Development of Methodologies for the Chemical Quality Control of Zircon, A Precursor for Zirconium Production

Abstract

Methodologies have been developed for the chemical quality control of zircon mineral by EDXRF and D.C.Arc carrier distillation technique. EDXRF technique was found to be preferred for major and minor constituents including non‐metal analytes, while D.C.Arc carrier distillation OES was found to be good for minor and trace metallic constituents including low Z elements. A comparative evaluation of the analytical performance (detection limit, sensitivity, precision, linear dynamic range) was performed. A multipoint standardization was carried out using the base material of 1 : 1 SiO2 : ZrO2 powder mixture to establish calibration curves for the analytes after identification of interference free and the best performed emission and X‐ray analytical lines. In zircon sample, Si, Zr and Y were found to be present as major constituent, with Ga, Ca, Ru, Rh, Fe, Mn, Mg, I, S as minor and Zn, Cr, Sn, Li as trace constituents. The total uncertainty of the EDXRF measurements was evaluated. The statistical t‐test analysis was carried out for 10 degrees of freedom with 95 % confidence interval. The experimentally obtained t‐values were found to be lower compared to the corresponding tcri value revealing the reliability of the measurements. Elemental distributions of the analytes were also investigated using five different zircon samples.

Utilization of ionic liquids for preferential separation of thorium during the determination of trace metallic constituents in thorium matrix using ICP-OES

“…The t -value for each analyte was calculated as described in the literature. 17,19 For N = 10 and at 95% confidence level critical t value ( t critical ) is 2.228. The experimentally obtained t value for Cu, fe, Mg, Ni, Pb, and Zn were 1.5 and below, whereas that for Ca, Co, Na, B and Cd were in the range of 1.5–2.0.…”

“…The variance F is basically the square of the experimentally obtained standard deviation values. 17,19 For N = 10 and at 95% confidence limit, critical F value ( F critical ) is 2.98 ( F c ). The experimentally obtained F values for Ca, Co, Cr, Fe, Mg, Mn, Ni, Zn, were found to be less than 2, while those for Al, Cu, Na, B, Cd, Ag, Eu, Gd, Dy and Sm were greater than equal to 2.…”

“…10–14 Though in D.C.Arc atomic emission spectrometry, where solid samples are directly analyzed; physical separation is performed in terms of distillation of analytes in the presence of a suitable carrier such as AgCl. 15–20 However, D.C.Arc carrier distillation is having poorer analytical performance with respect to detection limits, linear dynamic range, sensitivity and more predominantly with respect to precision (in comparison with ICP-OES). 15,16 Due to the arc wandering and other individual arc characteristics, the precision in D.C.Arc AES is in the range of 15–25% compared to less than 5% precision of ICP-OES.…”

Optimization of external (in air) particle induced gamma-ray emission (PIGE) methodology for rapid, non-destructive, and simultaneous quantification of fluorine, sodium, and phosphorus in nuclear waste immobilization matrices

“…The Jordan valley EX 3600 M spectrometer procured from Israel was used in the experiment. 36,37 The spectrometer contains a Rh source and Be window. Samples were irradiated with X-rays at room temperature.…”

The standardization and application of an external (in air) particle induced gamma emission (PIGE) method for the rapid and non-destructive quantification of light elements at major to trace concentrations in coal, bottom ash and coke samples

“…Hence, chemical quality control (CQC) exercises have become a pre-requisite before the use of coal in power plants and the disposal of coal ash. Several classical and instrumental analytical methods have been utilized for the quantification of low Z -elements in solid materials, including graphite furnace atomic absorption spectroscopy (GF-AAS), direct current-arc optical emission spectroscopy (DC-Arc OES), spark OES, X-ray fluorescence (XRF), 4 and laser-induced breakdown spectroscopy (LIBS). 5 The above spectroscopic techniques are precise and accurate, having high sensitivities and wide linear dynamic ranges with low detection limits.…”