SU1078297A1 - X-ray spectral analysis method - Google Patents

Abstract

The REPTGENOSPECTRAL ANALYSIS METHOD, which consists in simultaneously fusing the test sample and the comparison sample, which has known contents of the analyzed and interfering elements, with the flux, measures the intensities of the analytical: analytical lines of the analyzed elements in the test sample and the comparison sample, determine the ratio corresponding intensities, excitation, absorption and mass changes of the sample during fusion, taking into account which determine the concentrations of the elements being analyzed, which differ In order to improve the accuracy and rapid analysis, before fusing the test sample and the comparison sample are mixed with a refractory powdery substance that does not contain the elements to be analyzed, the intensity of the analytical line of one of the elements of the introduced substance is measured with energy sufficient for independence the intensity of its analytical line on the particle size of the sample, and the coefficient of change of the sample mass during fusion is determined by comparing the intensities of the analytical line of this element REFERENCE substance before and after the test sample with a fusion flyussm.

Description

The invention relates to the field of chemical and physical studies of the properties of substances, in particular, X-ray fluorescence analysis, and can be used in the exploration of deposits, at the stage of technological studies of the enrichment of mineral raw materials and the extraction of useful components from it, as well as in geochemical and mineralogical studies. A known method of X-ray fluorescence analysis is that the sample is irradiated with a primary x-ray flux and quantum fluxes are recorded coherently and incoherently of the assay characteristic of the x-ray tube and are measured by standard samples for each detectable (analyzed) element Correction factors are determined, which take into account the desired C13 contents. However, this method is not sufficiently effective, since not all the materials of the anode are not ntgenovskoy pipes ki at X-ray analysis is possible to obtain intense coherent and noncoherent tube anode lines required for determining analytes NIL elements. The closest technical solution to the invention is method 2 of an X-ray spectral analysis, concluding that at the same time fusing the test sample and a comparison sample having known contents of the analyzed and interfering elements at the same time, with flux, measure the intensities of the analytical lines of the analyzed elements in the test sample and comparison sample, determine the ratios of the respective intensities, the excitation, absorption and mass change coefficients of the sample during fusion, taking into account determine the concentration of the analyzed elemental samples based on the expression (pr / - 3 where Cjjp is the concentration of the element being analyzed in the sample; C is the concentration of the element being analyzed in the comparison sample; Jpjp is the intensity of the analytical line of the element being analyzed being in the sample; J is the intensity of the analytical the lines of the element being analyzed are in comparison with the sample; k is the excitation correction factor; Ku is the absorption correction coefficient; K is the correction coefficient for changing the sample mass during fusion, equal to and (1-pp1) s (1-ppg} where N is the sample weight; Ng is the flux load; PP1 is the loss on ignition of the sample; PP2 is the loss on calcination of the flux. Disadvantages of the known The method is characterized by low express speed and accuracy of the analysis, since to determine the concentration of the analyzed elements, additional operations are required for the calcination of the sample and flux, the conditions of which are not identical to the conditions of fusion. The goal is achieved in that according to the method of x-ray spectral analysis, which consists in simultaneously fusing the test sample and the comparison sample, which has known contents of the analyzed and interfering elements, with the flux, the intensities of the analytical lines of the analyzed elements are measured in the sample and comparison sample, the ratios of the respective intensities, the excitation, absorption and mass change coefficients of the sample during fusion are determined, taking into account The concentrations of the analyzed elements, before fusion, the test sample and the comparison sample are mixed with a refractory powdery substance that does not contain the analyzed elements, the intensity of the analytical line of one of the elements of the introduced substance is measured with energy sufficient for independence of the intensity of its analytical line from the particle size of the sample, and the coefficient changes in sample mass during fusion are determined by comparing the intensities of the analytical line of this element of the introduced substance before and after fusion test sample with flux. The essence of the proposed method is as follows. The pre-test sample and the reference sample are mixed with a refractory powdery substance that does not contain the elements to be analyzed, and a flux. The intensity of the analytical line of one of the elements of the introduced substance is measured, which has an intensity of analytical line that is independent of the particle size.

samples. For the independence of the intensity of the analytical line from the particle size of the sample, the energy of this line must be large. Then, the resulting mixture and a reference sample containing known concentrations of the analyzed and interfering elements, mixed with the flux, are fused and the intensities of the analytical lines of the analyzed elements and the intensity of the same analytical line of the element of the injected powder are measured from them, which was measured before the sample was alloyed. . The ratios of the respective intensities of the analytical lines of the sample and sample elements are calculated, the excitation, absorption correction factors and the mass change coefficient for fusion, the latter by comparing the intensities of the analytical line of the element of the introduced substance before and after the lazy alloy. Taking into account the coefficients obtained, the intensity ratios of the analytical lines of the analyzed elements and the known concentrations of the comparison sample, the concentrations of the analyzed elements of the sample are determined.

ABP C (Jnp / J) K -K2Kg;

-i jn. . . l

J-L / CL 5; PCh VsinV sin

de D is the intensity of the analytical line of the element of the introduced substance in the sample prior to fusion;

2 the intensity of the analytical line of the element of the introduced substance in the sample after fusion;

ju. .. is the mass absorption coefficient of the primary radiation in the mixture of the sample substance, the flux and the substance introduced before fusion;

(i) - is the mass absorption coefficient of the analytical line of the introduced substance in the same mixture after fusion;

 - angle of incidence of the primary x-ray radiation;

1 is the angle of selection of secondary radiation.

Example. Take 1 g of the powder sample, crushed to a particle size of 300 MBiu, add 1 g of the powdery substance and 6 g of flux - lithium metaborate and mix for 5 minutes in an agate mortar. The resulting mixture is poured with a seal into a metal cup having a depth of 5 mm and a diameter of 40 mm. The cup is placed in the cuvette of the CPM-18 X-ray multichannel spectrometer and the intensity of the ana lytic line is measured, at a voltage of 25 kV, current Bhpg of the BHB-13 X-ray tube, it is equal to 4265 impulses / s. -1A in the amount of 1 g and 1 g of NbjOc. 6 g of lithium metaoorate flux is introduced into the mixture. Next, take 5 g from each prepared mixture and each of them is fused in graphite crucibles (30 mm in diameter) in a muffle.

oven for 5 min. The obtained melts are cooled to room temperature and the measured g-intensity of the analytical lines: QC, - CaK, - TIK, FeK

- and additionally, from the melt of the sample, the intensity of the analytical line NbKjj, which is equal to 4377 counts / s, is measured.

Measured from sample melt and sample versus intensity

The 0 analytical lines of the elements analyzed determine the corresponding ratios and intensity ratios of the NbK analytical line before and after fusion of the sample. Then by

5, the known excitation and absorption correction factors (K K) are determined by a known technique. The coefficient of change of the sample mass during fusion of K at fl / and is determined. concentration of the analyzed elements of the test sample.

The results of the analysis for the known and proposed method are given in the table.

The proposed method allows.

5 to improve the accuracy of the analysis by determining the change in sample mass during fusion and to increase the rapidity. The time of analysis by the proposed method is significantly less than that known, where it is equal to several hours due to the fact that it is necessary to determine the loss on ignition. In addition, the proposed method is cheaper than the known one, since it allows the use of crucibles from cheap non-inert materials, such as graphite, to fuse 1 samples containing elements of variable valence, like S, V, Cr, etc.

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Claims (1)

METHOD FOR X-RAY SPECTRAL ANALYSIS, which consists in simultaneously fusing the test sample and the comparison sample having known contents of the analyzed and interfering elements with flux, measure the intensities of the analytical lines of the analyzed elements in the test sample and the comparison sample, determine the ratios of the corresponding intensities, excitation coefficients, absorption and changes in the mass of the sample during fusion, taking into account which determine the concentration of the analyzed elements, characterized in that then, in order to increase the accuracy and expressness of the analysis, before fusion, the test sample and the comparison sample are mixed with a refractory powdery substance that does not contain the analyzed elements, the intensity of the analytical line of one of the elements of the introduced substance is measured with an energy sufficient for independence of the intensity of its analytical line from the size particles of the sample, and the coefficient of change in the mass of the sample during fusion is determined by comparing the intensities of the analytical line of this element of the introduced substance before and after fusion of the test sample with flux.