XRF analysis applied to chemical quality of quartz in Argentina.

PÉREZ, DANIEL; RUBIO, MARCELO; ALDO BONALUMI,; SFRAGULLA, JORGE; LÓPEZ, ALEJANDRA; GUERESCHI, ALINA BEATRIZ; VÁZQUEZ, C.; GOZÁLVEZ, M.; LUCHESI, M.; BADINI, R.; CUFFINI, SILVIA; SPAHN, G.; INGA, M.; GERMANIER, A.; SERVANT, R.

Berlín

Conferencia; European Conference on Energy Dispersive X-Ray Spectrometry-EDXRS 2002; 2002

The growing demand for high-purity quartz in the international market led to the systematic investigation of the quality of this mineral in deposits of the province of Cordoba (Argentina). This study was the first done over the central geographic zone of Argentina, being a contribution to the scarce information on the geochemical of quartz in our country [1]. A total of 525 multielemental chemical analyses were performed with XRF spectrometry in less than three months. As a result of this study, 36 sites over 150 sampled deposits have been identified with SiO2 ³ 99.99%. XRF analyses for these sites were controlled by atomic absorption. The Si particle size effect was studied for application in x-ray fluorescence analysis of quartz. A modified Blanquet model was used to calculate the Si(Ka) intensity as a function of silicate particle size. This theoretical result was used to develop an experimental method [2] to correct for particle size effect in Si fluorescent intensity getting very suitable low detection limit for traces, reproducibility and accuracy. Geochemical results were introduced in a database map where each sample was located by satellite GPS coordinates. The analytical geochemical results allow to classify geologically the quality of quartz according to its environment and genesis. It could be determined that the high-purity quartz corresponds to veins far away from the Achala and Alpa Corral batoliths and occur in metamorphic rocks, followed by pegmatitic quartz from inside the batoliths and lastly by quartz of well-known hydrothermal origin.