Method for preparing pigment carbon black from waste tires

Abstract

The invention provides a method for preparing pigment carbon black from waste tires, which solves the problems of low product quality and resource waste in traditional waste tire treatment by optimizing a synergistic process of thermal cracking, oxidation modification, pyrolysis oil carbonization and tail gas closed-loop utilization. The method comprises the following specific steps: crushing the waste tires into rubber powder, and performing thermal cracking to generate a carbon residue and oil-gas mixture; carrying out magnetic separation, grinding and oxidation treatment on the carbon residues to generate oxidized carbon black; fractionating and refining the pyrolysis oil, mixing with carbon black oil, and spraying into a carbon black reaction furnace to generate carbon black; and finally, mixing and granulating the two parts of carbon black to prepare the pigment carbon black. The specific surface area of the prepared pigment carbon black reaches 80-200 m < 2 > / g, the coloring strength is 80-120%, the ash content is smaller than or equal to 18%, and the pigment carbon black can be applied to color master batches and black plastic products by limiting thermal cracking conditions, oxidation conditions and the ratio of mixed oil. The tail gas is recycled after being dedusted and purified, so that efficient cyclic utilization of resources is realized.

Description

Technical Field

[0001] The invention relates to the technical field of waste tire recycling and reuse, and in particular to a method for preparing pigment carbon black from waste tires. Background Art

[0002] The massive accumulation of waste tires poses a dual challenge to environmental pollution and resource reuse. With the rapid development of the global transportation industry, the amount of waste tires has increased annually. Waste tires not only occupy significant land resources but also pollute soil and water sources. Therefore, the recycling and treatment of waste tires has become a crucial issue in resource recycling. Pyrolysis technology, with its ability to convert waste tires into solid, liquid, and gas products, and its advantages of fully processing and maximizing product utilization, has become an effective method for reusing waste tires.

[0003] At present, traditional thermal cracking technology has many technical problems. For example, the product quality is low, especially the cracking carbon black, which has the characteristics of small specific surface area, low tinting strength and poor reinforcement performance, making it difficult to use as a rubber reinforcing agent or black pigment; and the cracking oil has a complex composition and a wide distillation range, so it needs further refining before it can be used as an effective fuel or chemical raw material. In addition, the combustible non-condensable gases produced during the thermal cracking process are often directly incinerated, resulting in H2S and NO x The emission of harmful gases such as pyrolysis products causes environmental pollution and energy waste. The application areas of pyrolysis products are limited, the utilization rate of waste tire resources is low, and the economic value is low.

[0004] This application solves the technical problems of low product quality and resource waste in traditional waste tire treatment by optimizing the thermal cracking process, producing carbon black after distillation and refining of cracking oil, modifying cracking carbon residue and closed-loop utilization of tail gas. Summary of the Invention

[0005] The invention provides a method for preparing pigment carbon black from waste tires, which is used to solve the technical problems of low product quality and waste of resources in the waste tire treatment technology in the prior art.

[0006] The present invention provides a method for preparing pigment carbon black from waste tires, comprising the following steps: (1) Rubber powder is obtained from waste tires after crushing, screening and magnetic separation. The rubber powder is transported to a thermal cracking reactor. After the thermal cracking reactor is adjusted to a negative pressure, it is heated to generate a solid phase carbon residue and an oil and gas mixture; (2) The solid carbon residue is subjected to magnetic separation and grinding to form carbon black powder and temporarily stored, and the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor, and the pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing device of the carbon black plant, and the oil residue component is filtered out. After the light oil and mid-section oil components are separated, the fraction with a temperature of ≥150°C is stored in an oil tank as raw oil; (3) introducing an oxidizing gas into the carbon black powder of step (2) for oxidation treatment to obtain oxidized carbon black; (4) mixing the raw oil from step (2) with carbon black oil to form a mixed oil, spraying the mixed oil into a carbon black reaction furnace at a furnace temperature of 180-250°C, and reacting to generate carbon black at a combustion temperature of 1500-2000°C; (5) mixing the oxidized carbon black of step (3) and the carbon black of step (4), grinding, granulating, and drying to obtain pigment carbon black; (6) The tail gas generated in each step is recovered after dust removal and purification, and reused as fuel for the thermal cracking reactor or carbon black reactor; In step (1), the temperature of the heating treatment is 450-650° C., and the time of the heating treatment is 40-90 minutes; In step (3), the oxidation treatment temperature is 50-90°C, and the oxidation treatment time is 2-4 hours; In step (4), when the mixed oil is sprayed into the carbon black reactor, the oil-air ratio is 0.3-0.5.

[0007] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the particle size of the rubber powder in step (1) is 20-70 mesh, and the steel wire content of the rubber powder is ≤0.5%.

[0008] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the negative pressure in step (1) is -10 kPa to -20 kPa.

[0009] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the particle size D97 of the carbon black powder in step (2) is ≤10 μm.

[0010] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the oxidizing gas in step (3) is one or more of hot air, ozone or nitrogen dioxide.

[0011] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the concentration of the oxidizing gas in step (3) is 20-40 g / m 3 The flow rate of oxidizing gas is 150~250m 3 / h.

[0012] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the mass ratio of raw material oil to carbon black oil in the mixed oil in step (4) is 50-99%:1-50%, the flow rate of the mixed oil sprayed into the carbon black reactor is 3000-5000 kg / h, and the residence time of the mixed oil in the throat of the carbon black reactor is ≥0.4 ms.

[0013] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the mixing ratio of the oxidized carbon black and the carbon black in step (5) is 1-3:1.

[0014] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the pigment carbon black prepared in step (5) has a specific surface area of ​​80 to 200 m 2 / g, ash content is 8~18%, and tinting strength is 80~120%.

[0015] According to a method for preparing pigment carbon black from waste tires provided by the present invention, the tail gas recovery and reuse in step (6) includes collecting and treating the unreacted gas in the oxidation reaction through professional equipment, and returning the non-condensable gas produced by cracking and the flue gas produced by carbon black to the thermal cracking reactor or the carbon black reactor as fuel after passing through a desulfurization and denitrification device.

[0016] The method for preparing pigment carbon black from waste tires provided by the present invention has the following advantages compared with the prior art: (1) The present invention provides a method for preparing pigment carbon black from waste tires. The surface activity of waste tire pyrolysis carbon black is restored through oxidation treatment, oxygen-containing functional groups are increased, and its specific surface area and tinting strength are improved. This solves the technical problems of small specific surface area and low tinting strength of pyrolysis carbon black in the prior art. The method can be used as a black pigment to meet the needs of the masterbatch industry.

[0017] (2) The present invention provides a method for preparing pigment carbon black from waste tires, which comprises distilling and cutting pyrolysis oil and mixing it with carbon black oil at a ratio of 50-99%:1-50%, spraying it into a carbon black reactor, and generating carbon black at a combustion temperature of 1500-2000°C. This method solves the technical problem in the prior art that the pyrolysis oil components are complex and the yield of directly using it to produce carbon black is low.

[0018] (3) The present invention provides a method for preparing pigment carbon black from waste tires. The tail gas is recycled and reused after dust removal and purification, and is used as fuel for waste tire cracking or carbon black production, thereby reducing energy waste.

[0019] (4) The present invention provides a method for preparing pigment carbon black from waste tires. By limiting the mass-to-volume ratio of the mixed oil to air and the furnace feeding process conditions, pyrolysis oil is used as a raw material to produce carbon black, which can be used in masterbatches and black plastic products. This achieves the coordinated utilization of all products and improves the efficient industrial conversion of waste tire resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The present invention provides a process flow diagram of a method for preparing pigment carbon black from waste tires. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] The present invention provides a method for preparing pigment carbon black from waste tires, comprising the following steps: (1) Rubber powder is obtained from waste tires after crushing, screening and magnetic separation. The rubber powder is transported to a thermal cracking reactor. After the thermal cracking reactor is adjusted to a negative pressure, it is heated to generate a solid phase carbon residue and an oil and gas mixture; (2) The solid carbon residue is subjected to magnetic separation and grinding to form carbon black powder and temporarily stored, and the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor, and the pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing device of the carbon black plant, and the oil residue component is filtered out. After the light oil and mid-section oil components are separated, the fraction with a temperature of ≥150°C is stored in an oil tank as raw oil; (3) introducing an oxidizing gas into the carbon black powder of step (2) for oxidation treatment to obtain oxidized carbon black; (4) mixing the raw oil from step (2) with carbon black oil to form a mixed oil, spraying the mixed oil into a carbon black reaction furnace at a furnace temperature of 180-250°C, and reacting to generate carbon black at a combustion temperature of 1500-2000°C; (5) mixing the oxidized carbon black of step (3) and the carbon black of step (4), grinding, granulating, and drying to obtain pigment carbon black; (6) The tail gas generated in each step is recovered after dust removal and purification, and reused as fuel for the thermal cracking reactor or carbon black reactor; In step (1), the temperature of the heating treatment is 450-650°C, preferably 490-610°C, more preferably 530-570°C; the time of the heating treatment is 40-90 minutes, preferably 50-80 minutes, more preferably 60-70 minutes; In step (3), the temperature of the oxidation treatment is 50-90°C, preferably 58-82°C, and more preferably 66-74°C; the time of the oxidation treatment is 2-4 hours, preferably 2.4-3.6 hours, and more preferably 2.8-3.2 hours; In step (4), when the mixed oil is sprayed into the carbon black reactor, the oil-air ratio is 0.3-0.5.

[0024] In the present invention, the particle size of the rubber powder in step (1) is 20-70 mesh, preferably 30-60 mesh, and more preferably 40-50 mesh; the steel wire content of the rubber powder is ≤0.5%.

[0025] In the present invention, the negative pressure in step (1) is -10 kPa to -20 kPa, preferably -12 kPa to -18 kPa, and more preferably -14 kPa to -16 kPa.

[0026] In the present invention, the particle size D97 of the carbon black powder in step (2) is ≤ 10 μm.

[0027] In the present invention, the oxidizing gas in step (3) is one or more of hot air, ozone or nitrogen dioxide, preferably ozone or nitrogen dioxide, and more preferably ozone.

[0028] In the present invention, the concentration of the oxidizing gas in step (3) is 20-40 g / m 3 , preferably 24~36g / m 3 , more preferably 28~32g / m 3 ; The gas flow rate of the oxidizing gas is 150~250m 3 / h, preferably 170~230m 3 / h, more preferably 190~210m 3 / h.

[0029] In the present invention, the mass ratio of the feedstock oil to the carbon black oil in the mixed oil in step (4) is 50-99%:1-50%, the flow rate of the mixed oil sprayed into the carbon black reactor is 3000-5000 kg / h, preferably 3400-4600 kg / h, and more preferably 3800-4200 kg / h; the residence time of the mixed oil in the throat of the carbon black reactor is ≥0.4 ms.

[0030] In the present invention, the mixing ratio of the oxidized carbon black and the carbon black in step (5) is 1-3:1.

[0031] In the present invention, the specific surface area of ​​the pigment carbon black prepared in step (5) is 80 to 200 m 2 / g, ash content is 8~18%, and tinting strength is 80~120%.

[0032] In the present invention, the tail gas recovery and reuse in step (6) includes collecting and treating the unreacted gas in the oxidation reaction through professional equipment, and sending the non-condensable gas produced by cracking and the flue gas produced by carbon black back to the thermal cracking reactor or the carbon black reactor as fuel after passing through the desulfurization and denitrification device.

[0033] Example 1 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -18±2kPa, heating is started and the temperature is maintained at 500°C. The thermal decomposition reaction time of the rubber powder is about 70 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form a carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil-gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the fraction at 200-360° C. as raw oil in an oil tank; Towards carbon black powder at 200m 3 / h gas flow rate and the concentration is 35g / m 3 ozone, and oxidized at 70 ° C for 3.5 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed at a ratio of 90%:10% to form a mixed oil. This mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 4600 kg / h, with an oil-to-air ratio of 0.4. The mixed oil resides in the throat of the carbon black reactor for 0.6 milliseconds and reacts at a combustion temperature of 1900°C to produce carbon black. The oxidized carbon black and carbon black are mixed in a ratio of 1:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0034] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 170 m 2 / g, ash content is 10%, and tinting strength is 110%.

[0035] Example 2 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -19±2kPa, heating is started and the temperature is maintained at 600°C. The thermal decomposition reaction time of the rubber powder is about 50 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant. The oil residue component is filtered out, and after separating the light oil and mid-section oil components, the fraction with a temperature of 200-360° C. is stored in an oil tank as raw oil; Towards carbon black powder at 200m 3 / h gas flow rate and the concentration is 35g / m 3 ozone, and oxidized at 70 ° C for 3.5 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed in a ratio of 90%:10% to form a mixed oil. The mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 3800 kg / h, with an oil-to-air ratio of 0.4. The mixed oil resides in the throat of the carbon black reactor for 0.6 milliseconds and reacts at a combustion temperature of 1900°C to produce carbon black. The oxidized carbon black and carbon black are mixed in a ratio of 2:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0036] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 155m 2 / g, ash content is 13%, and tinting strength is 89%.

[0037] Example 3 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -17±2kPa, heating is started and the temperature is maintained at 480°C. The thermal decomposition reaction time of the rubber powder is about 60 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant. The oil residue component is filtered out, and after separating the light oil and mid-section oil components, the fraction with a temperature of 200-360° C. is stored in an oil tank as raw oil; Towards carbon black powder at 200m 3 / h gas flow rate and the concentration is 35g / m 3 ozone, and oxidized at 70 ° C for 3.5 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed at a ratio of 90%:10 to form a mixed oil. The mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 3000 kg / h. The oil-air ratio is 0.4. The mixed oil stays in the throat of the carbon black reactor for 0.6ms and reacts at a combustion temperature of 1900°C to produce carbon black. The oxidized carbon black and carbon black are mixed in a ratio of 3:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0038] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 140m 2 / g, ash content is 15%, and tinting strength is 80%.

[0039] Example 4 After the waste tires are crushed, screened, and magnetically separated, 60-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -16±2kPa, heating is started and the temperature is maintained at 550°C. The thermal decomposition reaction time of the rubber powder is about 80 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form carbon black powder with a D97 of 10 μm and temporarily stored. At the same time, the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the 300-360° C. fraction as raw oil in an oil tank; Towards carbon black powder at 210m 3 Hot air was introduced at a gas flow rate of / h, and oxidation treatment was performed at 90°C for 4 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed in a ratio of 70%:30 to form a mixed oil. The mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 3800kg / h. The oil-air ratio is 0.39. The mixed oil stays in the throat of the carbon black reactor for 0.7ms and reacts at a combustion temperature of 2000°C to produce carbon black. Oxidized carbon black and carbon black are mixed in a ratio of 2:1, double-stage ground, granulated and dried to obtain pigment carbon black.

[0040] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 132m 2 / g, ash content is 13%, and tinting strength is 93%.

[0041] Example 5 After the waste tires are crushed, screened, and magnetically separated, 20-mesh rubber powder with a steel wire content of ≤0.3% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -20±2kPa, heating is started and the temperature is maintained at 650°C. The thermal decomposition reaction time of the rubber powder is about 90 minutes, generating a mixture of carbon residue and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form carbon black powder with a D97 of 10 μm and temporarily stored. At the same time, the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing device of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the fraction at 200-280° C. as raw oil in an oil tank; Towards carbon black powder at 205m 3 / h gas flow rate and the concentration is 32g / m 3 The nitrogen dioxide was oxidized at 75 ° C for 3.8 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed at a ratio of 95%:5% to form a mixed oil. The mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 3800 kg / h. The oil-air ratio is 0.49. The mixed oil stays in the throat of the carbon black reactor for 0.65ms and reacts at a combustion temperature of 1950°C to produce carbon black. The oxidized carbon black and carbon black are mixed in a ratio of 2:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0042] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 180 m 2 / g, ash content is 13.5%, and tinting strength is 99%.

[0043] Comparative Example 1 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -18±2kPa, heating is started and the temperature is maintained at 700°C. The thermal decomposition reaction time of the rubber powder is about 70 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form a carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil-gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the fraction at 200-360° C. as raw oil in an oil tank; Towards carbon black powder at 200m 3 / h gas flow rate and the concentration is 35g / m 3 ozone, and oxidized at 70 ° C for 3.5 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed at a ratio of 90%:10% to form a mixed oil. This mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 4600 kg / h, with an oil-to-air ratio of 0.4. The mixed oil resides in the throat of the carbon black reactor for 0.6 milliseconds and reacts at a combustion temperature of 1900°C to produce carbon black. The oxidized carbon black and carbon black are mixed in a ratio of 1:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0044] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 200 m 2 / g, ash content is 10%, and tinting strength is 72%.

[0045] Comparative Example 2 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -19±2kPa, heating is started and the temperature is maintained at 600°C. The thermal decomposition reaction time of the rubber powder is about 70 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form a carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil-gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the fraction at 200-360° C. as raw oil in an oil tank; The raw oil and carbon black oil are mixed at a ratio of 90%:10% to form a mixed oil. This mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 4600 kg / h, with an oil-to-air ratio of 0.4. The mixed oil resides in the throat of the carbon black reactor for 0.6 milliseconds and reacts at a combustion temperature of 1900°C to produce carbon black. The carbon black powder and carbon black are mixed in a ratio of 1:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0046] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 180 m 2 / g, ash content is 10%, and tinting strength is 82%.

[0047] Comparative Example 3 After the waste tires are crushed, screened, and magnetically separated, 50-mesh rubber powder with a steel wire content of ≤0.5% is obtained. The rubber powder is fed into a thermal cracking reactor. After the internal pressure of the thermal cracking reactor is adjusted to -18±2kPa, heating is started and the temperature is maintained at 500°C. The thermal decomposition reaction time of the rubber powder is about 70 minutes, generating a mixture of carbon slag and oil and gas. The carbon residue is subjected to magnetic separation and grinding to form a carbon black powder with a D97 of 8 μm and temporarily stored. At the same time, the oil-gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor. The pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing equipment of the carbon black plant to filter out the oil residue component, separate the light oil and mid-section oil components, and store the fraction at 200-360° C. as raw oil in an oil tank; Towards carbon black powder at 200m 3 / h gas flow rate and the concentration is 35g / m 3 ozone, and oxidized at 70 ° C for 3.5 hours to obtain oxidized carbon black; The raw oil and carbon black oil are mixed at a ratio of 90%:10% to form a mixed oil. This mixed oil is sprayed into the carbon black reactor at a furnace temperature of 200-230°C and a flow rate of 4600 kg / h, with an oil-to-air ratio of 0.4. The mixed oil resides in the throat of the carbon black reactor for 0.6 milliseconds and reacts at a combustion temperature of 1900°C to produce carbon black. Oxidized carbon black and carbon black are mixed in a ratio of 5:1, graded and ground, and then granulated and dried to obtain pigment carbon black.

[0048] After testing, the specific surface area of ​​the carbon black prepared from waste tires provided in this embodiment is 115 m 2 / g, ash content is 17%, and tinting strength is 61%.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing pigment carbon black from waste tires, characterized in that: The following steps are involved: (1) Rubber powder is obtained from waste tires after crushing, screening and magnetic separation. The rubber powder is transported to a thermal cracking reactor. After the thermal cracking reactor is adjusted to a negative pressure, it is heated to generate a solid phase carbon residue and an oil and gas mixture; (2) The solid carbon residue is subjected to magnetic separation and grinding to form carbon black powder and temporarily stored, and the oil and gas mixture is condensed and separated into pyrolysis oil and non-condensable gas, wherein the non-condensable gas is reused as fuel for the thermal cracking reactor or the carbon black reactor, and the pyrolysis oil is filtered, fractionated, and refined using the coal tar deep processing device of the carbon black plant, and the oil residue component is filtered out. After the light oil and mid-section oil components are separated, the fraction with a temperature of ≥150°C is stored in an oil tank as raw oil; (3) introducing an oxidizing gas into the carbon black powder of step (2) for oxidation treatment to obtain oxidized carbon black; (4) mixing the raw oil from step (2) with carbon black oil to form a mixed oil, spraying the mixed oil into a carbon black reaction furnace at a furnace temperature of 180-250°C, and reacting to generate carbon black at a combustion temperature of 1500-2000°C; (5) mixing the oxidized carbon black of step (3) and the carbon black of step (4), grinding, granulating, and drying to obtain pigment carbon black; (6) The tail gas generated in each step is recovered after dust removal and purification, and reused as fuel for the thermal cracking reactor or carbon black reactor; In step (1), the temperature of the heating treatment is 450-650° C., and the time of the heating treatment is 40-90 minutes; In step (3), the oxidation treatment temperature is 50-90°C, and the oxidation treatment time is 2-4 hours; In step (4), when the mixed oil is sprayed into the carbon black reactor, the oil-air ratio is 0.3-0.

5.

2. The method for preparing pigment carbon black from waste tires according to claim 1, characterized in that: The particle size of the rubber powder in step (1) is 20-70 mesh, and the steel wire content of the rubber powder is ≤0.5%.

3. The method for preparing pigment carbon black from waste tires according to claim 1, characterized in that: The negative pressure in step (1) is -10 kPa to -20 kPa.

4. The method for preparing pigment carbon black from waste tires according to any one of claims 1 to 3, characterized in that: The particle size D97 of the carbon black powder in step (2) is ≤ 10 μm.

5. The method for preparing pigment carbon black from waste tires according to claim 4, characterized in that: The oxidizing gas in step (3) is one or more of hot air, ozone or nitrogen dioxide.

6. The method for preparing pigment carbon black from waste tires according to claim 5, characterized in that: The concentration of the oxidizing gas in step (3) is 20~40g / m 3 The flow rate of oxidizing gas is 150~250m 3 / h.

7. The method for preparing pigment carbon black from waste tires according to claim 5 or 6, characterized in that: The mass ratio of the raw material oil to the carbon black oil in the mixed oil in step (4) is 50~99%:1~50%, the flow rate of the mixed oil sprayed into the carbon black reactor is 3000~5000kg / h, and the time the mixed oil stays in the throat of the carbon black reactor is ≥0.4ms.

8. The method for preparing pigment carbon black from waste tires according to claim 7, characterized in that: The mixing ratio of the oxidized carbon black and the carbon black in step (5) is 1 to 3:

1.

9. The method for preparing pigment carbon black from waste tires according to claim 8, characterized in that: The specific surface area of ​​the pigment carbon black prepared in step (5) is 80~200 m 2 / g, ash content is 8~18%, and tinting strength is 80~120%.

10. The method for preparing pigment carbon black from waste tires according to claim 8 or 9, characterized in that: The tail gas recovery and reuse described in step (6) includes collecting and treating the unreacted gas in the oxidation reaction through professional equipment, and sending the non-condensable gas produced by cracking and the flue gas produced by carbon black back to the thermal cracking reactor or carbon black reactor as fuel after passing through the desulfurization and denitrification device.

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