An automatic mercury analyzer catalytic tube and its preparation method

Abstract

The present invention discloses a catalytic tube for an automatic mercury analyzer and a preparation method thereof, which includes a tube body and three catalytic sections; for the three catalytic sections, the first catalytic section includes manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide; the second catalytic section includes aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide; the third catalytic section includes manganese dioxide, calcium oxide, and potassium oxide. The catalytic tube for an automatic mercury analyzer and the preparation method thereof disclosed by the present invention can achieve better purification effect on the decomposition products of samples through the proportioning of each part of the catalyst and multi-stage purification, have good versatility, enable more types of samples to be measured by the automatic mercury analyzer, and are beneficial to improving the diversity of measurements; are convenient to operate and have high practicality; the catalytic tube for an automatic mercury analyzer and the preparation method thereof are simple and easy to operate, have mild conditions, no safety hazards, and no environmental pollution, and are beneficial to wide industrial popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical instruments, and particularly relates to an automatic mercury analyzer catalytic tube and a preparation method thereof. Background Art

[0002] An automatic mercury analyzer is an atomic absorption spectroscopy instrument with high sensitivity for mercury measurement, used to detect mercury vapor; during detection, the sample to be measured is first dried and decomposed in a decomposition furnace, and the decomposition products are directly transported to the catalytic reaction part of the furnace through oxygen. Oxides, halogens, hydrocarbons, and nitrogen and sulfur oxides are captured through catalytic reactions here, and the remaining decomposition products are brought into the amalgamation tube. When all the remaining gases and decomposition products have passed through the amalgamation tube, the amalgamation tube is heated to release vapor mercury. The carrier gas brings the vapor mercury into a single-wavelength optical path absorption cell. The vapor mercury selectively absorbs ultraviolet light at 253.7 nm, and within a certain concentration range, the absorbed light is proportional to the mercury concentration. In the absorption cell of the mercury analyzer, since water, halogens, nitrogen, sulfur, and hydrocarbons in the decomposition gas will seriously affect the detection results of the mercury analyzer, purification must be carried out before the decomposition gas enters the absorption cell of the mercury analyzer.

[0003] The prior art published patent 201710491421.2, a catalytic tube, preparation method and use method for eliminating matrix interference disclose that calcium oxide, cobalt tetroxide and manganese tetroxide are used as catalysts to catalytically purify the decomposition gas before it enters the absorption cell of the mercury analyzer; in the actual use of the above-mentioned catalytic purification catalytic tube disclosed in the prior art, the three catalysts of calcium oxide, cobalt tetroxide and manganese tetroxide have the defects of low catalytic efficiency for nitrogen oxides, halogens and hydrocarbons and being prone to failure.

[0004] Therefore, the technical personnel in this field are committed to developing an automatic mercury analyzer catalytic tube and a preparation method thereof to solve the above-mentioned deficiencies of the prior art. Summary of the Invention

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is the defect problem that the catalyst of the automatic mercury analyzer catalytic tube disclosed in the current prior art has low catalytic efficiency for nitrogen oxides, halogens and hydrocarbons and is prone to failure.

[0006] To achieve the above object, the first aspect of the present invention provides an automatic mercury analyzer catalytic tube, including a tube body and three catalytic sections;

[0007] Further, in the three catalytic sections, the first catalytic section includes manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide;

[0008] Further, in the three catalytic sections, the second catalytic section includes aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide;

[0009] Further, in the three-stage catalytic section, the III-stage catalytic section includes manganese dioxide, calcium oxide, and potassium oxide;

[0010] Further, in the three-stage catalytic section, in the I-stage catalytic section, the length of the catalytic section is about 1 - 8 cm;

[0011] Further, in the three-stage catalytic section, in the I-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide is (1 - 3):(0.5 - 2):(0.5 - 2):(0.5 - 2);

[0012] Further, in the three-stage catalytic section, in the II-stage catalytic section, the length of the catalytic section is about 5 - 10 cm;

[0013] Further, in the three-stage catalytic section, in the II-stage catalytic section, the mass ratio (g:g) of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide is (3 - 5):(2 - 4):(0.5 - 2):(0.5 - 2);

[0014] Further, in the three-stage catalytic section, in the III-stage catalytic section, the length of the catalytic section is about 1 - 5 cm;

[0015] Further, in the three-stage catalytic section, in the III-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, and potassium oxide is (2 - 4):(0.5 - 2):(0.5 - 2);

[0016] Further, in the three-stage catalytic section, in the I, II, and III-stage catalytic sections, the particle size of the catalyst particles is 20 - 100 mesh; preferably, the particle size of the catalyst particles is 40 - 60 mesh;

[0017] Further, in the three-stage catalytic section, the length ratio (cm) between the I, II, and III-stage catalytic sections is (3 - 4):(6 - 7):(2 - 3);

[0018] Further, the tube body is a straight tube with both ends open, the feed port is located on the left side of the tube body, the discharge port is located on the right side of the tube body, and the opening size of the feed port is larger than the opening size of the discharge port;

[0019] Further, there is insulating cotton between the three-stage catalytic sections;

[0020] In a specific embodiment of the present invention, in the three-stage catalytic section, in the I-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide is 1:1:1:1;

[0021] In another specific embodiment of the present invention, in the three-stage catalytic section, in the first-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide is 2:1:1:1;

[0022] In another specific embodiment of the present invention, in the three-stage catalytic section, in the first-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide is 3:2:2:2;

[0023] In a specific embodiment of the present invention, in the three-stage catalytic section, in the second-stage catalytic section, the mass ratio (g:g) of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide is 3:2:0.5:0.5;

[0024] In another specific embodiment of the present invention, in the three-stage catalytic section, in the second-stage catalytic section, the mass ratio (g:g) of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide is 4:3:1:1;

[0025] In another specific embodiment of the present invention, in the three-stage catalytic section, in the second-stage catalytic section, the mass ratio (g:g) of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide is 5:4:2:2;

[0026] In a specific embodiment of the present invention, in the three-stage catalytic section, in the third-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, and potassium oxide is 2:0.5:0.5;

[0027] In another specific embodiment of the present invention, in the three-stage catalytic section, in the third-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, and potassium oxide is 3:1:1;

[0028] In another specific embodiment of the present invention, in the three-stage catalytic section, in the third-stage catalytic section, the mass ratio (g:g) of manganese dioxide, calcium oxide, and potassium oxide is 4:2:2;

[0029] In a specific embodiment of the present invention, in the three-stage catalytic section, the length ratio (cm) between the first, second, and third-stage catalytic sections is 3:6:2;

[0030] In another specific embodiment of the present invention, in the three-stage catalytic section, the length ratio (cm) between the first, second, and third-stage catalytic sections is 4:6:2;

[0031] In another specific embodiment of the present invention, in the three-stage catalytic section, the length ratio (cm) between the first, second, and third-stage catalytic sections is 4:7:3;

[0032] In a specific embodiment of the present invention, the tube body is a quartz tube;

[0033] The second aspect of the present invention provides a preparation method of a catalytic tube for an automatic mercury analyzer, specifically including the following steps:

[0034] Step 1: Fill the isolation cotton into the tube body from the inlet of the tube body, block the outlet of the tube body to prevent the catalyst from leaking out;

[0035] Step 2: Fill the catalyst particles into the tube body of Step 1 from the inlet of the tube body respectively. After filling a section of the catalyst, fill the isolation cotton for isolation, and repeat three times to form catalytic sections I, II, and III in sequence from front to back, and combine them to make a catalytic tube for gas purification of an automatic mercury analyzer;

[0036] Further, in Step 1, the isolation cotton is quartz cotton;

[0037] Further, in Step 2, the catalytic section I is: a mixed particle of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide;

[0038] Further, in Step 2, the catalytic section II is: a mixed particle of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide;

[0039] Further, in Step 2, the catalytic section III is: a mixed particle of manganese dioxide, calcium oxide, and potassium oxide;

[0040] Further, in Step 2, the mass ratio (g:g) of the mixed particle of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the catalytic section I is (1-3):(0.5-2):(0.5-2):(0.5-2);

[0041] Further, in Step 2, the mass ratio (g:g) of the mixed particle of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the catalytic section II is (3-5):(2-4):(0.5-2):(0.5-2);

[0042] Further, in Step 2, the mass ratio (g:g) of the mixed particle of manganese dioxide, calcium oxide, and potassium oxide in the catalytic section III is (2-4):(0.5-2):(0.5-2);

[0043] Further, in Step 2, the particle size of the mixed particle of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the catalytic section I is 20-100 mesh; preferably, it is 40-60 mesh;

[0044] Further, in Step 2, the particle size of the mixed particle of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the catalytic section II is 20-100 mesh; preferably, it is 40-60 mesh;

[0045] Further, in step 2, the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the III-stage catalytic section have a particle size of 20 - 100 mesh; preferably, 40 - 60 mesh.

[0046] Further, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the I-stage catalytic section is 2 - 5 cm.

[0047] Further, in step 2, the length of the aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the II-stage catalytic section is 5 - 8 cm.

[0048] Further, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the III-stage catalytic section is 1 - 4 cm.

[0049] In a specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the I-stage catalytic section is 1:1:1:1.

[0050] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the I-stage catalytic section is 2:1:1:1.

[0051] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the I-stage catalytic section is 3:2:2:2; in a specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the II-stage catalytic section is 3:2:0.5:0.5.

[0052] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the II-stage catalytic section is 4:3:1:1.

[0053] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the II-stage catalytic section is 5:4:2:2.

[0054] In a specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the III-stage catalytic section is 2:0.5:0.5.

[0055] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the III-stage catalytic section is 3:1:1.

[0056] In another specific embodiment of the present invention, in step 2, the mass ratio (g:g) of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the III-stage catalytic section is 4:2:2;

[0057] In a specific embodiment of the present invention, in step 2, for the I-stage catalytic section, manganese acetate, calcium nitrate, magnesium nitrate, and potassium nitrate with a mass ratio (g:g) of 4:3:4:2 are dissolved in an appropriate amount of water, stirred for 1 hour, evaporated to dryness, calcined at 350 °C for 1 hour, and then calcined at 600 °C for 2 hours to form a mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide;

[0058] In another specific embodiment of the present invention, in step 2, for the II-stage catalytic section, aluminum nitrate nonahydrate, cobalt nitrate hexahydrate, cerium nitrate hexahydrate, and cesium nitrate with a mass ratio (g:g) of 74:12:37:3 are dissolved in an appropriate amount of water, stirred for 1 hour, the pH value is adjusted to about 9 with ammonia water, left standing for 24 hours, filtered, washed, dried at 120 °C for 24 hours, and calcined at 550 °C for 4 hours (heating rate 3 °C / min) to form a mixture of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide;

[0059] In another specific embodiment of the present invention, in step 2, for the III-stage catalytic section, manganese acetate, calcium nitrate, and potassium nitrate with a mass ratio (g:g) of 6:3:2 are dissolved in an appropriate amount of water, stirred for 1 hour, evaporated to dryness, calcined at 350 °C for 1 hour, and then calcined at 600 °C for 2 hours to form a complex mixture of manganese dioxide, calcium oxide, and potassium oxide;

[0060] In a specific embodiment of the present invention, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the I-stage catalytic section is 40 mesh;

[0061] In another specific embodiment of the present invention, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the I-stage catalytic section is 50 mesh;

[0062] In another specific embodiment of the present invention, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the I-stage catalytic section is 60 mesh;

[0063] In a specific embodiment of the present invention, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the II-stage catalytic section is 40 mesh;

[0064] In another specific embodiment of the present invention, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the II-stage catalytic section is 50 mesh;

[0065] In another specific embodiment of the present invention, in step 2, the particle size of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the second-stage catalytic section is 60 mesh;

[0066] In a specific embodiment of the present invention, in step 2, the particle size of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the third-stage catalytic section is 40 mesh;

[0067] In another specific embodiment of the present invention, in step 2, the particle size of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the third-stage catalytic section is 50 mesh;

[0068] In another specific embodiment of the present invention, in step 2, the particle size of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the third-stage catalytic section is 60 mesh;

[0069] In a specific embodiment of the present invention, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the first-stage catalytic section is 2.5 cm;

[0070] In another specific embodiment of the present invention, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the first-stage catalytic section is 3.5 cm;

[0071] In another specific embodiment of the present invention, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the first-stage catalytic section is 4.5 cm;

[0072] In a specific embodiment of the present invention, in step 2, the length of the mixed particles of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section is 5.5 cm;

[0073] In another specific embodiment of the present invention, in step 2, the length of the mixed particles of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section is 6.5 cm;

[0074] In another specific embodiment of the present invention, in step 2, the length of the mixed particles of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section is 7.5 cm;

[0075] In a specific embodiment of the present invention, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the third-stage catalytic section is 1.5 cm;

[0076] In another specific embodiment of the present invention, in step 2, the length of the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the third-stage catalytic section is 2.5 cm;

[0077] In another specific embodiment of the present invention, in step 2, the mixed particles of manganese dioxide, calcium oxide, and potassium oxide in the III-section catalytic section have a length of 3.5 cm;

[0078] In a specific embodiment of the present invention, the specific operation of step 1 is as follows:

[0079] Fill quartz wool into the quartz tube from the inlet of the quartz tube, block the outlet of the quartz tube to prevent the catalyst from leaking out;

[0080] In a specific embodiment of the present invention, the specific operation of step 2 is as follows:

[0081] First, fill the mixed particles of manganese dioxide, calcium oxide, and potassium oxide with a mass ratio of 3:1:1, a particle size of 50 mesh, and a length of about 2.5 cm into the quartz tube in sequence, fill quartz wool for isolation to form the III-section catalytic section; then fill the mixed particles of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide with a mass ratio (g:g) of 4:3:1:1, a particle size of 50 mesh, and a length of about 6.5 cm into the quartz tube, fill quartz wool for isolation to form the II-section catalytic section; finally, fill the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide with a mass ratio (g:g) of 2:1:1:1, a particle size of 50 mesh, and a length of 3.5 cm into the quartz tube from the inlet of the tube body, fill quartz wool for isolation to form the I-section catalytic section; combine to make a catalytic tube for gas purification of an automatic mercury analyzer;

[0082] The present invention also provides a catalytic tube for gas purification of an automatic mercury analyzer obtained by the preparation method according to any one of the second aspects of the present invention;

[0083] The present invention also provides the use of the catalytic tube for gas purification of an automatic mercury analyzer according to any one of the first aspects of the present invention and the catalytic tube for gas purification of an automatic mercury analyzer obtained by the preparation method according to any one of the second aspects of the present invention in the preparation for gas purification;

[0084] Adopting the above scheme, the automatic mercury analyzer catalytic tube and its preparation method disclosed by the present invention have the following advantages:

[0085] (1) The automatic mercury analyzer catalytic tube and its preparation method of the present invention, compared with the existing catalytic tubes, through different ratios of each part of the catalyst, make the I-section catalytic section of the catalyst purify and decompose a large amount of water vapor, carbon oxides, nitrogen oxides, sulfur oxides, and halogens in the decomposition products, the II-section catalytic section purifies and decomposes hydrocarbons, oily substances, and some nitrogen oxides in the decomposition products, and the III-section catalytic section purifies and decomposes trace water vapor, nitrogen oxides, and sulfur oxides in the decomposition products. Multiple sections are used for purification, and the purification effect on the sample decomposition products is better, enabling more types of samples to be measured by the automatic mercury analyzer, with good versatility, which is conducive to improving the diversity of measurements;

[0086] (2) The catalytic tube of the automatic mercury analyzer and its preparation method according to the present invention address the problem that the first section of the existing catalytic tube is prone to failure. By setting the first section of the catalyst at the position closest to the feed inlet, it is convenient for quick replacement of the catalyst, with easy operation and high practicality.

[0087] (3) The catalytic tube of the automatic mercury analyzer and its preparation method according to the present invention are simple and easy to operate, with mild conditions, no safety hazards, and no environmental pollution, which is conducive to realizing industrialized large-scale production and application.

[0088] In summary, the catalytic tube of the automatic mercury analyzer and its preparation method disclosed in the present invention can achieve better purification effect on the decomposition products of samples through the proportioning of each part of the catalyst and multi-stage purification, with good versatility, enabling a greater variety of sample types to be measured by the automatic mercury analyzer, which is conducive to improving the diversity of measurements; easy to operate and highly practical; the catalytic tube of the automatic mercury analyzer and its preparation method are simple and easy to operate, with mild conditions, no safety hazards, and no environmental pollution, which is conducive to wide industrial promotion and application.

[0089] The following will further illustrate the concept, specific technical solutions and technical effects of the present invention in combination with specific embodiments to fully understand the purpose, features and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 It is a schematic diagram of the catalytic tube of the automatic mercury analyzer according to Embodiment 1 of the present invention;

[0091] In the figure, 1, the first catalytic section; 2, the second catalytic section; 3, the third catalytic section; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0092] The following introduces multiple preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and these embodiments are for illustrative description. The protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0093] If there is no specific experimental method mentioned, it is usually carried out according to conventional conditions, such as those described in relevant specifications or manuals.

[0094] Working principle:

[0095] The catalytic tube of the automatic mercury analyzer of the present invention is used for the purification of sample water. The sample water is fed into the decomposition furnace, where the sample water is dried and decomposed. The decomposition products include water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products are directly transported into the furnace catalytic tube by oxygen. The decomposition products enter the tube body feed port, pass through the first-stage catalytic section 1. The first-stage catalytic section 1 absorbs water vapor, carbon oxides, nitrogen oxides, sulfur oxides, and halogens. The decomposition products absorbed by the first-stage catalytic section pass through the quartz wool and enter the second-stage catalytic section 2. The second-stage catalytic section 2 absorbs hydrocarbons, oily substances, and some nitrogen oxides in the decomposition products; the water vapor, nitrogen oxides, and sulfur oxides generated by the absorption reaction in the second-stage catalytic section 2 are absorbed in the third-stage catalytic section 3; the remaining decomposition products enter the amalgamation tube from the discharge port. When all the remaining gases and decomposition products have passed through the amalgamation tube, the amalgamation tube is heated to release mercury vapor; the carrier gas brings the mercury vapor into the single-wavelength optical path absorption cell, and the absorption of mercury is measured at a wavelength of 253.7 nm to obtain the mercury content.

[0096] Example 1. Preparation of the catalytic tube of the automatic mercury analyzer

[0097] Step 1. Fill quartz wool into the quartz tube from the inlet of the quartz tube and block the outlet of the quartz tube to prevent the catalyst from leaking out.

[0098] Step 2. Weigh 6 g of manganese acetate, 6 g of calcium nitrate, 8 g of magnesium nitrate, and 4 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate and dry, then calcine at 350 °C for 1 hour and at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide. Crush and sieve, and select 40 mesh; weigh 92.5 g of aluminum nitrate nonahydrate, 16 g of cobalt nitrate hexahydrate, 74 g of cerium nitrate hexahydrate, and 6 g of cesium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, adjust the pH value to about 9 with ammonia water, let stand for 24 hours, filter, wash, dry at 120 °C for 24 hours, calcine at 550 °C for 4 hours (heating rate 3 °C / min), crush and sieve, and select 40 mesh; weigh 8 g of manganese acetate, 6 g of calcium nitrate, and 4 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate and dry, then calcine at 350 °C for 1 hour and at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, and potassium oxide. Crush and sieve, and select 40 mesh.

[0099] Step 3: Fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, and potassium oxide into a quartz tube with a filling length of 2.5 cm, and then fill quartz wool for isolation to form the III-section catalytic section 3; then fill the mixed particles of the complex mixture of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide into the quartz tube with a filling length of 6.5 cm, and fill quartz wool for isolation to form the II-section catalytic section 2; finally, fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide into the quartz tube with a filling length of 3.5 cm, and finally fill quartz wool for isolation to form the I-section catalytic section 1, and combine them to make a catalytic tube for gas purification of an automatic mercury analyzer;

[0100] Perform a purification experiment on the sample water with a mercury content of 0.01 mg / L using the automatic mercury analyzer catalytic tube obtained in Example 1. Feed the sample water into the decomposition furnace. The sample water is dried and decomposed in the decomposition furnace, and the decomposition products include carbonaceous water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products are directly transported into the furnace catalytic tube through oxygen. The decomposition products enter the tube body feed port, pass through the I-section catalytic section 1. The I-section catalytic section 1 absorbs water vapor, carbon oxides, nitrogen oxides, and sulfur oxides. The decomposition products absorbed by the I-section catalytic section 1 enter the II-section catalytic section 2 through quartz wool. The II-section catalytic section 2 absorbs hydrocarbons, oily substances, and part of the nitrogen oxides in the decomposition products; the water vapor, nitrogen oxides, and sulfur oxides generated by the absorption reaction in the II-section catalytic section 2 are absorbed in the III-section catalytic section 3; the remaining decomposition products enter the amalgamation tube from the discharge port. When all the remaining gases and decomposition products have passed through the amalgamation tube, heat the amalgamation tube to release mercury vapor; the carrier gas brings the mercury vapor into the single-wavelength optical path absorption cell, and measures the absorption of mercury at a wavelength of 253.7 nm.

[0101] Result data:

[0102] The mercury absorption of the gas sample purified by the automatic mercury analyzer catalytic tube of Example 1 is 0.009 mg / L; compared with the mercury content of 0.01 mg / L in the original sample water, the detection error is 10%;

[0103] Example 2: Preparation of the automatic mercury analyzer catalytic tube

[0104] Step 1: Fill quartz wool into the quartz tube from the inlet of the quartz tube, block the outlet of the quartz tube to prevent the catalyst from leaking;

[0105] Step 2: Weigh 2 g of manganese acetate, 3 g of calcium nitrate, 4 g of magnesium nitrate, and 2 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate to dryness, calcine at 350 °C for 1 hour, and then calcine at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide. Crush and sieve it, and select 50 mesh. Weigh 98.7 g of aluminum nitrate nonahydrate, 18 g of cobalt nitrate hexahydrate, 37 g of cerium nitrate hexahydrate, and 3 g of cesium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, adjust the pH value to about 9 with ammonia water, let it stand for 24 hours, filter, wash, dry at 120 °C for 24 hours, calcine at 550 °C for 4 hours (heating rate 3 °C / min), crush and sieve it, and select 50 mesh. Weigh 8 g of manganese acetate, 3 g of calcium nitrate, and 2 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate to dryness, calcine at 350 °C for 1 hour, and then calcine at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, and potassium oxide. Crush and sieve it, and select 50 mesh.

[0106] Step 3: Fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, and potassium oxide into a quartz tube with a filling length of 2.5 cm, and then fill quartz wool for isolation to form the III-section catalytic section 3. Then fill the mixed particles of the complex mixture of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide into the quartz tube with a filling length of 6.5 cm, fill quartz wool for isolation to form the II-section catalytic section 2. Finally, fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide into the quartz tube with a filling length of 3.5 cm, and finally fill quartz wool for isolation to form the I-section catalytic section 1, and combine them to make a catalytic tube for gas purification of an automatic mercury analyzer.

[0107] Perform a purification experiment on the sample water with a mercury content of 0.01 mg / L using the automatic mercury analyzer catalytic tube obtained in Example 2. Feed the sample water into the decomposition furnace. The sample water is dried and decomposed in the decomposition furnace, and the decomposition products include carbonaceous water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products are directly transported into the furnace catalytic tube through oxygen. The decomposition products enter the tube body feed port, pass through the I-section catalytic section 1. The I-section catalytic section 1 absorbs water vapor, carbon oxides, nitrogen oxides, and sulfur oxides. The decomposition products absorbed by the I-section catalytic section 1 enter the II-section catalytic section 2 through quartz wool. The II-section catalytic section 2 absorbs hydrocarbons, oily substances, and some nitrogen oxides in the decomposition products. The water vapor, nitrogen oxides, and sulfur oxides generated by the absorption reaction in the II-section catalytic section 2 are absorbed in the III-section catalytic section 3. The remaining decomposition products enter the amalgamation tube from the discharge port. When all the remaining gases and decomposition products pass through the amalgamation tube, heat the amalgamation tube to release vapor mercury. The carrier gas brings the mercury vapor into a single-wavelength optical path absorption cell, and the absorption of mercury is measured at a wavelength of 253.7 nm.

[0108] Result data:

[0109] The mercury absorption of the gas sample purified by the catalytic tube of the automatic mercury analyzer in Example 1 is 0.0092 mg / L; compared with the mercury content of 0.01 mg / L in the original sample water, the detection error is 8%;

[0110] Example 3. Preparation of the catalytic tube of the automatic mercury analyzer

[0111] Step 1. Fill quartz wool into the quartz tube from the inlet of the quartz tube, block the outlet of the quartz tube to prevent the catalyst from leaking out;

[0112] Step 2. Weigh 4 g of manganese acetate, 3 g of calcium nitrate, 4 g of magnesium nitrate, and 2 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate and dry, calcine at 350 °C for 1 hour, and calcine at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide. Crush and screen, and select 50 meshes; Weigh 74 g of aluminum nitrate nonahydrate, 12 g of cobalt nitrate hexahydrate, 37 g of cerium nitrate hexahydrate, and 3 g of cesium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, adjust the pH value to about 9 with ammonia water, let stand for 24 hours, filter, wash, dry at 120 °C for 24 hours, calcine at 550 °C for 4 hours (heating rate 3 °C / min), crush and screen, and select 50 meshes; Weigh 6 g of manganese acetate, 3 g of calcium nitrate, and 2 g of potassium nitrate, dissolve them in an appropriate amount of water, stir for 1 hour, evaporate and dry, calcine at 350 °C for 1 hour, and calcine at 600 °C for 2 hours to finally form a complex mixture of manganese dioxide, calcium oxide, and potassium oxide. Crush and screen, and select 50 meshes.

[0113] Step 3. Fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, and potassium oxide into the quartz tube, with a filling length of 2.5 cm, and then fill quartz wool for isolation to form the III-section catalytic section 3; then fill the mixed particles of the complex mixture of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide into the quartz tube, with a filling length of 6.5 cm, fill quartz wool for isolation to form the II-section catalytic section 2; finally, fill the mixed particles of the complex mixture of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide into the quartz tube, with a filling length of 3.5 cm, and finally fill quartz wool for isolation to form the I-section catalytic section 1, and combine them to make the catalytic tube for gas purification of the automatic mercury analyzer;

[0114] The catalytic tube of the automatic mercury analyzer obtained in Example 3 was used to conduct a purification experiment on sample water with a mercury content of 0.01 mg / L. The sample water was fed into the decomposition furnace, where it was dried and decomposed. The decomposition products included water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products were directly transported into the furnace's catalytic tube through oxygen. The decomposition products entered the tube body's feed port and passed through the first-stage catalytic section 1. The first-stage catalytic section 1 absorbed water vapor, carbon oxides, nitrogen oxides, sulfur oxides, and halogens. The decomposition products absorbed by the first-stage catalytic section 1 passed through quartz wool and entered the second-stage catalytic section 2. The second-stage catalytic section 2 absorbed hydrocarbons, oily substances, and some nitrogen oxides of the decomposition products. The water vapor, nitrogen oxides, and sulfur oxides generated from the absorption reaction in the second-stage catalytic section 2 were absorbed in the third-stage catalytic section 3. The remaining decomposition products entered the amalgamation tube from the discharge port. After all the remaining gases and decomposition products passed through the amalgamation tube, the amalgamation tube was heated to release mercury vapor. The carrier gas carried the mercury vapor into a single-wavelength optical path absorption cell, and the absorption of mercury was measured at a wavelength of 253.7 nm.

[0115] Result data:

[0116] The mercury absorption of the gas sample purified by the catalytic tube of the automatic mercury analyzer in Example 1 was 0.0095 mg / L; compared with the mercury content of 0.01 mg / L in the original sample water, the detection error was 5%.

[0117] Example 4. Preparation of the catalytic tube of the automatic mercury analyzer

[0118] Step 1. Fill quartz wool into the quartz tube from the inlet of the quartz tube and block the outlet of the quartz tube to prevent the catalyst from leaking out.

[0119] Step 2.

[0120] Mix 3 grams of manganese dioxide, 1 gram of calcium oxide, and 1 gram of potassium oxide, then pass through a 50-mesh sieve. Fill the obtained mixed particles into the quartz tube with a filling length of 1.5 cm, and then fill quartz wool for isolation to form the third-stage catalytic section 3. Then mix 4 grams of aluminum oxide, 3 grams of cobalt tetroxide, 1 gram of cerium dioxide, and 1 gram of cesium oxide, pass through a 50-mesh sieve, fill the obtained mixed particles into the quartz tube with a filling length of 5.5 cm, and fill quartz wool for isolation to form the second-stage catalytic section 2. Finally, mix 2 grams of manganese dioxide, 1 gram of calcium oxide, 1 gram of magnesium oxide, and 1 gram of potassium oxide, pass through a 50-mesh sieve, fill the obtained mixed particles into the quartz tube with a filling length of 2.5 cm, and finally fill quartz wool for isolation to form the first-stage catalytic section 1, and combine them to make the catalytic tube for gas purification of the automatic mercury analyzer.

[0121] The purification experiment was carried out on the sample water with a mercury content of 0.01 mg / L using the catalytic tube of the automatic mercury analyzer obtained in Example 4. The sample water was fed into the decomposition furnace, where the sample water was dried and decomposed. The decomposition products included water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products were directly transported into the furnace catalytic tube through oxygen. The decomposition products entered the tube body feed port, passed through the first-stage catalytic section 1. The first-stage catalytic section 1 absorbed water vapor, carbon oxides, nitrogen oxides, sulfur oxides, and halogens. The decomposition products absorbed by the first-stage catalytic section 1 passed through the quartz wool and entered the second-stage catalytic section 2. The second-stage catalytic section 2 absorbed hydrocarbons, oily substances, and some nitrogen oxides of the decomposition products. The water vapor, nitrogen oxides, and sulfur oxides generated by the absorption reaction in the second-stage catalytic section 2 were absorbed in the third-stage catalytic section 3. The remaining decomposition products entered the amalgamation tube from the discharge port. After all the remaining gases and decomposition products passed through the amalgamation tube, the amalgamation tube was heated to release vapor mercury. The carrier gas brought the mercury vapor into the single-wavelength optical path absorption cell, and the absorption of mercury was measured at a wavelength of 253.7 nm.

[0122] Result data:

[0123] The mercury absorption amount of the gas sample purified by the catalytic tube of the automatic mercury analyzer in Example 1 was 0.0095 mg / L; compared with the mercury content of 0.01 mg / L in the original sample water, the detection error was 5%;

[0124] Example 5. Preparation of the catalytic tube of the automatic mercury analyzer

[0125] Step 1: Fill quartz wool into the quartz tube from the inlet of the quartz tube, block the outlet of the quartz tube to prevent the catalyst from leaking out;

[0126] Step 2: Mix 3 grams of manganese dioxide, 1 gram of calcium oxide, and 1 gram of potassium oxide, sieve them through a 60-mesh sieve, fill the obtained mixed particles into the quartz tube, with a filling length of 3.5 cm, and then fill quartz wool for isolation to form the third-stage catalytic section 3; then mix 4 grams of aluminum oxide, 3 grams of cobalt tetroxide, 1 gram of cerium dioxide, and 1 gram of cesium oxide, sieve them through a 60-mesh sieve, fill the obtained mixed particles into the quartz tube, with a filling length of 7.5 cm, fill quartz wool for isolation to form the second-stage catalytic section 2; finally, mix 2 grams of manganese dioxide, 1 gram of calcium oxide, 1 gram of magnesium oxide, and 1 gram of potassium oxide, sieve them through a 60-mesh sieve, fill the obtained mixed particles into the quartz tube, with a filling length of 4.5 cm, and finally fill quartz wool for isolation to form the first-stage catalytic section 1, and combine them to make the catalytic tube for gas purification of the automatic mercury analyzer;

[0127] The catalytic tube of the automatic mercury analyzer obtained in Example 5 was used to conduct a purification experiment on the sample water with a mercury content of 0.01 mg / L. The sample water was fed into the decomposition furnace, where it was dried and decomposed. The decomposition products included water vapor, carbon oxides, nitrogen oxides, sulfur oxides, halogens, hydrocarbons, oily substances, etc. The decomposition products were directly transported into the furnace's catalytic tube by oxygen. The decomposition products entered the tube body's feed port, passed through the first-stage catalytic section 1. The first-stage catalytic section 1 absorbed water vapor, carbon oxides, nitrogen oxides, sulfur oxides, and halogens. The decomposition products absorbed by the first-stage catalytic section 1 passed through the quartz wool and entered the second-stage catalytic section 2. The second-stage catalytic section 2 absorbed hydrocarbons, oily substances, and some nitrogen oxides in the decomposition products. The water vapor, nitrogen oxides, and sulfur oxides generated from the absorption reaction in the second-stage catalytic section 2 were absorbed in the third-stage catalytic section 3. The remaining decomposition products entered the amalgamation tube from the discharge port. After all the remaining gases and decomposition products passed through the amalgamation tube, the amalgamation tube was heated to release mercury vapor. The carrier gas carried the mercury vapor into the single-wavelength optical path absorption cell, and the absorption of mercury was measured at a wavelength of 253.7 nm.

[0128] Result data:

[0129] The mercury absorption of the gas sample purified by the catalytic tube of the automatic mercury analyzer in Example 1 was 0.0096 mg / L; compared with the mercury content of 0.01 mg / L in the original sample water, the detection error was 4%.

[0130] Comparative Example 6

[0131] The catalytic tube for eliminating matrix interference was prepared using Patent CN201710491421.2.

[0132] Step 1: Fill quartz wool into the quartz tube from the inlet of the quartz tube, block the outlet of the quartz tube to prevent the catalyst from leaking out.

[0133] Step 2: First, fill 2 g of calcium oxide with a particle size of 50 mesh into the quartz tube in sequence, fill a ceramic fiber layer for isolation to form the third-stage catalytic section 3. Then, fill 4 g of cobalt tetroxide with a particle size of 50 mesh into the quartz tube, fill a ceramic fiber layer for isolation to form the second-stage catalytic section 2. Finally, fill 4 g of manganese tetroxide with a particle size of 50 mesh into the quartz tube from the inlet of the tube body, fill a ceramic fiber layer for isolation to form the first-stage catalytic section 1, and combine them to make the catalytic tube for gas purification of the automatic mercury analyzer.

[0134] Test Example 7

[0135] After the catalytic tube of the automatic mercury analyzer obtained in Example 3 and the catalytic tube for eliminating matrix interference obtained in Comparative Example 6 were used to purify the gas of the sample with a mercury content of 0.01 mg / L at the same time, their mercury contents were detected.

[0136] Results: The mercury absorption amount in the detection result of Example 3 was: 0.0095 mg / L; the mercury absorption amount in the detection result of Comparative Example 6 was 0.0062 mg / L;

[0137] After the gas to be measured passed through the catalytic tube of Comparative Example 6 and was purified, only a mercury absorption amount of 0.0062 mg / L was detected; after the gas to be measured passed through the catalytic tube of the automatic mercury analyzer in Example 3 of the present invention and was purified, a mercury absorption amount of 0.0095 mg / L was detected; after analysis, there were still components such as water vapor, nitrogen oxides, and sulfur oxides in the gas to be measured after being purified by the catalytic tube of Comparative Example 6, which affected the detection result during the mercury absorption detection, and only 0.0062 mg / L was detected, with an error of 38%; after the gas to be measured passed through the catalytic tube of the automatic mercury analyzer in Example 3 of the present invention and was purified, a mercury absorption amount of 0.0095 mg / L was detected, and the error was only 5%;

[0138] It shows that after the gas to be measured was purified by the catalytic tube of the automatic mercury analyzer prepared in Example 3 using the method of the present invention, the error of the detected mercury absorption amount was greatly reduced compared with that of Comparative Example 6; the purification effect of the catalytic tube in Example 3 was much better than that of the catalytic tube in Comparative Example 6;

[0139] The catalytic tubes of the automatic mercury analyzers obtained in other embodiments of the present invention have similar beneficial effects as described above;

[0140] The catalytic tubes of the automatic mercury analyzers obtained in other embodiments of the present invention have similar beneficial effects as described above.

[0141] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field according to the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. An automatic mercury analyzer catalytic tube, characterized in that it includes a tube body and three catalytic sections; In the three catalytic sections, the first catalytic section (1) includes manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide; In the three catalytic sections, the second catalytic section (2) includes aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide; in the three catalytic sections, the third catalytic section (3) includes manganese dioxide, calcium oxide, and potassium oxide; The tube body is a straight tube with open ends. The feed inlet is located at the left part of the tube body, and the discharge outlet is located at the right part of the tube body. The opening size of the feed inlet is larger than that of the discharge outlet; There is insulating cotton between the three catalytic sections; In the three catalytic sections, in the first catalytic section (1), the length of the catalytic section is 1 - 8 cm; In the three catalytic sections, in the second catalytic section (2), the length of the catalytic section is 5 - 10 cm; In the three catalytic sections, in the third catalytic section (3), the length of the catalytic section is 1 - 5 cm; In the three catalytic sections, the length ratio (cm) between the first, second, and third catalytic sections is (3 - 4):(6 - 7):(2 - 3); In the three catalytic sections, in the first, second, and third catalytic sections, the particle size of the catalyst is 40 - 60 mesh; In the three catalytic sections, in the first catalytic section (1), the mass ratio of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide is (1 - 3):(0.5 - 2):(0.5 - 2):(0.5 - 2); In the three catalytic sections, in the second catalytic section (2), the mass ratio of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide is (3 - 5):(2 - 4):(0.5 - 2):(0.5 - 2); In the three catalytic sections, in the third catalytic section (3), the mass ratio of manganese dioxide, calcium oxide, and potassium oxide is (2 - 4):(0.5 - 2):(0.5 - 2).

2. The preparation method of the automatic mercury analyzer catalytic tube according to claim 1, characterized in that the preparation method specifically includes the following steps: Step 1: Fill the insulating cotton into the tube body from the inlet of the tube body, block the outlet of the tube body to prevent the catalyst from leaking; Step 2: Fill the catalyst particles into the tube body of Step 1 from the inlet of the tube body respectively. After filling each section of the catalyst, fill the insulating cotton for isolation, and repeat three times to form the first, second, and third catalytic sections (3) in sequence from front to back, and combine them to make the catalytic tube for gas purification of the automatic mercury analyzer.

3. The preparation method according to claim 2, characterized in that in Step 2, the first catalytic section (1) is: a mixed particle of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide; the second catalytic section (2) is: a mixed particle of aluminum oxide, cobalt tetroxide, cerium dioxide, and cesium oxide; the third catalytic section (3) is: a mixed particle of manganese dioxide, calcium oxide, and potassium oxide.

4. The preparation method according to claim 2, characterized in that in Step 2, the mass ratio (g:g) of the mixed particles of manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide in the first catalytic section (1) is (1 - 3):(0.5 - 2):(0.5 - 2):(0.5 - 2); The mass ratio (g:g) of the alumina, cobalt tetroxide, cerium dioxide, and cesium oxide mixed particles in the second-stage catalytic section (2) is (3-5):(2-4):(0.5-2):(0.5-2); The mass ratio (g:g) of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the third-stage catalytic section (3) is (2-4):(0.5-2):(0.5-2).

5. The preparation method according to claim 2, characterized in that, in step 2, the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the first-stage catalytic section (1) is 40-60 mesh; the particle size of the alumina, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section (2) is 40-60 mesh; the particle size of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the second-stage catalytic section (2) and the third-stage catalytic section (3) is 40-60 mesh.

6. The preparation method according to claim 2, characterized in that, in step 2, the length of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the first-stage catalytic section (1) is 2-5 cm; the length of the alumina, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section (2) is 5-8 cm; the length of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the second-stage catalytic section (2) and the third-stage catalytic section (3) is 1-4 cm.

7. The preparation method according to claim 2, characterized in that, in step 2, the mass ratio (g:g) of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the first-stage catalytic section (1) is 2:1:1:1; the mass ratio (g:g) of the alumina, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section (2) is 4:3:1:1; the mass ratio (g:g) of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the third-stage catalytic section (3) is 3:1:1; the length of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the first-stage catalytic section (1) is 3.5 cm; the particle size of the manganese dioxide, calcium oxide, magnesium oxide, and potassium oxide mixed particles in the first, second, and third-stage catalytic sections (3) is 50 mesh; the length of the alumina, cobalt tetroxide, cerium dioxide, and cesium oxide in the second-stage catalytic section (2) is 6.5 cm; the length of the manganese dioxide, calcium oxide, and potassium oxide mixed particles in the third-stage catalytic section (3) is 2.5 cm.

8. Use of the catalytic tube of the automatic mercury analyzer according to claim 1 in gas purification.

9. Use of the catalytic tube of the automatic mercury analyzer obtained by the preparation method according to any one of claims 2-7 in gas purification.

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