SU1315880A1 - Method of absorption x-ray analysis of ore - Google Patents

Abstract

The invention relates to a method for analyzing a substance analysis and can be used in mineral processing plants. The aim of the invention is to improve the accuracy of determination by taking into account the influence of the ore surface density and the inconsistency of the material composition of the filler on the results of the ore analysis on the content of the element being determined. The proposed method of analysis includes scanning the examined layer with y-radiation of three different energies, two of which are close in value and lie on both sides of the K-absorption edge of the element being determined. To achieve the goal, a third of the energy is selected in the area where the dominant interaction process is Compton Effect. The flux intensities of - and-radiation from at least one source are measured before and after the passage of the ore layer under investigation. Using the quasi-stability of the type of dependence of the mass Compton-effect coefficients on the energy of v-quanta for the filler components, find the ratio of the mass photo-absorption coefficients for energies close to the K-absorption edge of the element being determined. According to the found relation, the concentration of the element being determined in the ore is judged, table 3. i (L O1 00 oo o

Description

The invention relates to a method for analyzing a substance analysis and can be used in mineral processing plants.

The purpose of the invention is to increase the accuracy of determination by taking into account the influence of the surface density of the studied layer and the inconsistency of the material composition of the filler on the results of the analysis.

The method is carried out as follows.

The layer under study with a density j and thickness t is illuminated by three beams of gamma radiation with energies E, E ", Eg, the values of which satisfy the CONDITION:

E, "EZ 1.022MeV, (1

EC

where E is the K-absorption energy of the element being detected.

For example, to determine tungsten, the K-edge absorption energy of E is 69.5 keV, condition (I) is satisfied by the energy of E lines 60 keV (Am Ej 88 keB (E cd) and EZ 661 keV).

Sources Cs, 241 Al and placed in a narrow collimation channel of the collimator sources. The spectral intensities in the energy intervals corresponding to the photo peaks of lines 60; 88, and 661 keV in a non-attenuated beam and in a beam that has penetrated through the layer of material being analyzed, are measured with a scintillation detector located in a collimator. The scintillation detector consists of a 30x20 mm Nal (Tl) crystal and a PMT-35 photomultiplier.

The spectrometer channels corresponding to the position of the photopeaks of the 60 and 88 keV lines are counted by pulses (N, H): and the counting at the peak of the incoherent scattering is 661 keV (Nj} ea time interval t.

In addition, for the 60 and 88 keV lines, corrections are introduced into the measured account, taking into account the contribution of the Compton branch of the instrumental spectrum of the 661 keV line.

N N where N% N

3.1 ZD

3.1 N;

N; N. S, z "

value1 g adjusted

impulse counting; spectral coefficients previously determined by the instrumental spectrum of the line

661 keV, measured in the absence of sources

a3, 1

where is NJ

N.

 and

Nld and N3 Nj account in the photopic of the 661 keV line;

and N, - accounts on Compton branch, з, г

The instrument spectrum of the 661 keV line in the spectrometer channels corresponding to the position of the photo peaks of the 60 keV and 88 kzV line.

The shape of the instrumental spectrum of hard gamma lines, when measured in the ideal geometry of a narrow beam, does not depend on the properties of the sample, but is determined only by measuring parameters.

system.

Measurements are also made of the intensity of the three-energy radiation fluxes before passing through the ore layer under investigation.

Cement bars with a known tungsten trioxide content varying from 0.1 to 3.5% and a surface density varying from 8.8 to 12.0 g / cm are used as the analyzed samples.

For the main rock-forming elements, an analytical parameter is determined, which is proportional to the ratio of the mass absorption coefficients for the energies to the right and left of the K-edge, which is the concentration of the element to be determined, which serves as a measure of the concentration of C;

Taking into account that the weakening of the line with the energy Ej occurs only due to the Ko1 ston-effect, for the intensities of the three lines in the beams coming out of the layer, one gets

I, lo expHCf l + 1 Logor {- (| and | +) j) jj;

0

Where

1з lot

I "exp - (. E) J, I

-02

1g

Shat

N, and 1

five

 and the intensity of each line in the unmitigated beams; mass photoabsorption coefficients at energies E and the total mass attenuation coefficient at energy EJ.

The mass absorption ratio is found from this system.

F

fi.

 to and

,

k p-const; p - „- const

.

Ratio of Mass Factors

The Compton effect | Ug and, at energies E and E, to the total mass attenuation coefficient at energy E, do not depend on the material composition of the material under study.

The sensitivity of the analytical parameter d to tungsten and resistance to changes in the material composition of the ore-bearing rocks is illustrated in Table. 1 and 2.

In tab. 1, the values of the C parameter for the main lithological varieties of host rocks are calculated, in Table. 2 - for carbonate rocks with different tungsten contents or some interfering elements.

The stability of the analytical parameter c is estimated by measuring on samples of rocks of different material composition and surface density that do not contain tungsten.

The results of the experimental verification of the method for cement are given in Table. 3. Here, the theoretical values of the parameter d, calculated from the known material composition of the samples, are given. As oi for experimental data, the average value o / for samples of rocks not containing tungsten (marble, granite, shale, where) is calculated; for theoretical ones, the calculated values are for carbonate from table. one.

The data table. 3 indicate the stability of the testimony of the proposed method to changes in the material composition and surface density of the analyzed samples. The experimental sensitivity of the method coincides with its theoretical evaluation.

Claims (1)

Invention Formula An absorption X-ray analysis method for ores, comprising five 0 the scanning of the investigated ore by t-radiation of three different energies, the values of two of which are close to the energy of the K-absorption edge of the element being detected and are located on opposite sides of it, which is equivalent to. By the fact that, in order to increase the accuracy of the determination by taking into account the influence of the surface density of the ore and the inconsistency of the material composition of the filler on the analysis results, the value of the third energy is chosen in the area where the dominant interaction process is Compton effect the J-radiation fluxes measured before and after the passage of the ore under study are determined by the ratio of the mass photoabsorption coefficients for radiation beams with energy from the left to the right ot the energy of the K-absorption edge determined by element of the formula and Where five 0 five The photoabsorption ore of 1 - quanta with energies E and E, and E: E,; K and P - quasistable for the main breeds x of the elements of the ratio of the mass coefficients of Compton effect at energies E and El to the total mass attenuation coefficient for V-quanta of energy E .; 0 H -g I. 02 055 the intensity of the beams of LL radiation with energies E, E, EJ after passing through the ore; the same, before the passage of the ore, according to which the concentration of the element being determined in the ore is judged. Table D 13158808 Continuation of table 2 with 0.1% W 0.151 0.053 0.3511.114 with 0.5% W 0.163 0.077 0.4721.498 from 2.0% W 0.209 0.1687 0.8042.552 Cement properties Table 3