Structural Characterization of natural and processed zircons with X-rays and nuclear techniques

ANNA MARIA FERRARI; A. PASQUEVICH; GIORGIA CINELLI; FEDERICA BONDIOLI; PATRICIA RIVAS; LAURA TOSITTI; FERNANDA ANDREOLA; L. C. DAMONTE

Advances in Condensed Matters Physics

Hindawi

Lugar: Londres; Año: 2017

1687-8108

In ceramic industry, zircon sand is widely used in different applications because zirconia35 plays a role as common opacifying constituent. In particular, it is used as a basic component36 of glazes applied to ceramic tiles and sanitary ware as well as an opacifier in unglazed bulk37 porcelain stoneware. Natural zircon sands are the major source of zirconium minerals for38 industrial applications. They can be used in their typical grain size (100-300 m) in the39 refractory industry while ceramic application requires milling to reduce size distribution40 down to 40-50 m (zircon flour) and/or to less than 5 m (micronized zircon). In this paper41 long, medium and short range studies were conducted on zirconium minerals originated42 from Australia, South Africa and United States of America using conventional and less43 conventional techniques i.e.(X-ray diffraction (XRD), Positron Annihilation Lifetime44 Spectroscopy (PALS), Perturbed Angular Correlations, (PAC)) in order to reveal the type45 and the extension of the regions that constitute the metamict state of zircon sands and the46 modifications therein produced as a consequence of the industrial milling process and the47 thermal treatment in the production line. Additionally, HPGe gamma-ray spectroscopy48 confirms the occurrence of significant levels of natural radioactivity responsible for49 metamictization in the investigated zircon samples. Results from XRD, PALS and PAC50 analysis confirm that the metamict state of zircon is a dispersion of submicron disordered51 domains in a crystalline matrix of zircon.