A method for carbon and ash separation in gasification slag recovery

Abstract

This invention relates to the field of carbon ash separation technology, and more particularly to a carbon ash separation treatment method for gasification slag recovery, comprising: determining whether the ultrasonic treatment of the gasification slag is qualified based on the carbon enrichment rate of fixed carbon in the gasification slag with a preset particle size; in response to the qualified ultrasonic treatment of the gasification slag, determining the total drying time of the gasification slag based on the specific capillary water absorption time of the gasification slag; determining whether the drying of the gasification slag meets the standard based on the change rate of the specific capillary water absorption time of the gasification slag, so as to correct the remaining drying time; determining the addition of a modifier to chemically modify the gasification slag based on the angle of repose of the gasification slag, and determining the modifier and the amount of modifier added based on the specific capillary water absorption time after drying; determining whether the electrostatic treatment is qualified based on the change rate of the angle of repose of the gasification slag during the electrostatic treatment process, and in response to the qualified electrostatic treatment, determining that the carbon ash separation of the gasification slag is completed. This invention improves the carbon recovery rate and concentrate quality of carbon ash separation.

Description

Technical Field

[0001] This invention relates to the field of carbon ash separation technology, and in particular to a carbon ash separation treatment method for gasification slag recovery. Background Technology

[0002] Gasification ash is a solid waste generated during coal gasification, mainly composed of unburned carbon and inorganic ash. Due to the high degree of embedding of carbon and ash and the complex surface properties of the particles, traditional flotation or gravity separation methods are difficult to achieve efficient separation. In existing technologies, a multi-stage process combining ultrasonic treatment, drying, chemical modification, and electrostatic separation is often used for carbon-ash separation.

[0003] However, existing methods have the following problems: The embedded state and particle size distribution of fixed carbon in different batches of gasification slag vary significantly. The fixed ultrasonic treatment time leads to an uncontrollable degree of carbon-ash interface dissociation: insufficient dissociation results in unreleased carbon particles still adhering to ash, reducing separation efficiency; excessive ultrasonication causes carbon particles to be over-crushed, producing fine mud that interferes with subsequent sorting. The initial moisture content and moisture state of gasification slag fluctuate greatly. The traditional drying and weighing method requires 1 to 2 hours to determine the moisture content, and it is impossible to determine the drying endpoint online in real time. This results in the modifier being difficult to effectively adsorb when the drying is insufficient, and the change in particle surface energy when the drying is excessive, which affects the selectivity of electrostatic separation. The hydrophilic or hydrophobic properties of the gasification slag surface vary greatly depending on the degree of carbon particle oxidation and the ash coverage state. Existing methods usually use a single modifier, which cannot match the best modifier according to the surface properties, resulting in unstable modification effects. Once the preset particle size for ultrasonic treatment is set, it cannot be adjusted. It cannot track the slow drift of the gasification slag particle size distribution. After long-term operation, the dissociation effect is mismatched with the preset particle size, and the carbon and ash separation effect gradually deteriorates.

[0004] Chinese Patent Application Publication No. CN114534909A discloses a separation system and method for decarbonization of gasification slag flotation. The separation method is a combination of grinding and multi-stage flotation, which achieves the stepwise enrichment of low-ash carbon particles and high-ash mineral particles, solving the technical problems of poor selectivity, low recovery rate, and substandard ash content of clean coal and tailings in gasification slag flotation.

[0005] However, the aforementioned separation system and method for gasification slag flotation decarbonization has the following problems: 1. Carbon and ash are highly embedded in gasification slag. Although conventional flotation methods utilize the difference in hydrophilicity and hydrophobicity of particle surfaces to achieve separation, the surface properties of gasification slag are complex and the carbon-ash interface is tightly bound. During the flotation process, the reagent consumption is large and the selectivity is poor. Fine-grained ash easily covers the surface of carbon particles, resulting in high concentrate ash content and unsatisfactory carbon recovery rate. 2. The embedded state and particle size distribution of fixed carbon in different batches of gasification slag vary significantly. The grinding-integrated multi-stage flotation uses fixed process parameters, which cannot be adaptively adjusted, resulting in poor adaptability to raw material fluctuations and unstable carbon-ash separation effect. Summary of the Invention

[0006] Therefore, the present invention provides a carbon and ash separation treatment method for gasification slag recovery, which overcomes the problem in the prior art that it cannot respond to the fluctuation of particle size distribution of different batches of gasification slag, resulting in uncertain carbon and ash separation effect and poor process robustness.

[0007] To achieve the above objectives, the present invention provides a carbon and ash separation treatment method for gasification slag recovery, comprising: The quality of ultrasonic treatment of gasification slag is determined based on the carbon enrichment rate of fixed carbon in gasification slag with a preset particle size. In response to the ultrasonic treatment of the gasification slag being qualified, the total drying time of the gasification slag is determined based on the specific capillary water absorption time of the gasification slag. The drying time of the gasified slag is determined based on the change rate of the specific capillary water absorption time, and the remaining drying time is corrected if the gasified slag drying does not meet the standard. The modifier to be added is determined based on the angle of repose of the gasification slag to chemically modify the gasification slag, and the modifier and the amount of modifier added are determined based on the specific capillary water absorption time after drying. The success of electrostatic treatment is determined by the rate of change of the angle of repose of the gasified slag during the electrostatic treatment process. If the electrostatic treatment is successful, the carbon-ash separation of the gasified slag is confirmed to be complete.

[0008] Furthermore, based on the carbon enrichment rate being greater than the preset carbon enrichment rate, the ultrasonic treatment of the gasification slag was deemed qualified. The carbon enrichment rate is determined based on the fixed carbon mass content in the gasification slag with a preset particle size before and after ultrasonic treatment.

[0009] Furthermore, the process of determining whether the drying of the gasification slag meets the standards includes: The drying standard of gasification slag is determined based on the absolute value of the change rate of specific capillary water absorption time being less than or equal to the preset change rate of specific capillary water absorption time. Based on the fact that the absolute value of the change rate of specific capillary water absorption time is greater than the preset change rate of specific capillary water absorption time, it is determined that the drying of the gasification slag is substandard. The rate of change of specific capillary water absorption time is determined based on the specific capillary water absorption time of the gasified slag before and after drying and the drying time.

[0010] Furthermore, the process for determining whether electrostatic treatment is qualified includes: The rate of change of the angle of repose is compared with the first preset rate of change of the angle of repose and the second preset rate of change of the angle of repose, respectively. The electrostatic treatment is deemed qualified based on the fact that the rate of change of the angle of repose is greater than or equal to the first preset rate of change of the angle of repose and less than or equal to the second preset rate of change of the angle of repose. If the rate of change of the angle of repose is less than the first preset rate of change of the angle of repose, or greater than the second preset rate of change of the angle of repose, the electrostatic treatment is deemed unqualified.

[0011] Furthermore, the total drying time of the gasification slag is determined based on the drying coefficient, the specific capillary water absorption time of the gasification slag, and the baseline drying time.

[0012] Furthermore, the process of adjusting the remaining drying time includes: Calculate the ratio of the rate of change of capillary water absorption time; The remaining drying time is determined based on the difference between the total drying time and the time already dried. Based on the product of the ratio of the specific capillary water absorption time change rate and the remaining drying time, the remaining drying time is determined for further drying of the gasification slag. The ratio of the specific capillary water absorption time change rate is determined based on the ratio of the specific capillary water absorption time change rate to a preset specific capillary water absorption time change rate.

[0013] Furthermore, based on the angle of repose being greater than or equal to a preset angle of repose, a modifier is added to chemically modify the gasification slag.

[0014] Furthermore, the process of determining the modifier includes: Based on the fact that the specific capillary water absorption time after drying is greater than the preset specific capillary water absorption time, the modifier is determined to be kerosene; Based on the fact that the specific capillary water absorption time after drying is less than or equal to the preset specific capillary water absorption time, the modifier was determined to be salicylic acid.

[0015] Furthermore, the amount of kerosene added is determined based on the kerosene adsorption coefficient, the true density of the gasification slag, the specific surface area of ​​the gasification slag, the specific capillary water absorption time after drying, and the baseline specific capillary water absorption time after complete hydrophobication.

[0016] Furthermore, the amount of salicylic acid added is determined based on the salicylic acid adsorption coefficient, the true density of the gasification slag, the specific surface area of ​​the gasification slag, the baseline specific capillary water absorption time after complete hydrophilization, and the specific capillary water absorption time after drying.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention determines the qualification of ultrasonic dissociation of gasification slag by the carbon enrichment rate of fixed carbon in the preset particle size, avoiding the dilution of separation efficiency by undissociated gasification slag; it uses the specific capillary water absorption time to determine the total drying time, solving the problem of inconsistent drying endpoints caused by batch-to-batch moisture content fluctuations; it determines the degree of drying by the rate of change of specific capillary water absorption time during the drying process and corrects the total drying time, avoiding particle hard agglomeration caused by over-drying or modifier failure caused by under-drying; it determines the modifier and modifier dosage based on the specific capillary water absorption time after drying, solving the problem of poor electrostatic separation selectivity caused by the mismatch between the hydrophilic and hydrophobic properties of the modifier and the surface of the gasification slag; and it uses the rate of change of the angle of repose to provide real-time feedback on particle charge and dispersion state during electrostatic treatment, solving the problem of sudden drop in separation efficiency caused by fluctuations in modification effect, and improving the stability of carbon ash separation effect.

[0018] Furthermore, this invention quantifies the degree of dissociation of the carbon-ash interface by ultrasonic cavitation by comparing the carbon enrichment rate of fixed carbon in a preset particle size with a preset carbon enrichment rate. This allows for the selection of gasification slag with fully exposed carbon-ash interfaces for drying, improving the accuracy of ultrasonic treatment qualification determination. It avoids the dilution and separation efficiency of undissociated gasification slag due to insufficient dissociation, or the energy waste and fine mud interference caused by excessive ultrasonication and over-grinding. It solves the problem of uncontrollable ultrasonic dissociation degree and uncertain carbon-ash separation effect caused by the difference in the fixed carbon embedding state in different batches of gasification slag. It also prevents inconsistencies in the drying endpoint caused by fluctuations in the gasification slag interface state, enhancing the robustness of the carbon-ash separation method.

[0019] Furthermore, by utilizing the characteristic that the capillary water absorption time monotonically increases as the moisture content decreases during the drying process, this invention solves the problem of the inability to control the drying time in real time due to the lag in the measurement of the moisture content of gasification slag. This avoids the modification effect of gasification slag due to insufficient drying, or the decrease in electrostatic separation selectivity caused by excessive dehydration of the particle surface due to excessive drying. The comparison between the rate of change of capillary water absorption time and the preset rate of change of capillary water absorption time determines whether the drying meets the standard. This solves the problem that it is difficult to uniformly define the drying endpoint due to the difference in the initial moisture content and moisture occurrence state of different batches of gasification slag, avoids subjective errors caused by experience-based judgment, and enhances the stability of the chemical modification and electrostatic separation process.

[0020] Furthermore, this invention determines whether chemical modification of the gasification slag is necessary by comparing the angle of repose with a preset angle of repose. This solves the problem of uneven distribution of material on the electrostatic rollers caused by differences in the fluidity of the gasification slag, avoids the decrease in separation efficiency caused by particle accumulation and blockage when the fluidity is poor, and uses the capillary water absorption time after drying as a quantitative characterization of the hydrophobicity of the gasification slag surface. Kerosene or salicylic acid is selected as the modifier, which solves the problem of poor adaptability of a single modifier due to the different hydrophilic and hydrophobic states of carbon particle surfaces. This avoids the defects of low adsorption efficiency and poor modification effect when the modifier does not match the surface properties, enhances the difference in the charging behavior of carbon particles and ash particles in electrostatic separation, improves the selectivity and stability of carbon and ash separation, and makes the method adaptable to gasification slag from different sources and with different surface properties.

[0021] Furthermore, this invention determines whether electrostatic treatment is qualified by comparing the rate of change of the angle of repose of the gasified slag with the first preset rate of change of the angle of repose and the second preset rate of change of the angle of repose. This solves the problem of uncertain separation effect caused by the difference in particle charge state, and avoids the decrease in carbon and ash separation efficiency caused by insufficient particle charge and poor dispersion when the rate of change of the angle of repose is too low, or the decrease in separation selectivity caused by excessive particle charge and electrostatic agglomeration when the rate of change of the angle of repose is too high. According to the deviation direction of the rate of change of the angle of repose, the electrostatic voltage is increased by the voltage adjustment coefficient or the roller speed is increased by the speed adjustment coefficient, which avoids the defect of unstable separation effect under fixed parameters and enhances the difference in the motion trajectory of carbon particles and ash particles in the electric field.

[0022] Furthermore, this invention determines whether the current preset particle size matches the actual particle size distribution of the gasification slag by comparing the matching degree with the preset matching degree, and corrects the preset particle size of the next batch in reverse according to the offset direction using the first particle size coefficient or the second particle size coefficient. This solves the problem of uncertain ultrasonic dissociation effect caused by fluctuations in the source of gasification slag or drift in particle size distribution, and avoids the defects of insufficient carbon and ash dissociation and coarse ash mixed in the concentrate when the preset particle size is too large, or excessive crushing and fine mud interference in separation when the preset particle size is too small. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the steps of a carbon and ash separation treatment method for gasification slag recovery according to an embodiment of the present invention. Figure 2 A logic diagram for determining whether the ultrasonic treatment of gasification slag is qualified in an embodiment of the present invention; Figure 3 This is a logic diagram illustrating the determination of whether the drying of gasification slag meets the standards in an embodiment of the present invention. Figure 4 This is a logic diagram for determining whether electrostatic treatment is qualified in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0025] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0027] Please see Figure 1 The diagram shown is a flowchart of the carbon and ash separation treatment method for gasification slag recovery according to an embodiment of the present invention.

[0028] The present invention provides a carbon and ash separation treatment method for gasification slag recovery, comprising: Step S1: Determine whether the ultrasonic treatment of the gasification slag is qualified based on the carbon enrichment rate of fixed carbon in the gasification slag with a preset particle size. In response to the qualified ultrasonic treatment of the gasification slag, determine the total drying time of the gasification slag based on the specific capillary water absorption time of the gasification slag. Step S2: Determine whether the drying of the gasification slag meets the standard based on the change rate of the specific capillary water absorption time of the gasification slag, and correct the remaining drying time if the drying of the gasification slag does not meet the standard. Step S3: Determine the addition of a modifier to chemically modify the gasification slag based on the angle of repose of the gasification slag, and determine the modifier and the amount of modifier added based on the specific capillary water absorption time after drying. Step S4: Determine whether the electrostatic treatment is qualified based on the rate of change of the angle of repose of the gasified slag during the electrostatic treatment process, so as to adjust the electrostatic voltage or the drum speed. Step S5: In response to the qualified electrostatic treatment, the carbon and ash separation of the gasification slag is determined to be completed, and the matching degree between the concentrate particle size and the preset particle size of the gasification slag is determined based on the particle size deviation index of the concentrate separated from the gasification slag, so as to adjust the preset particle size of the next batch of gasification slag.

[0029] In this embodiment of the invention, the gasification slag is fine slag discharged from a coal chemical gasifier, with a moisture content of 45% to 60%, a fixed carbon content of 15% to 35%, an ash content of 50% to 70%, and a particle size distribution D50 of 30 μm to 80 μm.

[0030] Specifically, this invention determines the qualification of ultrasonic dissociation of gasification slag by the carbon enrichment rate of fixed carbon in a preset particle size, avoiding the dilution of separation efficiency by undissociated gasification slag. It also uses the specific capillary water absorption time to determine the total drying time, solving the problem of inconsistent drying endpoints caused by batch-to-batch moisture content fluctuations. Furthermore, it determines the degree of drying by the rate of change of specific capillary water absorption time during the drying process and corrects the total drying time, avoiding particle agglomeration due to over-drying or modifier failure due to under-drying. Based on the specific capillary water absorption time after drying, it determines the modifier and its dosage, solving the problem of poor electrostatic separation selectivity caused by the mismatch between the hydrophilic and hydrophobic properties of the modifier and the gasification slag surface. Finally, it uses the rate of change of the angle of repose to provide real-time feedback on particle charge and dispersion during electrostatic treatment, solving the problem of a sudden drop in separation efficiency caused by fluctuations in the modification effect and improving the stability of carbon-ash separation.

[0031] Please see Figure 2 As shown, it is a logic judgment diagram for determining whether the ultrasonic treatment of gasification slag is qualified in an embodiment of the present invention.

[0032] Specifically, the carbon enrichment rate of fixed carbon in the gasification slag with a preset particle size is used to determine whether the gasification slag treated by ultrasound is qualified. If the carbon enrichment rate is greater than the preset carbon enrichment rate, then the ultrasonic treatment of the gasification slag is deemed qualified. If the carbon enrichment rate is less than or equal to the preset carbon enrichment rate, the ultrasonic treatment of the gasification slag is deemed unqualified.

[0033] In this embodiment of the invention, the preset particle size ranges from [0.045 mm to 0.075 mm], preferably 0.074 mm. The preset particle size is determined based on the following experiment: For each batch of gasification slag, the original sample is sieved and analyzed using a standard sieve to obtain a particle size distribution curve. The particle size corresponding to the cumulative distribution of 50% is denoted as D50. Four particle size grades of 0.045 mm, 0.055 mm, 0.065 mm, and 0.075 mm are taken respectively, and the initial content of fixed carbon in each particle size grade is measured. The samples are then ultrasonically treated for 15 minutes, and the fixed carbon content is measured again. The carbon enrichment rate is calculated. The results show that the carbon enrichment rate is the highest at a particle size of 0.074 mm, with a mass ratio of 35%, which balances the desorption efficiency and the throughput. However, the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0034] In this embodiment of the invention, the initial value of the preset particle size is set to 0.074 mm. If the ultrasonic treatment qualification results of three consecutive batches are all qualified, the initial value of the preset particle size of 0.074 mm is fixed for subsequent batches. If the qualification is not qualified, the initial value of the preset particle size of the next batch is corrected according to the particle size offset coefficient in step S5.

[0035] In this embodiment of the invention, the ultrasonic treatment process is as follows: gasification slag and water are mixed at a mass ratio of 1:3 to 1:5, and ultrasonic treatment is performed at 20kHz to 40kHz for 10 to 20 minutes, with an ultrasonic power density of 0.5W / mL to 1.0W / mL and a treatment temperature of 25℃ to 40℃.

[0036] In this embodiment of the invention, the carbon enrichment rate is determined by the following formula: ; Where E is the carbon enrichment rate, F1 is the fixed carbon mass content of the gasification slag with a preset particle size after ultrasonic treatment, and F0 is the fixed carbon content of the gasification slag with a preset particle size before ultrasonic treatment. The fixed carbon content is obtained by subtraction after determining the moisture, ash, and volatile matter of the gasification slag according to the slow ashing method specified in GB / T 212-2008.

[0037] In this embodiment of the invention, the preset carbon enrichment rate ranges from [15%, 25%], preferably 20%. The preset carbon enrichment rate is determined based on the following experiment: the same batch of gasification slag was subjected to ultrasonic treatment for 5 min, 10 min, 15 min, 20 min, and 25 min respectively. The fixed carbon content in the 0.074 mm particle size fraction was measured under each condition, the carbon enrichment rate was calculated, and the subsequent carbon-ash separation efficiency was determined using flotation. Experimental results show that when the carbon enrichment rate is below 15%, the separation of carbon and ash is insufficient, and the flotation concentrate recovery rate is below 65%. When the carbon enrichment rate is above 25%, further extending the ultrasonic time increases the separation efficiency by less than 5%, but increases energy consumption by more than 30%. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the values ​​according to actual needs.

[0038] Specifically, if the ultrasonic treatment of gasified slag is unqualified, the ultrasonic treatment time should be extended or the ultrasonic power density should be increased.

[0039] In this embodiment of the invention, the extension step of the ultrasonic treatment time is 5 min, and the adjustment range is 10 min to 30 min. The adjustment step of the ultrasonic power density is 0.2 W / mL, and the adjustment range is 0.5 W / mL to 1.5 W / m. If the carbon enrichment rate is still less than or equal to the preset carbon enrichment rate after both the ultrasonic treatment time and ultrasonic power density have reached the upper limit of the adjustment range, an alarm is issued and the processing is stopped.

[0040] Specifically, this invention quantifies the degree of dissociation of the carbon-ash interface by ultrasonic cavitation by comparing the carbon enrichment rate of fixed carbon in a preset particle size with a preset carbon enrichment rate. It selects gasification slag with fully exposed carbon-ash interface for drying, improves the accuracy of ultrasonic treatment qualification judgment, avoids the dilution and separation efficiency of undissociated gasification slag due to insufficient dissociation, or the energy waste and fine mud interference caused by excessive ultrasonication and over-grinding. It solves the problem of uncontrollable ultrasonic dissociation degree and uncertain carbon-ash separation effect caused by the difference in the fixed carbon embedding state in different batches of gasification slag, prevents the inconsistency of drying endpoint caused by the fluctuation of the gasification slag interface state, and enhances the robustness of the carbon-ash separation method.

[0041] Specifically, in response to the qualified gasification slag after ultrasonic treatment, the total drying time of the gasification slag is determined by adding the product of the drying coefficient and the specific capillary water absorption time of the gasification slag to the baseline drying time.

[0042] In this embodiment of the invention, the total drying time of the gasification slag is determined by the following formula: ; Where T is the total drying time, α is the drying coefficient ranging from 0.5 min / s to 1.2 min / s, CST is the specific capillary water absorption time of the gasification slag, and β is the baseline drying time ranging from 5 min / s to 15 min. The specific values ​​of α and β were determined based on calibration experiments. Gasification slag samples that passed ultrasonic treatment were taken and adjusted to different initial moisture contents of 35%, 40%, 45%, 50%, 55%, and 60%. The CST values ​​were measured for each sample, and the samples were dried in a 105℃ constant temperature drying oven to a target moisture content of 10%. The drying time was recorded, and a linear regression was performed between the CST values ​​and the drying time, yielding α = 0.85 min / s, β = 8 min, and R... 2 =0.94.

[0043] In this embodiment of the invention, the method for determining the specific capillary water absorption time is as follows: A capillary water absorption time measuring instrument, model CST-200, is used. 10g of the gasification slag sample to be tested is mixed with 50mL of deionized water and stirred at 300rpm for 5 minutes on a magnetic stirrer to prepare a uniform suspension. Whatman No.17 filter paper with a diameter of 7mm is placed at the bottom of the sample cell of the measuring instrument. 5mL of the suspension is quickly injected into the sample cell using a pipette. The instrument automatically records the time required for the liquid to penetrate from a radius of 3mm to 6mm on the filter paper. This time is the specific capillary water absorption time. Each sample is measured in parallel 3 times and the arithmetic mean is taken.

[0044] Understandably, the specific capillary water absorption time of gasification slag reflects its filtration and dehydration characteristics. Compared to directly measuring the moisture content of gasification slag, the specific capillary water absorption time reflects the state of moisture accumulation and the magnitude of dehydration resistance. The drying time of gasification slag depends precisely on the combined influence of its initial moisture content and the ease of dehydration. The traditional drying and weighing method for measuring moisture content requires 1 to 2 hours, which cannot meet the needs of real-time control in continuous production. In contrast, the specific capillary water absorption time only requires 1 to 2 minutes and can comprehensively characterize both moisture content and dehydration characteristics. Under the same moisture content, the greater the specific capillary water absorption time of gasification slag, the higher the proportion of capillary water in the gasification slag, and the longer the required drying time.

[0045] Please see Figure 3 As shown, it is a logic judgment diagram for determining whether the drying of gasification slag meets the standard in an embodiment of the present invention.

[0046] Specifically, the drying of the gasification slag is determined based on the change rate of the specific capillary water absorption time of the gasification slag. If the rate of change of capillary water absorption time is less than or equal to the preset rate of change of capillary water absorption time, then the drying of the gasification slag is determined to meet the standard. If the rate of change of capillary water absorption time is greater than the preset rate of change of capillary water absorption time, then the drying of the gasification slag is determined to be substandard.

[0047] In this embodiment of the invention, the rate of change of specific capillary water absorption time is the ratio of the difference between the specific capillary water absorption time of the dried gasification slag and the specific capillary water absorption time of the gasification slag before drying to the drying time.

[0048] It is understandable that during the drying process, the capillary water absorption time of the gasification slag increases as the moisture content decreases, and remains a positive value.

[0049] In this embodiment of the invention, the gasification slag drying process includes spreading the qualified gasification slag that has undergone ultrasonic treatment on a stainless steel tray with a thickness not exceeding 20 mm, sending it into a hot air circulating drying box, drying at a temperature of 105±5℃ and a hot air velocity of 1.5 m / s, and taking samples every 5 minutes during the drying process to measure the real-time specific capillary water absorption time change rate to monitor the drying progress of the gasification slag.

[0050] In this embodiment of the invention, the preset capillary water absorption time change rate ranges from 2 s / min to 5 s / min, preferably 3 s / min. This value is determined based on the following drying experiment: Gasification slag that has passed ultrasonic treatment is dried in an oven at 105°C. Samples are taken every 5 minutes to measure the real-time capillary water absorption time change rate, and the moisture content is also measured. The results show that: when the moisture content is higher than 25%, the real-time capillary water absorption time change rate is greater than 5 s / min, indicating a rapid evaporation rate and the gasification slag is in a constant-rate drying stage; when the moisture content drops to 10%–15%, the real-time capillary water absorption time change rate drops to 2–5 s / min, and the gasification slag enters a decreasing-rate drying stage; when the moisture content is less than 8%, the real-time capillary water absorption time change rate is less than 2 s / min, indicating that excessive drying is not conducive to carbon-ash separation and wastes energy. However, the above values ​​are not limited to these values, and those skilled in the art can adjust them according to actual needs.

[0051] In this embodiment of the invention, the target moisture content of the gasification slag corresponding to the drying standard is 8% to 12%. Based on the drying experiment, when the real-time specific capillary water absorption time change rate drops to 3 s / min, the corresponding moisture content has dropped to the range of 10% to 15%, which meets the requirements of modification treatment and electrostatic separation for the moisture content of the gasification slag.

[0052] Specifically, when the drying of gasification slag fails to meet standards, the process of correcting the remaining drying time includes: Calculate the ratio of the rate of change of capillary water absorption time; Based on the product of the ratio of the specific capillary water absorption time change rate and the drying time, the remaining drying time is determined for further drying of the gasification slag.

[0053] In this embodiment of the invention, the remaining drying time is determined based on the difference between the total drying time and the already dried time.

[0054] In this embodiment of the invention, the ratio of the specific capillary water absorption time change rate is the ratio of the specific capillary water absorption time change rate to a preset specific capillary water absorption time change rate.

[0055] In this embodiment of the invention, based on the gasified slag after re-drying, the change rate of capillary water absorption time is re-measured, and the remaining drying time is repeatedly corrected until the gasified slag reaches the drying standard.

[0056] Specifically, this invention utilizes the characteristic that the capillary water absorption time increases monotonically with decreasing moisture content during the drying process, thus solving the problem of the inability to control the drying time in real time due to the lag in measuring the moisture content of gasification slag. This avoids the modification effect of gasification slag due to insufficient drying, or the decrease in electrostatic separation selectivity caused by excessive dehydration of particle surfaces due to over-drying. The invention determines whether the drying meets the standard by comparing the change rate of capillary water absorption time with the preset change rate of capillary water absorption time. This solves the problem of the difficulty in uniformly defining the drying endpoint due to the differences in the initial moisture content and moisture occurrence state of different batches of gasification slag, avoids subjective errors caused by experience-based judgment, and enhances the stability of the chemical modification and electrostatic separation processes.

[0057] Specifically, in response to the drying of gasification slag meeting the standard, it is determined whether to add a modifier to chemically modify the gasification slag based on the angle of repose of the gasification slag, and the modifier and the amount of modifier added are determined based on the specific capillary water absorption time after drying. If the angle of repose is greater than or equal to the preset angle of repose, then it is determined that a modifier will be added to chemically modify the gasification slag. If the angle of repose is less than the preset angle of repose, then electrostatic treatment of gasified slag is determined.

[0058] In this embodiment of the invention, an angle of repose measuring instrument is used to measure the angle between the inclined surface of the accumulation cone and the horizontal plane after the dried gasification slag powder is freely dropped onto a horizontal disk through a funnel, and the angle of repose of the gasification slag is obtained.

[0059] In this embodiment of the invention, the preset angle of repose ranges from 40° to 50°, preferably 45°, determined based on flowability experiments: the angle of repose of gasification slag samples with dried and qualified moisture content of 8% to 12% were measured respectively, and separation tests were conducted using an electrostatic separator. The results showed that when the angle of repose is less than or equal to 45°, the gasification slag has good flowability, the particles are evenly distributed on the electrostatic roller, and the separation efficiency is greater than or equal to 80%. When the angle of repose is greater than 45°, the material has poor flowability and is prone to accumulation and blockage, with a separation efficiency less than or equal to 65%. However, the above values ​​are not limited to these, and those skilled in the art can adjust the values ​​according to actual needs.

[0060] In this embodiment of the invention, the chemical modification process includes mixing the dried gasification slag and the modifier in a high-speed mixer at a speed of 1000 rpm to 3000 rpm, a mixing time of 5 min to 10 min, and a temperature of 60℃ to 80℃. It can be understood that the chemical modification causes the modifier to form a hydrophobic coating layer on the surface of the carbon particles, thereby increasing the difference in surface properties between the carbon particles and the ash particles and enhancing the selectivity of electrostatic treatment.

[0061] In this embodiment of the invention, the modifier is kerosene or salicylic acid. Industrial-grade kerosene is added directly, and analytical-grade salicylic acid is added after being dissolved in 95% ethanol to prepare a solution. The concentration of the salicylic acid solution is a conventional concentration in the art.

[0062] Specifically, the modifier for the gasification slag is determined based on the comparison between the specific capillary water absorption time after drying and the preset specific capillary water absorption time. If the capillary water absorption time after drying is greater than the preset capillary water absorption time, then the modifier is determined to be kerosene. If the capillary water absorption time after drying is less than or equal to the preset capillary water absorption time, then the modifier is determined to be salicylic acid.

[0063] In this embodiment of the invention, the preset capillary water absorption time ranges from [15s, 25s], preferably 20s, based on the following experimental calibration: Gasification slag samples after drying were taken, and the capillary water absorption time after drying was measured while simultaneously measuring the water contact angle. The carbon-ash separation efficiency of each sample in electrostatic separation was recorded. The results showed that when the capillary water absorption time after drying was less than 15s, the water contact angle was less than 60°, the surface was highly hydrophilic, and the separation efficiency was less than 65% when kerosene was used directly, requiring the use of salicylic acid. When the capillary water absorption time after drying was in the range of 15s to 25s, the water contact angle was between 60° and 90°, and the surface was moderately hydrophobic. When the capillary water absorption time after drying was greater than 25s, the water contact angle was greater than 90°, the surface was highly hydrophobic, and the separation efficiency could reach over 85% when kerosene was used. However, the above values ​​are not limited to these, and those skilled in the art can adjust the values ​​according to actual needs.

[0064] It is understandable that the specific capillary water absorption time after drying is essentially a quantitative characterization of the hydrophobicity of the gasification slag surface: the lower the specific capillary water absorption time, the stronger the hydrophilicity of the gasification slag surface, and the easier it is for water molecules to be adsorbed onto the particle surface to form a continuous water film; the higher the specific capillary water absorption time, the stronger the hydrophobicity of the gasification slag surface, and the more difficult it is for water molecules to wet the particle surface, resulting in greater capillary flow resistance. Kerosene is a non-polar hydrophobic organic compound. By utilizing the strong adsorption capacity of residual carbon in the gasification slag for kerosene, a hydrophobic coating is formed on the surface of carbon particles, inhibiting charge dissipation and increasing the loose resistivity. After kerosene treatment, the hydrophobicity of residual carbon will be significantly enhanced, while the adsorption capacity of ash components for kerosene is extremely weak. This difference can be used to achieve selective hydrophobicity of carbon particles. Salicylic acid is a polar organic compound. Through the synergistic effect of -COOH and -OH functional groups, a charge-stabilizing layer is established on the particle surface, reducing the relative permittivity and enhancing the polarization response, thereby improving the charged behavior of particles in electrostatic separation.

[0065] In this embodiment of the invention, the amount of kerosene added is determined by the following formula: ; Wherein, M1 is the amount of kerosene added, in g / kg of gasification slag; k1 is the kerosene adsorption coefficient, ranging from 0.08 to 0.20, preferably 0.12; CST1 is the specific capillary water absorption time after drying; CST2 is the baseline specific capillary water absorption time after complete hydrophobication, ranging from 5s to 10s, preferably 8s; and ρ is the true density of the gasification slag, in g / cm³. 3 The specific surface area of ​​the gasification slag was determined using the specific gravity bottle method, where S is the specific surface area in m³. 2 / g, determined by the BET nitrogen adsorption method.

[0066] In this embodiment of the invention, the first difference is the difference between the specific capillary water absorption time CST1 after drying and the reference specific capillary water absorption time CST2 after complete hydrophobication.

[0067] In this embodiment of the invention, the amount of salicylic acid added is determined by the following formula: ; Wherein, M2 is the amount of salicylic acid added, in g / kg gasification residue; k2 is the salicylic acid adsorption coefficient, with a value of 0.05 to 0.15, preferably 0.09; and CST3 is the baseline capillary water absorption time after complete hydrophilization, with a value of 25s to 35s, preferably 30s.

[0068] In this embodiment of the invention, the second difference is the difference between the baseline capillary water absorption time CST3 after complete hydrophilization and the capillary water absorption time CST1 after drying.

[0069] In this embodiment of the invention, the preferred values ​​are determined based on the following experimental calibration method: Gasification slag samples that have been dried to the required standard are taken, and the saturated adsorption amounts of kerosene and salicylic acid on the surface of the gasification slag are measured using the Langmuir adsorption isotherm model. After fitting five sets of parallel samples, the adsorption coefficients for kerosene and salicylic acid are found to be 0.12 and 0.09, respectively. 2 The values ​​were 0.98 and 0.96, respectively, with relative standard deviations of 7.8% and 9.2%, and confidence intervals of 95%. The reference capillary water absorption time after complete hydrophobication was obtained by treating the gasification slag with excess kerosene. The values ​​for the five parallel samples ranged from 5.8 s to 8.2 s, with an average of 8 s. The reference capillary water absorption time after complete hydrophilication was obtained by treating the gasification slag with excess salicylic acid. The values ​​for the five parallel samples ranged from 27.4 s to 33.6 s, with an average of 30 s. The verification experiment showed that the carbon recovery rate of the concentrate after electrostatic separation reached more than 85% for the samples treated with the preferred values. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the values ​​according to actual needs.

[0070] Specifically, this invention determines whether chemical modification of the gasification slag is necessary by comparing the angle of repose with a preset angle of repose. This solves the problem of uneven distribution of material on the electrostatic rollers caused by differences in the fluidity of the gasification slag, avoids the decrease in separation efficiency caused by particle accumulation and blockage when the fluidity is poor, and uses the capillary water absorption time after drying as a quantitative characterization of the hydrophobicity of the gasification slag surface. Kerosene or salicylic acid is selected as the modifier, which solves the problem of poor adaptability of a single modifier due to the different hydrophilic and hydrophobic states of carbon particle surfaces. It avoids the defects of low adsorption efficiency and poor modification effect when the modifier does not match the surface properties, enhances the difference in the charging behavior of carbon particles and ash particles in electrostatic separation, improves the selectivity and stability of carbon and ash separation, and makes the method adaptable to gasification slag from different sources and with different surface properties.

[0071] Please see Figure 4 As shown, it is a logic diagram for determining whether electrostatic treatment is qualified in an embodiment of the present invention.

[0072] Specifically, for electrostatic treatment of gasification slag, the success of the electrostatic treatment is determined based on the rate of change of the angle of repose of the gasification slag during the electrostatic treatment process. The rate of change of the angle of repose is compared with the first preset rate of change of the angle of repose and the second preset rate of change of the angle of repose, respectively. If the rate of change of the angle of repose is greater than or equal to the first preset rate of change of the angle of repose, and less than or equal to the second preset rate of change of the angle of repose, then the electrostatic treatment is deemed qualified. If the rate of change of the angle of repose is less than the first preset rate of change of the angle of repose, or greater than the second preset rate of change of the angle of repose, then the electrostatic treatment is deemed unqualified.

[0073] In this embodiment of the invention, electrostatic treatment employs a roller-type electrostatic separator to separate the gasified slag. The roller is made of stainless steel, with a polished surface and reliable grounding. The electrodes are made of copper. A negative high-voltage electrostatic charge is applied, with an electrostatic voltage of 30kV to 50kV, a roller speed of 60rpm to 150rpm, an electrode spacing of 40mm to 60mm, a separation ambient temperature of 20℃ to 30℃, a relative humidity of less than 40%, a vibrating feeder frequency of 50Hz to 80Hz, and a feeding speed of 5kg / h to 15kg / h. The initial settings are: electrostatic voltage 35kV, roller speed 90rpm, electrode spacing 50mm, ambient temperature 25℃, relative humidity 35%, and feeding speed 10kg / h.

[0074] Understandably, the gasification slag is evenly distributed on the surface of the rotating roller by a vibrating feeder. Under the combined action of electric field force and centrifugal force, carbon particles and ash particles with different charge characteristics move along different trajectories to achieve separation. Because the carbon particles have high resistivity after modification, their charge is not easily leaked. They are adsorbed on the roller and rotate with the roller to the rear brush roller for collection as concentrate. Because the ash particles have low resistivity, their charge leaks quickly. Under the action of centrifugal force, they leave the roller in advance and are collected as tailings.

[0075] In this embodiment of the invention, the process of obtaining the rate of change of the angle of repose is as follows: during the electrostatic treatment process, a concentrate sample is taken from the concentrate outlet of the separator every 30 seconds, and the angle of repose of the concentrate sample is measured using an angle of repose measuring instrument. The change in the angle of repose between two adjacent samplings is calculated, and divided by the time interval of 30 seconds to obtain the rate of change of the angle of repose, in ° / min. Each sampling measurement is repeated three times and the average value is taken.

[0076] In this embodiment of the invention, the first preset angle of repose variation rate ranges from 1.5° / min to 2.5° / min, preferably 2° / min, and the second preset angle of repose variation rate ranges from 4° / min to 6° / min, preferably 5° / min. Based on electrostatic separation experiments, gasification slag samples with different modifier addition amounts were separated under electrostatic voltage of 35kV and roller speed of 90rpm. Simultaneously, the angle of repose variation rate of the concentrate outlet material was measured, and the carbon-ash separation efficiency was recorded. Experimental results show that when the angle of repose variation rate is less than 2° / min, the separation efficiency is less than 70%, and the dispersion is poor. When the angle of repose variation rate is in the range of 2 to 5° / min, the separation efficiency can reach over 85%, and the dispersion is good. When the angle of repose variation rate is greater than 5° / min, the separation efficiency drops below 75%. However, the above values ​​are not limited to these values, and those skilled in the art can adjust these values ​​according to actual needs.

[0077] Specifically, if the electrostatic treatment fails, adjust the electrostatic voltage or the drum speed. If the rate of change of the angle of repose is less than the first preset rate of change of the angle of repose, then the electrostatic voltage will be increased to the corresponding value by a voltage adjustment coefficient of 1.10. If the rate of change of the angle of repose is greater than the second preset rate of change of the angle of repose, the roller speed will be increased to the corresponding value by a speed adjustment coefficient of 1.15.

[0078] In this embodiment of the invention, the voltage regulation coefficient ranges from [1.05, 1.15], preferably 1.10, and the speed regulation coefficient ranges from [1.10, 1.20], preferably 1.15. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the values ​​according to actual needs.

[0079] In this embodiment of the invention, the increased electrostatic voltage is the product of the electrostatic voltage and the first adjustment coefficient.

[0080] In this embodiment of the invention, the increased roller speed is the product of the roller speed and the second adjustment coefficient.

[0081] In this embodiment of the invention, after adjusting the electrostatic voltage or roller speed, the rate of change of the angle of repose is remeasured, and the comparison and adjustment process is repeated until the electrostatic treatment is qualified or the upper limit of the equipment parameters is reached. If the rate of change of the angle of repose is still unqualified after the electrostatic voltage reaches 60kV and the roller speed reaches 200rpm, the current batch processing is stopped and the equipment status is checked.

[0082] Specifically, this invention determines whether electrostatic treatment is qualified by comparing the rate of change of the angle of repose of the gasified slag with the first and second preset rates of change of the angle of repose. This solves the problem of uncertain separation effect caused by differences in particle charge state, avoids the decrease in carbon-ash separation efficiency caused by insufficient particle charge and poor dispersion when the rate of change of the angle of repose is too low, or the decrease in separation selectivity caused by excessive particle charge and electrostatic agglomeration when the rate of change of the angle of repose is too high. According to the deviation direction of the rate of change of the angle of repose, the electrostatic voltage is increased by the voltage adjustment coefficient or the roller speed is increased by the speed adjustment coefficient, avoiding the defect of unstable separation effect under fixed parameters, and enhancing the difference in the motion trajectory of carbon particles and ash particles in the electric field.

[0083] Specifically, in response to the qualified electrostatic treatment, it is determined that the carbon and ash separation of the gasification slag has been completed, and the matching degree between the concentrate particle size and the preset particle size of the gasification slag is determined based on the particle size deviation index of the concentrate separated from the gasification slag, so as to adjust the preset particle size of the next batch of gasification slag. If the matching degree is greater than or equal to the preset matching degree, the preset particle size of the next batch of gasification slag will not be adjusted. If the matching degree is less than the preset matching degree, the preset particle size of the next batch of gasification slag will be adjusted.

[0084] In this embodiment of the invention, the particle size offset coefficient is determined by the following formula: ; Where δ is the particle size offset coefficient, D1 is the median particle size of the concentrate, which is measured by a laser particle size analyzer, and D0 is the preset particle size of the gasification slag of the current batch.

[0085] In this embodiment of the invention, the matching degree is determined by the following formula: ; Where P is the matching degree. This is the absolute value of the particle size offset coefficient.

[0086] In this embodiment of the invention, the preset matching degree ranges from [0.85, 0.95], preferably 0.90, and is determined based on the following experiment: continuous production tests were conducted on different batches of gasification slag, and the relationship between the concentrate particle size offset index and the carbon-ash separation efficiency was recorded. The results showed that when the matching degree is greater than or equal to 0.90, the separation efficiency is stable at over 85%, and when the matching degree is less than 0.90, the separation efficiency drops to below 80%. However, the above value is not limited to this, and those skilled in the art can adjust the value according to actual needs.

[0087] Specifically, the process of adjusting the preset particle size of the next batch of gasification slag includes: Based on the particle size offset coefficient being greater than 0, it is determined that the preset particle size of the next batch of gasification slag will be reduced to the corresponding value by the first particle size coefficient of 0.92. If the particle size offset coefficient is less than 0, then the preset particle size of the next batch of gasification slag will be increased to the corresponding value by the second particle size coefficient of 1.07.

[0088] In this embodiment of the invention, the value range of the first particle size coefficient is [0.90, 0.95], preferably 0.92, and the value range of the second particle size coefficient is [1.05, 1.10], preferably 1.07. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the values ​​according to actual needs.

[0089] In this embodiment of the invention, the preset particle size of the next batch of gasification slag after the increase is the product of the current preset particle size and the first particle size coefficient; the preset particle size of the next batch of gasification slag after the decrease is the product of the current preset particle size and the second particle size coefficient; the adjusted preset particle size must meet the process constraints: not less than 0.045 mm and not greater than 0.075 mm. If the calculation result exceeds the process constraints, the boundary value is taken.

[0090] It is understandable that the separation results of the previous batch of gasification slag can guide the adjustment of the preset particle size for the next batch. This is based on the engineering reality that the source of gasification slag is relatively stable and the particle size distribution has a slow change characteristic in the short term. Through rolling optimization in continuous production, the separation effect of the previous batch is used as a feedback signal to correct the process parameters for the next batch, so that the preset particle size can adaptively track the slow changes of the raw materials.

[0091] Specifically, this invention determines whether the current preset particle size matches the actual particle size distribution of gasification slag by comparing the matching degree with the preset matching degree. Based on the offset direction, the preset particle size of the next batch is corrected in reverse using the first particle size coefficient or the second particle size coefficient. This solves the problem of uncertain ultrasonic dissociation effect caused by fluctuations in the source of gasification slag or drift in particle size distribution. It avoids the defects of insufficient carbon and ash dissociation and coarse ash mixed in the concentrate when the preset particle size is too large, or excessive crushing and fine mud interference in separation when the preset particle size is too small.

[0092] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A method for separating and treating carbon ash in gasification slag recovery, characterized in that, include: The quality of ultrasonic treatment of gasification slag is determined based on the carbon enrichment rate of fixed carbon in gasification slag with a preset particle size. In response to the ultrasonic treatment of the gasification slag being qualified, the total drying time of the gasification slag is determined based on the specific capillary water absorption time of the gasification slag. The drying time of the gasified slag is determined based on the change rate of the specific capillary water absorption time, and the remaining drying time is corrected if the gasified slag drying does not meet the standard. The modifier to be added is determined based on the angle of repose of the gasification slag to chemically modify the gasification slag, and the modifier and the amount of modifier added are determined based on the specific capillary water absorption time after drying. The success of electrostatic treatment is determined by the rate of change of the angle of repose of the gasified slag during the electrostatic treatment process. If the electrostatic treatment is successful, the carbon-ash separation of the gasified slag is confirmed to be complete.

2. The carbon and ash separation treatment method for gasification slag recovery according to claim 1, characterized in that, Based on the carbon enrichment rate being greater than the preset carbon enrichment rate, the ultrasonic treatment of the gasification slag is deemed qualified. The carbon enrichment rate is determined based on the fixed carbon mass content in the gasification slag with a preset particle size before and after ultrasonic treatment.

3. The carbon and ash separation treatment method for gasification slag recovery according to claim 1, characterized in that, The process of determining whether the drying of gasification slag meets the standards includes: The drying standard of gasification slag is determined based on the absolute value of the change rate of specific capillary water absorption time being less than or equal to the preset change rate of specific capillary water absorption time. Based on the fact that the absolute value of the change rate of specific capillary water absorption time is greater than the preset change rate of specific capillary water absorption time, it is determined that the drying of the gasification slag is substandard. The rate of change of specific capillary water absorption time is determined based on the specific capillary water absorption time of the gasified slag before and after drying and the drying time.

4. The carbon and ash separation treatment method for gasification slag recovery according to claim 1, characterized in that, The process for determining whether electrostatic treatment is up to standard includes: The rate of change of the angle of repose is compared with the first preset rate of change of the angle of repose and the second preset rate of change of the angle of repose, respectively. The electrostatic treatment is deemed qualified based on the fact that the rate of change of the angle of repose is greater than or equal to the first preset rate of change of the angle of repose and less than or equal to the second preset rate of change of the angle of repose. If the rate of change of the angle of repose is less than the first preset rate of change of the angle of repose, or greater than the second preset rate of change of the angle of repose, the electrostatic treatment is deemed unqualified.

5. The carbon and ash separation treatment method for gasification slag recovery according to claim 1, characterized in that, The total drying time of the gasification residue is determined based on the drying coefficient, the specific capillary water absorption time of the gasification residue, and the baseline drying time.

6. The carbon and ash separation treatment method for gasification slag recovery according to claim 5, characterized in that, The process of correcting the remaining drying time includes: Calculate the ratio of the rate of change of capillary water absorption time; The remaining drying time is determined based on the difference between the total drying time and the time already dried. Based on the product of the ratio of the specific capillary water absorption time change rate and the remaining drying time, the remaining drying time is determined for further drying of the gasification slag. The ratio of the specific capillary water absorption time change rate is determined based on the ratio of the specific capillary water absorption time change rate to a preset specific capillary water absorption time change rate.

7. The carbon and ash separation treatment method for gasification slag recovery according to claim 1, characterized in that, Based on the angle of repose being greater than or equal to the preset angle of repose, it is determined that a modifier will be added to chemically modify the gasification slag.

8. The carbon and ash separation treatment method for gasification slag recovery according to claim 7, characterized in that, The process of determining the modifier includes: Based on the fact that the specific capillary water absorption time after drying is greater than the preset specific capillary water absorption time, the modifier is determined to be kerosene; Based on the fact that the specific capillary water absorption time after drying is less than or equal to the preset specific capillary water absorption time, the modifier was determined to be salicylic acid.

9. The carbon and ash separation treatment method for gasification slag recovery according to claim 8, characterized in that, The amount of kerosene added is determined based on the kerosene adsorption coefficient, the true density of the gasification slag, the specific surface area of ​​the gasification slag, the specific capillary water absorption time after drying, and the baseline specific capillary water absorption time after complete hydrophobication.

10. The carbon and ash separation treatment method for gasification slag recovery according to claim 9, characterized in that, The amount of salicylic acid added is determined based on the salicylic acid adsorption coefficient, the true density of the gasification slag, the specific surface area of ​​the gasification slag, the baseline specific capillary water absorption time after complete hydrophilization, and the specific capillary water absorption time after drying.

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