Rapid measurement device for energy spectrum data of ore product and nuclear radiation analysis method

Abstract

The invention discloses a rapid measurement device for energy spectrum data of an ore product and a nuclear radiation analysis method. The device comprises a lead chamber, a Marinin cup, a detector and a support, the lead chamber comprises a cylindrical body and a lead cover, the Marinin cup is movably assembled in the body, the lead cover is movably assembled at the top of the body, the support is fixedly connected to the bottom of the body, the top of the detector is located in a concave cylinder of the Marinin cup, and the bottom of the detector is located in a mounting cavity in the middle of the support. A concave cylinder of the Marinin cup is in a circular frustum shape, the thickness of the outer wall of the Marinin cup is 5 mm, the thickness of the wall face of the concave cylinder is 3 mm, and the size phi of the concave cylinder is 150 mm * 135 mm. The side wall of the main body sequentially comprises a stainless steel layer, a lead layer, a stainless steel layer and a copper layer from outside to inside, and the stainless steel layer, the lead layer, the stainless steel layer and the copper layer are 3mm, 30mm, 3mm and 2mm respectively. According to the nuclear radiation analysis method, characteristic peaks with large energy in energy spectrum data are selected for energy spectrum data. The device has the characteristics that the device is low in installation complexity and good in sealing performance, a sample does not need to be preprocessed, and time consumed by energy spectrum data measurement and analysis is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear radiation detection, and in particular to a rapid measurement device for energy spectrum data of ore products and a nuclear radiation analysis method. Background Art

[0002] my country's import demand for ore products is increasing day by day, and the particle size of the ore products to be tested is usually in the millimeter range. Since ore products contain three natural radioactive nuclides of uranium, thorium and actinium series and single decay radioactive nuclides such as K-40, in order to prevent the radioactivity level in imported ore products from exceeding the standard, the types and contents of radioactive nuclides in various ore products that exceed the initial inspection threshold need to be tested during customs clearance.

[0003] At present, the method used by customs to test the types and contents of radioactive nuclides in various mineral products that exceed the initial inspection threshold is to send samples that exceed the threshold to relevant testing institutions to use laboratory low-background gamma spectrometers to measure the energy spectrum data of the mineral products.

[0004] The measurement part of the existing laboratory low-background gamma spectrometer is usually composed of a detector and a lead chamber sleeved on the detector. However, the wall thickness of the lead chamber of the existing low-background gamma spectrometer is usually greater than or equal to 100mm, and the part of the entire lead chamber that forms the measurement cavity is composed of multiple lead rings stacked layer by layer, which is highly complex to install and has poor sealing. In addition, since the ore sample itself has a part of self-absorption of radioactive gamma rays, the existing laboratory low-background gamma spectrometer needs to pre-treat the sample to be tested when testing the ore product to ensure uniform average density and reduce the influence of sample self-absorption on the measurement result. Usually, the ore to be tested is pre-treated first, and the sample is crushed and ground to a size below 180μm before measurement, which increases the time consumption of spectrum data measurement. Summary of the invention

[0005] Based on this, it is necessary to provide a rapid measurement device for energy spectrum data of ore products and a nuclear radiation analysis method to address the above-mentioned technical problems. The lead chamber is an integral whole, the device has low installation complexity, good sealing and no need for sample pretreatment, which reduces the time spent on energy spectrum data measurement and analysis.

[0006] In a first aspect, the present invention provides a rapid measurement device for energy spectrum data of an ore product, comprising a lead chamber, a Marlin cup, a detector, and a support with a mounting cavity in the middle;

[0007] The lead chamber comprises a cylindrical main body and a lead cover, the Marlin cup is movably assembled inside the main body, the lead cover is movably assembled on the top of the main body, the support is fixedly connected to the bottom of the main body, and a first assembly hole is arranged at the bottom of the main body;

[0008] The end of the detector having the detection crystal is defined as the top of the detector. The detector passes through the first assembly hole. The top of the detector is located in the concave cylinder of the Marlin cup, and the bottom of the detector is located in the mounting cavity in the middle of the support.

[0009] The concave tube of the Marin Cup is a circular cone. The outer wall thickness of the Marin Cup is 5mm, the concave tube wall thickness of the Marin Cup is 3mm, and the size of the Marin Cup is

[0010] The side wall of the main body includes a stainless steel layer, a lead layer, a stainless steel layer and a copper layer from the outside to the inside, and the thicknesses of the stainless steel layer, the lead layer, the stainless steel layer and the copper layer are 3mm, 30mm, 3mm and 2mm respectively.

[0011] In one embodiment, the support includes a base, a detector mounting tube, a support tube and a limit tube;

[0012] The detector installation tube is sleeved on the outside of the limiting tube, the support tube is sleeved on the outside of the installation tube, the bottoms of the detector installation tube, the support tube and the limiting tube are all fixedly connected to the base, and the tops of the detector installation tube, the support tube and the limiting tube are all fixedly connected to the main body;

[0013] The detector installation tube is in contact with the limiting tube, a gap is provided between the support tube and the detector installation tube to form a lead filling cavity, and a lead filling hole is provided on the side wall of the support tube;

[0014] A first installation cavity is formed inside the detector installation tube, and the inner diameter of the detector installation tube is smaller than the aperture of the first assembly hole;

[0015] The bottom shell of the detector abuts against the top of the limiting cylinder.

[0016] In one embodiment, a sealing member is further provided inside the lead chamber, the sealing member comprises a sealing ring and a sealing ring, and the inner diameter of the sealing ring is equal to the aperture of the first assembly hole;

[0017] The sealing ring is fixedly connected to the bottom inner wall of the main body, the sealing ring is fixedly connected to the middle of the sealing ring, and the sealing ring is sleeved on the detector;

[0018] The Marlin cup abuts the top of the seal.

[0019] In one embodiment, the Marlin Cup is made of polyethylene.

[0020] In one embodiment, the detector is a NaI(Tl) detector.

[0021] In one of the embodiments, the support is further provided with a wiring tube, and a wiring hole penetrates the detector installation tube, the support tube and the limit tube.

[0022] In a second aspect, the present invention also provides a method for nuclear radiation analysis of ore products, comprising the following steps:

[0023] The energy spectrum data of the ore sample is measured by using the above-mentioned rapid measurement device for energy spectrum data of the ore product;

[0024] The characteristic peaks with larger energy of the main body or daughter of Th-232, U-238, Ra-226 and K-40 in the energy spectrum data are selected for energy spectrum data analysis to obtain the specific activity of the main body or daughter of Th-232, U-238, Ra-226 and K-40.

[0025] In one embodiment, the daughters of Th-232 are Th-234 and Pa-234m, the daughters of U-238 are Bi-214 and Pb-214, and the daughters of Ra-226 are Ac-228, Pb-212 and Tl-208.

[0026] Beneficial effects of the present invention:

[0027] (1) The concave cylinder of the Marin cup of the rapid measurement device for energy spectrum data of ore products of the present invention is in the shape of a circular frustum, so that the Marin cup can be easily installed in the lead chamber and matched with one end of the detector having a detection crystal. The Marin cup of the size of the present invention is used to ensure that the edge rays can penetrate the inner ore layer and enter the detector, thereby avoiding the influence of sample self-absorption on the measurement result. The nuclear radiation analysis method of ore products of the present invention selects the characteristic peaks with larger energy of the main body or daughter body of Th-232, U-238, Ra-226 and K-40 for energy spectrum data analysis. The energy of the characteristic peaks is greater than 1000 keV and is not easily absorbed by the sample. Therefore, there is no need to pre-treat the ore sample. Therefore, the time consumption of the energy spectrum data measurement of the present invention and the time consumption of the nuclear radiation analysis method of ore products are both relatively small.

[0028] (2) The side wall of the lead chamber body of the present invention includes a stainless steel layer, a lead layer, a stainless steel layer and a copper layer in sequence from the outside to the inside, which can effectively reduce the influence of the bremsstrahlung radiation after the lead material is excited on the measurement result, and the lead chamber body is a whole, does not need to be installed in multiple layers, and has good sealing performance. In addition, the body of the present invention is small in thickness and the entire lead chamber is light in weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the overall structure of a device for rapidly measuring energy spectrum data of an ore product provided by an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the assembly relationship of the main body, the Marlin cup and the support provided in an embodiment of the present invention;

[0031] Figure 3 for Figure 2 A schematic diagram of a top view structure;

[0032] Figure 4for Figure 3 Schematic diagram of the cross-sectional structure along the BB plane;

[0033] Figure 5 A schematic structural diagram of a sealing ring provided by an embodiment of the present invention.

[0034] Among them: 110, lead chamber; 111, main body; 112, lead cover; 113, sealing ring; 114, sealing ring; 110, Marlin cup; 130, detector; 140, support; 141, base; 142, detector mounting tube; 143, support tube; 144, limit tube; 145, lead filling cavity; 146, lead filling hole; 147, wiring tube. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] It should be noted that in the description of the present invention, “upper”, “lower”, “top”, “bottom”, orientation or position relationship is based on the attached Figure 1 Regarding the orientation or positional relationship shown, it should be understood that these orientation terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In one embodiment, Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the rapid measurement device for energy spectrum data of ore products in this embodiment includes a lead chamber 110, a Marin cup 110, a detector 130 and a support 140 with a mounting cavity in the middle; the lead chamber 110 includes a cylindrical main body 111 and a lead cover 112, the Marin cup 110 is movably assembled inside the main body 111, the lead cover 112 is movably assembled on the top of the main body 111, the support 140 is fixedly connected to the bottom of the main body 111, and a first assembly hole is provided at the bottom of the main body 111; it is defined that one end of the detector 130 having a detection crystal is the top of the detector 130, the detector 130 passes through the first assembly hole, the top of the detector 130 is located in the concave cylinder of the Marin cup 110, and the bottom is located in the mounting cavity in the middle of the support 140.

[0038] The function of the lead chamber 110 is to form a 4π lead shield, which effectively reduces the interference of the environment on the detection of the ore to be tested in the Marlin cup 110.

[0039] In this embodiment, the concave cylinder of the Marin cup 110 is in the shape of a circular cone, the outer wall thickness of the Marin cup 110 is 5 mm, the concave cylinder wall thickness of the Marin cup 110 is 3 mm, and the size of the Marin cup 110 is The material of the Marlin Cup 110 is polyethylene.

[0040] The concave cylinder of the Marlin cup 110 is in the shape of a circular cone, which facilitates the matching installation of the end of the detector 130 with the detection crystal when the Marlin cup 110 is installed in the lead chamber 110. Polyethylene has a lower background radiation and a material density of 0.92g / cm 3 ~0.96g / cm 3 , the absorption cross section of gamma rays is small, which helps to reduce interference in the measurement process and improve detection efficiency and accuracy. The concave wall thickness of the Marin cup 110 is 3mm, which can reduce the blocking and absorption of gamma rays. The outer wall thickness of the Marin cup 110 is 5mm, which can ensure the mechanical strength, durability and thermal stability of the Marin cup 110.

[0041] In addition, the gamma rays emitted from the ore must penetrate the surrounding ore materials before they have a chance to enter the detector 130. In this process, the gamma rays will also be absorbed by the surrounding materials. When the ore pile reaches a certain thickness, the gamma rays will be completely absorbed by the surrounding ore materials and cannot be incident on the scintillation crystal of the detector 130. Therefore, the use of the above-mentioned size of the Marlin cup 110 can ensure that the rays at the edge can penetrate the inner ore layer and enter the detector 130, avoiding the self-absorption of the sample affecting the measurement results.

[0042] The side wall of the main body 111 includes a stainless steel layer, a lead layer, a stainless steel layer and a copper layer from the outside to the inside, and the thicknesses of the stainless steel layer, the lead layer, the stainless steel layer and the copper layer are 3 mm, 30 mm, 3 mm and 2 mm respectively.

[0043] The main body 111 in this embodiment can effectively reduce the influence of the bremsstrahlung radiation of the lead material after being excited on the measurement result, and the main body 111 is a whole, does not need to be installed in multiple layers, and has good sealing performance. In addition, the main body 111 is 30 mm thick, which can reduce the mass of the entire lead chamber 110.

[0044] Specifically, in this embodiment, the detector 130 is a NaI (Tl) detector 130. The NaI (Tl) detector 130 is composed of a size of The integrated detector 130 (including sodium iodide crystal and photomultiplier tube), preamplifier circuit, multi-channel, communication circuit, etc. are composed of the integrated detector 130 and the circuit are wrapped by a stainless steel shell.

[0045] During the energy spectrum data measurement process, the gamma rays emitted by the radioactive nuclides in the ore to be tested pass through the surrounding ore materials, the wall of the Marlin cup 110 and the outer shell of the detector 130, and finally enter the detection crystal of the detector 130, that is, the scintillation crystal. This part of the gamma rays entering the scintillation crystal loses energy in the crystal, and this energy excites the atoms in the scintillation crystal. When these excited atoms de-excite, they emit visible light. The visible light is collected by the photomultiplier tube of the detector 130, converted into electrical signals, amplified and output to its electronic components. The electronic components amplify, process and convert the received electrical signals into digital signals. After the digital signals are "pre-processed" inside the detector 130, the energy spectrum data of the ore to be tested is obtained.

[0046] The rapid measurement device for energy spectrum data of ore products in this embodiment has low installation complexity, good sealing performance and no need for sample pretreatment, thereby reducing the time consumption of energy spectrum data measurement.

[0047] In one embodiment, the support 140 includes a base 141, a detector mounting tube 142, a support tube 143 and a stop tube 144; the bottom shell of the detector 130 abuts against the top of the stop tube 144. The support tube 143 is sleeved on the outside of the mounting tube, the bottoms of the detector mounting tube 142, the support tube 143 and the stop tube 144 are all fixedly connected to the base 141, and the tops of the detector mounting tube 142, the support tube 143 and the stop tube 144 are all fixedly connected to the main body 111. The base 141 is fixedly connected to a platform.

[0048] Among them, a first installation cavity is formed inside the detector installation tube 142, and the inner diameter of the detector installation tube 142 is smaller than the aperture of the first assembly hole; the detector installation tube 142 is abutted against the limiting tube 144, and the support 140 is also provided with a wiring tube 147, and the wiring hole penetrates the detector installation tube 142, the support tube 143 and the limiting tube 144.

[0049] In this embodiment, there is a gap between the support tube 143 and the detector mounting tube 142 to form a lead filling cavity 145, and the side wall of the support tube 143 is provided with a lead filling hole 146. The lead filling cavity 145 is used as a reserved cavity. When the device of this embodiment is detected under a large radiation background, lead can be injected into the lead filling cavity 145 through the lead filling hole 146 to achieve a higher shielding effect.

[0050] Specifically, the detector mounting tube 142 is used to assemble the detector 130, the supporting tube 143 supports the lead chamber 110 and forms a lead-filled cavity 145 with the detector mounting tube 142, the limiting tube 144 supports the detector 130 and provides an installation space for the connector at the front end of the detector 130, and the wiring tube 147 provides a connection space between the connector and the external analysis equipment.

[0051] In one embodiment, if Figure 5 As shown, a seal is also provided inside the lead chamber 110, and the seal includes a sealing ring 113 and a sealing ring 114. The inner diameter of the sealing ring 113 is equal to the aperture of the first assembly hole; the sealing ring 113 is fixedly connected to the bottom inner wall of the main body 111, and the sealing ring 114 is fixedly connected to the middle of the sealing ring 113, and the sealing ring 114 is sleeved on the detector 130; the Marlin cup 110 abuts against the top of the seal.

[0052] Specifically, the function of the seal is to fix the detector 130 to prevent the detector 130 from shaking during the movement of the entire device.

[0053] Based on the same invention, the present invention also provides a method for nuclear radiation analysis of ore products, comprising the following steps:

[0054] S1. Use the device for rapid measurement of energy spectrum data of ore products according to any of the above embodiments to measure energy spectrum data of ore samples.

[0055] S2. Select characteristic peaks with larger energy of the main body or daughter of Th-232, U-238, Ra-226 and K-40 in the energy spectrum data, and perform energy spectrum data analysis to obtain the specific activity of the main body or daughter of Th-232, U-238, Ra-226 and K-40.

[0056] Among them, the daughters of Th-232 are Th-234 and Pa-234m, the daughters of U-238 are Bi-214 and Pb-214, and the daughters of Ra-226 are Ac-228, Pb-212 and Tl-208.

[0057] The characteristic peaks with larger energy of the main body or daughter of Th-232, U-238, Ra-226 and K-40 are selected for energy spectrum data analysis. The energy of the characteristic peaks is greater than 1000keV, which is not easily absorbed by the sample, so there is no need to pre-treat the ore sample, which can reduce the time consumption of the nuclear radiation analysis method of the ore product. The characteristic peak information selection table is shown in Table 1.

[0058] Table 1 Characteristic peak information selection table

[0059]

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A rapid measurement device for energy spectrum data of ore products, characterized in that: It comprises a lead chamber (110), a Marlin cup (110), a detector (130), and a support (140) with a mounting cavity in the middle; The lead chamber (110) comprises a cylindrical main body (111) and a lead cover (112); the Marlin cup (110) is movably assembled inside the main body (111); the lead cover (112) is movably assembled on the top of the main body (111); the support (140) is fixedly connected to the bottom of the main body (111); and a first assembly hole is provided on the bottom of the main body (111); The detector (130) is defined as having one end of the detection crystal as the top of the detector (130), the detector (130) passes through the first assembly hole, the top of the detector (130) is located in the concave cylinder of the Marlin cup (110), and the bottom is located in the installation cavity in the middle of the support (140); The concave cylinder of the Marin cup (110) is in the shape of a circular cone, the outer wall thickness of the Marin cup (110) is 5 mm, the concave cylinder wall thickness of the Marin cup (110) is 3 mm, and the size of the Marin cup (110) is φ150 mm×135 mm; The side wall of the main body (111) comprises a stainless steel layer, a lead layer, a stainless steel layer and a copper layer from the outside to the inside, and the thicknesses of the stainless steel layer, the lead layer, the stainless steel layer and the copper layer are 3 mm, 30 mm, 3 mm and 2 mm respectively.

2. The rapid measurement device for energy spectrum data of ore products according to claim 1 is characterized in that: The support (140) comprises a base (141), a detector mounting tube (142), a supporting tube (143) and a limiting tube (144); The detector mounting tube (142) is sleeved on the outside of the limiting tube (144), and the support tube (143) is sleeved on the outside of the mounting tube. The bottoms of the detector mounting tube (142), the support tube (143) and the limiting tube (144) are all fixedly connected to the base (141), and the tops of the detector mounting tube (142), the support tube (143) and the limiting tube (144) are all fixedly connected to the main body (111); The detector installation tube (142) is in contact with the limiting tube (144), a gap is provided between the support tube (143) and the detector installation tube (142) to form a lead filling cavity (145), and a lead filling hole (146) is provided on the side wall of the support tube (143); A first installation cavity is formed inside the detector installation tube (142), and the inner diameter of the detector installation tube (142) is smaller than the aperture of the first assembly hole; The bottom shell of the detector (130) abuts against the top of the limiting cylinder (144).

3. The rapid measurement device for energy spectrum data of ore products according to claim 2, characterized in that: A sealing member is also provided inside the lead chamber (110), the sealing member comprising a sealing ring (113) and a sealing ring (114), the inner diameter of the sealing ring (113) being equal to the aperture of the first assembly hole; The sealing ring (113) is fixedly connected to the inner wall of the bottom of the main body (111), the sealing ring (114) is fixedly connected to the middle of the sealing ring (113), and the sealing ring (114) is sleeved on the detector (130); The Marlin cup (110) abuts against the top of the seal.

4. The rapid measurement device for energy spectrum data of ore products according to claim 3, characterized in that: The material of the Marlin cup (110) is polyethylene.

5. The rapid measurement device for energy spectrum data of ore products according to claim 3, characterized in that: The detector (130) is a NaI(Tl) detector (130).

6. The rapid measurement device for energy spectrum data of mineral products according to claim 4 or 5, characterized in that: The support (140) is also provided with a wiring tube (147), and the wiring hole passes through the detector installation tube (142), the support tube (143) and the limit tube (144).

7. A method for nuclear radiation analysis of ore products, characterized in that: The following steps are involved: The ore product energy spectrum data rapid measurement device as claimed in any one of claims 1 to 6 is used to measure the energy spectrum data of the ore sample; The characteristic peaks with larger energy of the main bodies or daughters of Th-232, U-238, Ra-226 and K-40 in the energy spectrum data are selected for energy spectrum data analysis to obtain the specific activities of the main bodies or daughters of Th-232, U-238, Ra-226 and K-40.

8. The method for nuclear radiation analysis of ore products according to claim 7, characterized in that: The daughters of Th-232 are Th-234 and Pa-234m, the daughters of U-238 are Bi-214 and Pb-214, and the daughters of Ra-226 are Ac-228, Pb-212 and Tl-208.

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