X-Ray Fluorescence Determination of Ore Elements in Ferromanganese Formations

Elemental analysis of ferromanganese formations (first of all, the determination of ore elements) is a necessary stage in the development of ore deposits. A technique for X-ray fluorescence quantitative analysis was proposed for the determination of iron, manganese, cobalt, nickel, copper, and zinc in oceanic ferromanganese formations (nodules and crusts). The studies were performed using a S4 Pioneer wavelength-dispersive spectrometer equipped with a LiF (200) crystal and a scintillation detector. In order to plot the calibration curves, sets of certified reference materials such as ferromanganese nodules, cobalt-bearing ferromanganese crusts, and pelagic sediments previously dried at 105°C for 24 h to remove hygroscopic moisture were used. Two sample preparation techniques were compared: pressing of powder samples with the use a boric acid substrate and homogenizing via fusion with lithium tetraborate at a ratio of 1 : 30 in an electric furnace at 1050°C. For each sample preparation technique, spectral overlaps and matrix correction methods (theoretical and empirical) were considered, and optimal calibration curves for determining ore elements were chosen. The accuracy of the X-ray fluorescence technique was assessed via analyzing a reference material FeMn-1 with a certified content of ore elements and a reference ferromanganese nodule sample preliminarily analyzed using a PerkinElmer M403 atomic absorption spectrometer. Both homogenization via fusion and analysis of pressed samples provide quantitative X-ray fluorescence determination of the main ore elements and can be used to assess the industrial significance of oceanic ferromanganese formations.