A scheme for the complete elemental characterisation of brannerite mineral using ICP-AES

Brannerite occurs along with other refractory minerals in pegmatite veins. Literature survey indicates lack of systematic and detailed chemical analysis procedure for brannerites. This paper report suitable sample decomposition procedures, yielding stable sample solution, suitable for the ICP-AES determination of major, minor and certain trace elements normally associated with brannerite mineral. Three different simple decomposition procedures such as (i) acid digestion (ii) fusion with lithium metaborate (iii) fusion with mixture of tetra sodium pyrophosphate and monosodium dihydrogen phosphate are used to obtain the sample solution for elemental analysis. In presence of higher concentrations of uranium and titanium, the major elements in brannerite mineral, a detailed study of the influence of uranium and titanium on ICP-AES determination of other elements, three commonly used emission lines of each element was carried out. The REEs, Y, Sc and Th have been determined after the removal of major matrix elements using oxalate precipitation. The accuracy of the proposed procedures is established by analyzing synthetic brannerite samples prepared by mixing high purity oxides or chlorides in a proportion similar to natural brannerite samples. The results indicate the method is accurate. The reproducibility studies carried out on one sample shows the % RSD varied from 2 to 5%. (author)