Quantitative analysis or rare earths by x-ray fluorescence spectrometry

• Autor(a) principal: Taam, Isabel
• Data de Publicação: 2013
• Outros Autores: Mantovano, José Luiz, Gante, Valdir, Instituto de Engenharia Nuclear
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional do IEN
• Texto Completo: http://carpedien.ien.gov.br:8080/handle/ien/2384
• topic: INAC 2013; Rare earths elements; Fluorescence spectrometry; X-ray

Rare earths ores and compounds are of growing importance to the worldwide industry. Its applications range from raw material to catalysts, manufacturing of electronics and even supermagnets. Therefore, the demand for quick and accurate quantitative analysis methods is continuously growing. Current quantification methods of rare earths involve the separation of these elements by ion exchange and liquid-liquid extraction prior to the analysis itself, processes both time and reagent consuming. In the present work, we propose a method that directly quantifies by XRF technique the following rare earths: La, Pr, Nd, Sm and Gd in a concentrated liquor whose matrix also contains Ca, Y, PO4, U and Th. We evaluated the analytical interference of each element present on the sample on X-rays spectrum. The studied samples are certified standards and the obtained results have been compared to EDTA titration results, an already well-stablished and widely trusted method. We also measured the matrix effect thus using a complex rare earths standard. Results show that quantification by XRF technique is as accurate as the results in dose titration with EDTA for the same elements, with the advantage of exempting the previous separation step from each rare earth and from other elements present in the matrix (such as U and Th).