Regeneration process of waste tire carbon slag

Abstract

The invention discloses a waste tire carbon residue regeneration process, which belongs to the technical field of waste tire regeneration, and comprises the following steps: pretreatment: carrying out mechanical crushing on collected waste tires, separating out steel wires and large rubber blocks, and screening to remove large impurities and uncrushed tire blocks so as to obtain waste tire carbon residues; separating out steel wires in the crushed material by adopting magnetic separation equipment, carrying out secondary crushing on the separated rubber blocks to obtain small blocks, and feeding the small blocks into thermal cracking equipment to carry out thermal cracking reaction to obtain carbon residues; rotary kiln treatment: feeding the carbon residues into a carbon-carbon rotary kiln, and introducing Freon gas to obtain carbon black; and post-treatment: cooling the carbon black, then removing residual metal impurities in the carbon black again by using magnetic separation equipment, and screening the carbon black to obtain carbon black products with different granularities. According to the process, through thermal cracking and rotary kiln treatment, the waste tires are converted into carbon black products conforming to the tires, high-value utilization of the waste tires is achieved, environmental pollution is reduced, and resources are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste tire regeneration, and in particular relates to a regeneration process for waste tire carbon residue. Background Art

[0002] The carbon residue after the pyrolysis of waste tires is an important product of the pyrolysis of waste tires, also called carbon black, which mainly comes from carbon black and other inorganic fillers added during the tire production process. The pyrolysis rate of waste tires reaches more than 99% (national standard). The main component of carbon black is carbon, and it also contains a small amount of hydrogen, oxygen, nitrogen and other elements. The crude carbon black after the pyrolysis of tires is a black powdery solid and can be reused. After proper treatment and reasonable processing and utilization, carbon black has high economic value and can be used as a reinforcing agent and filler for rubber products. It is used in many rubber and plastic products such as bicycle tires. Otherwise, it will cause secondary pollution to the environment and waste of resources.

[0003] The crude carbon black after thermal cracking contains a certain amount of inorganic impurities, which will affect the performance of carbon black. Therefore, it is necessary to reduce the content of inorganic impurities through impurity removal treatment, mainly to remove the silica in the carbon slag. For example, through pickling and surface modifier treatment, however, a large amount of waste water and waste gas will be generated during the pickling process, especially when strong acids (such as hydrochloric acid and sulfuric acid) are used, which will cause environmental pollution. The use of pickling and surface modifiers increases the treatment cost, especially in large-scale production, the cost of treating waste water and waste gas will increase significantly. Summary of the invention

[0004] In view of the above problems, the present invention provides a regeneration process for waste tire carbon residue, which converts waste tires into carbon black products that meet the requirements of tires through thermal cracking and rotary kiln treatment, thereby achieving high-value utilization of waste tires, reducing environmental pollution and saving resources.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A recycling process for waste tire carbon residue comprises the following steps:

[0007] Step 1, pretreatment: mechanically crush the collected waste tires to separate steel wires and large rubber pieces, remove larger impurities and uncrushed tire pieces through screening, and then use magnetic separation equipment to separate the steel wires from the crushed materials, and perform secondary crushing on the separated rubber pieces to break them into small pieces, which are then sent to a thermal cracking device for thermal cracking reaction to obtain carbon slag;

[0008] Step 2, rotary kiln treatment: the carbon slag obtained in step 1 is fed into a carbon-carbon rotary kiln at 500-1200°C, and Freon gas is introduced to react for 1-6 hours to obtain carbon black;

[0009] Step 3, post-processing: cool the carbon black obtained in step 2, then use magnetic separation equipment to remove the residual metal impurities in the carbon black again, and screen the carbon black to obtain carbon black products of different particle sizes.

[0010] In a preferred implementation, the particle size of the small pieces crushed in step 1 is controlled within 8-40 meshes.

[0011] In a preferred embodiment, the cracking reaction temperature in step 1 is 400-700° C., and the reaction time is 0.5-2 h.

[0012] In a preferred implementation, the ratio of the amount of Freon gas introduced to the amount of carbon slag in step 2 is: 1L: 100-300g, and the flow rate of Freon gas is 0.8-3.5L / min.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) the present invention converts waste tires into valuable carbon black products, reduces the visual pollution and potential soil and water pollution caused by the accumulation of waste tires, reduces the exploitation of primary resources, meets the requirements of sustainable development, saves rubber resources, and reduces dependence on petroleum-based products;

[0014] (2) The present invention adopts a carbon-carbon rotary kiln to carry out impurity removal treatment of carbon slag, and adopts Freon gas as a treatment agent. The carbon-carbon rotary kiln is resistant to high temperature corrosion, can support the introduction of Freon at high temperature, and can also rotate, so that the carbon slag can fully contact and react with the Freon, and react with the inorganic impurities in the carbon slag to generate fluoride and be discharged. The crude carbon black after thermal cracking contains a certain amount of inorganic impurities, and these inorganic impurities will affect the performance of the carbon black, so it is necessary to carry out impurity removal treatment to reduce their content.

[0015] The principle of impurity removal reaction is:

[0016] CCl2F2→C+Cl2+F2

[0017] SiO2+2F2+C→SiF4↑+CO2↑. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution, the present invention is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0019] The carbon-carbon rotary kiln used in the following embodiments is an ultra-high temperature continuous rotary kiln of the patent CN117213225A which has been applied for, and the applicant is the same and the inventor is the same.

[0020] Embodiment 1:

[0021] A recycling process for waste tire carbon residue comprises the following steps:

[0022] Step 1, pretreatment: mechanically crush the collected waste tires to separate steel wires and large rubber pieces, remove larger impurities and uncrushed tire pieces by screening, and then use magnetic separation equipment to separate the steel wires from the crushed materials, and perform secondary crushing on the separated rubber pieces to break them into small pieces with a particle size of 25-40 mesh, and send them to the thermal cracking equipment for thermal cracking reaction at a cracking reaction temperature of 400°C and a reaction time of 2h to obtain carbon slag;

[0023] Step 2, rotary kiln treatment: the carbon slag obtained in step 1 is fed into a carbon-carbon rotary kiln at 500°C, and Freon gas is introduced, the ratio of the amount of Freon gas introduced to the amount of carbon slag is: 1L:300g, the Freon gas flow rate is 3.5L / min, and the reaction is carried out for 6h to obtain carbon black;

[0024] Step 3, post-processing: cool the carbon black obtained in step 2, then use magnetic separation equipment to remove the residual metal impurities in the carbon black again, and screen the carbon black to obtain carbon black products of different particle sizes.

[0025] Embodiment 2:

[0026] A recycling process for waste tire carbon residue comprises the following steps:

[0027] Step 1, pretreatment: mechanically crush the collected waste tires to separate steel wires and large rubber pieces, remove larger impurities and uncrushed tire pieces by screening, and then use magnetic separation equipment to separate the steel wires from the crushed materials, and perform secondary crushing on the separated rubber pieces to break them into small pieces with a particle size of 8-20 mesh, and send them to a thermal cracking device for thermal cracking reaction at a cracking reaction temperature of 460°C and a reaction time of 1h to obtain carbon slag;

[0028] Step 2, rotary kiln treatment: the carbon slag obtained in step 1 is fed into a carbon-carbon rotary kiln at 800°C, and Freon gas is introduced, the ratio of the amount of Freon gas introduced to the amount of carbon slag is: 1L:100g, the Freon gas flow rate is 0.8L / min, and the reaction is carried out for 3h to obtain carbon black;

[0029] Step 3, post-processing: cool the carbon black obtained in step 2, then use magnetic separation equipment to remove the residual metal impurities in the carbon black again, and screen the carbon black to obtain carbon black products of different particle sizes.

[0030] Embodiment 3:

[0031] A recycling process for waste tire carbon residue comprises the following steps:

[0032] Step 1, pretreatment: mechanically crush the collected waste tires to separate steel wires and large rubber pieces, remove larger impurities and uncrushed tire pieces by screening, and then use magnetic separation equipment to separate the steel wires from the crushed materials, and perform secondary crushing on the separated rubber pieces to break them into small pieces with a particle size of 10-30 mesh, and send them to a thermal cracking device for thermal cracking reaction at a cracking reaction temperature of 700°C and a reaction time of 0.5h to obtain carbon slag;

[0033] Step 2, rotary kiln treatment: the carbon slag obtained in step 1 is fed into a carbon-carbon rotary kiln at 1200°C, and Freon gas is introduced, the ratio of the amount of Freon gas introduced to the amount of carbon slag is: 1L:150g, the Freon gas flow rate is 2.0L / min, and the reaction is carried out for 2h to obtain carbon black;

[0034] Step 3, post-processing: cool the carbon black obtained in step 2, then use magnetic separation equipment to remove the residual metal impurities in the carbon black again, and screen the carbon black to obtain carbon black products of different particle sizes.

[0035] The performance of the cracked carbon slag and the carbon black product obtained after treatment in the above Example 1 was tested, and the test results are shown in the following table.

[0036] Table 1

[0037]

[0038]

[0039] It should be noted that, in this article, the terms: include, contain and any other variants are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Specific examples are used in this article to illustrate the principle and implementation of the technical solution of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, and the above technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the present invention to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A process for regenerating carbon residue from waste tires, characterized in that: The following steps are involved: Step 1, pretreatment: mechanically crush the collected waste tires to separate steel wires and large rubber pieces, remove larger impurities and uncrushed tire pieces through screening, and then use magnetic separation equipment to separate the steel wires from the crushed materials, and perform secondary crushing on the separated rubber pieces to break them into small pieces, which are then sent to a thermal cracking device for thermal cracking reaction to obtain carbon slag; Step 2, rotary kiln treatment: the carbon slag obtained in step 1 is fed into a carbon-carbon rotary kiln at 500-1200°C, and Freon gas is introduced to react for 1-6 hours to obtain carbon black; Step 3, post-processing: cooling the carbon black obtained in step 2, and then using magnetic separation equipment to remove the residual metal impurities in the carbon black again, and screening the carbon black to obtain carbon black products of different particle sizes.

2. The process for regenerating carbon residue from waste tires according to claim 1, characterized in that: The particle size of the small pieces crushed in step 1 is controlled to be 8-40 meshes.

3. The process for regenerating carbon residue from waste tires according to claim 1, characterized in that: In step 1, the cracking reaction temperature is 400-700° C., and the reaction time is 0.5-2 h.

4. The process for regenerating carbon residue from waste tires according to claim 1, characterized in that: In step 2, the ratio of the amount of Freon gas introduced to the amount of carbon slag is: 1L: 100-300g, and the flow rate of Freon gas is 0.8-3.5L / min.

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