On-line detection device and method for resin adsorption process elements

Abstract

The invention discloses an online detection device and method for resin adsorption process elements. The device comprises a shell, a neutron source item system, a shielding body module, a gamma detector system and a control system, wherein the neutron source item system, the shielding body module and the gamma detector system are sequentially arranged in the shell from top to bottom, and the control system is used for controlling work of all parts and analysis of detection results. Continuous neutrons or pulsed neutrons are generated through the neutron source item system, instant gamma rays are generated through interaction between the continuous neutrons and resin atomic nucleuses, quantitative analysis of non-fissile elements is achieved by analyzing energy and intensity of the gamma rays, fissile nuclides are excited through the pulsed neutrons to generate instant fissile neutrons, and quantitative analysis of the non-fissile elements is achieved. According to the method, fission nuclides are quantitatively analyzed by analyzing the intensity of the generated instant fission neutrons, the whole detection process is simple and convenient, a detection sample is not damaged by detection, and in-situ measurement and online analysis can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of element detection, and in particular relates to an online detection device and method for elements in a resin adsorption process. Background Art

[0002] Hydrometallurgical processes are often used in the mining of rare mineral resources such as rare earths and uranium. In the resin adsorption stage of the hydrometallurgical process, timely acquisition of information on the content of each element in the solution and resin is of great significance to the intelligent regulation of the hydrometallurgical process. At present, in actual industrial applications, the adsorption of elements in the resin is mainly judged by detecting changes in the element content in the tail liquid, and it is difficult to accurately obtain changes in the element content in the resin; or by taking resin samples to accurately analyze the adsorbed elements, but there are problems such as poor sampling representativeness and complex and time-consuming sample preparation process. Summary of the invention

[0003] The object of the present invention is to provide an on-line detection device and method for resin adsorption process elements to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an online detection device for elements in a resin adsorption process, comprising a shell and a neutron source system, a shielding module, and a gamma detector system arranged inside the shell from top to bottom, wherein the neutron source system is used to generate and emit pulsed neutrons, and neutron detection systems for collecting neutron time spectra in a pulsed neutron working state are arranged on both sides of the neutron source system, and the shielding module is used to slow down the absorption of neutrons and reduce the influence of fast neutrons on the gamma detector.

[0005] Preferably, the neutron source system adopts a DT neutron generator, the neutron detection system includes a He-3 thermal neutron detector and a He-3 epithermal neutron detector, and the He-3 thermal neutron detector and the He-3 epithermal neutron detector are respectively arranged on both sides of the target position of the DT neutron generator, and the gamma detector system includes a LaBr 3 detector and a BGO detector, and DT neutron generator, He-3 thermal neutron detector, He-3 epithermal neutron detector, LaBr 3 Both the detector and the BGO detector are connected to the control system through circuits.

[0006] Preferably, the shell is made of aluminum alloy.

[0007] Preferably, the shielding module is made of a boron-containing polyethylene block.

[0008] A detection method for an online detection device for resin adsorption process elements, comprising the following steps:

[0009] S1: Place the device in the resin, turn on the DT neutron generator through the control system, select the continuous neutron working mode of the DT neutron generator, and turn on the LaBr 3 The detector and BGO detector collect gamma-ray spectra for recording;

[0010] S2: Switch the DT neutron generator working mode to the pulse working mode, set the pulse working period according to the time it takes for the thermal neutrons in the resin sample to completely decay, and select the narrowest pulse width while ensuring the number of pulse neutrons. Then use the neutron detection system to collect the epithermal neutron time spectrum and thermal neutron time spectrum respectively;

[0011] S3: The gamma energy spectrum collected in step S1 is subjected to noise reduction, smoothing, peak stabilization, channel merging, and total count normalization. 3 The 0-3MeV part of the detector energy spectrum is merged with the energy spectrum of the BGO detector greater than 3MeV, forming a 0-3MeV energy region for high-resolution LaBr 3 The dual-detector fusion energy spectrum is a detector energy spectrum and a BGO energy spectrum with high detection efficiency in the energy region greater than 3MeV.

[0012] S4: Calculate the net hydrogen peak counts of the dual-detector fusion spectrum, calculate the neutron self-shielding factor using the hydrogen peak counts as the internal standard, and process the dual-detector fusion spectrum using the weighted spectral library least squares method based on the neutron self-screening effect correction model to obtain the element content of non-fissile nuclides;

[0013] S5: Under the pulse width determined in step S2, obtain the time nodes when the epithermal neutrons and thermal neutrons in the resin sample completely decay after the DT neutron generator emits neutrons in a uranium-free environment, and respectively calculate the epithermal neutron counts and thermal neutron counts in the time interval between the time nodes when the epithermal neutrons and thermal neutrons completely decay in the neutron time spectrum obtained in step S2, calculate the ratio E / T of the epithermal neutron count to the thermal neutron count in the time interval, draw a calibration curve, and obtain the element content of the fissile nuclide in the resin by comparing the calibration curve with the E / T value of the fissile nuclide solution of known concentration.

[0014] Preferably, in step S4, the neutron self-shielding factor calculation formula is: Where f is the neutron self-shielding factor of the dual-detector fusion spectrum to be analyzed, H LaBr,j and H BGO,j The dual detector fusion spectrum to be analyzed corresponds to LaBr 3 The hydrogen peak counts of the detector and BGO detector energy spectrum, H Labr,0 and H BGO,0 They are respectively LaBr measured when the resin does not adsorb elements 3 The hydrogen peak counts of the detector and the BGO detector energy spectrum.

[0015] Preferably, in step S4, the calculation process of the element content of non-fissile nuclides is: first, let, X m =f m ·x m , where a nm is the nth channel count of the response spectrum of the mth element, y n is the nth channel count of the dual-detector fusion spectrum to be analyzed; f m is the neutron self-shielding factor of the mth element of the dual-detector fusion spectrum to be analyzed, x m is the content of the mth element in the resin to be tested; then introduce the weighting factor diagonal matrix In the formula, b i is the count of the ith channel of the dual detector fusion spectrum, and the matrix expression of the least square method of the weighted spectral library based on the neutron self-screening effect correction model is: WAX = WY; then, A T WAX=A T WY, solve for X: X = (A T WA) -1 A T WY, then the content of the mth element in the resin to be tested is, x m =X m / f m .

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention generates continuous neutrons or pulsed neutrons through a DT neutron generator, generates prompt gamma rays through the interaction between continuous neutrons and resin atomic nuclei, and realizes quantitative analysis of non-fissile elements by analyzing the energy and intensity of gamma rays. Then, pulsed neutrons are used to excite fissile nuclides to generate prompt fission neutrons, and quantitative analysis of fissile nuclides is performed by analyzing the intensity of the generated prompt fission neutrons. The whole detection process is simple and convenient, and the detection will not destroy the detection sample, and can realize in-situ measurement and online analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of an online detection device for resin adsorption process elements provided by an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the placement position of an online detection device for resin adsorption process elements provided by an embodiment of the present invention;

[0020] Figure 3 It is a flow chart of the detection process of the online detection device for resin adsorption process elements provided by an embodiment of the present invention;

[0021] Figure 4 The LaBr in the resin detection process provided by the embodiment of the present invention 3 The dual-detector fusion spectrum obtained by processing the energy spectra measured by the detector and the BGO detector;

[0022] Figure 5 The epithermal neutron and thermal neutron time spectra under different uranium concentration environments provided by the embodiments of the present invention;

[0023] Figure 6 It is a line graph of the element content analysis results of non-fissile nuclides provided by an embodiment of the present invention;

[0024] Figure 7 It is a comparison chart of the element analysis results of non-fissile nuclides and the PGNAA detection results provided by the embodiment of the present invention;

[0025] Figure 8 is a line graph of the element content of fissile nuclides provided by an embodiment of the present invention;

[0026] Fig. 9 is a line graph showing the corresponding relationship between known uranium concentration and E / T value provided by an embodiment of the present invention;

[0027] In the figure, 1-shell, 2-DT neutron generator, 3-thermal neutron detector, 4-epitothermal neutron detector, 5-shielding module, 6-LaBr 3 Detector, 7-BGO detector, 8-control system, 9-resin tank, 10-resin. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-Figure 6 The present invention provides a technical solution: an online detection device for resin adsorption process elements, comprising a sealed aluminum alloy shell 1, a DT neutron generator 2, a shielding body module 5, a LaBr 3 Detector 6, BGO detector 7, thermal neutron detector 3, epithermal neutron detector 4; among them, DT neutron generator 2, shielding module 5, LaBr 3The detector 6 and the BGO detector 7 are fixedly connected inside the shell from top to bottom in sequence. The thermal neutron detector 3 and the epithermal neutron detector 4 are arranged on both sides of the target position of the DT neutron generator 2, and the DT neutron generator 2 is arranged at the central axis of the device to generate continuous neutrons or pulsed neutrons. The thermal neutron detector 3 and the epithermal neutron detector 4 are used to collect the neutron time spectrum under the pulsed neutron working state. The shielding module 5 is a boron-containing polyethylene block, which is located between the DT neutron generator 2 and LaBr 3 Between detectors 6, used to slow down the absorption of neutrons and reduce the impact of fast neutrons on LaBr 3 Detector 6 and BGO detector 7 collect the effects of gamma rays, and DT neutron generator 2, thermal neutron detector 3, epithermal neutron detector 4, LaBr 3 The detector 6 and the BGO detector 7 are connected to a control system 8, which supplies power to each component and controls and feedbacks the working status.

[0030] The present invention is used in the process of online detection of resin adsorption process elements, and the specific steps are as follows:

[0031] S1: Press the device as Figure 2 (a) or Figure 2 (b) is placed in the resin tank 9, wherein, Figure 2 The application method shown in (a) can detect the change of the content of the adsorbed element in the resin 10 at the bottom of the resin tank 9, and can be used to determine the state of the adsorbed element in the resin 10; Figure 2 In the application mode shown in (b), the detection device can be moved up and down to detect the adsorption of elements in the resin layers at different heights in the resin tank 9; then the DT neutron generator 2 is turned on by the control system 8, and the continuous neutron working mode of the DT neutron generator 2 is selected, the neutrons are used to excite the resin to generate prompt gamma rays, and the LaBr is turned on. 3 Detector 6 and BGO detector 7 respectively collect gamma energy spectra for recording;

[0032] S2: Switch the working mode of DT neutron generator 2 to pulse working mode. According to the test of resin sample, the duration of thermal neutron is up to 1250μs, so the pulse working period of DT neutron generator 2 is set to 1250μs. In this test, the pulse width of DT neutron generator 2 is set to 130μs, and the thermal neutron detector 3 and the epithermal neutron detector 4 are turned on to collect the thermal neutron time spectrum and the epithermal neutron time spectrum respectively;

[0033] S3: The gamma energy spectrum collected in step S1 is subjected to noise reduction, smoothing, peak stabilization, channel merging, and total count normalization. 3 The 0-3MeV part of the detector energy spectrum is merged with the energy spectrum of the BGO detector greater than 3MeV, forming a 0-3MeV energy region for high-resolution LaBr 3The dual detector fusion energy spectrum is a dual detector fusion energy spectrum of the detector energy spectrum and the BGO energy spectrum with high detection efficiency in the energy region greater than 3MeV. The dual detector fusion energy spectrum obtained in this embodiment is as follows Figure 4 shown.

[0034] S4: Calculate the net hydrogen peak counts of the dual-detector fusion spectrum, calculate the neutron self-shielding factor using the hydrogen peak counts as the internal standard, and use the weighted spectral library least squares method based on the neutron self-screening effect correction model to analyze the dual-detector fusion spectrum to obtain the element content of non-fissile nuclides;

[0035] Among them, the calculation formula of neutron self-shielding factor is: Where f is the neutron self-shielding factor of the dual-detector fusion spectrum to be analyzed, H LaBr,j and H BGO,j The dual detector fusion spectrum to be analyzed corresponds to LaBr 3 The hydrogen peak counts of the detector and BGO detector energy spectrum, H Labr,0 and H BGO,0 They are respectively LaBr measured when the resin does not adsorb elements 3 The hydrogen peak counts of the detector and BGO detector energy spectra;

[0036] The calculation process of the element content of non-fissile nuclides is as follows: First, let, X m =f m ·x m , where a nm is the nth channel count of the response spectrum of the mth element, y n is the nth channel count of the dual-detector fusion spectrum to be analyzed; f m is the neutron self-shielding factor of the mth element of the dual-detector fusion spectrum to be analyzed, x m is the content of the mth element in the resin to be tested; then introduce the weighting factor diagonal matrix In the formula, b i is the count of the ith channel of the dual detector fusion spectrum, and the matrix expression of the least square method of the weighted spectral library based on the neutron self-screening effect correction model is: WAX = WY; then, A T WAX=A T WY, solve for X: X = (A T WA) - 1 A T WY, then the content of the mth element in the resin to be tested is, x m =X m / f m The final analyzed non-fissile nuclide element content is as follows: Figure 6As shown, the element analysis results of this embodiment are verified by PGNAA detection, and the verification results are as follows Figure 7 As shown, the results show that the element content of non-fissile nuclides in the sample obtained by this analytical method is consistent with the actual content in the sample.

[0037] S5: Figure 5 As shown in FIG. 1 , under different uranium concentration environments, the number of epithermal neutrons and thermal neutrons both rise rapidly within a time period of 0-130 μs. When the uranium concentration is 0, the epithermal neutrons decay rapidly within a time period of about 215 μs, while the thermal neutrons are further captured and absorbed by the uranium solution as they diffuse, and the duration is up to 1250 μs. Therefore, the epithermal neutrons generated after 215 μs are considered to be generated from uranium fission reactions. The epithermal neutron count at this time is only related to the uranium content in the uranium solution. Therefore, the uranium content in the test sample can be inferred by the epithermal neutron count and the thermal neutron count. Specifically, the ratio E / T of the epithermal neutron count to the thermal neutron count in the time interval of 215-1250 μs of the neutron time spectrum obtained in step S2 is calculated, and a calibration curve is drawn. The element content of the resin fissile nuclide is obtained by comparing the calibration curve with the E / T value of the fissile nuclide solution of known concentration (such as Figure 8 ), Fig. 9 It is a line graph showing the corresponding relationship between known uranium concentration and E / T value.

[0038] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An online detection device for resin adsorption process elements, characterized by: The invention comprises a shell and a neutron source system, a shielding module and a gamma detector system which are sequentially arranged inside the shell from top to bottom. The neutron source system is used to generate and emit pulsed neutrons, and neutron detection systems for collecting neutron time spectra in a pulsed neutron working state are arranged on both sides of the neutron source system. The shielding module is used to slow down and absorb neutrons to reduce the influence of fast neutrons on the gamma detector.

2. The online detection device for resin adsorption process elements according to claim 1 is characterized in that: The neutron source system adopts a DT neutron generator, the neutron detection system includes a He-3 thermal neutron detector and a He-3 epithermal neutron detector, and the He-3 thermal neutron detector and the He-3 epithermal neutron detector are respectively arranged on both sides of the target position of the DT neutron generator, the gamma detector system includes a LaBr3 detector and a BGO detector, and the DT neutron generator, the He-3 thermal neutron detector, the He-3 epithermal neutron detector, the LaBr3 detector and the BGO detector are all connected to the control system through circuits.

3. The online detection device for resin adsorption process elements according to claim 2 is characterized in that: The shell is made of aluminum alloy.

4. The online detection device for resin adsorption process elements according to claim 3 is characterized in that: The shielding module is made of boron-containing polyethylene block.

5. The detection method for the online detection device of resin adsorption process elements according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Place the device in the resin, turn on the DT neutron generator through the control system, select the continuous neutron working mode of the DT neutron generator, and turn on the LaBr3 detector and the BGO detector to collect the gamma energy spectrum for recording; S2: Switch the DT neutron generator working mode to the pulse working mode, set the pulse working period according to the time it takes for the thermal neutrons in the resin sample to completely decay, and select the narrowest pulse width while ensuring the number of pulse neutrons. Then use the neutron detection system to collect the epithermal neutron time spectrum and thermal neutron time spectrum respectively; S3: The gamma energy spectrum collected in step S1 is subjected to noise reduction, smoothing, peak stabilization, channel merging, and total count normalization processing, and the processed LaBr3 detector energy spectrum 0-3MeV part is fused with the BGO detector energy spectrum greater than 3MeV part to form a dual-detector fusion energy spectrum with a high-resolution LaBr3 detector energy spectrum in the 0-3MeV energy region and a BGO energy spectrum with high detection efficiency in the greater than 3MeV energy region; S4: Calculate the net hydrogen peak counts of the dual-detector fusion spectrum, calculate the neutron self-shielding factor using the hydrogen peak counts as the internal standard, and process the dual-detector fusion spectrum using the weighted spectral library least squares method based on the neutron self-screening effect correction model to obtain the element content of non-fissile nuclides in the resin; S5: Under the pulse width determined in step S2, obtain the time nodes when the epithermal neutrons and thermal neutrons in the resin sample completely decay after the DT neutron generator emits neutrons in the uranium-free environment test, and respectively calculate the epithermal neutron counts and thermal neutron counts in the time interval between the time nodes when the epithermal neutrons and thermal neutrons completely decay in the neutron time spectrum obtained in step S2, calculate the ratio E / T of the epithermal neutron count to the thermal neutron count in the time interval, draw a calibration curve, and obtain the element content of the fissile nuclide in the resin by comparing the calibration curve with the E / T value of the fissile nuclide solution of known concentration.

6. The detection method for the online detection device of resin adsorption process elements according to claim 5 is characterized in that: In step S4, the neutron self-shielding factor calculation formula is: Where f is the neutron self-shielding factor of the dual-detector fusion spectrum to be analyzed, H Labr,j and H BGO,j are the hydrogen peak counts of the LaBr3 detector and the BGO detector energy spectra corresponding to the dual detector fusion energy spectrum to be analyzed, H Labr,0 and H BGO,0 They are the hydrogen peak counts of the LaBr3 detector and BGO detector energy spectra measured when the resin does not adsorb elements.

7. The detection method for the online detection device of resin adsorption process elements according to claim 6 is characterized in that: In step S4, the calculation process of the element content of non-fissile nuclides is as follows: first, let, X m =f m ·x m , where a nm is the nth channel count of the response spectrum of the mth element, y n is the nth channel count of the dual-detector fusion spectrum to be analyzed; f m is the neutron self-shielding factor of the mth element of the dual-detector fusion spectrum to be analyzed, x m is the content of the mth element in the resin to be tested; then introduce the weighting factor diagonal matrix In the formula, b i is the count of the ith channel of the dual detector fusion spectrum, and the matrix expression of the least square method of the weighted spectral library based on the neutron self-screening effect correction model is: WAX = WY; then, A T WAX=A T WY, solve for X: X = (A T WA) -1 A T WY, then the content of the mth element in the resin to be tested is, x m =X m / f m .

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