Equipment for testing content of free carbon in boron carbide

Abstract

The invention discloses equipment for testing the content of free carbon in boron carbide, and relates to the technical field of detection equipment, the equipment comprises a control system and further comprises a case, the control system is installed on the case, a reaction unit is further arranged in the case, the output end of the reaction unit is connected with an electrolysis unit, a drying unit is arranged between the reaction unit and the electrolysis unit, and the drying unit is connected with the electrolysis unit. A PH value detection unit is arranged in the electrolysis unit; the control system controls the reaction unit to promote generation of carbon dioxide, the generated carbon dioxide is dried by the drying unit, enters the electrolysis unit to react and then is electrolyzed, and the content of free carbon is calculated according to the quantity of charges consumed by the electrolysis unit. The reaction unit, the electrolysis unit and the PH value testing unit used for detecting the completion degree of the electrolysis unit are integrated on the case, the control system controls the electrolysis reaction, rapid detection of free carbon such as boron carbide can be achieved through the number of charges consumed by electrolysis, and meanwhile the pH value testing unit is adopted for judging the completion degree. And the test efficiency and accuracy of the device are further improved.

Description

Technical Field

[0001] The invention relates to the technical field of detection equipment, in particular to a testing device for free carbon content in boron carbide. Background Art

[0002] Boron carbide (B4C) is an important component of abrasives. It has the advantages of high hardness (second only to diamond and cubic boron nitride), high elastic modulus, low density, low thermal expansion coefficient, high thermal conductivity, good thermal stability, etc. It is widely used in many fields such as grinding media, wear-resistant coatings, nuclear reactor control rods and shielding rods, lightweight armor, molten metal crucibles, etc. In particular, with the proposal of the "dual carbon" goal in recent years, the nuclear energy industry has developed vigorously, and boron carbide, as a core neutron absorption material, has become a hot spot in industry research. In the process of producing and using boron carbide, the requirements for its quality standards are particularly stringent, especially for the content of free carbon in boron carbide, where free carbon refers to free carbon that is not combined with boron to form boron carbide compounds in boron carbide materials. Its presence may affect the performance of the material, such as reducing hardness and flexural strength, and easily reacting with the environment. Testing the free carbon content is an important step to ensure the quality of boron carbide products, and its content directly affects the performance and application areas of the material.

[0003] At present, domestic enterprises generally use the wet oxidation decomposition combined with gas absorption weight method in JB / T 7993-2012 "Chemical Analysis Method of Boron Carbide" to measure the content of free carbon, that is, the boron carbide sample is placed in a hot potassium dichromate-concentrated sulfuric acid solution, and high-temperature treatment is carried out in an environment of oxygen and water vapor to completely oxidize the free carbon into carbon dioxide, and then the released carbon dioxide is collected and measured by gas absorption weight method, which involves letting the gas pass through a device containing an absorption liquid. By weighing the mass change of the device before and after absorption, the weight of carbon dioxide can be calculated, and then the content of free carbon in the original sample can be deduced. In addition, this test method is bottled in a series of flask devices, and it is difficult to meet the requirements of enterprises for accurate testing of free carbon in boron carbide without special test equipment.

[0004] In the prior art, the Chinese invention patent with publication number CN117805052A and publication date 2024-04-02 discloses a device and method for determining the free carbon content in boron carbide. The sodium dichromate-concentrated sulfuric acid-potassium iodate system is used as an oxidant, and a calibrated sodium hydroxide solution is used to collect the carbon dioxide generated by the reaction. Barium salt is used as a carbonate masking agent, and the acid-base titration method is used to obtain the free carbon content in the sample. The device for determining the free carbon content in boron carbide involved is composed of an oxidation device, a gas absorption device and a titration device. The gas absorption device is a set of absorption bottles connected in series and a precipitation bottle. The air inlet end of the absorption bottle group is connected to the oxidation device, and the exhaust end is connected to the precipitation bottle; the absorption bottle contains a calibrated sodium hydroxide solution, and the precipitation bottle contains a mixed solution of barium chloride and sodium hydroxide. Although the patent can obtain the measurement of the free carbon content through the carbon dioxide reaction, a series of flasks still need to be assembled, and the testing process is complicated. Summary of the invention

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a testing equipment for free carbon content in boron carbide, which solves the problem that the prior art uses wet oxidation decomposition combined with gas absorption weight method to measure free carbon content, requires a series of flasks to be assembled, and has a complicated testing process.

[0006] The technical solution of the present invention is achieved as follows: a test device for the free carbon content in boron carbide, including a control system and a chassis, the control system is installed on the chassis, a reaction unit is also arranged in the chassis, the output end of the reaction unit is connected to an electrolysis unit, a drying unit is arranged between the reaction unit and the electrolysis unit, and a pH value detection unit is arranged in the electrolysis unit; the control system controls the reaction unit to promote the generation of carbon dioxide and dries the generated carbon dioxide through the drying unit and enters the electrolysis unit for reaction and then electrolysis, and the free carbon content is calculated by the amount of charge consumed by the electrolysis unit.

[0007] Further preferably, the input end of the reaction unit is connected to a power gas source; the power gas source is a nitrogen gas source.

[0008] Further preferably, the reaction unit comprises a flask, and a condensation portion is provided on the gas outlet of the flask.

[0009] Further preferably, a heater is installed at the lower part of the flask, and the heater is connected to the control system.

[0010] Further preferably, the drying unit comprises a washing bottle 1 and a washing bottle 2, the air inlet end of the washing bottle 1 is connected to the flask, the air inlet end of the washing bottle 2 is connected to the washing bottle 1, and the air outlet end of the washing bottle 2 is connected to the electrolysis unit.

[0011] Further preferably, the first washing bottle contains anhydrous calcium chloride, and the second washing bottle contains silver metavanadate.

[0012] Further preferably, the electrolysis unit comprises a cathode cup and an anode cup connected to the cathode cup, wherein a cathode electrode connected to the control system is disposed in the cathode cup, and an anode electrode connected to the control system is disposed in the anode cup.

[0013] Further preferably, a driven permanent magnet for stirring the solution is provided in the cathode cup, and a magnetic stirring base corresponding to the driven permanent magnet is provided below the cathode cup, and the magnetic stirring base is connected to the control system.

[0014] Further preferably, the cathode cup and the anode cup contain a barium perchlorate solution, and the carbon dioxide generated by the reaction unit reacts with the barium perchlorate solution to generate perchloric acid, causing the pH value detection unit to detect a pH value change, and then electrolysis is performed through the cathode electrode and the anode electrode until the pH value detection unit detects that the pH value has returned to its original value.

[0015] Further preferably, the pH value detection unit includes a pH meter test head, which is placed on the cathode cup and connected to the control system.

[0016] The beneficial effects of the present invention are as follows: the device integrates the reaction unit, the electrolysis unit and the pH value test unit for detecting the completion of electrolysis of the electrolysis unit into the chassis, the control system controls the electrolysis reaction and can realize the rapid detection of free carbon such as boron carbide through the amount of charge consumed by electrolysis, and at the same time, the pH value detection unit is used to determine whether the electrolysis is completed, further improving the test efficiency and accuracy of the device. The reaction unit uses a flask with condensation, which can realize the first step of processing the reaction gas while realizing the reaction, and the purpose of the heater is to promote the reaction rate and accelerate the generation of carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] In the figure: 1. condensation part, 2. flask, 3. drying unit, 4. pH meter test head, 5. pH meter display screen, 6. end point indicator light, 7. electrolysis button, 8. working knob, 9. electrolysis speed adjustment knob, 10. charge quantity display screen, 11. temperature controller, 12. heating indicator light, 13. heating knob, 14. installation panel, 15. cathode cup knob, 16. cathode cup stirring indicator light, 17. cathode cup speed display screen, 18. driven permanent magnet, 19. cathode electrode, 20. cathode cup, 21. anode cup, 22. anode electrode, 23. heater, 24. chassis. DETAILED DESCRIPTION

[0020] 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.

[0021] like Figure 1 As shown, in Example 1, a test equipment for free carbon content in boron carbide includes a control system and a chassis 24. The control system is installed on the chassis 24. A reaction unit is also arranged in the chassis 24. The output end of the reaction unit is connected to an electrolysis unit. A drying unit 3 is arranged between the reaction unit and the electrolysis unit. A pH value detection unit is arranged in the electrolysis unit. The control system controls the reaction unit to promote the generation of carbon dioxide and dries the generated carbon dioxide through the drying unit 3 and enters the electrolysis unit for reaction before electrolysis, and calculates the free carbon content by the amount of charge consumed by the electrolysis unit. The device integrates the reaction unit, the electrolysis unit, and the pH value test unit for detecting the electrolysis degree of the electrolysis unit into the chassis 24. The control system controls the electrolysis reaction and can realize the rapid detection of free carbon such as boron carbide by the amount of charge consumed by electrolysis. At the same time, the pH value detection unit is used to determine the electrolysis degree, which further improves the test efficiency and accuracy of the device. The equipment occupies a small area, and the process control is convenient and the result display is more intuitive.

[0022] Further, the input end of the reaction unit is connected to a power gas source; the power gas source is a nitrogen gas source. The nitrogen gas source is used as a power gas source, and the nitrogen gas source drives the carbon dioxide generated in the reaction unit to evenly enter the electrolysis unit and fully react with the reaction solution in the electrolysis unit. The reaction unit includes a flask 2, and a condensation part 1 is provided at the gas outlet of the flask 2. The condensation part 1 cools the generated carbon dioxide and volatile water vapor, and is placed to bring heat into the cathode to affect the pH value measurement. A heater 23 is installed at the lower part of the flask 2, and the heater 23 is connected to the control system. The control system controls the heater 23 to heat the flask 2, thereby realizing the control of the reaction rate of the free carbon in the boron carbide and the chromium sulfate iodic acid solution. The reaction unit adopts a flask 2 with a condenser, and the first step of processing the reaction gas can be realized while realizing the reaction. The purpose of the heater 23 is to promote the reaction rate and accelerate the generation of carbon dioxide. The heater 23 is an electric heater 23, and the control system includes a temperature controller 11 connected to the electric heater 23. The temperature controller 11 is installed on a mounting plate 14, and the mounting plate 14 is installed on a chassis 24. The mounting plate 14 is provided with a heating knob 13 and a heating indicator light 12 that cooperate with the temperature controller 11. The heating knob 13 is adjusted to control the temperature of the electric heater 23. The temperature controller 11 can intuitively and clearly display the heating temperature, and the control effect is very good.

[0023] like Figure 1 As shown, Example 2 is a test equipment for the free carbon content in boron carbide. The difference from the technical solution of Example 1 is that the drying unit 3 includes a gas washing bottle 1 and a gas washing bottle 2. The air inlet end of the gas washing bottle 1 is connected to the flask 2, the air inlet end of the gas washing bottle 2 is connected to the gas washing bottle 1, and the air outlet end of the gas washing bottle 2 is connected to the electrolysis unit. The gas washing bottle 1 and the gas washing bottle 2 are installed in the chassis 24 to prevent the mobile device from affecting the sealing of the connection between the gas washing bottle, the flask 2 and the electrolysis unit, and further improve the integration effect. The gas washing bottle 1 contains anhydrous calcium chloride to further absorb water vapor in the gas; the gas washing bottle 2 contains silver metavanadate to remove sulfur dioxide that may be contained in the gas to avoid affecting the test results.

[0024] In this embodiment, the electrolysis unit includes a cathode cup 20 and an anode cup 21 connected to the cathode cup 20. The cathode cup 20 is provided with a cathode electrode 19 connected to the control system, and the anode cup 21 is provided with an anode electrode 22 connected to the control system. The cathode cup 20 and the anode cup 21 are both provided with cup covers that match the electrodes, which are used to fix the electrode positions without affecting the discharge of nitrogen. The cathode electrode 19 and the anode electrode 22 are both connected to the control system. The control system is also provided with an electrolysis button 7 for controlling the electrolysis of the electrodes, and the electrolysis button 7 is installed on the mounting plate 14. The cathode cup 20 is provided with a driven permanent magnet 18 for stirring the solution. A magnetic stirring base corresponding to the driven permanent magnet 18 is provided below the cathode cup 20. The magnetic stirring base is connected to the rotary switch of the control system. The control system controls the magnetic stirring base to drive the driven permanent magnet 18 to rotate and then drive the liquid in the cup to stir, which can accelerate the reaction of carbon dioxide with the solution and the electrolysis reaction. The stirring structure in the cathode cup 20 can also adopt the brushless DC electromagnetic stirring and brushed DC electromagnetic stirring in the prior art, which will not be described in detail here. The control system is also provided with a cathode cup 20 stirring indicator light 16, a cathode cup 20 speed display screen 17, a rotary knob for controlling the speed of the driven permanent magnet 18, and a charge display screen 10 for detecting the amount of electricity consumed by electrolysis. The charge display screen 10 displays a value that changes from the start of electrolysis to the pH value when electrolysis stops at the initial state.

[0025] In this embodiment, the cathode cup 20 and the anode cup 21 contain a barium perchlorate solution, and the carbon dioxide generated by the reaction unit reacts with the barium perchlorate solution to generate perchloric acid, so that the pH value detection unit detects a change in the pH value, and the cathode electrode 19 and the anode electrode 22 are electrolyzed until the pH value detection unit detects that the pH value is restored to the original value. The pH value detection unit includes a pH meter test head 4, which is fixed on the cup cover. The pH meter test head 4 is placed in the cathode cup 20 and in contact with the liquid. The pH meter test head 4 is connected to the pH meter display screen 5 of the control system. When the state of the pH meter display screen 5 is the initial value, the initial state indicator light is on. The pH meter display value is a key indicator for judging the amount of free carbon. The pH value of the solution tested by the pH meter test head 4 is more accurate, which improves the accuracy of free carbon measurement.

[0026] The other structures are the same as those in Example 1.

[0027] like Figure 1 As shown, Example 3, a testing device for free carbon content in boron carbide, includes a control system, the control system is connected to a power line, and the power line is connected to an external power source for supplying power to the control system.

[0028] Reaction unit: It includes nitrogen gas source, heater, reaction flask, dry gas washing bottle, anode cup and cathode cup. The reaction flask is placed on the heater and heated by the heater. The reaction flask is provided with a condenser for condensation. The dry bottle has two components, one of which contains anhydrous calcium chloride to absorb water vapor in the reaction gas, and the other contains silver metavanadate to absorb sulfur dioxide in carbon dioxide. The reaction flask, dry gas washing bottle and cathode cup are connected by a gas pipe, and the other end of the reaction flask is connected to an external nitrogen gas source. During the reaction, nitrogen is used as a power gas to bring the carbon dioxide generated by the reaction into the cathode cup for absorption.

[0029] Control system: heating control knob, temperature controller, heating indicator light, pH meter head, cathode cup stirring control knob, electrolysis control button, heating circuit connected to the heater, electrolysis circuit; when the heating knob 13 is turned on, the heating indicator light 12 is on; the pH meter head 5 is installed on the cathode cup 20, which is used to measure the pH value of the solution in the cathode cup; it also includes a cathode cup stirring indicator light 16, and when the cathode cup stirring control knob 15 is turned on, the indicator light 16 is on; the electrolysis control button mainly includes an end point indicator light 6, an electrolysis button 7, a working knob 8, and an electrolysis speed adjustment knob 9. The pH meter display screen 5 displays the pH value of the solution in the cathode cup in real time, thereby realizing the ability to observe the pH changes in the solution in real time. The charge display screen 10 displays the electrolysis charge in real time, and the cathode cup speed display screen 17 displays the cathode cup rotor speed in real time.

[0030] The cathode electrode 19 placed on the cathode cup, the magnetic rotor 18 in the cathode cup, and the anode electrode 22 on the anode cup. After the electrolysis switch is turned on, electrolysis is performed through the cathode electrode 19 and the anode electrode 22; after the cathode cup stirring control knob 15 is turned on, the magnetic rotor 18 in the cathode cup starts to rotate to ensure that the solution is evenly mixed.

[0031] The measurement control, display device and circuit of reactor heating, pH value determination, gas absorption, solution electrolysis, charge determination and calculation are integrated into one equipment, and the free carbon content in boron carbide is accurately tested based on a single equipment. Compared with the existing JB / T 7993-2012 "Chemical Analysis Method of Boron Carbide", the electrolysis method is more accurate for testing the free carbon content, and the integrated modular technology is used to effectively integrate the test vessels, so the equipment occupies a small area, the process control is convenient and the result display is more intuitive.

[0032] The specific measurement process of this device is:

[0033] 1. Add 100±20ml cathode cup solution into the cathode cup;

[0034] 2. Check the connecting air pipes and joints of the entire equipment to ensure good air tightness;

[0035] 3. Power on the equipment, turn on the cathode cup stirring knob, set the stirring speed to 600r / min, and observe whether the value displayed on the pH meter display screen 5 is between 9.70 and 10.00. If the displayed value is less than 9.70, press the electrolysis button 7. After the end point indicator 6 goes out, adjust the working knob 8 to the working state and start electrolysis until the pH value reaches 9.70. Assume that the pH value is 9.80 this time.

[0036] 4. Weigh 0.106g of boron carbide standard material and wrap it in aluminum foil. The standard material number is GBW06604, the nominal value of free carbon content is 0.436%, and the uncertainty is 0.035%.

[0037] 5. Add 30 mL of chromium sulfate iodic acid solution into the flask, connect nitrogen, and adjust the nitrogen flow rate to ensure that the bubbles in the cathode cup 20 emerge evenly;

[0038] 6. Operate the temperature controller 11, set the heating temperature to 230°C, turn on the heating knob 13, the heating indicator light 12 lights up, the heater 23 starts heating, and the temperature of the flask rises.

[0039] 7. When the temperature controller shows that the temperature reaches 230±3℃, start timing. After 5 minutes, put the sample wrapped in aluminum foil into the flask.

[0040] 8. Start timing after input. After 30 minutes, move the reaction container 2 out of the heater 23.

[0041] 9. Press the electrolysis button 7. After the end indicator light 6 goes out, adjust the working knob 8 to the working state and start electrolysis until the pH value reaches 9.80. Record the charge amount at this time as 13543 and adjust the working knob 8 to the closed state.

[0042] 10. Turn on nitrogen, move container 2 into heater 23, and restart timing.

[0043] 11. After 30 minutes, the reaction container 2 is removed from the heater 23, the heating knob 13 is turned off, and the heating indicator light 12 goes out.

[0044] 12. Adjust the working knob 8 to the working state and start electrolysis until the pH value reaches 9.80, and record the charge amount at this time as 13543. Adjust the working knob 8 to the closed state and record the charge amount at this time as 6262.

[0045] 13. After the test, restore the cathode cup solution and add 2 to 3 drops of (1+1) perchloric acid into the cathode cup. The solution becomes clear.

[0046] 14. Calculation of results:

[0047]

[0048] The nominal value of the standard material is 0.436%, the uncertainty is 0.035%, and the test result is 0.427%, which is within the uncertainty range of the standard material.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A testing device for free carbon content in boron carbide, including a control system, characterized in that: It also includes a chassis (24), a control system installed on the chassis (24), a reaction unit is also arranged in the chassis (24), an output end of the reaction unit is connected to an electrolysis unit, a drying unit (3) is arranged between the reaction unit and the electrolysis unit, and a pH value detection unit is arranged in the electrolysis unit; the control system controls the reaction unit to promote the generation of carbon dioxide and dries the generated carbon dioxide through the drying unit (3) and enters the electrolysis unit for reaction and then electrolysis, and calculates the free carbon content through the amount of charge consumed by the electrolysis unit.

2. The testing equipment for free carbon content in boron carbide according to claim 1, characterized in that: The input end of the reaction unit is connected to a power gas source; the power gas source is a nitrogen gas source.

3. The testing equipment for free carbon content in boron carbide according to claim 1, characterized in that: The reaction unit comprises a flask (2), and a condensation portion (1) is provided at the gas outlet of the flask (2).

4. The testing equipment for free carbon content in boron carbide according to claim 2, characterized in that: A heater (23) is installed at the bottom of the flask (2), and the heater (23) is connected to a control system.

5. The testing equipment for free carbon content in boron carbide according to any one of claims 1 to 4, characterized in that: The drying unit (3) comprises a first washing bottle and a second washing bottle, wherein the air inlet end of the first washing bottle is connected to the flask (2), the air inlet end of the second washing bottle is connected to the first washing bottle, and the air outlet end of the second washing bottle is connected to the electrolysis unit.

6. The testing equipment for free carbon content in boron carbide according to claim 5, characterized in that: The first gas washing bottle contains anhydrous calcium chloride, and the second gas washing bottle contains silver metavanadate.

7. The testing equipment for free carbon content in boron carbide according to any one of claims 1 to 4 and 6, characterized in that: The electrolysis unit comprises a cathode cup (20) and an anode cup (21) connected to the cathode cup (20); a cathode electrode (19) connected to a control system is arranged in the cathode cup (20); and an anode electrode (22) connected to the control system is arranged in the anode cup (21).

8. The testing equipment for free carbon content in boron carbide according to claim 7, characterized in that: A driven permanent magnet (18) is arranged in the cathode cup (20), and a magnetic stirring base corresponding to the driven permanent magnet (18) is arranged below the cathode cup (20), and the magnetic stirring base is connected to a control system.

9. The testing equipment for free carbon content in boron carbide according to claim 8, characterized in that: The cathode cup (20) and the anode cup (21) contain a barium perchlorate solution. The carbon dioxide generated by the reaction unit reacts with the barium perchlorate solution to generate perchloric acid, causing the pH value detection unit to detect a change in the pH value. The cathode electrode (19) and the anode electrode (22) are electrolyzed until the pH value detection unit detects that the pH value has returned to its original value.

10. The testing equipment for free carbon content in boron carbide according to claim 8 or 9, characterized in that: The pH value detection unit comprises a pH meter test head (4), the pH meter test head (4) is placed in the cathode cup (20), and the pH meter test head (4) is connected to a control system.

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