Use of multivariate and neutron activation analysis on studying element interrelationships in Brazilian phosphorite

Methods to determine U, Th, and other constituent elements in mineral matrices through Instrumental Neutron Activation Analysis (INAA), have been widely utilized due to their capability to extract a large quantity of information from small samples. In the present work, an experimental methodology based on INAA associated to the cluster statistics technique was used to determine the uranium concentration and its correlation with other elements present in the mineral phosphorites from the northeast region of Brazil. Data for 22 elements including rare-earth elements are presented. A good correlation between uranium and rare-earth elements is observed. For the transition metals, correlation with uranium was not noted.