Method for analyzing purity of carbon black prepared from organic hazardous waste

Abstract

The invention relates to the technical field of carbon black detection, in particular to a purity analysis method of carbon black prepared from organic hazardous waste. The purity analysis method comprises the following steps: S1, mixing carbon black with an organic amine solution to obtain a mixture; s2, mixing the mixture with an organic solvent, performing centrifugal filtration to obtain filtrate, and measuring the light transmittance; the organic amine comprises a mixed solvent of piperidine and N-methylaniline. The carbon black is prepared by the following method: (1) carrying out dehydration pretreatment on the organic hazardous waste, and crushing to obtain a particle sample; (2) pyrolyzing the particle sample under the inert gas condition at the pyrolysis temperature of 1100-1400 DEG C, separating out carbon black generated in the pyrolysis process along with a gas-phase product, and filtering and collecting by a filter membrane; and (3) cleaning the filter membrane with an organic solvent, filtering, and drying to obtain the carbon black. The purity analysis method is more accurate, and the analysis result can better represent the purity of the carbon black.

Description

Technical Field

[0001] The invention relates to the technical field of carbon black detection, and in particular to a purity analysis method for carbon black prepared through organic hazardous waste. Background Art

[0002] Carbon black for rubber products is widely used in rubber products such as automotive sealing strips, door and window sealing strips, shock-absorbing molded parts, etc. With the development of technology, especially the development of the automobile industry, higher requirements are put forward for carbon black for rubber products.

[0003] Carbon black is currently mainly used in tires, rubber products, plastics, inks, coatings, conductive materials and other fields. It accounts for a large proportion in the additive formula of the above products. After adding carbon black, the product's wear resistance, tensile strength, tear strength, anti-aging, conductivity, insulation and other properties can be greatly improved. However, the purity of carbon black is not high, which will have different degrees of influence on the quality and performance of the above products, and even directly affect the application performance and shorten the service life.

[0004] Hazardous wastes usually have one or more hazardous characteristics such as corrosiveness, toxicity, flammability, reactivity or infection. If they are not properly handled, they will not only damage the ecological environment such as the atmosphere, water sources, and soil, but also affect human health. At present, the main methods used to treat hazardous wastes are resource utilization, physical and chemical treatment, incineration, and landfill.

[0005] Pyrolysis is the process of heating organic materials in an oxygen-deficient or extremely low-oxygen environment to break and rearrange their chemical structures. During the pyrolysis process, organic matter undergoes three main stages: drying, thermal decomposition, and carbonization. Pyrolysis products mainly include three types: pyrolysis gas, pyrolysis oil, and coke. The use of organic hazardous waste pyrolysis to produce carbon black is conducive to resource processing. For example, the prior art (Dong Lei, Yin Minmin. A brief analysis of the application of pyrolysis treatment technology in the treatment of oily sludge [J]. Leather Manufacturing and Environmental Protection Technology, 2024, 5(8):99-101.) discloses the use of pyrolysis technology to treat oily sludge, and the prior art (Chen Guanyi, Liu Huanbo, Li Jian, et al. Research progress in antibiotic bacterial residue treatment technology [J]. Environmental Chemistry, 2021, 40(02):459-473.) discloses the use of pyrolysis technology to treat antibiotic bacterial residue. At present, the structure and composition of the product coke obtained by pyrolysis of organic hazardous waste are quite different from those of commercially available carbon black. In addition, the organic hazardous waste raw materials contain more impurities, which will inevitably be brought into the product carbon black. Therefore, it is particularly important to control the purity of carbon black.

[0006] During the processing of carbon black, the raw materials cannot react 100% completely and will be deposited on the surface of carbon black. In addition, some catalyst powders, other mineral particles, additives, reaction by-products, etc. in the raw materials may remain on the surface of carbon black. These are collectively referred to as carbon black surface impurities, which will affect the purity of carbon black. At present, the existing technology reflects the purity by detecting the light transmittance of the extracts extracted by organic solvents such as acetone, benzene or toluene. However, for extremely small amounts of residues or residues that cannot be directly extracted by organic solvents, this detection method has low accuracy.

[0007] Chinese patent publication number CN114720249A discloses a pretreatment method for detecting the surface purity of carbon black, which includes mixing carbon black with liquid organic amine and then extracting it, and the obtained extract is used for surface purity detection. However, the accuracy of this method for detecting the purity of carbon black, especially the purity of carbon black obtained by pyrolysis of organic hazardous waste, needs to be further improved.

[0008] Therefore, it is very necessary to develop a purity analysis method for carbon black prepared from organic hazardous waste that can solve the above technical problems. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for analyzing the purity of carbon black prepared from organic hazardous waste with high accuracy.

[0010] The present invention is achieved through the following technical solutions: The present invention provides a method for analyzing the purity of carbon black prepared from organic hazardous waste, comprising the following steps: S1: mixing carbon black with an organic amine solution to obtain a mixture; S2: mixing the mixture with an organic solvent, centrifuging and filtering to obtain a filtrate, and measuring the transmittance; The organic amines include piperidine and N-methylaniline; The carbon black is prepared by the following method: (1) Dehydrating and pre-treating the organic hazardous waste, crushing it, and obtaining a particle sample; (2) Pyrolyzing the particle sample under inert gas conditions at a temperature of 1100-1400°C. The carbon black generated during the pyrolysis process is precipitated with the gas phase product and filtered and collected by a filter membrane. The gas phase product obtained after filtration and the tar generated during the pyrolysis process are recovered; (3) The filter membrane in step (2) is cleaned with an organic solvent, filtered, and dried to obtain carbon black.

[0011] The operation process of step S2 of the present invention refers to GB / T 3780.15-2016 "Carbon black Part 15: Determination of light transmittance of toluene extract".

[0012] As an embodiment of the present invention, in S1, the volume ratio of piperidine to N-methylaniline is 15-20:1.

[0013] As an embodiment of the present invention, in S1, the volume percentage of piperidine in the organic amine solution is 15-20%.

[0014] As an embodiment of the present invention, in S1, the mass ratio of the carbon black to the organic amine solution is 1-5:1.

[0015] As an embodiment of the present invention, in S2, the organic solvent includes at least one of benzene, toluene and acetone.

[0016] As an embodiment of the present invention, in S2, the volume mass ratio of the organic solvent to the mixture is 10mL:1g.

[0017] As an embodiment of the present invention, in S1, carbon black is first mixed with a piperidine solution, and then mixed with N-methylaniline to obtain a mixture.

[0018] The present invention can extract impurities adsorbed on the surface and inside of carbon black into filtrate by optimizing the mixing order of two organic amines, and the light transmittance obtained by detection is used to more accurately indicate the purity.

[0019] As an embodiment of the present invention, the hazardous organic waste in step (1) includes at least one of oily sludge, waste paint residue and penicillin residue.

[0020] Oily sludge, waste paint residue and fungus residue belong to HW08, HW12 and HW02 hazardous wastes respectively as specified in my country's "List of Hazardous Wastes". In terms of composition, oily sludge is a mixture of water, petroleum hydrocarbons, solid mineral particles and metals, which contains a large amount of highly toxic teratogens and carcinogens; waste paint residue is mainly composed of waste paint and inorganic impurities, and the main components include vegetable oil, resin, additives, pigments and diluents; the main components of fungus residue are microbial mycelium and its metabolic intermediates, residual culture medium, organic solvents and a small amount of residual antibiotics.

[0021] Preferably, the hazardous organic waste in step (1) comprises a mixture of oily sludge and waste paint residue, and the calorific value of the mixture is 4000-5000 kcal / kg.

[0022] As an embodiment of the present invention, the process parameters of the dehydration pretreatment in step (1) are: drying at 105-120° C. for 20-24 hours.

[0023] As an embodiment of the present invention, after the pulverization in step (1), the granular sample is sieved through a 60-80 mesh sieve, and the moisture content of the granular sample is between 20-30%.

[0024] The water contained in the organic hazardous waste samples includes free water and bound water. The main purpose of drying is to remove the free water contained in the samples. Bound water is difficult to remove through the drying process. Therefore, the organic hazardous waste samples after drying mainly contain bound water. The dried samples are crushed to obtain fine particle samples of smaller size and stored in a drying container for later use.

[0025] As an embodiment of the present invention, the inert gas in step (2) includes but is not limited to N2.

[0026] As an embodiment of the present invention, the flow rate of the inert gas in step (2) is 1-3 L / min.

[0027] As an embodiment of the present invention, the pyrolysis time in step (2) is 8-15 minutes.

[0028] Preferably, during the pyrolysis process, the heating rate is 350-450° C. / min.

[0029] As an embodiment of the present invention, the filter membrane in step (2) is stainless steel fiber sintered felt.

[0030] As an embodiment of the present invention, the gas phase product obtained after filtration in step (2) is collected by an air bag, and the tar generated during the pyrolysis process is absorbed by an absorption bottle containing an organic solvent.

[0031] The carbon black particles generated during the pyrolysis reaction are precipitated with the gas phase products and accumulated on the metal filter membrane in the metal filter. The filter membrane is made of stainless steel fiber sintered felt with a micron-level pore size.

[0032] As an embodiment of the present invention, the air bag in step (2) is an aluminum air bag.

[0033] As an embodiment of the present invention, the organic solvent in step (2) or step (3) is dichloromethane.

[0034] As an embodiment of the present invention, the cleaning method in step (3) is ultrasonic shaking cleaning for 30 minutes, which is performed in 5 times to ensure that the oil substances adsorbed on the surface of the carbon black are completely eluted.

[0035] As an embodiment of the present invention, the filtration in step (3) is performed using a 0.22 μm organic filter membrane, the purpose of which is to filter the cleaned carbon black sample.

[0036] As an embodiment of the present invention, the drying process parameters in step (3) are: drying at 105-120° C. for 20-24 hours.

[0037] The beneficial effects of the present invention are: The present invention adopts piperidine and N-methylaniline to pretreat the carbon black sample, and then measures the light transmittance of the organic solvent extract. This analysis method can extract impurities on the surface and inside of the carbon black to a greater extent, and more accurately present the purity of the carbon black. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FTIR spectra of the carbon black samples prepared in Examples 1 to 3 and commercially available carbon black N220.

[0039] Figure 2 Transmission electron microscope pictures of the carbon black samples prepared in Examples 1 to 3. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

[0041] Example 1 A process for preparing carbon black from organic hazardous waste comprises the following steps: (1) Place penicillin residue in a constant temperature drying oven and dry at 105°C for 24 hours for dehydration pretreatment, then crush and sieve through a 60-mesh sieve to obtain a granular sample (water content 29%); (2) The particle sample was pyrolyzed under N2 conditions, with a N2 flow rate of 1 L / min, a pyrolysis temperature of 1400°C, a heating rate of 450°C / min, and a pyrolysis time of 8 min. The carbon black produced during the pyrolysis process was precipitated with the gas phase products and filtered and collected by a stainless steel fiber sintered felt filter membrane in the filter. The gas phase products obtained after filtration were collected by an aluminum air bag. The tar produced during the pyrolysis process was absorbed by an absorption bottle containing dichloromethane. (3) The carbon black collected by the stainless steel fiber sintered felt filter membrane in step (2) was cleaned by ultrasonic shaking with dichloromethane for 30 minutes, divided into 5 times, each time for 6 minutes. The cleaned carbon black was filtered by a 0.22 μm organic filter membrane and dried at 105° C. for 24 hours to obtain carbon black.

[0042] Example 2 A process for preparing carbon black from organic hazardous waste comprises the following steps: (1) Place the waste paint residue in a constant temperature drying oven and dry it at 120°C for 20 hours for dehydration pretreatment. After crushing, pass it through an 80-mesh sieve to obtain a particle sample (water content is 25%). (2) The particle sample was pyrolyzed under N2 conditions, with a N2 flow rate of 3 L / min, a pyrolysis temperature of 1100°C, a heating rate of 350°C / min, and a pyrolysis time of 15 min. The carbon black produced during the pyrolysis process was precipitated with the gas phase products and filtered and collected by a stainless steel fiber sintered felt filter membrane in the filter. The gas phase products obtained after filtration were collected by an aluminum air bag. The tar produced during the pyrolysis process was absorbed by an absorption bottle containing dichloromethane. (3) The carbon black collected by the stainless steel fiber sintered felt filter membrane in step (2) is cleaned by ultrasonic shaking with dichloromethane for 30 minutes, divided into 5 times, each time for 6 minutes. The cleaned carbon black is filtered by a 0.22 μm organic filter membrane and dried at 120° C. for 20 hours to obtain carbon black.

[0043] Example 3 A process for preparing carbon black from organic hazardous waste comprises the following steps: (1) The oily sludge was placed in a constant temperature drying oven and dried at 110°C for 22 h for dehydration pretreatment. After crushing, it was passed through a 70-mesh sieve to obtain a granular sample (with a moisture content of 22%). (2) The particle sample was pyrolyzed under N2 conditions, with a N2 flow rate of 2 L / min, a pyrolysis temperature of 1250°C, a heating rate of 400°C / min, and a pyrolysis time of 12 min. The carbon black produced during the pyrolysis process was precipitated with the gas phase products and filtered and collected by a stainless steel fiber sintered felt filter membrane in the filter. The gas phase products obtained after filtration were collected by an aluminum air bag. The tar produced during the pyrolysis process was absorbed by an absorption bottle containing dichloromethane. (3) The carbon black collected by the stainless steel fiber sintered felt filter membrane in step (2) was cleaned by ultrasonic shaking with dichloromethane for 30 minutes, divided into 5 times, each time for 6 minutes. The cleaned carbon black was filtered by a 0.22 μm organic filter membrane and dried at 110° C. for 22 hours to obtain carbon black.

[0044] Example 4 A purity analysis method for carbon black prepared from organic hazardous waste comprises the following steps: S1: mixing the carbon black prepared in Example 1 with an organic amine solution in a mass ratio of 1:1, wherein the organic amine includes piperidine and N-methylaniline in a volume ratio of 15:1, and the volume percentage of piperidine in the organic amine solution is 15%, to obtain a mixture; S2: The mixture is mixed with benzene at a liquid-to-solid ratio of 10 mL / g, and the mixture is centrifuged to obtain a filtrate, and the transmittance is measured.

[0045] The operation process of step S2 of this embodiment refers to GB / T 3780.15-2016 "Carbon black Part 15: Determination of light transmittance of toluene extract", and the following embodiments and comparative examples are the same.

[0046] Example 5 A purity analysis method for carbon black prepared from organic hazardous waste comprises the following steps: S1: mixing the carbon black prepared in Example 2 with an organic amine solution in a mass ratio of 5:1, wherein the organic amine includes piperidine and N-methylaniline in a volume ratio of 20:1, and the volume percentage of piperidine in the organic amine solution is 20%, to obtain a mixture; S2: The mixture is mixed with acetone at a liquid-to-solid ratio of 10 mL / g, and the mixture is centrifuged to obtain a filtrate, and the transmittance is measured.

[0047] Example 6 A purity analysis method for carbon black prepared from organic hazardous waste comprises the following steps: S1: mixing the carbon black prepared in Example 3 with an organic amine solution in a mass ratio of 3:1, wherein the organic amine includes piperidine and N-methylaniline in a volume ratio of 18:1, and the volume percentage of piperidine in the organic amine solution is 18%, to obtain a mixture; S2: The mixture is mixed with toluene at a liquid-to-solid ratio of 10 mL / g, and the mixture is centrifuged to obtain a filtrate, and the transmittance is measured.

[0048] Example 7 A purity analysis method for carbon black prepared from organic hazardous waste, which differs from Example 6 only in the mixing step with the organic amine solution, comprises the following steps: S1: mixing the carbon black prepared in Example 3 with the piperidine solution in the same amount and concentration as in Example 6, and then adding N-methylaniline in the same amount as in Example 6 to obtain a mixture; S2: The mixture is mixed with toluene at a liquid-to-solid ratio of 10 mL / g, and the mixture is centrifuged to obtain a filtrate, and the transmittance is measured.

[0049] Comparative Example 1 The only difference from Example 6 is that the total amount of organic amine used remains unchanged, the composition is different, and it is only piperidine. The other conditions are the same.

[0050] Comparative Example 2 The only difference from Example 6 is that the total amount of organic amines is unchanged, the composition is different, and it is only N-methylaniline. The other conditions are the same.

[0051] Comparative Example 3 The only difference from Example 7 is the mixing step with the organic amine solution, and the other conditions are the same. The details are as follows: S1. Mix the carbon black prepared in Example 3 with the same amount of N-methylaniline as in Example 6, and then add the same amount and concentration of piperidine solution as in Example 6 to obtain a mixture; S2: The mixture is mixed with toluene at a liquid-to-solid ratio of 10 mL / g, and the mixture is centrifuged to obtain a filtrate, and the transmittance is measured.

[0052] Comparative Example 4 The only difference from Example 6 is that the composition of the organic amine is different, and the same amount of tri-n-propylamine is used instead, and the other conditions are the same.

[0053] Comparative Example 5 The only difference from Example 6 is that no organic amine is added, and the prepared carbon black and toluene are directly mixed at a liquid-to-solid ratio of 10 mL / g, centrifuged and filtered to obtain a filtrate, and the transmittance is measured.

[0054] Test Example 1 Infrared Spectroscopy (FTIR) Analysis The surface functional groups of the carbon black samples prepared in Examples 1 to 3 and the commercially available carbon black N220 were detected using a Fourier transform infrared (FTIR) spectrometer. The carbon black samples were mixed with KBr at a ratio of 1:100, pressed into sheets using a tablet press, and then scanned using an FTIR spectrometer. The results are shown in FIG. Figure 1 shown.

[0055] Figure 1 The FTIR curves of the carbon black samples prepared in Examples 1-3 and the commercially available carbon black N220 are very similar, with several obvious broad peaks. Therefore, the carbon black samples prepared in the present invention are composed of different molecular substances. The FTIR spectrum is at 2800-3000cm -1 The absorption spectrum in the range is very weak, indicating that there is basically no aliphatic CH functional group in the carbon black sample prepared by the present invention, and the H element mainly exists in the form of aromatic CH bonds, 3068 cm -1 The weak absorption peak at 1700-925 cm -1 The obvious absorption bands in the range of 1637 cm-1 dominate, representing the π bonds in amorphous carbon. -1 The absorption peak at represents the aromatic C=C (sp 2 ) bond stretching vibration. 1400-1000cm -1 The broad absorption band at 1300 cm -1 The broad band at is due to aliphatic crosslinking in the aromatic sp 2The defects are caused by the formation of non-hexagonal rings inside the layer. 925-700 cm -1 The absorption spectrum appearing in the range represents the bending vibration of the aromatic out-of-plane CH bonds.

[0056] Test Example 2 Element Composition and Ash Content Analysis The content of different elements and ash content in the carbon black prepared in each embodiment were determined using the Vario MACRO cube element analyzer of Elementar Company of Germany, and the results are shown in Table 1. The carbon black yield was also calculated, and the results are shown in Table 1. Carbon black yield = carbon black mass / organic hazardous waste mass*100%. The higher the C content of the carbon black, the lower the ash content, indicating that the quality of the carbon black is better.

[0057] Table 1 Different element contents, ash contents and yields of carbon black in various examples

[0058] Test Example 3 Carbon Black Morphology Characteristics and Particle Size Distribution The microscopic morphology of the carbon black samples prepared in Examples 1 to 3 was analyzed using a 200 kV field emission transmission electron microscope (FETEM), model Tecnai G2 F20 (FEI, USA). The results are as follows: Figure 2 For analysis, the sample was ground and ultrasonically dispersed with anhydrous ethanol at room temperature for 10 minutes, and then the resulting supernatant was dripped onto a copper grid. The FETEM images were processed using DigitalMicrograph software, and the particle size distribution was analyzed using Nano Measurer software. The average particle size results are shown in Table 2.

[0059] Table 2 Carbon black particle size test results

[0060] Figure 2 In the examples 1 to 3 of the present invention, the carbon black prepared is a regular spherical structure, presenting an onion-like shell-core structure with concentric circles stacked in an orderly manner. The process of this carbon black structure from disorder to order is the graphitization process of carbon black, and the shell-core structure is a sign of the maturity of carbon black particles.

[0061] Test Example 4 Carbon Black Specific Surface Area Test The BET method was used to test the specific surface area of ​​carbon black in accordance with GBT19587-2017 Determination of the specific surface area of ​​solid substances by gas adsorption BET method. The results are shown in Table 3.

[0062] Table 3 Carbon black specific surface area test results

[0063] Test Example 5: Light transmittance test The filtrate for measuring the transmittance of Examples 4-7 and Comparative Examples 1-5 was filtered using filter paper. After the filtration was completed, it was found that there was no carbon black on the filter paper. Therefore, the substance extracted from the filtrate was the impurity present in the carbon black. The higher the transmittance of the filtrate, the less impurities extracted from the surface carbon black, and the less accurate the analysis method. The test results of the transmittance of the filtrate of each embodiment and comparative example are shown in Table 4.

[0064] Table 4 Filtrate transmittance test results

[0065] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A method for analyzing the purity of carbon black prepared from organic hazardous waste, characterized in that: The steps include: S1: mixing carbon black with an organic amine solution to obtain a mixture; S2: mixing the mixture with an organic solvent, centrifuging and filtering to obtain a filtrate, and measuring the transmittance; The organic amines include piperidine and N-methylaniline; The carbon black is prepared by the following method: (1) Dehydrating and pre-treating the organic hazardous waste, crushing it, and obtaining a particle sample; (2) Pyrolyzing the particle sample under inert gas conditions at a temperature of 1100-1400°C. The carbon black generated during the pyrolysis process is precipitated with the gas phase product and filtered and collected by a filter membrane. The gas phase product obtained after filtration and the tar generated during the pyrolysis process are recovered; (3) The filter membrane in step (2) is cleaned with an organic solvent, filtered, and dried to obtain carbon black.

2. The purity analysis method according to claim 1, characterized in that: In S1, the volume ratio of piperidine to N-methylaniline is 15-20:

1.

3. The purity analysis method according to claim 1, characterized in that: In S1, the volume percentage of piperidine in the organic amine solution is 15-20%.

4. The purity analysis method according to claim 1, characterized in that: In S1, the mass ratio of the carbon black to the organic amine solution is 1-5:

1.

5. The purity analysis method according to claim 1, characterized in that: In S2, the organic solvent includes at least one of benzene, toluene and acetone; and the volume mass ratio of the organic solvent to the mixture is 10 mL:1 g.

6. The purity analysis method according to claim 1, characterized in that: In S1, carbon black is first mixed with a piperidine solution and then mixed with N-methylaniline to obtain a mixture.

7. The purity analysis method according to claim 1, characterized in that: The organic hazardous waste in step (1) includes at least one of oily sludge, waste paint residue and penicillin residue.

8. The purity analysis method according to claim 1, characterized in that: The process parameters of the dehydration pretreatment in step (1) are: drying at 105-120° C. for 20-24 hours, and the moisture content of the particle sample is 20-30%.

9. The purity analysis method according to claim 1, characterized in that: The pyrolysis time in step (2) is 8-15 minutes; the heating rate during the pyrolysis process is 350-450°C / min.

10. The purity analysis method according to claim 1, characterized in that: The flow rate of the inert gas in step (2) is 1-3 L / min; the cleaning method in step (3) is ultrasonic vibration cleaning for 25-35 min, divided into 4-6 times; the organic solvent in step (3) is dichloromethane; the filtration in step (3) is performed using a 0.22 μm organic filter membrane; the drying process parameters are: drying at 105-120° C. for 20-24 h.

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