A method for detecting and analyzing cloth scraps

Abstract

The present invention relates to a method for detecting and analyzing cloth scraps, comprising S1, obtaining a weight W1, a volatile matter content V1, and a content of constituent elements of a cloth scrap sample; S2, obtaining a thermogravimetric analysis curve and a calorific value Q1 of the cloth scrap sample, and a peak temperature T1 of the thermogravimetric analysis curve; S3, performing a first carbonization experiment; S4, performing a second carbonization experiment to obtain a weight W2; and obtaining the content of constituent elements, a volatile matter content V2, and a calorific value Q2; S5, comparing changes in the cloth scrap sample before and after carbonization, and when the conditions of 10%≦(W1-W2) / W1≦17%, (V1-V2) / V1≦10%, and (Q1-Q2) / Q1≦10% are satisfied, the corresponding carbonization temperature is used as a screening temperature; and S6, reviewing the screening temperature. This method can quickly screen out the appropriate low-temperature shallow carbonization temperature, so that the weight loss rate of the cloth scraps after treatment at the screened temperature is 12-15%, which is within the normal low range. The raw material calorific value retention rate is about 90%. The calorific value of the raw material after treatment remains at a high level, and it has high grindability.

Description

Technical Field

[0001] The present invention relates to a cloth scrap recycling technology, and in particular to a cloth scrap detection and analysis method. Background Art

[0002] Cloth scraps are common waste in textile processing and daily life. They are fragments of fabric left over from cutting, often in the form of long strips or irregular blocks of varying sizes. Recycling these scraps promotes resource reuse and environmental sustainability.

[0003] At present, the main recycling methods are: physical recycling method, chemical recycling method and energy recovery method. Among them, the physical recycling method refers to further crushing the cloth scraps and converting them into small pieces or granules. The crushed cloth scraps can be used to make recycled fibers, filling materials or as other industrial raw materials. The chemical recycling method is mainly used to process synthetic fiber cloth scraps. The high molecular polymers in the cloth scraps are depolymerized by chemical methods, and then repolymerized and spun to obtain monomers, and then new fibers are made. However, this method has a complicated process and requires the addition of many chemical solvents and chemicals, and the recycling cost is relatively high. The energy recovery method refers to converting the cloth scraps into products with a certain calorific value after combustion, gasification and other treatments. For example, the heat energy generated by its incineration is converted into electricity, or RDF fuel rods are made through an RDF preparation machine.

[0004] Most of the aforementioned methods for recycling fabric scraps require the sample to be uniform in texture. This not only refers to uniform composition but also uniform size, preferably a uniformly small size, to facilitate further processing. For example, patent application CN118256283A discloses a system and method for treating domestic waste, including a pretreatment unit for pre-processing the waste to obtain waste particles, primarily through shear shredder shredding. The resulting waste particles are required to have a particle size of less than 1.5 mm.

[0005] It can be seen that before gasification, the sample to be processed is preferably in granular or powdered form to ensure a high degree of gasification. However, due to the inherent softness of the fabric and the fact that most of it is entangled and clumped together, the actual crushing effect is not ideal, the process takes a long time, and the energy consumption is high. Summary of the Invention

[0006] The purpose of the present invention is to overcome the difficulties in further crushing cloth scraps to a size smaller than millimeters. A method for detecting and analyzing cloth scraps is provided. The appropriate carbonization temperature of the cloth scrap sample is determined through the detection and analysis process, and then low-temperature shallow carbonization is performed at the optimal temperature to improve the Hardgrove grindability index of the cloth scrap sample, thereby reducing the difficulty of grinding the cloth scrap sample into powder.

[0007] The specific solution is as follows:

[0008] A method for detecting and analyzing scraps of cloth, comprising the following steps:

[0009] S1. Evenly divide the scrap cloth samples to be detected into 4 identical portions, numbered 1#, 2#, 3#, and 4#. Take the 1# scrap cloth sample to be detected for industrial analysis and elemental analysis to obtain the weight W1, volatile content V1, and the content of constituent elements of the scrap cloth sample;

[0010] S2. Take the 2# scrap cloth sample to be detected for thermogravimetric analysis to obtain the thermogravimetric analysis curve and calorific value Q1 of the scrap cloth sample, and the peak temperature T1 of the thermogravimetric analysis curve;

[0011] S3. Take the 3# scrap cloth sample to be detected, with T1 - X as the starting temperature, T1 - Y as the ending temperature, and t1 as the temperature interval, where Y < X < T1 and 5°C < t1 < 20°C, conduct the first carbonization experiment. Observe the appearance of the scrap cloth sample during the carbonization process. The carbonization temperature corresponding to when the appearance of the scrap cloth sample starts to change is recorded as T2, and the carbonization temperature corresponding to when the scrap cloth sample turns black is recorded as T3;

[0012] S4. Take the 4# scrap cloth sample to be detected, with T2 as the starting temperature, T3 as the ending temperature, and t2 as the temperature interval, where t2 < t1, conduct the second carbonization experiment. Test the scrap cloth samples treated at different carbonization temperatures to obtain the weight W2; obtain the content of constituent elements, volatile content V2, and calorific value Q2;

[0013] S5. Compare the changes in the scrap cloth sample before and after carbonization. When 10% ≤ (W1 - W2) / W1 ≤ 17%, (V1 - V2) / V1 ≤ 10%, and (Q1 - Q2) / Q1 ≤ 10%, the corresponding carbonization temperature is used as the screening temperature;

[0014] S6. Recheck the screening temperature, and test the Hardgrove grindability index HGI of the scrap cloth sample. If 50 ≤ HGI ≤ 100, then the recheck is passed; otherwise, repeat S1 to S6 until the recheck is passed.

[0015] Furthermore, the industrial analysis in S1 includes the volatile content on a dry basis. Preferably, it also includes at least one of the moisture content on an air - dry basis, volatile content on an air - dry basis, ash content on an air - dry basis, volatile content on a dry basis, ash content on a dry basis, volatile content on a dry ash - free basis, and fixed - carbon content.

[0016] Further, the elemental analysis in S1 includes carbon content analysis. Preferably, it further includes at least one of nitrogen content analysis, hydrogen content analysis, sulfur content analysis, oxygen content analysis, and chlorine content analysis.

[0017] Further, the thermogravimetric analysis in S2 includes plotting at least one of a TG curve, a DTG curve, and a DSC curve, preferably a DSC curve.

[0018] Further, the peak temperature in S2 is unique, and 300°C ≤ T1 ≤ 350°C.

[0019] Further, if the peak temperature in S2 is not unique, then the maximum peak temperature is taken as the peak temperature T1.

[0020] Further, in S3, Y ≤ 1 / 3(T1) ≤ X ≤ 2 / 3(T1).

[0021] Further, in S3, 8°C ≤ t1 ≤ 15°C, and in S4, 0.1°C < t2 ≤ 7°C. Preferably, 1°C ≤ t2 ≤ 5°C.

[0022] Further, in S5, when 11% ≤ (W1 - W2) / W1 ≤ 15%, (V1 - V2) / V1 ≤ 5%, and (Q1 - Q2) / Q1 ≤ 10%, the corresponding carbonization temperature is used as the screening temperature.

[0023] Further, in S6, if 90 ≤ HGI ≤ 100, then it passes the review. [[ID=CHINESE]]

[0024] Beneficial effects: The method of the present invention can quickly screen out appropriate low-temperature and shallow carbonization temperatures, such that the weight loss rate of the shredded sample after being treated at the screened temperature is in the range of 12 - 15%, which belongs to the normal and relatively low range. The raw material calorific value retention rate is about 90%, and the calorific value of the treated raw material remains at a relatively high level. At the same time, it has high grindability, low energy consumption during the grinding process, and good powder-forming property of the sample. It can be used as a raw material for a fluidized bed boiler or a gasifier, which helps to promote the industrialized recycling treatment of the shredded sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present invention, the drawings will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention and do not limit the present invention.

[0026] Figure 1 It is a photo of a shredded sample provided by Embodiment 2 of the present invention;

[0027] Figure 2 It is a thermogravimetric analysis diagram of a shredded sample provided by Embodiment 2 of the present invention;

[0028] Figure 3 ​This is an appearance diagram of a cloth scrap sample provided in Example 2 of the present invention after carbonization at 240°C;

[0029] Figure 4 This is an appearance diagram of a cloth scrap sample provided in Example 2 of the present invention after carbonization at 250°C;

[0030] Figure 5 This is an appearance diagram of a cloth scrap sample provided in Example 2 of the present invention after carbonization at 255°C;

[0031] Figure 6 This is a photo of a cloth scrap sample provided in Example 3 of the present invention;

[0032] Figure 7 This is a thermogravimetric analysis diagram of a cloth scrap sample provided in Example 3 of the present invention;

[0033] Figure 8 This is a diagram showing the appearance of a cloth scrap sample provided in Comparative Example 1 of the present invention after carbonization at 245°C;

[0034] Figure 9 This is a diagram showing the appearance of a cloth scrap sample provided in Comparative Example 2 of the present invention after carbonization at 250°C;

[0035] Figure 10 This is the appearance of the cloth scrap sample provided in Comparative Example 3 of the present invention after carbonization at 255°C. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the examples, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially. In the following examples, if not clearly stated, "%" refers to weight percentage.

[0037] The test methods used below include:

[0038] For industrial analysis methods of scrap samples, please refer to the national standard GB / T 28731-2012 "Industrial Analysis Methods for Solid Biomass Fuels"

[0039] For the element content test method of cloth scraps, please refer to the industry standard CJ / T 96-2013 "General Test Method for Chemical Properties of Domestic Waste"

[0040] Thermogravimetric analysis of the cloth scraps was performed using a thermogravimetric analyzer. The thermogravimetric analysis was conducted under continuous heating conditions. The gas atmosphere was air, the heating rate was 10°C / min, and the test temperature range was from room temperature to 350°C.

[0041] The Hardgrove Grindability Index (HGI) is tested using a Hardgrove Grindability Tester. The test method is based on the national standard GB / T 2565-2014 "Method for Determination of Grindability Index of Coal".

[0042] Example 1

[0043] A method for detecting and analyzing cloth scraps comprises the following steps:

[0044] S1. Divide the cloth scraps to be tested into 4 equal parts, numbered 1#, 2#, 3#, and 4#. Take the cloth scraps 1# to be tested for industrial analysis and elemental analysis to obtain the weight W1, volatile matter content V1, and content of constituent elements of the cloth scraps.

[0045] The cloth scraps are divided into four equal parts to facilitate their use in subsequent steps. The cloth scraps will change during some analyses, such as thermogravimetric analysis. In order to ensure sample consistency, the four cloth scraps should have as little difference as possible.

[0046] Industrial analysis mainly includes dry basis volatile matter content, air-dried basis moisture content, air-dried basis volatile matter content, air-dried basis ash content, dry basis volatile matter content, dry basis ash content, dry ash-free basis volatile matter content and fixed carbon content. The physical properties of the cloth scraps are obtained through industrial analysis, among which the dry basis volatile matter content is the basis for subsequent calculations, and other indicators can assist in judging the changes of the cloth scraps after carbonization treatment.

[0047] Elemental analysis can be performed using a photometer or atomic absorption spectrometer. Analytical targets include carbon content, which is a key indicator of interest due to its modification during the carbonization process. Other indicators such as nitrogen, hydrogen, sulfur, oxygen, and chlorine can serve as supplementary indicators to assess the chemical properties of the fabric scraps.

[0048] S2. Take 2# of the cloth scrap sample to be tested and perform thermogravimetric analysis to obtain the thermogravimetric analysis curve and calorific value Q1 of the cloth scrap sample, as well as the peak temperature T1 of the thermogravimetric analysis curve.

[0049] Thermogravimetric analysis includes drawing at least one of a TG curve, a DTG curve, and a DSC curve, preferably a DSC curve, and the peak temperature can be obtained more intuitively. Specifically, the focus of the thermogravimetric analysis curve is mainly the point at which the sample weight begins to change, and the rate of this change. The inflection point on the curve (i.e., the peak) is generally of research significance. When multiple peaks occur, the maximum temperature inflection point is used as the peak temperature, so that the subsequent steps can quickly find the appropriate screening temperature and pass the review.

[0050] S3. Take the 3# cloth fragment sample to be tested, use T1-X as the starting temperature, T1-Y as the ending temperature, and t1 as the temperature interval, where Y < X < T1 and 5°C < t1 < 20°C, conduct the first carbonization experiment, observe the appearance of the cloth fragment sample during the carbonization process, record the carbonization temperature corresponding to when the appearance of the cloth fragment sample starts to change as T2, and record the carbonization temperature corresponding to when the cloth fragment sample turns black as T3.

[0051] To save testing time, appropriate starting temperature, ending temperature, and temperature interval are very important. The temperature interval in this embodiment refers to the temperature range from the starting temperature to the ending temperature, which is divided into multiple test nodes, and the temperature difference between adjacent nodes. If the interval is too large, although the number of test nodes is small, the optimal screening temperature may be missed, leading to a repeated analysis process; if the interval is too small, the number of test nodes may be too many, causing unnecessary waste. Considering both the accuracy of the test and time saving, as a preferred solution, Y ≤ 1 / 3(T1) ≤ X ≤ 2 / 3(T1).

[0052] S4. Take the 4# cloth fragment sample to be tested, use T2 as the starting temperature, T3 as the ending temperature, and t2 as the temperature interval, where t2 < t1, conduct the second carbonization experiment, test the cloth fragment samples treated at different carbonization temperatures, and obtain the weight W2; obtain the content of the constituent elements, the volatile content V2, and the calorific value Q2.

[0053] As a preferred solution, 8°C ≤ t1 ≤ 15°C and 0.1°C < t2 ≤ 7°C to obtain the best test accuracy.

[0054] S5. Compare the changes in the cloth fragment sample before and after carbonization. When 10% ≤ (W1 - W2) / W1 ≤ 17%, (V1 - V2) / V1 ≤ 10%, and (Q1 - Q2) / Q1 ≤ 10%, the corresponding carbonization temperature is used as the screening temperature;

[0055] S6. Recheck the screening temperature, test the Hardgrove grindability index HGI of the cloth fragment sample. If 50 ≤ HGI ≤ 100, then it passes the recheck; otherwise, repeat S1 to S6 until it passes the recheck.

[0056] Example 2 <​​​​​​​​​​

[0060] Table 1 Industrial analysis of cloth scraps samples from Example 2

[0061]

[0062]

[0063] The elemental analysis results of the cloth scrap raw material samples are shown in Table 2.

[0064] Table 2 Elemental analysis of cloth scraps sample from Example 2 (dry basis)

[0065]

[0066] Thermogravimetric analysis of cloth scraps Figure 2 Thermogravimetric analysis was conducted under continuously increasing temperature conditions, with an air atmosphere and a temperature range from room temperature to 350°C. The sample began to lose weight at around 200°C due to volatilization. After 250°C, volatilization accelerated, causing the rate of weight loss to increase. This rate of weight loss reached an inflection point around 330°C, where it began to decrease. At 350°C, the sample had lost 27.51%.

[0067] The calorific value analysis results of the scrap sample are shown in Table 3 below. The sample's calorific value is relatively high, approximately 22.2 MJ / kg. Using the calorific values ​​of coal and biomass as a reference, the calorific value of standard coal is 29.3 MJ / kg; the calorific value of biomass ranges from 13 to 22 MJ / kg. The calorific value of the scrap sample is approximately 35% higher than the generally accepted average calorific value of biomass.

[0068] Table 3 Calorific value analysis of cloth scraps sample in Example 2

[0069]

[0070] Low-temperature shallow carbonization treatment is carried out in an inert atmosphere (such as nitrogen) using a tubular heating furnace, and the carbonization time is set to 1 hour. Based on the results of thermogravimetric analysis, the low-temperature shallow carbonization temperature starts from 200°C and goes up to 280°C, with a temperature interval of 10°C. After finding the critical treatment temperature range, the temperature interval is set at 5°C.

[0071] Experiments have shown that when samples are treated at temperatures between 200°C and 230°C, the appearance of the fabric shreds changes minimally, and initial shreds demonstrate strong toughness. Therefore, temperatures below 230°C are insufficient for achieving low-temperature, shallow carbonization of the fabric shreds and achieving reasonable grindability. At shallow carbonization temperatures above 260°C, the shreds turn black. Therefore, the ideal temperature range for low-temperature, shallow carbonization should be between 240°C and 260°C.

[0072] Example 2 The samples were lightly carbonized at 240, 245, and 250°C, respectively, and the carbonization time was set to 1 hour. The appearance of the samples was as follows: Figure 3 、 Figure 4 and Figure 5 As shown in the figure, it can be seen that after carbonization at 245℃, the overall color of the cloth pieces darkened, and the color became even darker at 250℃.

[0073] During the low-temperature shallow carbonization process, the fibers of the sample are thermally damaged and broken, and some volatile substances are also lost. In principle, it is hoped that low-temperature shallow carbonization can achieve an increase in the grindability index while minimizing the weight loss of the sample.

[0074] The weight loss of the cloth scraps after low-temperature shallow carbonization is shown in Table 4. As can be seen, when the treatment temperature is controlled below 245°C, the weight loss of the samples can be controlled to approximately 15%. Compared with biomass, this weight loss is within a reasonable and low range.

[0075] Table 4 Weight loss rate of cloth scraps sample after low temperature shallow carbonization in Example 2

[0076]

[0077] The elemental analysis of the samples is shown in Table 5 below. Overall, compared with the original cloth pieces, the carbon content increased and the oxygen content decreased after low-temperature shallow carbonization.

[0078] Table 5 Elemental analysis of samples after low temperature shallow carbonization in Example 2

[0079]

[0080] The volatile matter and calorific value of the samples after shallow carbonization are shown in Table 6. The calorific value of the raw material after low-temperature shallow carbonization decreases slightly compared to the pretreatment. This is due to the volatilization of light components, which typically have a relatively high calorific value. This results in a slight decrease in calorific value per unit weight, but the decrease is not significant. At treatment temperatures of 245°C and 250°C, the calorific value loss per unit weight of the sample is approximately 10%. The calorific value of the cloth after low-temperature shallow carbonization is approximately 20-21 MJ / kg, which is approximately 90% of the calorific value of the raw material.

[0081] Table 6 Volatile matter and calorific value of cloth scraps after low-temperature shallow carbonization in Example 2

[0082]

[0083]

[0084] The grindability index of the sample from Example 2 after shallow carbonization is shown in Table 7. The Hardgrove Grindability Index (HGI) is an important parameter that measures the ease with which a solid can be ground into powder and is used to evaluate mill energy consumption. A higher HGI indicates a higher grindability. It can be seen that the grindability index of the cloth scrap sample is very sensitive to the treatment temperature. In this example, the cloth scrap sample achieved a Hardgrove Grindability Index of approximately 65 after carbonization at 245°C, and a Hardgrove Grindability Index as high as 95 after treatment at 250°C.

[0085] Table 7 Grindability index of Example 2 after shallow carbonization treatment

[0086]

[0087] Example 3

[0088] This embodiment demonstrates the cloth scrap detection and analysis method in embodiment 1 through a specific sample analysis process.

[0089] The cloth scraps were subjected to physical and chemical property analysis. Figure 6 ) Unlike Example 2, which consisted mainly of broken cloth and a small amount of plastic and shredded paper, and contained a small amount of dust, the sample in Example 3 consisted mainly of various cloth strips, with very little dust.

[0090] The physicochemical properties of the samples in Example 3 are shown in the table below.

[0091] Table 8 Industrial analysis of cloth scraps samples from Example 3

[0092]

[0093] The elemental analysis results of the cloth scrap raw material samples are shown in the table.

[0094] Table 9 Elemental analysis of cloth scraps sample from Example 3 (dry basis)

[0095]

[0096]

[0097] Thermogravimetric analysis of cloth scraps Figure 7 As shown. Thermogravimetric analysis was conducted under continuously increasing temperature conditions, with the gas atmosphere being air, and the test temperature range being room temperature to 350°C. The sample began to volatilize significantly at around 230°C, and began to volatilize rapidly at around 275°C, with volatilization significantly slowing down at around 310°C. At 350°C, the sample had only lost 11.06% of its weight. Overall, the treatment temperature required for the sample in this example should be higher than that in Example 2, but the weight loss during the heat treatment process was much lower than that in Example 2.

[0098] The calorific value analysis results of the cloth scraps are shown in the table below. The calorific value of the sample is relatively high, approximately 24.2 MJ / kg.

[0099] Table 10 Calorific value analysis of cloth scraps samples in Example 3

[0100]

[0101] Low-temperature shallow carbonization treatment is carried out in an inert atmosphere (such as nitrogen) using a tubular heating furnace, and the carbonization time is set to 1 hour. Based on the results of thermogravimetric analysis, the low-temperature shallow carbonization temperature starts from 200°C and goes up to 280°C, with a temperature interval of 10°C. After finding the critical treatment temperature range, the temperature interval is set at 5°C.

[0102] Experiments have shown that when samples are treated at temperatures between 200°C and 230°C, the appearance of the fabric shreds changes minimally, and initial shreds demonstrate strong toughness. Therefore, temperatures below 230°C are insufficient for achieving reasonable grindability through low-temperature, shallow carbonization of the fabric shreds. At shallow carbonization temperatures above 260°C, the fabric shreds turn black. Therefore, the ideal temperature range for low-temperature, shallow carbonization should be between 245°C and 260°C.

[0103] Example 3 The samples were lightly carbonized at 245, 250, and 255°C, respectively, and the carbonization time was set to 1 hour. The appearance of the samples was as follows: Figure 8 、 Figure 9 and Figure 10 As shown in the figure, it can be seen that as the carbonization temperature increases, the overall color of the cloth pieces gradually deepens.

[0104] During the low-temperature shallow carbonization process, the fibers of the sample are thermally damaged and broken, and some volatile substances are also lost. In principle, it is hoped that low-temperature shallow carbonization can achieve an increase in the grindability index while minimizing the weight loss of the sample.

[0105] The weight loss of the cloth scraps after low-temperature shallow carbonization is shown in the table below. Compared to biomass, the weight loss of the samples is within a reasonable and low range.

[0106] Table 11 Weight loss rate of cloth scraps sample after low temperature shallow carbonization in Example 3

[0107]

[0108] The elemental analysis of the samples is shown in the table below. Overall, compared with the original cloth pieces, the carbon content increased and the oxygen content decreased after low-temperature shallow carbonization.

[0109] Table 12 Elemental analysis of samples after low temperature shallow carbonization in Example 3

[0110]

[0111] The volatile matter and calorific value of the samples after shallow carbonization are shown in the table below. The calorific value of the raw materials after low-temperature shallow carbonization is lower than that before treatment. This is due to the volatilization of light components, which usually have relatively high calorific values. This leads to a decrease in calorific value per unit weight, but the decrease is not significant.

[0112] Table 13 Volatile matter and calorific value of cloth scraps after low-temperature shallow carbonization in Example 3

[0113]

[0114] The grindability index of the sample in Example 2 after shallow carbonization is shown in the following table.

[0115] Table 14 Grindability index of the cloth scraps after shallow carbonization treatment of Example 3

[0116]

[0117] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0118] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0119] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for detecting and analyzing cloth scraps, characterized by: It includes the following steps: S1. Evenly divide the cloth fragment sample to be detected into 4 identical parts, numbered 1#, 2#, 3#, and 4#. Take the 1# cloth fragment sample to be detected for industrial analysis and elemental analysis to obtain the weight W1, dry basis volatile content V1, and the content of constituent elements of the cloth fragment sample; S2. Take the 2# cloth fragment sample to be detected for thermogravimetric analysis to obtain the thermogravimetric analysis curve and calorific value Q1 of the cloth fragment sample, and the peak temperature T1 of the thermogravimetric analysis curve; S3. Take the 3# cloth fragment sample to be detected. Use T1 - X as the starting temperature, T1 - Y as the ending temperature, and t1 as the temperature interval, where Y < X < T1 and 5°C < t1 < 20°C, to conduct the first carbonization experiment. Observe the appearance of the cloth fragment sample during the carbonization process. Record the carbonization temperature corresponding to when the appearance of the cloth fragment sample starts to change as T2, and record the carbonization temperature corresponding to when the cloth fragment sample turns black as T3; S4. Take the 4# cloth fragment sample to be detected. Use T2 as the starting temperature, T3 as the ending temperature, and t2 as the temperature interval, where t2 < t1, to conduct the second carbonization experiment. Test the cloth fragment samples treated at different carbonization temperatures to obtain the weight W2; obtain the content of constituent elements, dry basis volatile content V2, and calorific value Q2; S5. Compare the changes in the cloth fragment sample before and after carbonization. When 10% ≤ (W1 - W2) / W1 ≤ 17%, (V1 - V2) / V1 ≤ 10%, and (Q1 - Q2) / Q1 ≤ 10%, the corresponding carbonization temperature is used as the screening temperature; S6. Recheck the screening temperature. Test the Hardgrove grindability index HGI of the cloth fragment sample. If 50 ≤ HGI ≤ 100, it passes the recheck; otherwise, repeat S1 to S6 until it passes the recheck.

2. The method for detecting and analyzing cloth scraps according to claim 1, characterized in that: The industrial analysis in S1 further includes at least one of air - dried basis moisture content, air - dried basis volatile content, air - dried basis ash content, dry basis ash content, dry ash - free basis volatile content, and fixed carbon content.

3. The method for detecting and analyzing cloth scraps according to claim 1 or 2, characterized in that: The elemental analysis in S1 includes carbon content analysis.

4. The method for detecting and analyzing cloth scraps according to claim 3, wherein: The elemental analysis in S1 further includes at least one of nitrogen content analysis, hydrogen content analysis, sulfur content analysis, oxygen content analysis, and chlorine content analysis.

5. The method for detecting and analyzing cloth scraps according to claim 1, characterized in that: The thermogravimetric analysis in S2 includes plotting at least one of TG curve, DTG curve, and DSC curve.

6. The method for detecting and analyzing cloth scraps according to claim 5, characterized in that: The thermogravimetric analysis in S2 is a DSC curve.

7. The method for detecting and analyzing cloth scraps according to claim 5, characterized in that: The peak temperature in S2 is unique, and 300°C ≤ T1 ≤ 350°C.

8. The method for detecting and analyzing cloth scraps according to claim 5, characterized in that: If the peak temperature in S2 is not unique, take the maximum peak temperature as the peak temperature T1.

9. The method for detecting and analyzing cloth scraps according to claim 7 or 8, characterized in that: In S3, Y ≤ 1 / 3(T1) ≤ X ≤ 2 / 3(T1).

10. The method for detecting and analyzing cloth scraps according to claim 9, characterized in that: In S3, 8°C ≤ t1 ≤ 15°C, and in S4, 0.1°C < t2 ≤ 7°C.

11. The method for detecting and analyzing cloth scraps according to claim 10, characterized in that: [[ID= 12. The method for detecting and analyzing cloth scraps according to claim 1, characterized in that: ​ 13. The method for detecting and analyzing cloth scraps according to claim 12, characterized in that: ​

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