Method for detecting mixing amount of modified asphalt active warm mixing agent for prebaked anode

Abstract

The invention provides a method for detecting the mixing amount of a modified asphalt active warm mixing agent for a prebaked anode, and relates to the technical field of industrial detection. The method for detecting the mixing amount of the modified asphalt active warm-mixing agent for the prebaked anode comprises the following steps: preparing a sample: uniformly mixing a modified asphalt sample to be detected to ensure that the active warm-mixing agent is uniformly distributed in asphalt, and putting a proper amount of the sample into a sample crucible of a thermal analyzer to ensure that the surface of the sample is flat; carrying out thermogravimetric analysis, namely heating the sample by using a thermogravimetric analyzer, setting the heating speed to be 10-20 DEG C / min and the heating range to be room temperature to 800 DEG C, and in the heating process, recording a change curve of the sample mass along with the temperature, namely a thermogravimetric curve; differential thermogravimetric analysis: carrying out differential processing on the thermogravimetric curve to obtain a differential thermogravimetric curve, so as to recognize the change of the mass loss rate more clearly. The use amount of adopted samples is small, the samples cannot be damaged, chemical reagents are not needed, and chemical pollution and potential safety hazards are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of industrial detection, in particular to a method for detecting the dosage of a modified asphalt active warm mix agent for prebaked anodes. Background Art

[0002] Prebaked anodes are important materials in the aluminum electrolysis industry, and their quality directly affects the production efficiency and product quality of electrolytic aluminum. As the main binder of prebaked anodes, the performance of modified asphalt is crucial to the quality of the anode. In order to improve the construction performance and environmental friendliness of modified asphalt, active warm mix agents are usually added to it. However, during the production process, the amount of active warm mix agents in modified asphalt needs to be strictly controlled to ensure that the mechanical strength, conductivity and antioxidant properties of the anode meet the requirements.

[0003] At present, the detection methods of active warm mix agent dosage mainly include chemical titration and thermogravimetric analysis. The chemical titration method is complicated and time-consuming, and requires the use of a large amount of chemical reagents, which poses a safety hazard; although the thermogravimetric analysis method is simple to operate, it has low accuracy and is difficult to meet the requirements of detection accuracy and speed in industrial production. Therefore, the technicians in this field provide a detection method for the dosage of modified asphalt active warm mix agent for prebaked anode to solve the problems raised in the above background technology. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the shortcomings of the prior art, the present invention provides a method for detecting the dosage of modified asphalt active warm mix agent for prebaked anodes, which solves the problems that the chemical titration method is complicated and time-consuming to operate, and requires the use of a large amount of chemical reagents, posing a safety hazard; although the thermogravimetric analysis method is simple to operate, it has low accuracy and is difficult to meet the requirements of detection accuracy and speed in industrial production.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for detecting the dosage of modified asphalt active warm mix agent for prebaked anodes, comprising:

[0008] Sample preparation: Evenly mix the modified asphalt sample to be tested to ensure that the active warm mix agent is evenly distributed in the asphalt. Take an appropriate amount of sample and put it into the sample crucible of the thermal analyzer to ensure that the sample surface is flat;

[0009] Thermogravimetric analysis: use a thermogravimetric analyzer to heat the sample, with the heating rate set at 10 to 20 degrees Celsius per minute and the heating range from room temperature to 800 degrees Celsius. During the heating process, record the curve of the sample mass changing with temperature, i.e., the thermogravimetric curve;

[0010] Differential thermogravimetric analysis: Differentiate the thermogravimetric curve to obtain a differential thermogravimetric curve to more clearly identify the change in mass loss rate;

[0011] Characteristic peak identification: By analyzing the DTG curve, the characteristic peaks related to the decomposition of active warm mix agents are identified. The characteristic decomposition temperature of active warm mix agents usually appears in the following range:

[0012] 200 to 300 degrees Celsius: Decomposition of organic active ingredients;

[0013] 300 to 500 degrees Celsius: Decomposition of inorganic active ingredients;

[0014] Quantitative analysis: calculate the mass loss percentage of the active warm mix agent within the characteristic decomposition temperature range, establish a quantitative relationship model between the mass loss percentage and the dosage through standard samples with known active warm mix agent dosage, substitute the mass loss percentage of the sample to be tested into the model, and calculate the dosage of the active warm mix agent;

[0015] The result output is to output the calculated active warm mix agent dosage result, and judge it according to the preset quality standard to give a qualified or unqualified conclusion.

[0016] Preferably, the sample preparation comprises the following steps:

[0017] S1. Sample collection: randomly collect modified asphalt samples from the prebaked anode production line to ensure that the samples are representative. The sample volume should be sufficient for multiple repeated tests, usually 50 to 100 grams;

[0018] S2. Sample pretreatment: fully stir the collected modified asphalt samples at room temperature to ensure that the active warm mix agent is evenly distributed in the asphalt. If the sample is too viscous, it can be heated to 50 to 80 degrees Celsius to reduce the viscosity and facilitate stirring;

[0019] S3. Sample weighing: Use a precision electronic balance to weigh 10 to 20 mg of sample, accurate to 0.1 mg. When weighing, avoid the sample adhering to the weighing container to ensure weighing accuracy;

[0020] S4. Sample loading: Place the weighed sample into a clean TGA sample crucible. The crucible is usually made of alumina or platinum. Use a scraper to flatten the surface of the sample to ensure that the sample is evenly heated during the heating process.

[0021] Preferably, the thermogravimetric analysis comprises the following steps:

[0022] S1. Instrument calibration: Use standard materials to calibrate the temperature and mass of the thermogravimetric analyzer to ensure the accuracy of the instrument. The calibration frequency should be determined according to the instrument usage frequency and accuracy requirements, usually once a week;

[0023] S2. Parameter setting, set to 10-20 degrees Celsius / minute. A heating rate that is too high may cause decomposition peaks to overlap, while a heating rate that is too low may extend the detection time. Heating range: set room temperature to 800 degrees Celsius to ensure that all decomposition temperature ranges of active temperature mixing agents are covered; Atmosphere: Nitrogen is usually used as a protective atmosphere to prevent sample oxidation. If oxidation behavior needs to be studied, it can be switched to air atmosphere;

[0024] S3. Sample testing: Place the crucible loaded with the sample on the sample holder of the TGA instrument, make sure the holder is clean, start the TGA instrument, and start the heating program. During the heating process, the TGA instrument will automatically record the change of sample mass with temperature and generate a thermogravimetric curve.

[0025] Preferably, the differential thermogravimetric analysis comprises the following steps:

[0026] S1. Data processing: Use the data processing software provided by the TGA instrument to perform differential calculations on the TG curve to obtain the DTG curve. The ATG curve reflects the change of the sample mass loss rate with temperature and can more accurately identify the decomposition peak;

[0027] S2. Curve analysis: observe the DTG curve, identify all obvious decomposition peaks, and record the peak temperature and corresponding mass loss of each decomposition peak.

[0028] Preferably, the characteristic peak identification comprises the following steps:

[0029] S1. Standard sample analysis: Use a standard sample of active warm mix agent with a known dosage to perform TGA test, obtain its DTG curve, identify the characteristic decomposition peak of the active warm mix agent, and record its peak temperature and temperature range;

[0030] S2. Analyze the sample to be tested, compare the DTG curve of the sample to be tested with the DTG curve of the standard sample, and identify the peak corresponding to the characteristic decomposition peak of the active warm mix agent;

[0031] S3. Peak shape analysis: observe the peak shape and symmetry of the characteristic decomposition peaks to determine whether there are overlaps or shoulder peaks.

[0032] Preferably, the quantitative analysis comprises the following steps:

[0033] S1. Establishment of standard curve: Use a series of active warm mix agent standard samples with known dosage to conduct TGA test, calculate the mass loss percentage within the characteristic decomposition temperature range of each standard sample, and establish the standard curve with the mass loss percentage as the horizontal axis and the active warm mix agent dosage as the vertical axis;

[0034] S2. Model selection: select an appropriate quantitative model based on the linear relationship of the standard curve and use the least squares statistical method to determine the model parameters;

[0035] S3. Sample dosage calculation: Substitute the mass loss percentage of the sample to be tested into the quantitative model to calculate the dosage of the active warm mix agent. The linear range of the standard curve should cover the dosage range of the sample to be tested. If necessary, repeated tests can be performed and the average value can be taken to improve the detection accuracy.

[0036] Preferably, the result output comprises the following steps:

[0037] S1. Record the results, record the calculated active warm mix agent dosage results, record the test date, sample number, instrument parameters and calculation method information;

[0038] S2. Result determination: comparing the test result with the preset quality standard. If the dosage is within the standard range, it is determined to be qualified; otherwise, it is determined to be unqualified;

[0039] S3. Report generation: Generate a test report containing sample information, test methods, test results and judgment conclusions. The test report should be reviewed and approved and archived for future reference.

[0040] (III) Beneficial effects

[0041] The present invention provides a method for detecting the dosage of modified asphalt active warm mix agent for prebaked anodes. It has the following beneficial effects:

[0042] 1. In the present invention, by adopting thermal analysis technology with high sensitivity and high resolution, accurate detection of the amount of active warm mix agent can be achieved. Thermogravimetric analysis and data processing speed are fast, and the entire detection process can be completed within 30 minutes.

[0043] 2. In the present invention, the sample dosage is small, the sample will not be damaged, no chemical reagents are needed, chemical pollution and safety hazards are avoided, the sample preparation and analysis steps are simple and easy to operate, and the dosing calculation is accurate and reliable through the standard curve and quantitative model. DETAILED DESCRIPTION

[0044] The following will be combined with 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 making creative work are within the scope of protection of the present invention.

[0045] Embodiment 1:

[0046] The embodiment of the present invention provides a method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode, comprising:

[0047] Sample preparation: Evenly mix the modified asphalt sample to be tested to ensure that the active warm mix agent is evenly distributed in the asphalt. Take an appropriate amount of sample and put it into the sample crucible of the thermal analyzer to ensure that the sample surface is flat;

[0048] Thermogravimetric analysis: use a thermogravimetric analyzer to heat the sample, with the heating rate set at 10 to 20 degrees Celsius per minute and the heating range from room temperature to 800 degrees Celsius. During the heating process, record the curve of the sample mass changing with temperature, i.e., the thermogravimetric curve;

[0049] Differential thermogravimetric analysis: Differentiate the thermogravimetric curve to obtain a differential thermogravimetric curve to more clearly identify the change in mass loss rate;

[0050] Characteristic peak identification: By analyzing the DTG curve, the characteristic peaks related to the decomposition of active warm mix agents are identified. The characteristic decomposition temperature of active warm mix agents usually appears in the following range:

[0051] 200 to 300 degrees Celsius: Decomposition of organic active ingredients;

[0052] 300 to 500 degrees Celsius: Decomposition of inorganic active ingredients;

[0053] Quantitative analysis: calculate the mass loss percentage of the active warm mix agent within the characteristic decomposition temperature range, establish a quantitative relationship model between the mass loss percentage and the dosage through standard samples with known active warm mix agent dosage, substitute the mass loss percentage of the sample to be tested into the model, and calculate the dosage of the active warm mix agent;

[0054] The result output is to output the calculated active warm mix agent dosage result, and judge it according to the preset quality standard to give a qualified or unqualified conclusion.

[0055] Sample preparation includes the following steps:

[0056] S1. Sample collection: randomly collect modified asphalt samples from the prebaked anode production line to ensure that the samples are representative. The sample volume should be sufficient for multiple repeated tests, usually 50 to 100 grams;

[0057] S2. Sample pretreatment: fully stir the collected modified asphalt samples at room temperature to ensure that the active warm mix agent is evenly distributed in the asphalt. If the sample is too viscous, it can be heated to 50 to 80 degrees Celsius to reduce the viscosity and facilitate stirring;

[0058] S3. Sample weighing: Use a precision electronic balance to weigh 10 to 20 mg of sample, accurate to 0.1 mg. When weighing, avoid the sample adhering to the weighing container to ensure weighing accuracy;

[0059] S4. Sample loading: Place the weighed sample into a clean TGA sample crucible. The crucible is usually made of alumina or platinum. Use a scraper to flatten the surface of the sample to ensure that the sample is evenly heated during the heating process.

[0060] Thermogravimetric analysis involves the following steps:

[0061] S1. Instrument calibration: Use standard materials to calibrate the temperature and mass of the thermogravimetric analyzer to ensure the accuracy of the instrument. The calibration frequency should be determined according to the instrument usage frequency and accuracy requirements, usually once a week;

[0062] S2. Parameter setting, set to 10-20 degrees Celsius / minute. A heating rate that is too high may cause decomposition peaks to overlap, while a heating rate that is too low may extend the detection time. Heating range: set room temperature to 800 degrees Celsius to ensure that all decomposition temperature ranges of active temperature mixing agents are covered; Atmosphere: Nitrogen is usually used as a protective atmosphere to prevent sample oxidation. If oxidation behavior needs to be studied, it can be switched to air atmosphere;

[0063] S3. Sample testing: Place the crucible loaded with the sample on the sample holder of the TGA instrument, make sure the holder is clean, start the TGA instrument, and start the heating program. During the heating process, the TGA instrument will automatically record the change of sample mass with temperature and generate a thermogravimetric curve.

[0064] Differential thermogravimetric analysis includes the following steps:

[0065] S1. Data processing: Use the data processing software provided by the TGA instrument to perform differential calculations on the TG curve to obtain the DTG curve. The ATG curve reflects the change of the sample mass loss rate with temperature and can more accurately identify the decomposition peak;

[0066] S2. Curve analysis: observe the DTG curve, identify all obvious decomposition peaks, and record the peak temperature and corresponding mass loss of each decomposition peak.

[0067] Characteristic peak identification includes the following steps:

[0068] S1. Standard sample analysis: Use a standard sample of active warm mix agent with a known dosage to perform TGA test, obtain its DTG curve, identify the characteristic decomposition peak of the active warm mix agent, and record its peak temperature and temperature range;

[0069] S2. Analyze the sample to be tested, compare the DTG curve of the sample to be tested with the DTG curve of the standard sample, and identify the peak corresponding to the characteristic decomposition peak of the active warm mix agent;

[0070] S3. Peak shape analysis: observe the peak shape and symmetry of the characteristic decomposition peaks to determine whether there are overlaps or shoulder peaks.

[0071] Quantitative analysis includes the following steps:

[0072] S1. Establishment of standard curve: Use a series of active warm mix agent standard samples with known dosage to conduct TGA test, calculate the mass loss percentage within the characteristic decomposition temperature range of each standard sample, and establish the standard curve with the mass loss percentage as the horizontal axis and the active warm mix agent dosage as the vertical axis;

[0073] S2. Model selection: select an appropriate quantitative model based on the linear relationship of the standard curve and determine the model parameters using the least squares statistical method;

[0074] S3. Sample dosage calculation: Substitute the mass loss percentage of the sample to be tested into the quantitative model to calculate the dosage of the active warm mix agent. The linear range of the standard curve should cover the dosage range of the sample to be tested. If necessary, repeated tests can be performed and the average value can be taken to improve the detection accuracy.

[0075] The output of the results includes the following steps:

[0076] S1. Record the results, record the calculated active warm mix agent dosage results, record the test date, sample number, instrument parameters and calculation method information;

[0077] S2. Result determination: comparing the test result with the preset quality standard. If the dosage is within the standard range, it is determined to be qualified; otherwise, it is determined to be unqualified;

[0078] S3. Report generation: Generate a test report containing sample information, test methods, test results and judgment conclusions. The test report should be reviewed and approved and archived for future reference.

[0079] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the amount of modified asphalt active warm mix agent for prebaked anode, characterized in that: include: Sample preparation: Evenly mix the modified asphalt sample to be tested to ensure that the active warm mix agent is evenly distributed in the asphalt. Take an appropriate amount of sample and put it into the sample crucible of the thermal analyzer to ensure that the sample surface is flat; Thermogravimetric analysis: use a thermogravimetric analyzer to heat the sample, with the heating rate set at 10 to 20 degrees Celsius per minute and the heating range from room temperature to 800 degrees Celsius. During the heating process, record the curve of the sample mass changing with temperature, i.e., the thermogravimetric curve; Differential thermogravimetric analysis: Differentiate the thermogravimetric curve to obtain a differential thermogravimetric curve to more clearly identify the change in mass loss rate; Characteristic peak identification: By analyzing the DTG curve, the characteristic peaks related to the decomposition of active warm mix agents are identified. The characteristic decomposition temperature of active warm mix agents usually appears in the following range: 200 to 300 degrees Celsius: Decomposition of organic active ingredients; 300 to 500 degrees Celsius: Decomposition of inorganic active ingredients; Quantitative analysis: calculate the mass loss percentage of the active warm mix agent within the characteristic decomposition temperature range, establish a quantitative relationship model between the mass loss percentage and the dosage through standard samples with known active warm mix agent dosage, substitute the mass loss percentage of the sample to be tested into the model, and calculate the dosage of the active warm mix agent; The result output is to output the calculated active warm mix agent dosage result, and judge it according to the preset quality standard to give a qualified or unqualified conclusion.

2. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The sample preparation includes the following steps: S1. Sample collection: randomly collect modified asphalt samples from the prebaked anode production line to ensure that the samples are representative. The sample volume should be sufficient for multiple repeated tests, usually 50 to 100 grams; S2. Sample pretreatment: fully stir the collected modified asphalt samples at room temperature to ensure that the active warm mix agent is evenly distributed in the asphalt. If the sample is too viscous, it can be heated to 50 to 80 degrees Celsius to reduce the viscosity and facilitate stirring; S3. Sample weighing: Use a precision electronic balance to weigh 10 to 20 mg of sample, accurate to 0.1 mg. When weighing, avoid the sample adhering to the weighing container to ensure weighing accuracy; S4. Sample loading: Place the weighed sample into a clean TGA sample crucible. The crucible is usually made of alumina or platinum. Use a scraper to flatten the surface of the sample to ensure that the sample is evenly heated during the heating process.

3. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The thermogravimetric analysis comprises the following steps: S1. Instrument calibration: Use standard materials to calibrate the temperature and mass of the thermogravimetric analyzer to ensure the accuracy of the instrument. The calibration frequency should be determined according to the instrument usage frequency and accuracy requirements, usually once a week; S2. Parameter setting, set to 10-20 degrees Celsius / minute. A heating rate that is too high may cause decomposition peaks to overlap, while a heating rate that is too low may extend the detection time. Heating range: set room temperature to 800 degrees Celsius to ensure that all decomposition temperature ranges of active temperature mixing agents are covered; Atmosphere: Nitrogen is usually used as a protective atmosphere to prevent sample oxidation. If oxidation behavior needs to be studied, it can be switched to air atmosphere; S3. Sample testing: Place the crucible loaded with the sample on the sample holder of the TGA instrument, make sure the holder is clean, start the TGA instrument, and start the heating program. During the heating process, the TGA instrument will automatically record the change of sample mass with temperature and generate a thermogravimetric curve.

4. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The differential thermogravimetric analysis comprises the following steps: S1. Data processing: Use the data processing software provided by the TGA instrument to perform differential calculations on the TG curve to obtain the DTG curve. The ATG curve reflects the change of the sample mass loss rate with temperature and can more accurately identify the decomposition peak; S2. Curve analysis: observe the DTG curve, identify all obvious decomposition peaks, and record the peak temperature and corresponding mass loss of each decomposition peak.

5. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The characteristic peak identification comprises the following steps: S1. Standard sample analysis: Use a standard sample of active warm mix agent with a known dosage to perform TGA test, obtain its DTG curve, identify the characteristic decomposition peak of the active warm mix agent, and record its peak temperature and temperature range; S2. Analyze the sample to be tested, compare the DTG curve of the sample to be tested with the DTG curve of the standard sample, and identify the peak corresponding to the characteristic decomposition peak of the active warm mix agent; S3. Peak shape analysis: observe the peak shape and symmetry of the characteristic decomposition peaks to determine whether there are overlaps or shoulder peaks.

6. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The quantitative analysis comprises the following steps: S1. Establishment of standard curve: Use a series of active warm mix agent standard samples with known dosage to conduct TGA test, calculate the mass loss percentage within the characteristic decomposition temperature range of each standard sample, and establish the standard curve with the mass loss percentage as the horizontal axis and the active warm mix agent dosage as the vertical axis; S2. Model selection: select an appropriate quantitative model based on the linear relationship of the standard curve and determine the model parameters using the least squares statistical method; S3. Sample dosage calculation: Substitute the mass loss percentage of the sample to be tested into the quantitative model to calculate the dosage of the active warm mix agent. The linear range of the standard curve should cover the dosage range of the sample to be tested. If necessary, repeated tests can be performed and the average value can be taken to improve the detection accuracy.

7. The method for detecting the dosage of modified asphalt active warm mix agent for prebaked anode according to claim 1, characterized in that: The result output includes the following steps: S1. Record the results, record the calculated active warm mix agent dosage results, record the test date, sample number, instrument parameters and calculation method information; S2. Result determination: comparing the test result with the preset quality standard. If the dosage is within the standard range, it is determined to be qualified; otherwise, it is determined to be unqualified; S3. Report generation: Generate a test report containing sample information, test methods, test results and judgment conclusions. The test report should be reviewed and approved and archived for future reference.