Rubber powder as well as production method, production system and application thereof

Abstract

The invention discloses rubber powder as well as a production method, a production system and application thereof, and relates to the technical field of rubber powder preparation. The production method of the rubber powder comprises the steps of tire bead cutting, crushing into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, specifically, in the coarse crushing step, atomization spraying and air draft exhausting are carried out on a coarse crushing working area; the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are atomized and sprayed; the rubber particles obtained by screening in the secondary screening step are rubber powder finished products. The rubber production system comprises a ring cutting machine, a crusher, a rubber crusher, a first magnetic separator, a first screening machine, a fine powder machine, a second magnetic separator and a second screening machine which are sequentially connected through a conveyor, and further comprises a first atomizing machine, a second atomizing machine and a negative pressure fan, and the first atomizing machine and the negative pressure fan are arranged in a working area where the rubber crusher is located; and the second atomizing machine is connected with atomizing nozzles on the conveyor between the rubber crusher and the first magnetic separator and between the fine powder machine and the second magnetic separator. The rubber powder produced by the rubber powder production method and the rubber powder production system is good in quality, does not cake in subsequent storage, and can effectively improve the performance of modified asphalt.

Description

Technical Field

[0001] The invention relates to the technical field of rubber powder preparation, and in particular to rubber powder and a production method, a production system and application thereof. Background Art

[0002] At present, my country produces more than 50 million waste tires every year. With the increase in the number of household cars, the amount of waste tires will increase significantly. The so-called waste tires refer to tires that have been replaced or eliminated and have lost their use value as tires, as well as scrap tires produced by factories. Waste tires have strong heat resistance and mechanical resistance, and are difficult to degrade. They will not disappear naturally for decades. Therefore, how to recycle and utilize these waste tires, turn waste into treasure, and turn harm into benefit, this is a very serious problem we face.

[0003] At present, the production of rubber powder from waste tires is a recycling method that combines environmental protection and resource recycling. However, in the process of producing rubber powder from waste tires, due to improper processing, it is not only easy to cause the fineness, iron content, fiber content, appearance, etc. of the rubber powder to fail to meet the standards, but also when the rubber is ground and crushed at room temperature, the interaction of extrusion and friction between rubber particles and between rubber particles and production equipment can easily cause the rubber temperature to rise, which may cause the rubber powder temperature to be too high to cause a fire, or the rubber powder is squeezed into a mass and difficult to disperse for subsequent use. Summary of the invention

[0004] In view of the above shortcomings, the present invention provides a rubber powder and a production method, a production system and use thereof. The rubber powder production method and the production system produce rubber powder of good quality, will not agglomerate during subsequent storage, and can effectively improve the performance of modified asphalt.

[0005] The specific technical solutions are as follows:

[0006] The present invention provides a method for producing rubber powder, comprising the steps of cutting off tire beads, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein in the coarse crushing step, atomizing spraying and exhausting are performed on the coarse crushing working area; and atomizing spraying is performed on the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step; and the rubber particles screened in the secondary screening step are the rubber powder finished product.

[0007] Furthermore, the temperature of the finished rubber powder is 47-49°C.

[0008] Furthermore, the temperature of the finished rubber powder is 48°C.

[0009] Furthermore, the particle size of the rubber particles in the finished rubber powder product is 30 meshes or above.

[0010] Furthermore, the rubber particles obtained by screening in the first screening step have a particle size of 10-15 meshes.

[0011] The invention also provides rubber powder produced by the production method.

[0012] The present invention also provides a use of the rubber powder in preparing modified asphalt.

[0013] The present invention also provides a rubber powder production system, comprising a ring cutter, a crusher, a rubber crusher, a first magnetic separator, a first screening machine, a fine powder machine, a second magnetic separator and a second screening machine, wherein the ring cutter is connected to the crusher through a first conveyor, the crusher is connected to the rubber crusher through a second conveyor, the rubber crusher is connected to the first magnetic separator through a third conveyor, the first magnetic separator is connected to the first screening machine through a fourth conveyor, the first screening machine is connected to the rubber crusher and the fine powder machine through a fifth conveyor and a sixth conveyor, respectively, the fine powder machine is connected to the second magnetic separator through a seventh conveyor, the second magnetic separator is connected to the second screening machine through an eighth conveyor, and the second screening machine is connected to the fine powder machine and a finished product packaging port through a ninth conveyor and a tenth conveyor, respectively;

[0014] It also includes a first atomizer, a second atomizer and a negative pressure fan. The first atomizer and the negative pressure fan are arranged in the working area where the rubber breaker is located. The second atomizer is connected to the atomizing nozzles arranged in the third conveyor and the seventh conveyor.

[0015] Furthermore, the production system also includes a dust removal device, and the dust removal device is connected to the second magnetic separator.

[0016] Furthermore, the production system also includes a temperature sensor, and the temperature sensor is arranged at the finished product packaging port.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention combines tire bead cutting, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening with atomizing spraying and exhaust ventilation. On the one hand, the entire production process is simple and the production efficiency is high, and rubber powder with suitable fineness can be produced, and the rubber powder has good iron content, fiber content and appearance. On the other hand, the air cooling in a specific stage combined with the rubber powder cooling treatment can make the rubber powder loose and not easy to clump when stored in bags.

[0019] 2. The present invention controls the temperature of the rubber powder finished product at 47-49°C, especially at 48°C. On the one hand, at this temperature, the rubber powder can be kept in a loose state when stored in bags, thereby maintaining high production efficiency and low production cost. On the other hand, the finished product is controlled at this temperature, and the modified asphalt prepared has the best performance.

[0020] 3. The whole production system of the present invention is reasonably arranged and runs smoothly, which can reduce the occupied space. By arranging atomizing equipment and negative pressure fans in the coarse crushing working area, the hot air and dust generated in the coarse crushing link can be effectively extracted, so as to achieve the effect of cooling by air as the main and cooling by rubber powder as the auxiliary. Atomizing nozzles connected to the atomizing equipment are arranged on the conveyors after coarse crushing and fine crushing for atomization, which can effectively cool the rubber powder with low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0022] Figure 1 This is a state diagram of the rubber powder in the bags of the experimental groups 1-3 of the present invention and the comparative examples 2-4 after being stored for 20 days.

[0023] Figure 2 This is a state diagram of the rubber powder in bag storage of Comparative Example 1 of the present invention after 20 days.

[0024] Figure 3 The present invention is a process flow chart for producing rubber powder. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0026] Example 1

[0027] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening (refer to Figure 3 ), wherein, in the coarse crushing step, the coarse crushing work area is sprayed and exhausted; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed. The particle size of the rubber particles obtained by the first screening is 10 mesh, and the rubber particles obtained by the second screening step are the finished rubber powder, and the temperature of the finished rubber powder is 47°C and the particle size is 30 mesh or above.

[0028] Example 2

[0029] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening (refer to Figure 3 ), wherein, in the coarse crushing step, the coarse crushing work area is sprayed and exhausted; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed. The particle size of the rubber particles obtained by the first screening is about 12 meshes, and the rubber particles obtained by the second screening step are the finished rubber powder, and the temperature of the finished rubber powder is 48°C and the particle size is 30 meshes or above.

[0030] Example 3

[0031] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening (refer to Figure 3 ), wherein, in the coarse crushing step, the coarse crushing work area is sprayed and exhausted; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed. The particle size of the rubber particles obtained by the first screening is about 15 mesh, and the rubber particles obtained by the second screening step are the finished rubber powder, and the temperature of the finished rubber powder is 49°C and the particle size is 30 mesh or above.

[0032] Example 4

[0033] A method for preparing modified asphalt using the rubber powder of Example 1, the method comprising the following steps:

[0034] (1) Place the base asphalt in a first oven and dehydrate it at 180°C; at the same time, place the rubber powder in a second oven and bake it at 60°C for 2 hours;

[0035] (2) raising the temperature of the first oven to 185° C., adding 20% ​​of the above rubber powder, and then turning on the shearing machine for shearing for 10 minutes;

[0036] (3) The sheared material is placed in an environment of 180°C for stirring and swelling for 1 hour to obtain a modified asphalt material.

[0037] Example 5

[0038] Reference Figure 3 A rubber powder production system includes a ring cutter, a crusher, a rubber crusher, a first magnetic separator, a first screening machine, a fine powder machine, a second magnetic separator, a second screening machine, a first atomizer, a second atomizer and a negative pressure fan.

[0039] Specifically, the tire bead cutting machine is used to cut off the tire bead of the waste tire to obtain a whole piece of rubber. The tire bead cutting machine is connected to the crusher through the first conveyor. The crusher is used to crush the whole piece of rubber into rubber blocks. The diameter of the obtained rubber blocks is 3-8 cm. The crusher is connected to the rubber crusher through the second conveyor. The rubber crusher is used to roughly crush the rubber blocks. The first atomizer and the negative pressure fan are arranged in the working area where the rubber crusher is located. On the one hand, they are used to remove the hot air and dust generated during the rough crushing process, and on the other hand, they are used to spray and cool the air in the working area. The rubber crusher is connected to the first magnetic separator through the third conveyor. The first magnetic separator is used to remove iron impurities in the rubber particles obtained by rough crushing. The first magnetic separator is connected to the first screening machine through the fourth conveyor. The first screening machine is connected to the fifth conveyor and the sixth conveyor. The first screener is connected to the rubber crusher and the fine powder machine respectively. The first screener is used to screen the rubber particles after the steel wire is removed once, and the rubber particles below 10 mesh are transported back to the rubber crusher for coarse crushing, and the rubber particles above 10 mesh are transported to the fine powder machine for fine crushing. The fine powder machine is connected to the second magnetic separator through the seventh conveyor. The second magnetic separator is used to remove steel wire impurities from the rubber particles obtained by fine crushing. The second magnetic separator is connected to the second screener through the eighth conveyor. The second screener is connected to the fine powder machine and the finished product packaging port through the ninth conveyor and the tenth conveyor respectively. The second screener is used to screen the rubber particles after the steel wire is removed twice, and the rubber particles below 30 mesh are transported back to the fine powder machine for re-crushing, and the rubber particles above 30 mesh are transported to the finished product packaging port for bagging and packaging. The second atomizer is connected to the atomizing nozzles arranged in the third conveyor and the sixth conveyor, and is used to spray and cool the rubber particles in the conveyor.

[0040] In a more preferred embodiment of the present invention, the production system further comprises a temperature sensor, which is arranged at the finished product packaging port and is used to sense the temperature of the finished rubber powder product so as to adjust the atomization spray volume of the atomization equipment according to the sensed temperature.

[0041] In a more preferred embodiment of the present invention, the production system also includes a dust removal device, which is connected to the second magnetic separator and is used to remove impurities such as fibers and dust in the secondary magnetic separation process to further improve the quality of the rubber powder product.

[0042] Comparative Example 1

[0043] A rubber powder, the production method of which includes the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein in the coarse crushing step, the coarse crushing work area is sprayed and exhausted by ventilation; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed. The particle size of the rubber particles obtained by the primary screening is about 12 meshes, and the rubber particles obtained by the secondary screening step are the finished rubber powder, and the temperature of the finished rubber powder is 52°C and the particle size is 30 meshes or more.

[0044] Comparative Example 2

[0045] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein in the coarse crushing step, the coarse crushing work area is sprayed and exhausted by ventilation; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed. The particle size of the rubber particles obtained by the primary screening is about 12 meshes, and the rubber particles obtained by the secondary screening step are the finished rubber powder, and the temperature of the finished rubber powder is 45°C and the particle size is 30 meshes or more.

[0046] Comparative Example 3

[0047] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein in the coarse crushing step, atomization spraying and exhaust of the coarse crushing work area are performed. The particle size of the rubber particles obtained by the primary screening is about 12 meshes, and the rubber particles obtained by the secondary screening step are the finished rubber powder, and the temperature of the finished rubber powder is 48°C and the particle size is 30 meshes or more.

[0048] Comparative Example 4

[0049] A rubber powder, the production method of which comprises the following steps: cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are sprayed by atomization. The particle size of the rubber particles obtained by the primary screening is about 12 meshes, and the rubber particles obtained by the secondary screening step are the finished rubber powder, and the temperature of the finished rubber powder is 48°C and the particle size is 30 meshes or more.

[0050] Comparative Example 5

[0051] A method for preparing modified asphalt using the rubber powder of Comparative Example 1, wherein the method is the same as that of Example 4.

[0052] Comparative Example 6

[0053] A method for preparing modified asphalt using the rubber powder of Comparative Example 2, the method being the same as that of Example 4.

[0054] Comparative Example 7

[0055] A method for preparing modified asphalt using the rubber powder of Comparative Example 3, the method is the same as Example 4.

[0056] Comparative Example 8

[0057] A method for preparing modified asphalt using the rubber powder of Comparative Example 4, the method is the same as Example 4.

[0058] Effect verification:

[0059] 1. Rubber powder performance test

[0060] (1) Test object: 1 kg of each of the rubber powders of the above-mentioned Examples 1-3 and Comparative Examples 1-4.

[0061] (2) Testing basis: GB / T 19208-2020 “Vulcanized rubber powder” and JT / T 797-2019 “Road tire rubber powder.

[0062] (3) Test items: heating loss, ash content, acetone extract, rubber hydrocarbon content, carbon black content, iron content, density, sieve residue and fiber content.

[0063] (4) Main testing instruments: electronic balance, electric blast drying oven, box-type resistance high temperature furnace, thermogravimetric analyzer.

[0064] The test results are shown in Table 1 below.

[0065] Table 1 Performance test results of various rubber powders

[0066]

[0067] As shown in Table 1, the performance tests of the rubber powders of Examples 1-3 and Comparative Examples 1-4 all meet the standard requirements, indicating that the slight change in the process steps of the present invention has little effect on the final test performance of the rubber powder. Among them, since the raw materials (waste tires) of all rubber powders come from the same source, and the values ​​of the test items No. 2-5 are only related to the raw materials, their values ​​are the same.

[0068] 2. Appearance of rubber powder and bag storage effect

[0069] The appearance of the rubber powders of Examples 1-3 and Comparative Examples 1-4 was observed, and the agglomeration state of each rubber powder after being stored in bags for 20 days was observed. The results are shown in Table 2.

[0070] Table 2 Appearance and bag storage status of various rubber powders

[0071]

[0072] As shown in Table 2, controlling the temperature of the rubber powder product below 49°C (experimental groups 1-3 and comparative examples 2-4) is beneficial to maintaining the dispersed state of the rubber powder during bag storage (such as Figure 1 As shown), it is beneficial to subsequent use, but when the temperature of the rubber powder is controlled at 47-49°C, only two sets of atomizing equipment and one set of negative pressure fans are needed, while when the temperature of the rubber powder needs to be controlled below 47°C (Comparative Example 2), two sets of negative pressure fans and two sets of atomizing equipment are needed. On the one hand, adding equipment increases investment costs and energy consumption, and on the other hand, it affects production efficiency; when the temperature is 49°C (Comparative Example 1), the rubber powder is prone to agglomeration during storage (such as Figure 2 Therefore, controlling the temperature of the rubber powder product at 47-49°C can not only maintain the dispersed state of the rubber powder, but also minimize the production cost and increase the production efficiency.

[0073] 3. Modified asphalt performance test

[0074] (1) Test object: modified asphalt prepared in Example 4 and Comparative Examples 5-8.

[0075] (2) Test basis: "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering" JTG E20-2011.

[0076] (3) Test items: softening point, ductility and anti-aging performance.

[0077] The test results are shown in Table 3 below.

[0078] Table 3 Performance test results of various modified asphalts

[0079]

[0080] As shown in Table 2, the softening point, ductility and anti-aging performance of the modified asphalt of Example 5 are all good. However, the performance of Comparative Examples 5-8 is reduced to a certain extent, indicating that whether it is the change of the rubber powder production temperature or the change of the cooling process of the rubber powder preparation, the rubber powder prepared by the application in the preparation of modified asphalt will affect the performance of the modified asphalt.

[0081] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for producing rubber powder, It is characterized in that The method comprises the steps of cutting off the tire bead, breaking into blocks, coarse crushing, primary magnetic separation, primary screening, fine crushing, secondary magnetic separation and secondary screening, wherein in the coarse crushing step, the coarse crushing working area is subjected to atomization spraying and exhaust by ventilation; and the rubber particles obtained in the coarse crushing step and the rubber particles obtained in the fine crushing step are subjected to atomization spraying; and the rubber particles screened in the secondary screening step are the finished rubber powder product.

2. A method for producing rubber powder according to claim 1, It is characterized in that The temperature of the finished rubber powder is 47-49°C.

3. A method for producing rubber powder according to claim 2, It is characterized in that The temperature of the finished rubber powder is 48°C.

4. A method for producing rubber powder according to claim 1 or 2, It is characterized in that The particle size of the rubber particles in the finished rubber powder product is 30 meshes or above.

5. The method for producing rubber powder according to claim 1, It is characterized in that The rubber particles obtained by screening in the first screening step have a particle size of 10-15 meshes.

6. The rubber powder produced as claimed in any one of claims 1 to 5.

7. Use of the rubber powder as claimed in claim 6 in the preparation of modified asphalt.

8. A system for producing rubber powder, It is characterized in that It includes a ring cutter, a crusher, a rubber crusher, a first magnetic separator, a first screening machine, a fine powder machine, a second magnetic separator and a second screening machine, wherein the ring cutter is connected to the crusher through a first conveyor, the crusher is connected to the rubber crusher through a second conveyor, the rubber crusher is connected to the first magnetic separator through a third conveyor, the first magnetic separator is connected to the first screening machine through a fourth conveyor, the first screening machine is connected to the rubber crusher and the fine powder machine through a fifth conveyor and a sixth conveyor respectively, the fine powder machine is connected to the second magnetic separator through a seventh conveyor, the second magnetic separator is connected to the second screening machine through an eighth conveyor, and the second screening machine is connected to the fine powder machine and a finished product packaging port through a ninth conveyor and a tenth conveyor respectively; It also includes a first atomizer, a second atomizer and a negative pressure fan. The first atomizer and the negative pressure fan are arranged in the working area where the rubber breaker is located. The second atomizer is connected to the atomizing nozzles arranged in the third conveyor and the seventh conveyor.

9. A rubber powder production system according to claim 8, It is characterized in that It also includes a dust removal device, which is connected to the second magnetic separator.

10. A rubber powder production system according to claim 8, It is characterized in that It also includes a temperature sensor, which is arranged at the finished product packaging port.

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