated before nal deposition. This treatment is imperativein diluted wastes to separate the contaminantfrom the main water volume in order to achievea safe disposal and an adequate recovery of both constituents.This problem mainly occurs with Sr2+ andCs+ contaminated waters. To safely remove the cations,an electrochemical method is selected. The methodconsist on the design of electrodes using Al2O3-Nicomposites. The electrodes are obtained using a mechanicallytreated mixture of C, Al and Ni powders.Pellets of Al-Ni are compacted using C as a pore generator.Once obtained, pellets are sintered at 1400 for 12 h. As a result, porous samples of Al2O3-Niand Al2O2 are obtained. Samples with NiO are reducedin H2 to analyze the stability of the Ni contentin the Al2O3 matrix. Structure and microstructureis studied by XRD. Morphology and crystallinehabits of the composites is analyzed by combinedSEM-EDS. The combined presence of Al2O3, NiOand NiAl2O4 is observed. Samples present crystallinehabits associated to the Fm3m space group with sizesbetween 5 and 20. Samples with diverse carboncontents show porous with sizes between 5 and 50. Pellets are mechanically and morphologically appropriatedfor the task designed for.The characterizationby SEM shows predominant surfaces associatedto Ni-content Fm3m phases. These phases are intimatelymixed to the Al2O3 ones. This fact ensuresa stable structure that works properly when submergedin contaminated water. Electrochemical measurementsshows a removal of cations by reduction near70% of the nominal content on the selected solution.