Method for detecting sealing performance of anode coating

Abstract

The invention discloses a method for detecting the sealing performance of an anode coating, and the method comprises the steps: S1, preparing a test carbon block, and weighing the test carbon block; s2, preparing a to-be-detected coating; s3, coating the test carbon block with a to-be-tested coating, weighing the test carbon block, and drying the test carbon block; s4, firing the dried test carbon block, and weighing the test carbon block; and S5, calculating the sealing amount loss rate of the test carbon block. The carbon rod high-temperature weightlessness detection under the simulated electrolysis high-temperature environment can quickly and accurately judge the sealing performance of the coating material and whether the coating material has the anti-oxidation performance or not, a basis is provided for performance detection and selection of the coating material, input of a large amount of cost and time is avoided, interference values generated in the experiment process are effectively eliminated, and the test efficiency is improved. And the accuracy and comparability of the test data are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic material performance testing, and in particular to a method for detecting the sealing performance of anode coatings with small experimental interference and high precision. Background Art

[0002] The coating technology of prebaked anode for aluminum is an important new technology development direction in the aluminum electrolysis industry. It is directly related to improving the service life of the electrolytic cell, electrolysis efficiency, aluminum output and quality, reducing anode consumption, etc. The post-intervention coating technology of prebaked anode for aluminum electrolysis is in the process of vigorous development, and there is still no complete set of detection methods and technical indicators. A large amount of CO2, CO, fluorine, carbon compounds, etc. will be produced during aluminum electrolysis. After the high-temperature anode contacts with air, CO2, and CO, negative reactions will occur and cause the structural instability of the anode surface. In addition, due to the penetration of sodium, the erosion and scouring of electrolyte solution and aluminum cause erosion and peeling to form slag; the anode will be scour by electrolyte and CO2 at the bottom and side of the electrolytic cell. CO2 enters the pores inside the anode from the bottom of the anode and escapes from the open pores to the top and sides of the anode to the outside of the anode, causing the anode surface structure to become unstable and slag. The surface slag accelerates the generation of negative reactions and accelerates the pollution of the electrolytic cell. Therefore, the mechanical loss of the anode surface has a major impact on the contradiction and failure in the electrolytic cell.

[0003] Patents and technologies such as CN202410539141.4 "A coating for aluminum electrolytic carbon anode, its preparation method and aluminum electrolytic carbon anode" and CN2024410679355.1 "A controlled operation method for prebaked anode coating" that have been applied for involve the verification and improvement of various series of anode coating technologies. The process requires the introduction of the maximum value (non-fully enclosed) and the minimum value (fully enclosed value) of the loss amount, which can be used as the introduction and record of the constant values ​​required for modeling calculations.

[0004] Therefore, the sealing performance of the coating can be used as a test indicator in the coating development process, as an indicator to predict the effect of the coating on the anode, and as a measurement indicator for different coatings by users. How to provide a method that can accurately detect the full sealing performance and non-full sealing performance of the coating to be tested is a topic that urgently needs to be studied in this field; in the detection process, how to eliminate the influence of some process interference values ​​(such as moisture content, coating dosage, carbon block location and size, etc.) is also a problem that needs to be faced in the design of the detection method.

[0005] CN202311263232.1 provides a method for detecting the anti-oxidation performance of electrolytic aluminum prebaked anode coating materials, and its technical solution includes uniformly coating the electrolytic aluminum prebaked anode coating material to be detected on the surface of a carbon rod to obtain sample A, and the weight of sample A is recorded as M2; calcining sample A to obtain sample B, and the weight of sample B is recorded as M3; calculating the weight loss rate of the sample △M%, △M% = (M2-M3) / M2×100%, and judging whether the electrolytic aluminum prebaked anode coating material to be detected has anti-oxidation performance according to the weight loss rate. However, the high-temperature anti-oxidation performance of the test coating obtained in this scheme cannot be referenced by the fully enclosed effect value and the non-fully enclosed effect value, and there are the following problems: 1. The difference in moisture content and burnout rate between coatings with different formulas and coatings with the same formula but different mixing mechanisms will lead to errors in the data related to carbon block weight loss; 2. This method cannot eliminate the physical differences in the geometric locations of carbon rod sampling and the data bias caused by the physical differences in carbon block sampling size; 3. This method cannot eliminate the differences in moisture content, loss on ignition rate, and optimal coating amount of each coating; 4. The requirements for the amount of coating applied for the test cannot fully reflect the optimal coating performance amount required by each electrolytic aluminum plant for each production coating.

[0006] Therefore, the existing technologies and standards in the industry cannot accurately and effectively determine the sealing performance of the coating. Summary of the invention

[0007] The present invention provides a method for detecting the sealing performance of an anodic coating, so as to solve the technical problem mentioned in the background technology.

[0008] In order to solve the above technical problems, the technical solution proposed by the present invention is: A method for detecting the sealing performance of an anodic coating comprises the following steps: S1, preparing a test carbon block, and weighing the test carbon block to obtain a mass M1; S2, preparing the coating to be tested; S3, coating the test carbon block with the coating to be tested, the coating thickness being a preset standard value, weighing the coated test carbon block to obtain a mass M2, and drying the coated test carbon block after the weighing is completed; S4, firing the dried test carbon block at a temperature of 400-1000° C. for 72 h, and weighing the fired test carbon block to obtain a mass M3; S5. Calculate the sealing loss rate of the test carbon block by formula (1), and evaluate the sealing performance of the coating to be tested by the sealing loss rate: Closure volume loss rate = (1); Wherein, M1, M2, M3 are the M1, M2, M3 described in steps S1 to S4.

[0009] As a further preferred embodiment of the above technical solution, in step S1, the test carbon block is prepared by the following method: A carbon rod at the same relative coordinate position of the same anode is selected as a basic carbon rod, and the top of the basic carbon rod is removed to the same size and cut into basic carbon blocks with the same height; the basic carbon block is pretreated to obtain the test carbon block.

[0010] As a further preferred embodiment of the above technical solution, the pretreatment includes surface blowing and drying operations; the surface is blown until the dust degree on the surface of the basic carbon block is ≤ level 3; the drying temperature is 65°C, and the basic carbon block is dried until the weight is constant.

[0011] As a further preferred embodiment of the above technical solution, the height of the basic carbon block is 50 mm.

[0012] As a further optimization of the above technical solution, when detecting the sealing performance of different coatings to be tested, in step S3, the coating to be tested is applied to the surfaces of different test carbon blocks supported by carbon rods based on the carbon rods at the same relative coordinate position of the same anode, and then subsequent operations are performed.

[0013] As a further preferred embodiment of the above technical solution, in step S3, the deviation between the coating thickness of the coating to be tested and the preset standard value is within 5%. The coating thickness on the surface of the carbon rod after coating should be uniform, without sagging and wrinkles, and the coating thickness should meet the requirements.

[0014] As a further optimization of the above technical solution, in step S3, a unified standard is selected for the preset standard value. If there is a recommended coating thickness for the paint, it is recorded as the preset standard value; if the recommended coating thickness of the paint is an interval value, the middle value of the interval is taken as the preset standard value.

[0015] As a further optimization of the above technical solution, in step S3, when measuring the fully enclosed performance of the coating to be tested, the coating to be tested is applied to the top, bottom and sides of the test carbon block; when measuring the non-fully enclosed performance of the coating to be tested, the coating to be tested is applied to the top and sides of the test carbon block.

[0016] As a further preferred embodiment of the above technical solution, in step S3, the drying operation of the coated test carbon block includes: first heating the test carbon block to 65°C for drying for more than 1.5 hours, and then heating it to 110°C for further drying for more than 1.5 hours. The temperature should be raised slowly during drying to avoid bulging of the coating during the drying process. The drying operation can eliminate the data deviation caused by bubbling during the firing process of the coating to be tested.

[0017] As a further optimization of the above technical solution, in step S4, the furnace can be opened to observe the state of the test carbon block during the firing process; but in order to avoid excessive cold air entering the firing furnace and causing the coating to crack in the furnace, the number of times the furnace is opened for observation during the entire firing process should be controlled to not exceed 3 times.

[0018] As a further preferred embodiment of the above technical solution, in step S4, the test carbon block that has been fired is directly weighed or weighed after being cooled to room temperature; when the test carbon block that has been fired is cooled to room temperature, the test carbon block is placed in a drying oven for cooling.

[0019] The present invention has the following beneficial effects: The present invention refers to the residual polarity rate detection method of the anode carbon block reacting with air and carbon dioxide, and on this basis simulates the high-temperature weightlessness detection of the carbon rod in the high-temperature environment of electrolysis. It can quickly and accurately determine the sealing energy value and the anti-oxidation energy value of the coating material, provide a basis for the performance detection and selection of the coating material, and supplement key data for the establishment of the anode consumption simulation model, avoiding the investment of a large amount of cost and time, and effectively eliminating the interference values ​​generated by the experimental process, thereby improving the accuracy and comparability of the test data.

[0020] The present invention will be further described in detail below with reference to specific implementation modes. DETAILED DESCRIPTION

[0021] The following is a detailed description of embodiments of the present invention, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0022] Embodiment 1: The method for detecting the sealing performance of the anodic coating of this embodiment is used to measure the sealing performance of different coatings to be tested, and comprises the following steps: 1. Preparation of test carbon block: First, the corners of an anode are sampled at the same coordinates. The sampling size is : 50mm, H: 250mm. The corners of the same anode with the same coordinates are grouped together, and four groups of eight basic carbon rods are taken in total; Preparation of basic carbon blocks: Remove 15mm from the top of 8 basic carbon rods, cut a 50mm high carbon block and number it for storage. Each group of test carbon blocks has 2 blocks; The dust on the surface of the test carbon block is removed by blowing and adsorption to ensure that there is no large dust particles on the surface of the carbon rod and the surface dust degree is ≤ level 3; (reference standard: GB / T18570.3) Drying of the test carbon block: Weigh the prepared test carbon block to obtain the initial mass M0, then place it in a tray, and put the tray into an oven. When drying the test carbon block, the oven temperature is set to 65°C, and the drying time needs to be 2 hours until it becomes constant. The dried test carbon block is weighed, and the obtained mass is calculated as M1 and then placed in a desiccator for storage for later use.

[0023] (II) Preparation of coating to be tested: The coatings to be tested used in the four groups of tests in this embodiment are all prepared coatings; The water loss on ignition of the four groups of coatings to be tested were tested at the target burn-out temperature; about 100g of the coating sample (m1) was weighed accurately to 0.01g, placed in a porcelain crucible that had been burned and kept at a constant temperature, the lid was placed obliquely on the crucible, and the temperature was gradually increased from a low temperature in a high-temperature electronic furnace, and burned at the same temperature for 15 to 30 minutes, then the crucible was taken out and placed in a desiccator to cool to room temperature, and weighed. Repeat the burning until a constant weight (m2) is reached. The mass percentage HZJI of the water loss on ignition of the coating to be tested is calculated according to the following formula (2): HZJI= ×100% (2); Where HZJI is the mass percentage (%) of the loss on ignition, m1 is the mass of the coating sample to be tested (g), and m2 is the mass of the coating sample to be tested after the loss on ignition (g).

[0024] The water loss rate of the tested coatings is shown in Table 1.

[0025] (III) Coating operation of test carbon block: Preset standard value of coating thickness: 0.16g / cm 2 ; The surface area of ​​the carbon block to be coated for the fully enclosed test is: 127.80cm 2 ; The mass of the coating used is 20.45g±1g / test carbon block; The surface area of ​​the carbon block to be coated for the non-fully enclosed test is: 103.15cm 2 ; The mass of the coating used is 16.5g±0.83g / carbon block; Use a brush to evenly apply the prepared coating to be tested on the surface of the test carbon block; after coating, the coating thickness on the surface of the test carbon block should be uniform, and no sagging or wrinkles should occur; The coated test carbon block should be weighed before drying, and the obtained mass is recorded as M2; In order to eliminate the data deviation caused by bubbles in the coating in the muffle furnace, the moisture in the coating should be pre-dried before the test carbon block enters the furnace; The weighed test carbon blocks are placed in a tray according to the number and put into the oven. The oven is set to 65℃ for drying for 2 hours, and then the oven temperature is increased to 110℃ for further drying for 2.5 hours. The heating rate of the oven should be set to a slow rate during drying to avoid bulging of the coating during the drying process.

[0026] (IV) Muffle furnace firing: The dried test carbon block is placed in the ceramic ark, numbered and weighed to obtain the total mass of the test carbon block after it is placed in the ceramic ark. The firing time in the muffle furnace is 72 hours; The simulation calculation condition is 800℃, and the temperature of the muffle furnace is set to 800℃; During the firing process of the muffle furnace, the furnace is opened every 24 hours to observe the state of the coating in the furnace. After 72 hours, the carbon blocks are taken out and weighed to obtain the mass M3. When weighing each carbon block, the environmental factors during weighing should be ensured to be uniform.

[0027] (V) Calculation of closed volume: The sealing loss rate is calculated according to formula (1), and the sealing performance of the tested coating is evaluated by the sealing loss rate: Closure volume loss rate = (1).

[0028] The sealing amount data of each group of coatings are shown in Table 2.

[0029] Table 1. Water loss rate test results of different tested coatings

[0030] Table 2. Test results of sealing amount and loss rate of different tested coatings

[0031] Embodiment 2: The method for detecting the sealing performance of the anodic coating of this embodiment is used to measure the sealing performance of the coating to be tested with different additives added, and comprises the following steps: 1. Preparation of test carbon block: First, the corners of an anode are sampled at the same coordinates. The sampling size is : 50mm, H: 250mm. The corners of the same anode with the same coordinates are grouped together, and three groups of six basic carbon rods are taken in total; Preparation of basic carbon blocks: Remove the top 25mm of each of the 6 basic carbon rods, cut a 50mm high carbon block and number it for storage. Each group of test carbon blocks consists of 2 blocks; The dust on the surface of the test carbon block is removed by blowing and adsorption to ensure that there is no large dust particles on the surface of the carbon rod and the surface dust degree is ≤ level 3; (reference standard: GB / T18570.3) Drying of the test carbon block: Weigh the prepared test carbon block to obtain the initial mass M0, then place it in a tray, and put the tray into an oven. When drying the test carbon block, the oven temperature is set to 65°C, and the drying time needs to be 2 hours until it becomes constant. The dried test carbon block is weighed, and the obtained mass is calculated as M1 and then placed in a desiccator for storage for later use.

[0032] (II) Preparation of coating to be tested: The first group of tested coatings are prepared coatings; the second group of tested coatings are prepared by adding 5% of A additive to the first group of tested coatings; the third group of tested coatings are prepared by adding 3% of B additive to the first group of tested coatings; The three groups of coatings were tested for their water loss on ignition at the target burn-out temperature; about 100g of the coating sample (m1) was weighed accurately to 0.01g, placed in a porcelain crucible that had been burned and kept at a constant temperature, the lid was placed obliquely on the crucible, and placed in a high-temperature electronic furnace to gradually increase the temperature from a low temperature, burned at the same temperature for 15 to 30 minutes, took out the crucible and placed it in a desiccator to cool to room temperature, and weighed. Repeated burning until constant weight (m2). The mass percentage HZJI of the water loss on ignition of the coating to be tested is calculated according to the following formula (2): HZJI= ×100% (2); Where HZJI is the mass percentage (%) of the loss on ignition, m1 is the mass of the coating sample to be tested (g), and m2 is the mass of the coating sample to be tested after the loss on ignition (g).

[0033] (III) Coating operation of test carbon block: Preset standard value of coating thickness: 0.16g / cm 2 ; The surface area of ​​the carbon block to be coated for the fully enclosed test is: 127.80cm 2 ; The mass of the coating used is 20.45g±1g / test carbon block; Use a brush to evenly apply the prepared coating to be tested on the surface of the test carbon block; after coating, the coating thickness on the surface of the test carbon block should be uniform, and no sagging or wrinkles should occur; The coated test carbon block should be weighed before drying, and the obtained mass is recorded as M2; In order to eliminate the data deviation caused by bubbles in the coating in the muffle furnace, the moisture in the coating should be pre-dried before the test carbon block enters the furnace; The weighed test carbon blocks are placed in a tray according to the number and put into the oven. The oven is set to 65℃ for drying for 2 hours, and then the oven temperature is increased to 110℃ for further drying for 2.5 hours. The heating rate of the oven should be set to a slow rate during drying to avoid bulging of the coating during the drying process.

[0034] (IV) Muffle furnace firing: The dried test carbon block is placed in the ceramic ark, numbered and weighed to obtain the total mass of the test carbon block after it is placed in the ceramic ark. The firing time in the muffle furnace is 72 hours; The simulation calculation condition is 800℃, and the temperature of the muffle furnace is set to 800℃; During the firing process of the muffle furnace, the furnace is opened every 24 hours to observe the state of the coating in the furnace. After 72 hours, the carbon blocks are taken out and weighed to obtain the mass M3. When weighing each carbon block, the environmental factors during weighing should be ensured to be uniform.

[0035] (V) Calculation of closed volume: The sealing loss rate is calculated according to formula (1), and the sealing performance of the tested coating is evaluated by the sealing loss rate: Closure volume loss rate = (1).

[0036] The sealing amount data of each group of tested coatings are shown in Table 3.

[0037] Table 3. Test results of sealing amount and loss rate of different tested coatings

[0038] Embodiment 3: The method for detecting the sealing performance of the anodic coating of this embodiment is used to measure the sealing performance of different coatings to be tested, and comprises the following steps: 1. Preparation of test carbon block: First, the corners of an anode are sampled at the same coordinates. The sampling size is : 50mm, H: 250mm. The corners of the same anode with the same coordinates are grouped together, and three groups of six basic carbon rods are taken in total; Preparation of basic carbon blocks: Remove the top 25mm of 6 carbon rods, cut them into 50mm high carbon blocks, and then number and save them. The test carbon blocks of the same group are cut from the same carbon rod, and each group of test carbon blocks consists of 2 blocks; The dust on the surface of the test carbon block is removed by blowing and adsorption to ensure that there is no large dust particles on the surface of the carbon rod and the surface dust degree is ≤ level 3; (reference standard: GB / T18570.3) Drying of the test carbon block: Weigh the prepared test carbon block to obtain the initial mass M0, then place it in a tray, and put the tray into an oven. When drying the test carbon block, the oven temperature is set to 65°C, and the drying time needs to be 2 hours until it becomes constant. The dried test carbon block is weighed, and the obtained mass is calculated as M1 and then placed in a desiccator for storage for later use.

[0039] (II) Preparation of coating to be tested: The three groups of coatings were tested for their water loss on ignition at the target burn-out temperature; about 100g of the coating sample (m1) was weighed accurately to 0.01g, placed in a porcelain crucible that had been burned and kept at a constant temperature, the lid was placed obliquely on the crucible, and placed in a high-temperature electronic furnace to gradually increase the temperature from a low temperature, burned at the same temperature for 15 to 30 minutes, took out the crucible and placed it in a desiccator to cool to room temperature, and weighed. Repeated burning until constant weight (m2). The mass percentage HZJI of the water loss on ignition of the coating to be tested is calculated according to the following formula (2): HZJI= ×100% (2); Where HZJI is the mass percentage (%) of the loss on ignition, m1 is the mass of the coating sample to be tested (g), and m2 is the mass of the coating sample to be tested after the loss on ignition (g).

[0040] (III) Preset standard value of coating thickness: According to the recommended value given in the manufacturer's manual, the recommended value for the first group of coatings to be tested is 0.18g / cm 2 The second group of coatings to be tested gave a range of 0.16g-0.24g / cm 2 The middle value is 0.2g / cm2; the preset standard value of the third group of coating thickness: the recommended value is 0.25g / cm 2 ; The surface area of ​​the test carbon blocks is: 127.8cm 2 The coating mass used in the first group of coatings to be tested is 23g±1.15g / test carbon block; the coating mass used in the second group of coatings to be tested is 25.56g±1.28g / test carbon block; the coating mass used in the third group of coatings to be tested is 31.93g±1.6g / test carbon block; Use a brush to evenly apply the prepared coating to be tested on the surface of the test carbon block; after coating, the coating thickness on the surface of the test carbon block should be uniform, and no sagging or wrinkles should occur; The coated test carbon block should be weighed before drying, and the obtained mass is recorded as M2; In order to eliminate the data deviation caused by bubbles in the coating in the muffle furnace, the moisture in the coating should be pre-dried before the test carbon block enters the furnace; The weighed test carbon blocks are placed in a tray according to the number and put into the oven. The oven is set to 65℃ for drying for 2 hours, and then the oven temperature is increased to 110℃ for further drying for 2.5 hours. The heating rate of the oven should be set to a slow rate during drying to avoid bulging of the coating during the drying process.

[0041] (IV) Muffle furnace firing: The dried test carbon block is placed in the ceramic ark, numbered and weighed to obtain the total mass of the test carbon block after it is placed in the ceramic ark. The firing time in the muffle furnace is 72 hours; The simulation calculation condition is 900℃, and the temperature of the muffle furnace is set to 900℃; During the firing process of the muffle furnace, the furnace is opened every 24 hours to observe the state of the coating in the furnace. After 72 hours, the carbon blocks are taken out and weighed to obtain the mass M3. When weighing each carbon block, the environmental factors during weighing should be ensured to be uniform.

[0042] (V) Calculation of closed volume The sealing loss rate is calculated according to formula (1), and the sealing performance of the tested coating is evaluated by the sealing loss rate: Closure volume loss rate = (1).

[0043] The sealing amount data of each group of tested coatings are shown in Table 4.

[0044] Table 4. Test results of sealing amount and loss rate of different tested coatings

[0045] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

[0046] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for detecting the sealing performance of an anodic coating, characterized in that: The following steps are involved: S1, preparing a test carbon block, and weighing the test carbon block to obtain a mass M1; S2, preparing the coating to be tested; S3, coating the test carbon block with the coating to be tested, the coating thickness being a preset standard value, weighing the coated test carbon block to obtain a mass M2, and drying the coated test carbon block after the weighing is completed; S4, firing the dried test carbon block at a temperature of 400-1000° C. for 72 h, and weighing the fired test carbon block to obtain a mass M3; S5. Calculate the sealing loss rate of the test carbon block by formula (1), and evaluate the sealing performance of the coating to be tested by the sealing loss rate: Closure volume loss rate = (1); Wherein, M1, M2, M3 are the M1, M2, M3 described in steps S1 to S4.

2. The method for detecting the sealing performance of anodizing coating according to claim 1, characterized in that: In step S1, the test carbon block is prepared by the following method: A sampling carbon rod with the same absolute coordinate size of the same anode is selected as a basic carbon rod, and the basic carbon rod is removed from the top with the same size and cut into basic carbon blocks with the same height; the test carbon block is obtained after pre-treating the basic carbon block.

3. The method for detecting the sealing performance of anodizing coating according to claim 2, characterized in that: The pretreatment includes surface blowing and drying operations; the surface is blown until the dust degree of the basic carbon block surface is ≤ level 3; the drying temperature is 65° C., and the basic carbon block is dried until the weight is constant.

4. The method for detecting the sealing performance of anodizing coating according to claim 2, characterized in that: When testing the sealing performance of different coatings to be tested, in step S3, the coatings to be tested are applied to the surfaces of different test carbon blocks supported by carbon rods at the same relative coordinate position of the same anode as the base carbon rod, and then subsequent operations are performed.

5. The method for detecting the sealing performance of anodizing coating according to claim 1, characterized in that: In step S3, the deviation between the coating thickness of the coating to be tested and the preset standard value is within 5%.

6. The method for detecting the sealing performance of anodizing coating according to claim 1, characterized in that: In step S3, when measuring the fully enclosed performance of the coating to be tested, the coating to be tested is applied to the top, bottom and sides of the test carbon block; when measuring the non-fully enclosed performance of the coating to be tested, the coating to be tested is applied to the top and sides of the test carbon block.

7. The method for detecting the sealing performance of anodizing coating according to claim 1, characterized in that: In step S3, the drying operation of the coated test carbon block includes: firstly heating the test carbon block to 65°C and drying it for more than 1.5 hours, and then heating it to 110°C and continuing to dry it for more than 1.5 hours.

8. The method for detecting the sealing performance of an anodic coating according to any one of claims 1 to 6, characterized in that: In step S4, the fired test carbon block is weighed directly or weighed after being cooled to room temperature; when the fired test carbon block is cooled to room temperature, the test carbon block is placed in a drying oven for cooling.

Images