JPS5832150A - Measuring device for measuring concentration of one element in sample and its method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved apparatus and method for elemental analysis based on the simultaneous measurement of the intensity of two or more neutron-induced r-rays from different elements in a sample. These intensities are processed together to obtain a high-density 1[K element abundance ratio that is essentially unaffected.

This method is particularly applicable when either (&) one element is at a fixed or known concentration, or (b) the correlation between two elements in the sample is known. Preferred applications of this technique include the analysis of sulfur in lead sinter feed ores, concentrates and return ores, and the moisture analysis of coal and other organic materials.

When a sample is irradiated with accelerated neutrons, these neutrons react with the sample and generate prompt i-rays mainly through inelastic scattering and thermal neutron capture. Thermal neutron capture also results in delayed r@O emission due to the formation of unstable nuclei. These prompt and repeated r@ strong TO measurements can be used for elemental analysis of stationary samples or on-line analysis (e.g. run-run analysis). Regarding work in this field, it is possible to do that of ores on a pair of belts, recently Nargolvallae
8eL other "' N**1sar M@th@d in
Mineral Exploration and P
roda@tlem (neutron method in ore exploration and production)”, edited by JaG* Mars@ (Elsevier 1. Amsterdam, 1977), p. 113, and B@rry
aP @ to @ and Mar t l na T -C
@emdv.

Mu@tlvatlonmu nalyais i (1972
It was reviewed in 1989.

Accurate elemental analysis often requires a correction method for r# yield due to variations in density! become. The correction method includes Gesaml, T.
Other ANL-79-62,266, also! l5la@s.

R*J* M@ms@ng@re人, J++e and Mi
l*se JeG-Proe, Awgtralas
, lm5L Mis@lI@tall@3i4(19
Separate measurements of rIl propagation reported in 17; US Pat. Nos. 4,314,156 and 541W@rb7*
B-Do's Nn5l@ar Imstrmmsm
ta andM@th・da, 160 (1979)
173#C specified nine [match・d]
Another measurement of Jr-ray backscatter; and St@vart
R, F'** Hall, person.

W,,Martim,J,W,s 1Farrior
+W*L** and Fast@n, AaM, U, S*
Bur@am at Min@sTeahmi@al
Progr@ms Rspert 74 e 1974
January, also HalLA, W, e Martil J, W
, 8t@vartR,F, and P@stem,A,M
, U,L Bur@au @fMinss Repo
The r-line spectrum reported in rt IIM-R1-8038 (197) includes normalization to all other peaks.

The one reported by St. Tart et al. is the closest to the concept of the present invention, which concerns the development of a neutron capture method for on-line analysis of sulfur in coal. and measure sulfur using 5,42 MaV thermal neutron capture r-rays from sulfur. One method used to correct for changes in moisture and density is to normalize the measured sulfur r-line yield to the region of the 222M VH capture peak.

However, with this method alone, l/11! Element abundance ratios that are not affected by IK will not be measured. For example, ash content 20
Consider a coal containing vtl e moisture Ovtl, H4vtl, if the moisture increases by 5 vtlK, the hydrogen content in the sample will increase by about 4.5wt1GK,
Similarly, if the ash content increases to 25 vtlG, the hydrogen content will decrease by about 3.75 wtlG, in fact St@vart acknowledges that hydrogen standardization did not improve the accuracy of measurements. There is.

The above description primarily relates to online and high-level analysis of samples. Another field of application is the use of neutron techniques in elemental analysis.
Ca1dv@lL R, La and others are “N+a@l@arT
s@hniqn*m and Min@ral R@m
omr@*s'(1'ra*.

8ymp, Δ-Zinnia, 1977), I Mayuzumi A, Parkinia (1977), 3) [K-reported,-
This is Ahole logging. In this field, techniques have been developed to measure elemental ratios (Jl[/oxygen and silicon/calcium) to identify oil/water ratios in porous rocks. This technique relies primarily on inelastic scattering of neutrons. However, this technique does not use K to obtain the concentration of the element.

The measured flux F1 of prompt gamma rays generated by neutron interaction in the sample is determined by the equation: % Formula % (1) [where φ(r) = neutron flux r = radial distance from the neutron source and detector = Number of gamma rays generated per neutron interaction in element l Density N0 = Gadro's number Ci = Concentration A of element l = Element 1 OM quantum town = Neutron cross section f (μr) = μ and rO Function (-2r-ray absorption coefficient) ■=Volume (under consideration)] It is given by: This equation is valid for both inelastic neutron scattering and thermal neutron capture.

As a first approximation, the ratio of the measured γ-ray yield F1e F'J is given below in the margin. This equation is accurate for two similar energy r ll1K')v% generated by the same interaction process (i.e., inelastic scattering or neutron capture), but if the gamma rays are generated by different interaction processes. If that's the case, it's a mistake
is rising. Since the value line element 1゜j of n, σ, and mu is known, if cj can be known, F l/F
C1 can be derived using the J ratio.

The result is reduced to 1 as a good approximation! 4, which does not depend on F degree.

In general, it is difficult to determine an accurate one-ray yield that is not affected by Pa, Kuglaun PK, and the following relational expression: % Formula % (3) [In the formula, "eb + @ is a constant]" should be used. I can do it.

Therefore, using this method, if the aK of one element is known, or if the relationship between elemental concentrations is known, it is possible to perform a high-density [K-independent measurement of can.

The method and apparatus of the invention find particular application in the determination of moisture O in coal. The most common nuclear method for moisture determination is the International Atomi
@En@rgy Agency+”N@wt@r@n
M11tur*Gaug@s', T@@h, Rep
ort S@ries A 112+IAEA, Vienna, based on the deceleration effect of accelerated neutrons due to hydrogen in a sample, reported in 1970. This method is relatively suitable for many applications as long as the effects of density and matrix are compensated for on the results. However, the neutron moisture measurement method (n@utron) based on this principle
moister・glg・) cannot distinguish between hydrogen in coal and hydrogen in water.φCoal contains about Svt, 1vt
1 of water contains only 0.11 vtl of H, so changes in the hydrogen content of the coal must be very small for accurate moisture measurements.

One method for measuring moisture in lump coal samples is described in U.S. Pat.
314155 and 80W@Tb7a
B*De is Nwal@ar Ilstrwm*mts
andM@thods* 1 mutual 0 (1979) 173
The neutron gauge method and sign r-ray backscattering tr-
It involves accurate determination of carbon and hydrogen using the dimethod. However, if carbon and hydrogen analysis is not required, the moisture line in the coal can be compared with the one-line backscatter gauge method (a match@dr-rayba*kse) using this method.
att@r ga+H@).

This simplifies accurate measurement of moisture in coal.

In this preferred method, moisture is determined essentially based on the O deviation of the measured carbon/hydrogen ratio from that of dry coal. Published 112C) Analysis of Australian black coal, Jolnt C@al Il@ard/Qt+s*
n5land Coal BersL All5tr@
11mm lla・kCoals R@port, 1
According to September 1976, the ratio of dry coal was 16.45±1
．． It is 78. The deviation from this ratio is a considerable decrease in p for coal from a particular thin layer:'·t.

, the moisture change in lvt ratio is approximately 2.8 relative (
It will be changed within Sorry r@1atima@).

Therefore, the present invention is a measuring device that quantitatively measures the concentration of an element in a wrinkle in a sample containing one element and another element, and which includes thermal neutron capture or neutron non-capture by atoms of the one element. a source of neutrons having sufficient energy to generate one gamma ray by elastic scattering and another r-ray by thermal neutron capture by atoms of said other element or by inelastic scattering of neutrons, said one r-ray and said detection means adapted to detect other r-rays; shielding means assembled to said detection means and for reducing the intensity of the r-rays and neutrons of the direct radiation source; A measuring device is provided, comprising energy analysis means adapted to distinguish between one r-ray and said other one line, and calculation means for calculating said concentration, coupled to the output of said energy analysis means.

Similarly, the present invention relates to (1) one r generated by thermal neutron capture or inelastic neutron scattering by atoms of one element;
@(1) Measurement and scratches) 9 Other r caused by thermal neutron capture or inelastic neutron scattering by atoms of other elements
Provided is a method for quantitatively measuring the #1 degree of an O element in a sample containing one element and another element, the method comprising combining the results of at least one measurement of the lines.

Suitable neutron sources include various beryllium-based (α, 1) neutron sources (e.g., plutonium 238/1
1., Radium 226h., Americium 241/B@
, geltonium 239A・, boronium 210/11・
, actinium-22 '178·), spontaneous fission neutron sources (e.g. californium-252), and (d, r
), (a, d) includes a neutron generator that utilizes reactions.

Suitable r-ray detectors are scintillators, n detectors, e.g.
aI(Tt) e C5I(Na), l'luma-limate bis is, and solid state detectors, e.g. G.(Ll),
＾Contains gender G.

Suitable neutron shields include thermal neutron absorbers such as boron or lithium. The shielding between the neutron source and the detector, which similarly contains hydrogen that slows down the neutrons into thermal energy, is primarily used to reduce the flux of neutron source gamma rays reaching the detector. be. Suitable materials are dense metals such as tungsten, lead, and bismuth.

The signal from the detector is processed by Grian! before being supplied to the energy analysis means (energy analyzer). or gain stabilization, the energy analyzer is preferably a hard-wired multichannel analyzer (e.g. H@v
l@tt-Pa@kard 5401B+Canb@r
ra model 3(L 3L 40e 8(L N
m5l@armot@l 60.600s 660).

Optionally, it can consist of an analog-to-digital converter (either Wil-Central Sonnteig or continuous approximation) connected to a combiator, or it can consist of a series of single-channel analyzers.

The calculation means for calculating elemental concentrations from line measurement count rates is preferably a combination calculator, preferably a combination calculator, which would be PDP 11103.

Preferred embodiments will be described below with reference to the drawings.

The method of the invention was tested by measuring the moisture content of coal samples using the experimental setup shown in FIG. In this device, a neutron source l (for example, “@Pu −1ie
) emits a 4.43M@VOr beam and a neutron, and the neutron enters the sample 3° (for example, a coal sample) through a path such as 2, which hits the atom of the element at the 40th position, causing r It generates @, passes through a neutron shield 6 according to a path such as 5, is further blocked by another O shield 8 from the neutron source 1, and reaches a detector 7.

Suitable shielding 6#i boron dioxide, which blocks the detection a7 from scattered neutrons, while tanodasten, lead, bismuth would be suitable as a shielding 8 to shield the detector 7 from the neutron source l, suitable detection , if! 7 is a crystal with a diameter of iso×a thickness of 100−0 NaI (τt).

NaI of the neutron device (from the Tt crusher is amplified using the OΔRussian stabilizing amplifier 9, and ■・wl@tt-Pa
gk@r4541OB-v Lute Channel Anatsuide 1
0 was supplied. A pulse height spectrum #O window was defined, and the count rate and ΔTsukugakukunr were determined. deaf/
4. The high spectra are shown in the 3rd wA.

Element concentrations were calculated from the count rate measured with PDP 11/30 Combi-Yu 11.

If the sample being analyzed is of substantially uniform thickness, the neutron source and detector may be placed on either side of the sample.

In FIG. 2, curve B and Cti are 10 and 50 times larger than curve A. Beak 19 is 1.78
M5V81.20 is 2.22 M@V H, 21U3,
92 M*V “C escape, 22 Ha4.43 M@V
The peak of @3.92 M@V representing C is the escape of one 0.51↓M@v annihilation r-ray from the r-ray interaction with 12c of 4,43 M@V in the detector. This is caused by K.

Figure 3(a) shows 2 glotted against water in a chemical experiment.
, 22 shows the pure count rate of r-rays due to M@VOH capture. These results were obtained using a coal sample with water added, and then changing the high density by a predetermined amount through compression treatment.*2.22 The count rate of M@V has a correlation with water. It shows that there are almost no. However, if the water content is 2, 22 M using equation (3)
@V (DH If there is a correlation with the measured intensity of both r-rays due to H capture and r-rays due to C inelastic scattering of 4,43M@V,
The moisture content is 0.36 vt as shown in Figure 3).
It can be determined within a reasonable deviation. Neutron and r-ray backscatter method, US Pat. No. 4,314,155 and 8*v@rb
y* B, D** )iw@1@arImatrt+m
@nta and M@th@ds+ 160* (1
Even if you use 979$) 173, you cannot get the correct name *a.

The method of the invention can be used for the determination of moisture in all organic materials, such as agricultural and forestry products where the dry Φ1 ratio is fairly constant (eg wood, cotton, wheat).

The method and apparatus of the present invention can also be used for the analysis of sulfur in molten lead samples. In many lead melting factories, lead ore is processed in a sintering machine before being melted in a blast furnace. Extending on-line sulfur measurement of sinter feed ores is particularly useful to achieve better control of bulk size and sintering machines.

In this application, the lead concentration is approximately 5% (regret r@1ativ@
), which is theoretically suitable for the technique of the present invention. Sulfur (2,23M@V) and lead (2,6
The energies of the r-rays due to significant inelastic scattering from 2M·■) are sufficiently similar that equation (2) is an accurate approximation.

The method was tested in a neutron setup similar to that shown in Figure 1 using nine sample tubes of sintered feed, concentrate and return ore from the Isa mine. The results in Figure 4 are 2.23 and 2.6.
0.24 vtl of sulfur using a γ-ray intensity of 2M@V
It shows that the scales are determined within the deviation of . By comparison, the root mean square deviation between sulfur content and 2.23 M@V yield alone was 0.6 vt. Sulfur and 2-23M@V*l with r-ray backscatter US Pat. No. 4,314,155
The root mean square deviation was 0.5vt'1g.An analysis method using r-rays captured by neutrons of 5.42 M@V from sulfur is also optionally possible.

[Brief explanation of drawings]

Figure 1 is an orthogonal cross-sectional view of the device used in the measurement according to the present invention, Figure 2 is a wave height spectrum diagram obtained using the device shown in Figure 1, and Figure 3 (&) is a diagram of moisture in a chemical experiment. Against fa mitsuta 2
, Figure 3(b) shows the pure count rate of γ-rays due to H capture of 22 MeV, 2.22 M@VOH
Figure 4 shows the chemical experimental water content plotted against the measured intensities of both γ-rays due to capture and γ-rays due to inelastic C scattering of 4.43 MeV. Figure 3 shows chemical experimental sulfur plotted against the measured intensity of both gamma rays and 2.62 M@VOPb inelastic scattering gamma rays. DESCRIPTION OF SYMBOLS 1... Neutron source, 3... Sample, 6.8... Shielding means, 7... Detection means, 9... Amplifier, 10... Analyzer, 11... Calculation means, 19. ...1.7
8 M@V81.20 ”・2.22 M@VH, 21
-3,92MeV C escape, 22・” 4.43 M
eV Ceh The following margins are 4 (keto CWf'/,) FIG, 4 □. Procedural amendment (method) % formula % 1. Indication of the case 1982 Patent Application No. 077634 2. Name of the invention Measuring device and method for measuring the concentration of one element in a sample 3. Case of the person making the amendment Relationship with Patent applicant name: AustClean ATZTSUKU ENERGY CONTSUSHICIN 4゜ Agent (3 others) 5. Date of amendment order: August 31, 1980 (shipment date) 6. Subject of amendment (1) ) l! 11111B (2) Drawing ($3 figure) 7. Contents of amendment (1) Engraving of specification (no change in content) (2)
Drawing (Fig. 3) t-Correct excessive number of attached sheets 08, #& 0 of attached documents

Claims (1)

[Scope of Claims] 1. A measurement device for quantitatively measuring the concentration of one element in a sample containing one element and another element, which captures thermal neutrons or neutrons by atoms of the one element. A neutron O having sufficient energy to generate one r-ray by inelastic scattering and a thermal neutron m1lI by the atoms of the other element or another ray by inelastic neutron scattering.
a source, detection means adapted to detect the one R-ray and the other R-ray, and shielding means assembled to the detection means for directly reducing the intensity of the R-rays and neutrons of the radiation source; energy analysis means coupled to the output of the detection means and adapted to distinguish between the one rlm and the so@or@; and calculating the concentration, coupled to the output of the energy analysis means. a measuring device comprising calculation means. λ The neutron source is based on a beryllium target (αt
n) The measuring device according to claim 1, which is a neutron source, a spontaneous fission neutron source, or a neutron generator that utilizes (1, T) and (d, d) reactions. 3. The (α, n) neutron source is Pm/Be 122'
Ra/Be, 24'Am/Be, ``'Pu/B
Claim 2: A ship-mounted measuring device, in which: The measuring device according to claim 2. The O measuring device according to any one of claims 1 to 4, wherein the detection means is a scintillation detector or a solid state detector. 6. The scintillation detection Power aI (TL). Cm (TA), C5I (Na), or) f #
w = bismuth lamite, the measuring device according to claim 5. 7. The measuring device according to claim 5, wherein the solid-state detector is G.(Ll) or intrinsic r-rumanium. 8□ The measuring device according to any one of claims 1 to 7, wherein the energy analysis means is a multi-channel analyzer, an analog-to-desomer converter, or a plurality of single-channel analyzers. 9. (1) One o r l1l generated many times due to thermal neutron capture or inelastic neutron scattering by atoms of one element
t) measurements and (ii) other r generated (by thermal neutron capture or inelastic neutron scattering by atoms of other elements).
A method for quantitatively measuring the concentration of one element in a sample containing one element and another element, the method comprising measuring at least one of the lines and processing the zero results together. 10. The method according to claim 9, wherein the sample is coal and the one element is hydrogen or sulfur. 11. The method according to claim 10, which quantitatively measures water content using hydrogen content measurement. 12. @The sample is lead sintered feed ore (1ead 51st
1. The method according to claim 9, wherein: @rf..d) and said one element is sulfur.