A method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks

Abstract

The present application relates to the technical field of magnesia carbon brick production, and specifically to a magnesia carbon brick production method for recycling waste magnesia carbon bricks, the method comprising: turning over the recycled waste magnesia carbon bricks to obtain homogenized waste magnesia carbon bricks; coarsely crushing and deeply crushing the homogenized waste magnesia carbon bricks in sequence to obtain waste magnesia carbon brick granules and powder; mixing the waste magnesia carbon brick granules and powder with fused magnesia sand particles, heat-treated magnesia sand particles, high-temperature asphalt powder, synthetic antioxidant, metal silicon powder, graphite, and resin binder according to a specific mass ratio; transferring the evenly mixed material into a mold for pressing and molding to obtain a brick blank; performing segmented heat treatment on the brick blank, and controlling the temperature stability during the heat treatment and heat preservation process to obtain a magnesia carbon brick; the present application aims to improve the quality of the reproduced magnesia carbon bricks.

Description

Technical Field

[0001] The present application relates to the technical field of magnesia carbon brick production, and in particular to a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks. Background Art

[0002] The traditional recycling of waste magnesia carbon bricks to produce magnesia carbon bricks mainly covers the steps of selection and homogenization, crushing, mixing, molding, heat treatment, etc. In the production process of magnesia carbon bricks, the heat treatment link after the bricks are pressed is crucial. Accurate temperature control plays a key role in ensuring that the physical and chemical reactions between magnesia sand, carbon materials and additives are fully carried out, and can effectively avoid excessive thermal stress in the brick body due to rapid temperature changes.

[0003] However, when using an automated control system to control the production process, the raw material properties, environmental conditions, thermal inertia and other factors may change in actual production, which will affect the temperature stability of the heat treatment process during the production of magnesia carbon bricks, resulting in stability deviation in the heat treatment. This may cause physical damage to the magnesia carbon bricks, such as cracks and deformation, and will lead to a decrease in the consolidation strength of the magnesia carbon bricks, which will have an adverse effect on the final quality of the magnesia carbon bricks. Summary of the invention

[0004] In view of the above, it is necessary to provide a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks to solve the above problems.

[0005] One embodiment of the present application provides a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks, the method comprising:

[0006] S1: turning over the recycled waste magnesia carbon bricks to obtain homogenized waste magnesia carbon bricks;

[0007] S2: coarsely crushing and deeply crushing the homogenized waste magnesia carbon bricks in sequence to obtain waste magnesia carbon brick granules and powder;

[0008] S3: Mixing and stirring the waste magnesia carbon brick particles and powder with fused magnesia sand particles, heat-treated magnesia sand particles, high-temperature asphalt powder, synthetic antioxidant, metal silicon powder, graphite, and resin binder according to a specific mass ratio;

[0009] S4: transferring the uniformly stirred material into a mold for pressing and forming to obtain a brick;

[0010] S5: performing heat treatment on the bricks in stages, and controlling the temperature stability during the heat treatment and heat preservation process to obtain magnesia carbon bricks;

[0011] The specific process of controlling the temperature stability is as follows:

[0012] S501: Collect all temperature data at different positions during the insulation stage of the magnesia carbon brick production process;

[0013] S502: using mutation detection on the temperature data of each position, obtaining the superposition comparison interval of each position according to the acquisition time corresponding to the mutation point in the temperature data; using trend analysis to obtain the trend statistics of each superposition interval divided at each position, and obtaining the cumulative deviation coefficient of each superposition comparison interval at each position according to the similarity of the temperature data between each superposition comparison interval at each position and the difference of the trend statistics with the other superposition comparison intervals;

[0014] S503: obtaining the temperature trend coefficient of each position according to the difference of all accumulated deviation coefficients between each position and the other positions and the distance between each position and the other positions; adjusting the temperature trend coefficient of each position according to the information quantity characteristics of the temperature data of all positions;

[0015] S504: According to the distribution of the adjusted temperature trend coefficient of each position, combined with the difference between the current control temperature of each position and the preset expected temperature, the comprehensive feedback error coefficient is calculated, and combined with the PID controller, the temperature stability of the magnesia carbon brick during the heat treatment and insulation process is controlled.

[0016] The speed of turning the material in S1 is set to 5-10 rpm.

[0017] Among them, the specific operation of deep crushing in S2 is to control the dynamic cone stroke at 10~20mm and the eccentric shaft speed at 300~400 rpm; the waste magnesium carbon brick particles and powder are obtained, specifically: particles with a particle size of 3~10mm account for 40%, particles with a particle size of 0.074~3mm account for 40%, and powders with a size of 0~0.074mm account for 20%.

[0018] Among them, the specific mass ratio described in S3 is: waste magnesium carbon brick particles and powder: fused magnesia sand particles: heat-treated magnesia sand particles: high-temperature asphalt powder: synthetic antioxidant: metallic silicon powder: graphite: resin binder = 62:25:22:1:5:2:7:2~7; the mixing and stirring operation is specifically a stirring speed of 20~30 rpm, and continuous stirring for 20~30 minutes.

[0019] The parameters for the compression molding operation in S4 are as follows: the molding pressure is between 100 and 300 MPa, and the holding time is between 10 and 30 seconds.

[0020] The specific operation process of the staged heat treatment described in S5 is as follows: the initial heating rate is 5-10°C / min, and the temperature is raised to 1000°C; then the temperature is raised to 1400°C at a heating rate of 3-5°C / min; finally, the temperature is raised to 1600-1800°C at a heating rate of 1-3°C / min, and kept at this temperature for 3-4 hours.

[0021] The obtained superposition comparison interval of each position is specifically an interval consisting of the acquisition time from the initial acquisition time of each position to the acquisition time corresponding to each mutation data, and an interval consisting of the acquisition time corresponding to adjacent mutation data;

[0022] The cumulative deviation coefficient of each superimposed comparison interval at each position is obtained as follows:

[0023] For each superposition comparison interval divided at each location, all temperature data in the superposition comparison interval are used as input, and the trend verification algorithm is used to obtain the trend statistics of each superposition comparison interval;

[0024] Based on the negative correlation mapping results of the difference in trend statistics between each stacking comparison interval and all other stacking comparison intervals, combined with the difference characteristics of temperature data between stacking comparison intervals, the cumulative deviation coefficient of each stacking comparison interval at each location is obtained.

[0025] The temperature trend coefficient of each position is obtained as follows:

[0026] The vector composed of the cumulative deviation coefficients of all superimposed comparison intervals at each position during the temperature control process of the heat treatment of magnesia carbon bricks is used as the comparison feature vector of each position;

[0027] Based on the similarity of the feature vectors of each position compared with all other positions, combined with the negative correlation mapping results of the distances between each position and all other positions, the temperature trend coefficient of each position is obtained.

[0028] Wherein, the adjusting of the temperature trend coefficient of each position includes:

[0029] The temperature data collected at all locations are taken as input, and the objective weighting method is used to obtain the weight of the correlation comparison relationship of the temperature data at each location. The product of the temperature trend coefficient of each location and the weight corresponding to each location is taken as the adjusted temperature trend coefficient of each location.

[0030] The calculation of the comprehensive feedback error coefficient, combined with the PID controller, controls the temperature stability of the magnesia carbon brick during the heat treatment and insulation process, including:

[0031] The calculation formula of the comprehensive feedback error coefficient is: ;in, represents the comprehensive feedback error coefficient; Indicates The difference between the current controlled temperature at each location and the set desired temperature; , Respectively represent , Normalized result of temperature trend coefficient after position adjustment; Indicates the number of temperature collection locations;

[0032] The comprehensive feedback error coefficient is used as the feedback error for the heat treatment temperature control at the current moment, and the temperature is controlled during the heat treatment insulation process using a PID controller.

[0033] This application has at least the following beneficial effects:

[0034] In the present application, when waste magnesia carbon bricks are used to produce magnesia carbon bricks according to the existing traditional method, there is a problem of hysteresis trend correlation difference in the heat treatment process after pressing and forming due to the influence of thermal inertia, resulting in low processing accuracy, and then in the existing heat treatment temperature control process, the temperature may produce control deviation due to the long-term change of the state of the heating element; therefore, all temperature data at different positions in the insulation stage of the magnesia carbon brick production process are collected, and the superimposed cumulative effect of the temperature change in the local range caused by the continuous fluctuation of the heating wires at different positions is fully considered, the cumulative deviation coefficient is calculated, and the temperature trend coefficient is obtained based on this. The beneficial effect is that this method combines the hysteresis trend correlation characteristics caused by the inertial change of the temperature data at different positions in the heat treatment space during the heat treatment process, and the relative change relationship of the temperature at different positions in the overall space, which can accurately reflect the influence of the hysteresis trend correlation difference at different positions during the heat treatment process on the temperature feedback control deviation, thereby realizing the precise adjustment of the temperature control deviation of the magnesia carbon brick heat treatment, and finally improving the quality of the produced magnesia carbon bricks. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a method for producing magnesium carbon bricks by recycling waste magnesium carbon bricks provided in this application;

[0036] Figure 2 A schematic diagram of the process for temperature stability control provided in this application. DETAILED DESCRIPTION

[0037] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0039] It should also be noted that the terms "first" and "second" in this application and its drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The method disclosed in the embodiments of the present application or the method shown in the flow chart includes one or more steps for implementing the method. Without departing from the scope of protection of this application, the execution order of multiple steps can be interchanged with each other, and some steps can also be deleted.

[0040] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0041] Example 1

[0042] Example 1 of the present application proposes a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks, which is applied to the technical field of magnesia carbon brick production. Figure 1 , the method comprises the following steps:

[0043] S1: First, the recycled waste magnesium carbon bricks are preliminarily graded and screened on the selection workbench according to appearance, degree of damage, etc.; the waste magnesium carbon bricks are transferred to the processing area by a loader with a bucket capacity of 5 cubic meters, and then the material turning machine is used to turn the material to remove steel slag, soil and other impurities, and then the material turning and mixing are continued until the proportion of waste bricks of the same material but different components is sufficiently consistent, and the homogenized waste magnesium carbon bricks are obtained. The turning speed in this embodiment is 5 revolutions per minute.

[0044] S2: The homogenized waste magnesium carbon bricks are transported to the crushing system, and the large waste magnesium carbon bricks are coarsely crushed by a jaw crusher with a discharge opening width of 20mm, so that the waste magnesium carbon bricks are initially broken into smaller block materials; then the coarsely crushed materials are deeply crushed by a cone crusher, in which the dynamic cone stroke is controlled at 10mm and the eccentric shaft speed is 300 rpm; the materials are screened by a vibrating screen, and the screen aperture is precisely set to 10mm, 3mm and 0.074mm, and finally 40% of the granular materials with a particle size of 3~10mm, 40% of the granular materials with a particle size of 0.074~3mm, and 20% of the powder materials with a particle size of 0~0.074mm.

[0045] S3: The crushed waste magnesia carbon brick particles and powder are put into a strong countercurrent mixer together with fused magnesia sand particles, heat-treated magnesia sand particles, high-temperature asphalt powder, synthetic antioxidant, metal silicon powder, graphite, and resin binder according to a specific mass ratio for mixing and stirring. The mass ratio of each raw material is 62:25:22:1:5:2:7:2, and the stirring paddle speed of the mixer is 20 rpm, and the stirring is continued for 20 minutes; high-temperature asphalt powder, synthetic antioxidant and other additives can be evenly coated on the surface of magnesia sand and waste magnesia carbon brick particles under the action of resin binder to form an effective bonding and protective layer. This structure not only enhances the antioxidant capacity of magnesia carbon bricks, but also improves their stability in high temperature environments.

[0046] S4: Transfer the evenly mixed material to the mold of the hydraulic press for pressing and molding; adjust the molding pressure of the press to 100MPa, and set the holding time to 30 seconds, so that the material is tightly compacted in the mold, ensuring that the brick is formed and the internal structure is tight and stable, effectively reducing the porosity, and improving the overall strength and density of the magnesia carbon brick, so that it can better withstand high temperature and mechanical stress.

[0047] S5: The pressed bricks are heat treated. The specific heat treatment adopts a segmented control strategy. The initial heating rate is 5°C / min, so that the temperature rises rapidly to 1000°C to promote the initial physical and chemical reactions and structural changes of the material; then the temperature is raised to 1400°C at a heating rate of 3°C / min to further optimize the crystal structure and bonding state inside the material; finally, the temperature is slowly raised to 1700°C at a heating rate of 1°C / min and kept at this temperature for 3 hours; during the heat treatment and insulation process, the heat treatment temperature is stabilized by an automatic control system, and the influence of the temperature spatial deviation caused by thermal inertia on the temperature control is reduced to obtain magnesia carbon bricks.

[0048] The specific process of heat treatment temperature control of pressed bricks is as follows:

[0049] S501: Collect temperature data at different positions during the insulation stage of the magnesia carbon brick production process.

[0050] Set up in the device for heat treatment of magnesia carbon bricks A temperature sensor, wherein in this application The value is 10. The actual number of sensors is determined according to the size of the heat treatment device used, and the temperature sensors are evenly arranged around the center of the device at equal intervals. For example, if the top view of the device is circular, the temperature sensors are evenly arranged around the center of the circle, and the angle between the temperature sensors compared to the center of the circle is 36 degrees; it should be noted that the temperature is high during the actual heat treatment process, so the temperature sensor used in this application is a thermocouple, which is suitable for temperature sensors in high temperature environments. In this embodiment, the time interval for collecting temperature data is 0.5 minutes, which can be adjusted by the implementer according to the actual situation, and this application does not limit this.

[0051] During the insulation stage of heat treatment of magnesia carbon bricks, temperature data at different positions are collected using temperature sensors. Since the collection process may be disturbed by the stability of the environment, the collected temperature data is affected by noise; therefore, the collected temperature data is used as input and a Wiener filter is used to perform noise reduction on the collected temperature data. The specific processing process of the Wiener filter is a technology well known to those skilled in the art and will not be repeated here.

[0052] So far, the pre-processed temperature data of different positions in the insulation stage of magnesia carbon brick production have been obtained.

[0053] S502: Mutation detection is performed on the temperature data of each location, and the superposition comparison interval of each location is obtained according to the collection time corresponding to the mutation point in the temperature data; trend analysis is performed to obtain the trend statistics of each superposition interval divided for each location, and the cumulative deviation coefficient of each superposition comparison interval at each location is obtained according to the similarity of the temperature data between each superposition comparison interval at each location and the other superposition comparison intervals and the difference in trend statistics.

[0054] Normally, in the production process of magnesia carbon bricks, the insulation stage of heat treatment after pressing and forming is a key step to ensure that the magnesia sand particles are fully combined, and various additives and raw materials undergo sufficient chemical reactions to form a stable phase structure and a bonding network with excellent performance, so that the magnesia carbon bricks can obtain good high temperature resistance, corrosion resistance and thermal shock resistance, and meet the strict requirements of the steel and other industries for refractory materials; therefore, in the heat treatment stage of pressing and forming magnesia carbon bricks, the stability of heat treatment temperature control has a greater impact on the quality of the produced magnesia carbon bricks.

[0055] Furthermore, in the actual production process of magnesium carbon bricks, the environmental conditions are complex and changeable, and in the heat treatment process, given the large number of batch production, during the pressing and forming heat treatment of the same batch of magnesium carbon bricks, if the state of the heating wires at different positions continues to fluctuate, it will cause temperature changes in the local range, and this temperature fluctuation has a superimposed cumulative effect. In other words, over a long period of time, the continuous accumulation of temperature fluctuations will lead to temperature deviations in the local space. At the same time, at different positions in the heat treatment space, the heat treatment temperature deviation is affected by the thermal inertia characteristics, and its temperature change response shows a lagging correlation characteristic.

[0056] At this time, the heat treatment temperature feedback adjustment of the magnesia carbon brick has a large response deviation to the inertia effect, resulting in a large control deviation; in response to the above problems, the present application evenly arranges temperature sensors at different positions during the heat treatment process, and combines the hysteresis correlation characteristics caused by the inertia effect at different positions during the heat treatment process to analyze the influence of inertia changes on temperature control during the production process of magnesia carbon bricks. The specific analysis and processing process is as follows:

[0057] Since the significant temperature change in the local area during the heat treatment of magnesia-carbon bricks is the result of the cumulative effect of the superposition of temperature fluctuations; therefore, the superposition change characteristics of the temperature change at each position in different time periods are analyzed: Specifically, for the temperature data collected at each position, all temperature data are used as input, and the mutation point detection algorithm is used to obtain the mutation data in all temperature data, the purpose of which is to determine the range of temperature changes in different time periods based on the temperature mutation characteristics; for each position, the superposition comparison interval is divided based on the acquisition time corresponding to the mutation data, and the interval composed of the acquisition time corresponding to the initial acquisition moment to each mutation data is used as the superposition comparison interval, and the interval composed of the acquisition time corresponding to the adjacent mutation data is also used as the superposition comparison interval; for example, the acquisition time corresponding to the mutation data at one position is respectively , , , then the superposition comparison interval is .

[0058] For each stacking comparison interval divided at each location, all temperature data in the stacking comparison interval are taken as input, and the trend verification algorithm is used to obtain the trend statistics of all temperature data in each stacking comparison interval; based on the negative correlation mapping results of the difference in trend statistics between each stacking comparison interval and the other stacking comparison intervals, combined with the difference characteristics of temperature data between the stacking comparison intervals, the cumulative deviation coefficient of each stacking comparison interval at each location is obtained. The specific calculation relationship is: ;in, Indicates Cumulative deviation coefficient of heat treatment temperature in the superimposed comparison interval; , Respectively represent , A set of all temperature data in the superimposed comparison interval, Represents the Hausdorff distance function, which is used to measure the difference characteristics between temperature data in the superposition comparison interval; , Respectively represent , The trend statistics of the temperature data in the stacked comparison intervals, represents an exponential function with a natural constant as base; It indicates the number of superimposed contrast intervals; that is, the trend difference between different superimposed contrast intervals is small, and there are similar trend change differences, but the temperature contrast difference caused by the superimposed effect of temperature data is large, then the calculated cumulative deviation coefficient of heat treatment temperature is large.

[0059] S503: Obtain the temperature trend coefficient of each position according to the difference of all accumulated deviation coefficients between each position and other positions and the distance between each position and other positions; and adjust the temperature trend coefficient of each position according to the information quantity characteristics of the temperature data of all positions.

[0060] Furthermore, the correlation characteristics of the lagging trends between different locations due to inertial effects are analyzed based on the interval characteristics of the superimposed cumulative impact of each location.

[0061] Since the temperature change deviation in different local intervals during the heat treatment of magnesium carbon bricks is the influence of the long-term cumulative changes in the heating elements, and the temperature changes between different positions may show hysteresis trend correlation changes in different directions due to thermal inertia, the hysteresis trend correlation characteristics are analyzed based on the cumulative influence characteristics of the temperature changes at different positions during the heat treatment process; specifically, the vector composed of the cumulative deviation coefficients of all superimposed comparison intervals at each position in the temperature control process of magnesium carbon brick heat treatment in the order of position arrangement is used as the comparison feature vector of each position, and the temperature trend coefficient of each position is obtained based on the similarity of the comparison feature vectors between each position and all other positions, combined with the negative correlation mapping results of the distance between each position and all other positions; wherein, in this embodiment, the position arrangement order is clockwise starting from the leftmost position.

[0062] In this embodiment, the specific calculation relationship is: ;in, Indicates the first step in the heat treatment process of magnesia carbon bricks after pressing and forming The temperature trend coefficient of each location; , Respectively represent , The contrast feature vector of the position, Represents the cosine similarity function, which is used to measure the similarity between two vectors; Represents the Euclidean distance function, which is used to measure the distance relationship between two locations; Indicates the number of temperature collection positions; if a temperature deviation occurs at one position during the heat treatment of magnesia carbon bricks, the temperature in the corresponding adjacent area will also change over time. If the range of the lag trend correlation caused by thermal inertia is large, the calculated temperature trend coefficient will be larger.

[0063] After analyzing the hysteresis trend correlation characteristics caused by thermal inertia between different positions during the heat treatment of magnesia-carbon bricks, a comprehensive analysis of the characteristics of temperature control deviations at different positions during the heat treatment process is performed based on the analysis results; specifically, firstly, the inertial influence weight of the heat treatment temperature control at each position is determined in combination with the correlation comparison relationship of the temperature data changes at different positions during the heat treatment of magnesia-carbon bricks and the temperature trend characteristics; the temperature data collected at all positions are used as input, and the objective weighting method is used to obtain the weight of the correlation comparison relationship of the temperature data at each position; wherein, the objective weighting method used in this embodiment is the entropy weight method, which is an existing well-known technology and will not be described in detail in this application; the temperature trend coefficient of each position is adjusted based on the weight, and the specific adjustment relationship is: ,in, Indicates The temperature trend coefficient of each location; Indicates The weight of the correlation comparison relationship between the temperature data at each location; Indicates The temperature trend coefficient after position adjustment.

[0064] It should be noted that the purpose of adjusting the temperature trend coefficient of each position through the correlation comparison relationship of different positions is to combine the correlation differences of temperature data changes at different positions in the entire space during the heat treatment process, that is, the more significant the relative correlation characteristics of the position, the greater the degree of correlation influence of its temperature trend characteristics on the lagging trend of temperature control deviation.

[0065] S504: According to the distribution of the adjusted temperature trend coefficient of each position, combined with the difference between the current control temperature of each position and the preset expected temperature, the comprehensive feedback error coefficient is calculated, and combined with the PID controller, the temperature stability of the magnesia carbon brick during the heat treatment and insulation process is controlled.

[0066] The above steps obtain the adjusted temperature trend coefficient of each position. The adjusted temperature trend coefficient reflects the temperature control deviation caused by the inertial influence characteristics of each position, that is, the greater the degree of correlation with the lag trend of temperature fluctuation changes in a longer time range, that is, the more significant the temperature trend characteristics, the greater the deviation of the temperature error analysis at the current position caused by the lag trend correlation.

[0067] Based on this, according to the adjusted temperature trend coefficient of each position of the heat treatment of the magnesia-carbon brick after pressing and forming, the comprehensive feedback error coefficient of the temperature control of the heat treatment of the magnesia-carbon brick is calculated. Specifically, for the current moment, the adjusted temperature trend coefficients of all positions are used as input, and the Z-score normalization algorithm is used to obtain the normalized result of the adjusted temperature trend coefficient of each position; the temperature difference between the current control temperature and the set expected temperature at each position is obtained, and the comprehensive feedback error coefficient is calculated based on the temperature difference at different positions and the adjusted temperature trend characteristics. The specific calculation relationship is: ;in, It represents the comprehensive feedback error coefficient of heat treatment of magnesia carbon brick after pressing and forming; Indicates The difference between the current control temperature at each location and the set desired temperature, measuring the difference between the actual temperature and the desired temperature; , Respectively represent , Normalized result of temperature trend coefficient after position adjustment; Indicates the number of temperature collection locations; wherein the desired temperature is specifically 1700°C, that is, the temperature that needs to be kept warm.

[0068] During the heat treatment process of the magnesia-carbon bricks after pressing and forming, a PID controller is used for temperature control, wherein the control parameters of the PID controller are determined by the attenuation curve method, and the calculated comprehensive feedback error coefficient is used as the feedback error of the heat treatment temperature control at the current moment, and the PID controller is used to adjust and control the temperature of the heat treatment of the magnesia-carbon bricks in real time to obtain magnesia-carbon bricks.

[0069] Among them, the flow chart of temperature stability control is as follows: Figure 2 shown.

[0070] Example 2

[0071] Example 2 of the present application proposes a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks, which is applied to the technical field of magnesia carbon brick production. Figure 1 , the method comprises the following steps:

[0072] S1: The same as the steps of S1 in Example 1, wherein the turning speed is 7 rpm.

[0073] S2: The steps are the same as those of S2 in Example 1, wherein, during deep crushing, the stroke of the moving cone is controlled at 15 mm and the rotation speed of the eccentric shaft is 360 rpm.

[0074] S3: The steps are the same as those in S3 of Example 1, wherein the mass ratio of the various raw materials is 62:25:22:1:5:2:7:5; the stirring paddle speed of the mixer is 24 rpm, and stirring is continued for 25 minutes.

[0075] S4: The same as the step of S4 in Example 1, wherein the molding pressure is adjusted to 300 MPa and the holding time is 15 seconds.

[0076] S5: The same as the steps of S5 in Example 1, wherein, during the operation of the staged heat treatment: the initial heating rate is 8°C / min, and the temperature is raised to 1000°C; then the temperature is raised to 1400°C at a heating rate of 3°C / min; finally, the temperature is raised to 1600°C at a heating rate of 1°C / min, and kept at this temperature for 4 hours to obtain a magnesia carbon brick.

[0077] Example 3

[0078] Example 3 of the present application proposes a method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks, which is applied to the technical field of magnesia carbon brick production. Figure 1 , the method comprises the following steps:

[0079] S1: The same as the steps of S1 in Example 1, wherein the turning speed is 7 rpm.

[0080] S2: The same as the steps of S2 in Example 1, wherein, during deep crushing, the dynamic cone stroke is controlled at 20 mm and the eccentric shaft speed is 400 rpm.

[0081] S3: The steps are the same as those in S3 of Example 1, wherein the mass ratio of the various raw materials is 62:25:22:1:5:2:7:7; the stirring paddle speed of the mixer is 30 rpm, and stirring is continued for 30 minutes.

[0082] S4: The same as the step of S4 in Example 1, wherein the molding pressure is adjusted to 300 MPa and the holding time is 10 seconds.

[0083] S5: The same as the steps of S5 in Example 1, wherein, during the operation of the staged heat treatment: the initial heating rate is 10°C / min, and the temperature is raised to 1000°C; then the temperature is raised to 1400°C at a heating rate of 5°C / min; finally, the temperature is raised to 1800°C at a heating rate of 3°C / min, and kept at this temperature for 4 hours to obtain a magnesia carbon brick.

[0084] In this application, the magnesium carbon bricks produced by controlling the temperature stability during heat treatment and insulation (Example) and without controlling the temperature stability (Comparative Example) are compared, and the statistical results are shown in the following table:

[0085] Table 1: Performance test results of magnesia carbon bricks produced in examples and comparative examples

[0086]

[0087] The present application provides a method for producing magnesium carbon bricks by recycling waste magnesium carbon bricks, the method comprising: when the existing traditional method utilizes waste magnesium carbon bricks to produce magnesium carbon bricks, there is a problem of hysteresis trend correlation difference due to the influence of thermal inertia in the heat treatment process after pressing and forming, resulting in low processing accuracy, and then in the existing heat treatment temperature control process, the temperature may produce control deviation due to the long-term change of the state of the heating element; therefore, all temperature data at different positions in the insulation stage of the magnesium carbon brick production process are collected, and the superimposed cumulative influence of the temperature change in the local range caused by the continuous fluctuation of the heating wires at different positions is fully considered, the cumulative deviation coefficient is calculated, and the temperature trend coefficient is obtained based on this, and its beneficial effect is that the method combines the hysteresis trend correlation characteristics caused by the inertial change of the temperature data at different positions in the heat treatment space during the heat treatment process, and the relative change relationship of the temperature at different positions in the overall space, and can accurately reflect the influence of the hysteresis trend correlation difference at different positions during the heat treatment process on the temperature feedback control deviation, thereby realizing the precise adjustment of the temperature control deviation of the magnesium carbon brick heat treatment, and finally improving the quality of the produced magnesium carbon bricks.

[0088] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two continuous boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two continuous operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0089] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks, characterized in that: The method comprises the following steps: S1: turning over the recycled waste magnesia carbon bricks to obtain homogenized waste magnesia carbon bricks; S2: coarsely crushing and deeply crushing the homogenized waste magnesia carbon bricks in sequence to obtain waste magnesia carbon brick granules and powder; S3: Mixing and stirring the waste magnesia carbon brick particles and powder with fused magnesia sand particles, heat-treated magnesia sand particles, high-temperature asphalt powder, synthetic antioxidant, metal silicon powder, graphite, and resin binder according to a specific mass ratio; S4: transferring the uniformly stirred material into a mold for pressing and forming to obtain a brick; S5: performing heat treatment on the bricks in stages, and controlling the temperature stability during the heat treatment and heat preservation process to obtain magnesia carbon bricks; The specific process of controlling the temperature stability is as follows: S501: Collect all temperature data at different positions during the insulation stage of the magnesia carbon brick production process; S502: using mutation detection on the temperature data of each position, obtaining the superposition comparison interval of each position according to the collection time corresponding to the mutation point in the temperature data; using trend analysis to obtain the trend statistics of each superposition interval divided at each position, and obtaining the cumulative deviation coefficient of each superposition comparison interval at each position according to the similarity of the temperature data between each superposition comparison interval at each position and the difference of the trend statistics with the other superposition comparison intervals; S503: obtaining the temperature trend coefficient of each position according to the difference of all accumulated deviation coefficients between each position and the other positions and the distance between each position and the other positions; adjusting the temperature trend coefficient of each position according to the information quantity characteristics of the temperature data of all positions; S504: according to the distribution of the adjusted temperature trend coefficient of each position, combined with the difference between the current control temperature of each position and the preset expected temperature, the comprehensive feedback error coefficient is calculated, and the temperature stability of the magnesia carbon brick during the heat treatment and insulation process is controlled in combination with the PID controller; The obtained superposition comparison interval for each position is specifically an interval consisting of the acquisition time from the initial acquisition time of each position to the acquisition time corresponding to each mutation data, and an interval consisting of the acquisition time corresponding to adjacent mutation data.

2. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The speed of turning the material described in S1 is set to 5-10 rpm.

3. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The specific operation of deep crushing in S2 is to control the dynamic cone stroke at 10~20mm and the eccentric shaft speed at 300~400 rpm; the waste magnesium carbon brick particles and powder are obtained, specifically: particles with a particle size of 3~10mm account for 40%, particles with a particle size of 0.074~3mm account for 40%, and powders with a size of 0~0.074mm account for 20%.

4. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The specific mass ratio described in S3 is: waste magnesia carbon brick particles and powder: fused magnesia sand particles: heat-treated magnesia sand particles: high-temperature asphalt powder: synthetic antioxidant: metallic silicon powder: graphite: resin binder = 62:25:22:1:5:2:7:2~7; the mixing and stirring operation is specifically a stirring speed of 20~30 rpm, and continuous stirring for 20~30 minutes.

5. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks as claimed in claim 1, characterized in that: The parameters for the compression molding operation described in S4 are specifically: the molding pressure is between 100 and 300 MPa, and the holding time is 10 to 30 seconds.

6. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks as claimed in claim 1, characterized in that: The specific operation process of the staged heat treatment described in S5 is: the initial heating rate is 5~10℃ / min, and the temperature is raised to 1000℃; then the temperature is raised to 1400℃ at a heating rate of 3~5℃ / min; finally, the temperature is raised to 1600~1800℃ at a heating rate of 1~3℃ / min, and kept warm for 3~4 hours.

7. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The cumulative deviation coefficient of each superimposed comparison interval at each position is obtained as follows: For each superposition comparison interval divided at each location, all temperature data in the superposition comparison interval are used as input, and the trend verification algorithm is used to obtain the trend statistics of each superposition comparison interval; Based on the negative correlation mapping results of the difference in trend statistics between each stacking comparison interval and all other stacking comparison intervals, combined with the difference characteristics of temperature data between stacking comparison intervals, the cumulative deviation coefficient of each stacking comparison interval at each location is obtained.

8. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks as claimed in claim 1, characterized in that: The temperature trend coefficient of each position is obtained as follows: The vector composed of the cumulative deviation coefficients of all superimposed comparison intervals at each position during the temperature control process of the heat treatment of magnesia carbon bricks is used as the comparison feature vector of each position; Based on the similarity of the feature vectors of each position compared with all other positions, combined with the negative correlation mapping results of the distances between each position and all other positions, the temperature trend coefficient of each position is obtained.

9. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The step of adjusting the temperature trend coefficient of each position includes: The temperature data collected at all locations are taken as input, and the objective weighting method is used to obtain the weight of the correlation comparison relationship of the temperature data at each location. The product of the temperature trend coefficient of each location and the weight corresponding to each location is taken as the adjusted temperature trend coefficient of each location.

10. The method for producing magnesia carbon bricks by recycling waste magnesia carbon bricks according to claim 1, characterized in that: The calculation of the comprehensive feedback error coefficient, combined with the PID controller, controls the temperature stability of the magnesia carbon brick during the heat treatment and insulation process, including: The calculation formula of the comprehensive feedback error coefficient is: ;in, represents the comprehensive feedback error coefficient; Indicates The difference between the current control temperature at each location and the set desired temperature; , Respectively represent , Normalized result of temperature trend coefficient after position adjustment; Indicates the number of temperature collection locations; The comprehensive feedback error coefficient is used as the feedback error for the heat treatment temperature control at the current moment, and the temperature is controlled during the heat treatment insulation process using a PID controller.

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