CL. Analytics

X-RAY SPECTRAL FLUORESCENCE ANALYSIS

Silicate analysis is performed using fused tablets: the analyzed sample is mixed with flux (50% lithium metaborate and 50% lithium tetraborate) in a ratio of 1:9; the mixture is melted in gold-platinum crucibles on the Classe Fluxer-Bis manufactured by Claisse Fluxer (Canada).

ARL 9800 f. ARL X-ray spectrometer is a fully automated high-performance unit with a control computer system. Tablet coordinates input device for sample presentation is designed to analyze 98 samples

In addition to basic rock-forming oxides, Ba, Cr, V content is also determined. The analysis is carried out using the ARL 9800 f. ARL X-ray spectrometer, Switzerland, following the procedure “Determination of contents of main petrogenic elements and some trace elements in rock, soil, bottom and loose sediments from pressed tablets of finely grinded source material of samples using X-ray fluorescence method", VSEGEI MP No. 14/2010, third category of accuracy.

Ranges of determined components,% wt.

Component	Range of determined concentrations, %
SiO₂ Al₂O₃ TiO₂ Fe₂O₃ MnO MgO CaO Na₂O K₂O P₂O₅	0.02 – 100 0.02 – 50 0.01 – 10 0.01 – 50 0.01 – 40 0.05 – 50 0.01 – 50 0.05 – 20 0.01 – 20 0.01 – 50
Ba Cr V	50 ppm – 2 % 20 ppm – 10 % 50 ppm – 2 %

The determination of trace elements is performed from pressed tablets: 4 g of the analyzed powdered sample is pressed into tablets of 40 mm in diameter using the HP 40 pressing machine (Herzog, Germany) with a force of 20 tons.

For chemical elements such as Bi, Br, Cs, Hf, Nb, Mo, Rb, Sr, Th, Pb, U, Y, Zr, the lower limit of determination is 2 ppm; for Co, Cu, Ni, Se, Ta, Te, Zn - 3 ppm; for As - 5 ppm.

The Fe (II) content in the samples is determined from a separate aliquot by the titrimetric method according to Instruction No. 50-X “Determination of iron (II) oxide in silicate rock, silicate and sulphide minerals by the titrimetric bichromate method”, 2006.