WDXRFS Method for Quantification of Heavy Minerals in Sand Samples

Estimation of industrial and strategic heavy minerals (HMs) in sands, viz, ilmenite, rutile, garnet, sillimanite, zircon and monazite, is usually carried out by Microscopic Gram-Counting (MGC) technique on heavy Liquid- and Magnetically-Separated fractions. This method is slow, laborious, Time-Consuming, costly, toxic and causes Eye-Strain. Its precision and accuracy depend on Microscope-Operator's skills in mineral identification and preparation, by microsplitting of representative portions of fractions for analysis. Instead, we are proposing here a WDXRFS-Based relatively simple, rapid, low-cost, non-toxic, eye Strain-Free and precise method. This involves (a) magnetic separation of a sand sample into 3 Sub-Samples that are magnetic at 0 4 and 1 2 A and Non-Magnetic at 1 2 A, (b) WDXRFS analysis of these for the oxides and elements in the formulae of HMs, and (c) computation of the contents of HMs, assuming their stoichiometric composition. The contents of HMs in sand samples, determined by this method, are in general agreement with that from MGC method on natural sand samples and prepared samples, with an overall error of <20%and coefficient of correlation (r) of -0 98. Furthermore, our method gives additional information on end-member composition of garnet, Th-content of monazite and proportion of Ortho- to Clino- in pyroxenes.