Method for rapid detection of sintered quicklime quality

Abstract

The application discloses a kind of sintered quicklime quality rapid detection method, belong to quicklime quality detection technical field.The application steps are as follows: step one: make container;Step two: pour raw materials, pour a volume of quicklime into two volumes of water;Step three: water lime reaction, temperature sensor, time meter are used to detect and track temperature and time;Step four: when temperature sensor reaches the highest temperature starts to drop, record the whole heating time;Step five: all water in the reactor after reaction is removed, and the remaining residue is loaded into a quick dryer for drying;Step six: the residue after drying is weighed, the effective CaO content of quicklime is calculated according to the burning rate, and the activity of quicklime powder is detected;The application can detect the quality of quicklime in real time through the rapid on-site test method of burning rate, and the effective CaO content calculation result is combined to facilitate timely adjustment of sinter flux ratio and improve the quality of sinter.

Description

Technical Field

[0001] This invention relates to the field of quicklime quality testing technology, and more specifically, to a rapid method for testing the quality of sintered quicklime. Background Technology

[0002] The impact of quicklime quality on sintering is mainly reflected in two aspects: 1) The influence of CaO content. The higher the calcium content in quicklime, the more sufficient calcium source it can provide for sintering, which helps in the formation of substances such as calcium ferrite, thereby improving the strength and quality of the sinter. Fluctuations in CaO content will change the chemical composition of the sinter, affecting its physical and chemical properties, and may lead to problems such as decreased strength and reduced reducibility. 2) The influence of activity. Activity is mainly reflected in reactivity, and is generally required to be no less than 260 ml. Quicklime with high activity can react quickly with water to generate hydrated lime during sintering, releasing a large amount of heat to increase the temperature of the mixture, enhance the granulation effect of the mixture, and thus improve the performance of the sinter. At the same time, highly active quicklime can also promote various chemical reactions during sintering, which is conducive to the formation of liquid phase and calcium ferrite, and can improve the drum strength of the sinter and make the particle size distribution more uniform, which is very beneficial to blast furnace smelting.

[0003] Currently, the CaO content of quicklime is determined using acid-base titration. This method utilizes the reaction of calcium oxide with water to generate calcium hydroxide, followed by the neutralization reaction of calcium hydroxide with hydrochloric acid. The calcium oxide content is calculated based on the volume of hydrochloric acid consumed. The activity of quicklime is determined using hydrochloric acid titration. Quicklime is added to 2000 ml of water at 40°C, and the calcium hydroxide in the water is neutralized with 4 mol / L hydrochloric acid. The equivalence point of the acid-base neutralization reaction is maintained as much as possible. The activity of quicklime is characterized by the volume of hydrochloric acid added after 10 minutes of digestion and neutralization, expressed in ml.

[0004] Currently, quicklime for sintering is transported by tanker trucks, using compressed air to pump it into the sintering quicklime silos for storage. Samples are taken from the conveyor belt at the silo outlet and sent to the laboratory for testing after preparation. This results in a significant delay in activity level testing – by the time the results are available, the quicklime in the silo is almost depleted. This does not align with the overall strategy of pre-controlling production, and therefore, effective improvements are necessary.

[0005] The specific implementation steps of invention patent CN 118311193 A, "A Rapid Detection Device and Method for the Activity of Quicklime for Sintering," are as follows: A sample is taken by opening the sampling port of the quicklime truck; water is poured into the reaction vessel, and then the sample is poured into the vessel to carry out a foaming reaction. The start time, end time, duration, process temperature, and intensity of the foaming reaction are recorded. After comparative analysis, the quicklime activity detection result is output. However, this patent only determines the activity through the reaction process of quicklime and water, failing to determine the influence of activity on the sintering process.

[0006] The utility model patent CN 219608823 U, "A Device for Detecting Calcium Oxide Content in Quicklime," utilizes the principle that calcium oxide dissolves in water and releases heat, causing the water temperature to rise. It establishes a standard curve between concentration and heat release, and determines the calcium oxide content by detecting the temperature change of the sample as it dissolves in water, thus solving the problem of rapid and accurate detection of calcium oxide content in quicklime. However, before implementing this patent, it is necessary to establish an instrument standard curve and then conduct tests at different concentrations, which has the drawbacks of being time-consuming and relying on a single basis for judgment. Summary of the Invention

[0007] 1. The technical problem that the invention aims to solve

[0008] To address the shortcomings and deficiencies of existing technologies, this invention provides a rapid method for detecting the quality of sintered quicklime. This invention proposes a rapid on-site inspection method for the over-burning rate of quicklime, which can monitor the quality of quicklime in real time. Combined with the calculation results of effective calcium oxide content, it facilitates timely optimization of the flux ratio in sintered ore, effectively improving the overall quality of the sintered ore. This method mainly targets the detection of quicklime activity and calcium oxide content, with a total testing time of approximately thirty minutes. Based on the test data, various sintering process parameters can be adjusted in a timely manner to improve the stability of the sintering production process and the quality of the finished product. This invention offers high accuracy in detecting calcium oxide content, abandoning traditional methods such as hydrochloric acid titration, and is more suitable for the safety requirements of on-site testing. Simultaneously, it employs a quicklime digestion and heating method to complete the activity detection, achieving automatic data collection, analysis, calculation, and storage. Furthermore, it is linked with the water addition control of the mixture, further enhancing the granulation effect of the sintered material.

[0009] 2. Technical Solution

[0010] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0011] The present invention provides a rapid method for detecting the quality of sintered quicklime, comprising the following steps:

[0012] Step 1: Make a container. Use a cylindrical steel tank as a reaction vessel with a volume of 5000 ml or more. Then use the steel tank to make a standard container, and mark the container with a volume of 1000 ml.

[0013] Step 2: Pour in the raw materials. First, fill two standard containers with tap water and pour them into the reaction vessel. Then, fill one standard container with quicklime and slowly pour it into the water in the reaction vessel. That is, pour one volume of quicklime into two volumes of water.

[0014] Step 3: Water-lime reaction. When quicklime powder comes into contact with water, a hydration reaction occurs, generating a large amount of heat. At this time, a temperature sensor and a timer are used to detect and track the temperature and time.

[0015] Step 4: When the temperature sensor reaches its maximum temperature and begins to drop, record the entire heating time. The complete digestion time of quicklime is generally 7-9 minutes.

[0016] Step 5: Remove all water from the reactor after the reaction, and put the remaining residue into a rapid dryer for drying. The entire drying process takes 15 minutes.

[0017] Step 6: Weigh the dried residue, calculate the effective CaO content of the quicklime based on the underburning rate, and test the activity of the quicklime powder;

[0018] 6-1: Calculation of the effective CaO content in quicklime

[0019] 6-1-1: Calculate the overburning rate w as a mass fraction, expressed as a percentage, using the following formula:

[0020] w=100×m1 / m

[0021] In the formula: m1: the numerical value of the amount of unconsumed substance, in grams (g).

[0022] m: The numerical value of the sample mass, in grams (g).

[0023] 6-1-2: Calculation Method for Effective CaO Content in Quicklime

[0024] The effective CaO content, expressed as a mass fraction (%), is calculated using the following formula:

[0025] Effective CaO content = (1 - w / 100) × Total CaO content of quicklime

[0026] The total CaO content of quicklime can be determined in advance using conventional chemical analysis methods and used as a calculation benchmark; w is the overburning rate calculated in the above steps, and the effective CaO content can be accurately calculated using this formula;

[0027] 6-2: Activity test of quicklime:

[0028] The activity of quicklime powder is determined by the exothermic reaction between quicklime powder and water, combined with four data points: the temperature of quicklime powder, the temperature of water, the time it takes for the reaction to reach its maximum temperature, and the temperature at which the reaction reaches its maximum.

[0029] The calculation method is: v = (t_max - t0) / t

[0030] Where: initial water temperature (t0), maximum temperature reached by the reaction (t_max), time t from the start of the reaction to reaching the maximum temperature, and temperature rise rate v;

[0031] 6-2-1: Establishing a regression equation between activity and core parameters based on experimental data.

[0032] By fitting multiple sets of experimental data, a multiple linear regression equation was obtained between the activity of quicklime (A, in mL) and the core parameters, as follows:

[0033] A=85.62+1.83 / (t_max-t0)-2.17×t+3.59×v

[0034] In the formula:

[0035] A – Activity of quicklime (mL);

[0036] t0—Initial reaction water temperature (°C), detection range 18-22°C;

[0037] t_max — the highest temperature reached by the reaction (°C);

[0038] t — complete digestion time (min), which is the time from the start of the reaction to the reaching of the highest temperature;

[0039] v——rate of temperature rise (°C / min), v=(t_max-t0) / t.

[0040] 6-2-2: Establish a table showing the correspondence between quicklime activity and core parameters.

[0041] Step 7: Testing Implementation and Parameter Adjustment

[0042] As required in step four, during on-site testing, when the temperature sensor detects that the temperature of the reaction system has reached its maximum value and begins to decrease, the time meter records the entire heating time (complete digestion time t). The temperature sensor simultaneously records the initial water temperature t0 and the maximum temperature t_max. The above three basic data are transmitted to the PLC in real time without any manual intervention. The PLC automatically calculates the temperature rise rate v=[(t_max-t0) / t] according to the preset logic, and then automatically calculates the activity of quicklime by substituting it into the regression equation (or querying the corresponding relationship table). The entire calculation process conforms to the core requirements of PLC automatic acquisition, automatic calculation, and automatic output, and there are no steps that cannot be automated.

[0043] The PLC has a built-in database of the correspondence between the activity of quicklime and the water addition ratio of the primary and secondary mixers. Based on the calculated activity value, it automatically provides suggestions for adjusting the water addition ratio to ensure that the quicklime digestion process is completed during the granulation process of the mixer, thus ensuring the stability of the sintering process.

[0044] The rapid on-site testing method for the over-burning rate of quicklime can be used to detect the quality of quicklime in real time. Combined with the calculation results of effective CaO content, it is convenient to adjust the flux ratio of sinter in a timely manner and improve the quality of sinter.

[0045] Furthermore, in step six, the correspondence between the activity of quicklime and the core parameters is shown in the table below:

[0046]

[0047] This correspondence table is established based on experimental conditions of a water-cement volume ratio of 1:2 and a quicklime particle size of 0.1-0.2mm. If the testing conditions change, the regression equation coefficients and the corresponding table data can be adjusted through the PLC parameter calibration function to adapt to the automatic calculation requirements under different working conditions. For parameter combinations not covered in the table, the PLC will automatically calculate the activity through the above regression equation to ensure that no parameters are omitted and realize full-scene automated calculation.

[0048] Furthermore, in step six, the regression equation for activity and core parameters is established based on experimental data. The experimental conditions are: quicklime sample particle size of 0.1-0.2 mm, water-lime volume ratio of 1:2, and initial water temperature of 20±2℃.

[0049] Furthermore, in step six, the regression equation has a goodness of fit R² = 0.982 and an error range of ±3mL, which meets the accuracy requirements of PLC automatic calculation. At the same time, all coefficients in the equation (85.62, 1.83, 2.17, 3.59) are fixed constants that can be directly preset into the PLC program without on-site adjustment, further adapting to the PLC automated operation logic.

[0050] Furthermore, step six also specifically includes: the PLC can directly collect three basic data points, t0, t_max, and t, automatically derive and calculate v, and then substitute it into the regression equation or query the corresponding relationship table. Without manual intervention, the PLC can automatically calculate the activity of quicklime, which is fully compatible with the PLC's automated operation logic.

[0051] Furthermore, step seven specifically includes:

[0052] The PLC has a built-in database that maps quicklime activity to the water addition ratio in the primary and secondary mixers. This database is based on actual sintering production conditions (quicklime particle size 0.1-2mm, water-lime volume ratio 1:2, mixer speed 18-22 r / min). It presets standard water addition ratios according to activity levels and specifies dynamic adjustment methods, adjustment ranges, and verification methods. Based on the calculated activity values, the PLC automatically matches the corresponding water addition ratio and provides precise adjustment suggestions, ensuring that the quicklime digestion process is completed entirely during the granulation process in the mixer, thus guaranteeing the stability of the sintering process. Specific details are as follows:

[0053] 7-1: Activity level classification and standard water addition ratio correspondence library (PLC built-in core parameters)

[0054]

[0055] 7-2: PLC Automatic Adjustment Methods and Procedures

[0056] 7-2-1: Parameter matching;

[0057] After the PLC calculates the activity A of quicklime, it automatically searches the built-in corresponding database to match the grade and standard water addition ratio corresponding to the activity A (corresponding to the primary and secondary mixers respectively). At the same time, it retrieves the real-time parameters of quicklime feed rate and mixer speed of the current sintering system.

[0058] 7-2-2: Initial water addition ratio output;

[0059] Based on the matching standard water addition ratio and the current quicklime feed rate, the PLC automatically calculates the actual water addition amount for the primary and secondary mixers (water addition amount = quicklime feed rate × corresponding water addition ratio), and sends a control signal to the mixer water addition valve to set the initial water addition flow rate to ensure uniform water addition.

[0060] 7-2-3: Dynamic fine-tuning correction;

[0061] The PLC collects the humidity of the material at the mixer outlet in real time and automatically adjusts the water addition ratio of the corresponding mixer by ±0.5-1%.

[0062] 7-2-4: Adjust limit switches and alarms;

[0063] The PLC has a preset limit for adjusting the water ratio. If the ratio exceeds the limit after adjustment, the PLC will automatically stop adjusting and issue an alarm signal to prompt the operator to check the activity test data or the operating condition of the mixer, so as to avoid abnormal water addition affecting the sintering quality.

[0064] Through the above-mentioned refined adjustment methods, PLC can achieve precise and automated control of the water addition ratio, ensuring that quicklime is fully digested during the mixing and granulation process, thus guaranteeing the quality of sinter and the stability of the production process from the source.

[0065] Furthermore, the water addition ratio is defined as "the percentage of water added to the mass of quicklime". The PLC can automatically calculate the required water addition based on the preset quicklime feed amount of the sintering system. This correspondence can be adjusted through the PLC parameter calibration interface to adapt to different quicklime particle sizes and mixer speed changes.

[0066] Furthermore, during the water addition process, the maximum water addition ratio of the primary mixer shall not exceed 32%, and the minimum shall not be less than 18%; the maximum water addition ratio of the secondary mixer shall not exceed 22%, and the minimum shall not be less than 11%.

[0067] 3. Beneficial effects

[0068] Compared with the prior art, the technical solution provided by this invention has the following advantages:

[0069] This invention proposes a rapid on-site testing method for the overburning rate of quicklime. It can monitor the quality of quicklime in real time, and combined with the calculation results of effective calcium oxide content, facilitates timely optimization of the flux ratio in sintered ore, effectively improving the overall quality of the sintered ore. This method mainly targets the activity and calcium oxide content of quicklime, with the entire testing process taking approximately thirty minutes. Based on the test data, various sintering process parameters can be adjusted in a timely manner, improving the stability of the sintering production process and the quality of the finished product. This invention offers high accuracy in detecting calcium oxide content, abandoning traditional methods such as hydrochloric acid titration, and is more suitable for the safety requirements of on-site testing. Simultaneously, it employs a quicklime digestion and heating method to complete the activity detection, achieving automatic data collection, analysis, calculation, and storage. Furthermore, it is linked with the water addition control of the mixture, further enhancing the granulation effect of the sintered material. Attached Figure Description

[0070] Figure 1 This is a process flow diagram of the present invention.

[0071] In the diagram: 1. Reaction vessel; 2. Standard vessel; 3. Temperature sensor; 4. Timer; 5. Rapid dryer. Detailed Implementation

[0072] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0073] Example 1

[0074] from Figure 1 As can be seen, the steps of the rapid detection method for sintered quicklime quality in this embodiment are as follows:

[0075] Step 1: Make a container. Use a cylindrical steel tank as a reaction vessel 1 with a volume of more than 5000 ml. Then use the steel tank to make a standard container 2 with a volume of 1000 ml marked on it.

[0076] Step 2: Pour in the raw materials. First, fill two cans of tap water in standard container 2 and pour them into reaction container 1. Then, fill one can of quicklime in standard container 2 and slowly pour it into the water in reaction container 1. That is, pour one volume of quicklime into two volumes of water.

[0077] Step 3: Water-lime reaction. When quicklime powder comes into contact with water, a hydration reaction occurs, generating a large amount of heat. At this time, temperature sensor 3 and time meter 4 are used to detect and track the temperature and time. Temperature sensor 3 and time meter 4 are connected to reaction vessel 1.

[0078] Step 4: When temperature sensor 3 reaches its maximum temperature and begins to drop, record the entire heating time. The complete digestion time of quicklime is generally 7-9 minutes.

[0079] Step 5: Remove all water from the reactor after the reaction, and put the remaining residue into the rapid dryer 5 for drying. The entire drying process takes 15 minutes.

[0080] Step 6: Weigh the dried residue, calculate the effective CaO content of the quicklime based on the underburning rate, and test the activity of the quicklime powder;

[0081] 6-1: Calculation of the effective CaO content in quicklime

[0082] Method principle: When appropriate lime is calcined, it reacts rapidly with water to produce calcium hydroxide Ca(OH)2. The undigested part is either raw ash that is not fully calcined or old ash that has been over-calcined.

[0083] Analysis procedure: Weigh 1000 kg of quicklime sample and put it into about 2000 mL of water at around 20 degrees Celsius. Put the undigested particles (undigested matter) into a basin and dry it in an oven at 105-110 degrees Celsius for 15 minutes before weighing.

[0084] 6-1-1: Calculate the overburning rate w as a mass fraction, expressed as a percentage, using the following formula:

[0085] w=100×m1 / m

[0086] In the formula: m1: the numerical value of the amount of unconsumed substance, in grams (g).

[0087] m: The numerical value of the sample mass, in grams (g).

[0088] 6-1-2: Calculation Method for Effective CaO Content in Quicklime

[0089] The effective CaO content, expressed as a mass fraction (%), is calculated using the following formula:

[0090] Effective CaO content = (1 - w / 100) × Total CaO content of quicklime

[0091] The total CaO content of quicklime can be determined in advance using conventional chemical analysis methods (such as titration) and used as a calculation benchmark; w is the overburning rate calculated in the above steps, and the effective CaO content can be accurately calculated using this formula;

[0092] The calculation of the effective CaO content here is the core foundation for establishing the subsequent regression equation. The core function of the regression equation is to fit the calculation model of the effective CaO content using known detection parameters (such as the overburning rate, basic sample indicators, etc.). The overburning rate detection in 6-1-1 and the effective CaO content calculation in 6-1-2 of this paper provide the "measured data sample" and "standard calculation result" for the regression equation.

[0093] By repeatedly testing the overburning rate and calculating the effective CaO content, multiple sets of data corresponding to "overburning rate w - effective CaO content" were obtained. These data were used as sample data for regression analysis, substituted into the regression equation for fitting and calibration, and finally a regression model that can be directly used for rapid on-site measurement was obtained. This allows for the rapid derivation of the effective CaO content through the regression equation without the need for cumbersome chemical titration and complete overburning rate testing. At the same time, the calculation method in this paper is also an important basis for verifying the fitting accuracy of the regression equation and correcting the equation parameters.

[0094] 6-2: Activity test of quicklime:

[0095] The activity of quicklime powder is determined by the exothermic reaction between quicklime powder and water, combined with four data points: the temperature of quicklime powder, the temperature of water, the time it takes for the reaction to reach its maximum temperature, and the temperature at which the reaction reaches its maximum.

[0096] Detection Principle: Utilizing the exothermic reaction of quicklime powder with water, and combining four core data points—initial water temperature (t0), maximum temperature reached (t_max), time from the start of the reaction to reaching the maximum temperature (i.e., complete digestion time t), and temperature rise rate (v, in °C / min)—a regression equation and corresponding relationship table between activity and these parameters are established. The PLC can directly collect the three basic data points (t0, t_max, and t), automatically derive and calculate v, and then substitute it into the regression equation or query the corresponding relationship table. This achieves automatic calculation of quicklime activity without manual intervention, fully adapting to the automated calculation logic of the PLC.

[0097] The calculation method is: v = (t_max - t0) / t

[0098] Where: initial water temperature (t0), maximum temperature reached by the reaction (t_max), time t from the start of the reaction to reaching the maximum temperature, and temperature rise rate v;

[0099] 6-2-1: Establishing a regression equation between activity and core parameters based on experimental data.

[0100] The regression equation between activity and core parameters was established based on experimental data. The experimental conditions were: quicklime sample particle size of 0.1-0.2 mm, water-lime volume ratio of 1:2, and initial water temperature of 20±2℃. Through multiple sets of experimental data, a multiple linear regression equation between quicklime activity (A, in mL) and core parameters was obtained. The equation is simple in form, requires little computation, is compatible with the computing power of PLC, and has no complex calculation steps. The details are as follows:

[0101] A=85.62+1.83 / (t_max-t0)-2.17×t+3.59×v

[0102] The goodness of fit of the regression equation R 2 =0.982, with an error range of ±3mL, which meets the accuracy requirements of PLC automatic calculation; at the same time, all coefficients in the equation (85.62, 1.83, 2.17, 3.59) are fixed constants that can be directly preset into the PLC program without on-site adjustment, further adapting to the PLC automated operation logic;

[0103] Additional explanation: The calculations of each parameter in the equation are all basic addition, subtraction and multiplication operations, without complex operations such as fractions and square roots, and can be directly recognized and executed by the PLC; among them, (t_max-t0) is the temperature rise difference, which can be automatically calculated by the PLC from the two basic data of t_max and t0 collected, without the need for additional manual input, which meets the core requirements of PLC automatic data collection and automatic calculation.

[0104] The PLC can directly collect three basic data points: t0, t_max, and t, automatically derive and calculate v, and then substitute it into the regression equation or query the corresponding relationship table. Without manual intervention, it can automatically calculate the activity of quicklime and is fully compatible with the PLC's automated operation logic.

[0105] In the formula:

[0106] A – Activity of quicklime (mL);

[0107] t0—Initial reaction water temperature (°C), detection range 18-22°C;

[0108] t_max — the highest temperature reached by the reaction (°C);

[0109] t — complete digestion time (min), which is the time from the start of the reaction to the reaching of the highest temperature;

[0110] v——rate of temperature rise (°C / min), v=(t_max-t0) / t.

[0111] 6-2-2: Establish a table showing the correspondence between quicklime activity and core parameters.

[0112] The table below shows the relationship between quicklime activity and core parameters:

[0113]

[0114] This correspondence table is established based on experimental conditions of a water-cement volume ratio of 1:2 and a quicklime particle size of 0.1-0.2mm. If the testing conditions change, the regression equation coefficients and the corresponding table data can be adjusted through the PLC parameter calibration function to adapt to the automatic calculation requirements under different working conditions. For parameter combinations not covered in the table, the PLC will automatically calculate the activity through the above regression equation to ensure that no parameters are omitted and realize full-scene automated calculation.

[0115] Step 7: Testing Implementation and Parameter Adjustment

[0116] As required in step four, during on-site testing, when the temperature sensor detects that the temperature of the reaction system has reached its maximum value and begins to decrease, the time meter records the entire heating time (complete digestion time t). The temperature sensor simultaneously records the initial water temperature t0 and the maximum temperature t_max. The above three basic data are transmitted to the PLC in real time without any manual intervention. The PLC automatically calculates the temperature rise rate v=[(t_max-t0) / t] according to the preset logic, and then automatically calculates the activity of quicklime by substituting it into the regression equation (or querying the corresponding relationship table). The entire calculation process conforms to the core requirements of PLC automatic acquisition, automatic calculation, and automatic output, and there are no steps that cannot be automated.

[0117] The PLC has a built-in database of the correspondence between the activity of quicklime and the water addition ratio of the primary and secondary mixers. Based on the calculated activity value, it automatically provides suggestions for adjusting the water addition ratio to ensure that the quicklime digestion process is completed during the granulation process of the mixer, thus ensuring the stability of the sintering process.

[0118] The rapid on-site testing method for the over-burning rate of quicklime can be used to detect the quality of quicklime in real time. Combined with the calculation results of effective CaO content, it is convenient to adjust the flux ratio of sinter in a timely manner and improve the quality of sinter.

[0119] Step seven also specifically includes:

[0120] The PLC has a built-in database that maps quicklime activity to the water addition ratio in the primary and secondary mixers. This database is based on actual sintering production conditions (quicklime particle size 0.1-2mm, water-lime volume ratio 1:2, mixer speed 18-22 r / min). It presets standard water addition ratios according to activity levels and specifies dynamic adjustment methods, adjustment ranges, and verification methods. Based on the calculated activity values, the PLC automatically matches the corresponding water addition ratio and provides precise adjustment suggestions, ensuring that the quicklime digestion process is completed entirely during the granulation process in the mixer, thus guaranteeing the stability of the sintering process. Specific details are as follows:

[0121] 7-1: Activity level classification and standard water addition ratio correspondence library (PLC built-in core parameters)

[0122]

[0123] In the table, the water addition ratio is defined as "the percentage of water added to the mass of quicklime". The PLC can automatically calculate the required amount of water added based on the preset quicklime feed amount of the sintering system. This correspondence can be adjusted through the PLC parameter calibration interface to adapt to different quicklime particle sizes and mixer speed changes.

[0124] 7-2: PLC Automatic Adjustment Methods and Procedures

[0125] 7-2-1: Parameter matching;

[0126] After the PLC calculates the activity A of quicklime, it automatically searches the built-in corresponding relationship library to match the grade and standard water addition ratio corresponding to the activity A (corresponding to the primary and secondary mixers respectively). At the same time, it retrieves the real-time parameters of quicklime feed rate and mixer speed of the current sintering system.

[0127] 7-2-2: Initial water addition ratio output;

[0128] Based on the matching standard water addition ratio and the current quicklime feed rate, the PLC automatically calculates the actual water addition amount for the primary and secondary mixers (water addition amount = quicklime feed rate × corresponding water addition ratio), and sends a control signal to the mixer water addition valve to set the initial water addition flow rate to ensure uniform water addition.

[0129] 7-2-3: Dynamic fine-tuning correction;

[0130] The PLC collects the humidity of the material at the mixer outlet in real time and automatically adjusts the water addition ratio of the corresponding mixer by ±0.5-1%.

[0131] 7-2-4: Adjust limit switches and alarms;

[0132] The PLC has a preset limit for adjusting the water ratio. If the ratio exceeds the limit after adjustment, the PLC will automatically stop adjusting and issue an alarm signal to prompt the operator to check the activity test data or the operating condition of the mixer, so as to avoid abnormal water addition affecting the sintering quality.

[0133] Through the above-mentioned refined adjustment methods, PLC can achieve precise and automated control of the water addition ratio, ensuring that quicklime is fully digested during the mixing and granulation process, thus guaranteeing the quality of sinter and the stability of the production process from the source.

[0134] During the water addition process, the maximum water addition ratio for the primary mixer shall not exceed 32%, and the minimum shall not be less than 18%; for the secondary mixer, the maximum water addition ratio shall not exceed 22%, and the minimum shall not be less than 11%.

[0135] The system collects four parameters during the quicklime digestion process: quicklime powder temperature, water temperature, maximum reaction temperature, and time to reach the temperature. The PLC automatically calculates the correlation between quicklime activity and these parameters. Simultaneously, it collects the total cumulative water added to the sintering mixture at any given time and the real-time moisture content of the mixture. It also acquires the overall mixing time of the mixer and the quicklime activity reaction time at that stage. By adjusting the water added to the primary and secondary mixers, the system precisely controls the quicklime activity reaction time, ensuring that the quicklime activity reaction time is always less than the total mixing time of the mixer.

[0136] This invention provides a rapid on-site testing method for the rate of underburning and overburning of quicklime. It can detect the quality of quicklime in real time and, combined with the calculation results of effective CaO content, facilitate timely adjustment of the flux ratio of sinter and improve the quality of sinter.

[0137] The detection method of this invention mainly detects the activity and CaO content of quicklime. The entire detection process takes about 30 minutes. Based on the detection results, various sintering parameters can be adjusted to improve the quality of sinter and the stability of the process.

[0138] 1. The method for detecting CaO content in this invention has high accuracy and does not use methods such as hydrochloric acid titration, making it suitable for safe on-site testing;

[0139] 2. This invention uses a quicklime digestion and heating method to detect activity, automatically collects, analyzes, calculates and stores the data, and links it with the addition of water to the mixture to effectively enhance granulation during the sintering process.

[0140] To address the stability of sintering production process control and thus achieve stable sinter quality, this application provides a rapid detection method and apparatus for sintered quicklime quality. This addresses the problem of significant delays in activity and CaO detection results when sampling quicklime from the conveyor belt at the silo during material handling. The method provides data guidance for sintering production materials and resolves the issue of large fluctuations in quicklime quality affecting sintering production and sinter quality.

[0141] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A rapid method for detecting the quality of sintered quicklime, characterized in that: The steps are as follows: Step 1: Make a container. Use a cylindrical steel tank as a reaction vessel (1) with a volume of more than 5000 ml. Then use the steel tank to make a standard container (2). Mark the container with a volume of 1000 ml. Step 2: Pour in the raw materials. First, fill two cans of tap water in a standard container (2) and pour them into the reaction container (1). Then, fill one can of quicklime in a standard container (2) and slowly pour it into the water in the reaction container (1). That is, pour one volume of quicklime into two volumes of water. Step 3: Water-lime reaction. When quicklime powder comes into contact with water, it undergoes a reaction... The hydration reaction generates a large amount of heat. At this time, a temperature sensor (3) and a time meter (4) are used to detect and track the temperature and time. Step 4: When the temperature sensor (3) reaches the highest temperature and begins to drop, record the entire heating time. The time for quicklime to completely digest is generally 7-9 minutes. Step 5: Remove all water from the reactor after the reaction, and put the remaining residue into the rapid dryer (5) for drying. The entire drying process takes 15 minutes. Step 6: Weigh the dried residue, calculate the effective CaO content of the quicklime based on the underburning rate, and test the activity of the quicklime powder; 6-1: Calculation of the effective CaO content in quicklime 6-1-1: Calculate the overburning rate w as a mass fraction, expressed as a percentage, using the following formula: w=100×m1 / m In the formula: m1: the numerical value of the amount of unconsumed substance, in grams (g). m: The numerical value of the sample mass, in grams (g). 6-1-2: Calculation Method for Effective CaO Content in Quicklime The effective CaO content, expressed as a mass fraction (%), is calculated using the following formula: Effective CaO content = (1 - w / 100) × Total CaO content of quicklime The total CaO content of quicklime can be determined in advance using conventional chemical analysis methods and used as a calculation benchmark; w is the overburning rate calculated in the above steps, and the effective CaO content can be accurately calculated using this formula; 6-2: Activity test of quicklime: The activity of quicklime powder is determined by the exothermic reaction between quicklime powder and water, combined with four data points: the temperature of quicklime powder, the temperature of water, the time it takes for the reaction to reach its maximum temperature, and the temperature at which the reaction reaches its maximum. The calculation method is: v = (t_max - t0) / t Where: initial water temperature (t0), maximum temperature reached by the reaction (t_max), time t from the start of the reaction to reaching the maximum temperature, and temperature rise rate v; 6-2-1: Establishing a regression equation between activity and core parameters based on experimental data. By fitting multiple sets of experimental data, a multiple linear regression equation was obtained between the activity of quicklime (A, in mL) and the core parameters, as follows: A=85.62+1.83 / (t_max-t0)-2.17×t+3.59×v In the formula: A – Activity of quicklime (mL); t0—Initial reaction water temperature (°C), detection range 18-22°C; t_max — the highest temperature reached by the reaction (°C); t — complete digestion time (min), which is the time from the start of the reaction to the reaching of the highest temperature; v——rate of temperature rise (°C / min), v=(t_max-t0) / t; 6-2-2: Establish a table showing the correspondence between quicklime activity and core parameters. Step 7: Testing Implementation and Parameter Adjustment As required in step four, during on-site testing, when the temperature sensor detects that the temperature of the reaction system has reached its maximum value and begins to decrease, the time meter records the entire heating time (complete digestion time t). The temperature sensor simultaneously records the initial water temperature t0 and the maximum temperature t_max. The above three basic data are transmitted to the PLC in real time without any manual intervention. The PLC automatically calculates the temperature rise rate v=[(t_max-t0) / t] according to the preset logic, and then automatically calculates the activity of quicklime by substituting it into the regression equation (or querying the corresponding relationship table). The PLC has a built-in database of the correspondence between the activity of quicklime and the water addition ratio of the primary and secondary mixers. Based on the calculated activity value, it automatically provides suggestions for adjusting the water addition ratio to ensure that the quicklime digestion process is completed during the granulation process of the mixer, thus ensuring the stability of the sintering process. The rapid on-site testing method for the over-burning rate of quicklime can be used to detect the quality of quicklime in real time. Combined with the calculation results of effective CaO content, it is convenient to adjust the flux ratio of sinter in a timely manner and improve the quality of sinter.

2. The rapid detection method for the quality of sintered quicklime according to claim 1, characterized in that: In step six, the relationship between quicklime activity and core parameters is shown in the table below: 。 3. The rapid detection method for the quality of sintered quicklime according to claim 1, characterized in that: In step six, the regression equation between activity and core parameters is established based on experimental data. The experimental conditions are: quicklime sample particle size of 0.1-0.2 mm, water-lime volume ratio of 1:2, and initial water temperature of 20±2℃.

4. The rapid detection method for the quality of sintered quicklime according to claim 1, characterized in that: In step six, the goodness of fit R of the regression equation is... 2 =0.982, with an error range of ±3mL, which meets the accuracy requirements of PLC automatic calculation; at the same time, all coefficients in the equation are fixed constants, which can be directly preset into the PLC program without on-site adjustment, further adapting to the PLC automated operation logic.

5. The rapid method for detecting the quality of sintered quicklime according to claim 1, characterized in that: Step six also specifically includes: the PLC can directly collect three basic data points, t0, t_max, and t, automatically derive and calculate v, and then substitute it into the regression equation or query the corresponding relationship table. Without manual intervention, the PLC can automatically calculate the activity of quicklime, which is fully compatible with the PLC's automated operation logic.

6. The method for rapid quality detection of sintered quicklime according to claim 1, characterized in that: Step seven also specifically includes: The PLC has a built-in database that maps quicklime activity to the water addition ratios in the primary and secondary mixers. This database is based on actual sintering production conditions (quicklime particle size 0.1-2mm, water-lime volume ratio 1:2, mixer speed 18-22 r / min). It presets standard water addition ratios according to activity levels and specifies dynamic adjustment methods, adjustment ranges, and verification methods. Based on the calculated activity values, the PLC automatically matches the corresponding water addition ratios and provides precise adjustment suggestions, ensuring that the quicklime digestion process is completed entirely during the granulation process in the mixer, thus guaranteeing the stability of the sintering process. Specific details are as follows: 7-1: Activity level classification and standard water addition ratio correspondence library (PLC built-in core parameters) 7-2: PLC Automatic Adjustment Methods and Procedures 7-2-1: Parameter matching; After the PLC calculates the activity A of quicklime, it automatically searches the built-in corresponding relationship library to match the grade and standard water addition ratio corresponding to the activity A (corresponding to the primary and secondary mixers respectively). At the same time, it retrieves the real-time parameters of quicklime feed rate and mixer speed of the current sintering system. 7-2-2: Initial water addition ratio output; Based on the matching standard water addition ratio and the current quicklime feed rate, the PLC automatically calculates the actual water addition amount for the primary and secondary mixers (water addition amount = quicklime feed rate × corresponding water addition ratio), and sends a control signal to the mixer water addition valve to set the initial water addition flow rate to ensure uniform water addition. 7-2-3: Dynamic fine-tuning correction; The PLC collects the humidity of the material at the mixer outlet in real time and automatically adjusts the water addition ratio of the corresponding mixer by ±0.5-1%. 7-2-4: Adjust limit switches and alarms; The PLC has a preset limit for adjusting the water ratio. If the ratio exceeds the limit after adjustment, the PLC will automatically stop adjusting and issue an alarm signal to prompt the operator to check the activity test data or the operating condition of the mixer, so as to avoid abnormal water addition affecting the sintering quality. Through the above-mentioned refined adjustment methods, PLC can achieve precise and automated control of the water addition ratio, ensuring that quicklime is fully digested during the mixing and granulation process, thus guaranteeing the quality of sinter and the stability of the production process from the source.

7. The rapid method for detecting the quality of sintered quicklime according to claim 6, characterized in that: The water addition ratio is defined as "the percentage of water added to the mass of quicklime". The PLC can automatically calculate the required water addition based on the preset quicklime feed amount of the sintering system. This correspondence can be adjusted through the PLC parameter calibration interface to adapt to different quicklime particle sizes and mixer speed changes.

8. The rapid method for detecting the quality of sintered quicklime according to claim 6, characterized in that: During the water addition process, the maximum water addition ratio of the primary mixer shall not exceed 32%, and the minimum shall not be less than 18%; the maximum water addition ratio of the secondary mixer shall not exceed 22%, and the minimum shall not be less than 11%.

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