Method for green rubber regeneration from waste tires

Abstract

The invention discloses a method for green rubber regeneration of waste tires, which comprises the following steps: crushing cleaned waste tires to obtain rubber fragments; adding petroleum sulfoxide into the rubber fragments, uniformly mixing, and then carrying out high-temperature desulfurization; and processing the desulfurized rubber material to obtain regenerated rubber. According to the method disclosed by the invention, the petroleum sulfoxide can destroy a cross-linked structure in the waste tire rubber, so that a sulfur cross-linked bond is broken, and de-cross-linking is realized; after decrosslinking, the viscosity of the waste rubber is reduced, the waste rubber becomes softer and more plastic, the processability is obtained again, and the prepared regenerated rubber material can be used for manufacturing new rubber products; the regenerated rubber with higher quality can be produced, and the performance of the regenerated rubber is closer to that of raw rubber, so that the regenerated rubber can be applied to wider application fields; rubber components in the waste tires can be fully utilized, resource waste is reduced, and the utilization rate of resources is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection and resource recycling, and in particular relates to a method for green regenerating rubber from waste tires. Background Art

[0002] The quantity of waste tires is huge and difficult to degrade. If they are not handled properly, they will cause serious pollution to the environment. At present, the mature waste tire recycled rubber production technologies on the market mainly include retreading, production of recycled rubber, production of rubber powder, thermal cracking, chemical regeneration, etc. Among them, the chemical regeneration method has attracted attention due to its higher quality recycled products, high resource utilization, environmental friendliness, and wide range of applications. However, the chemical regeneration method of the prior art often requires high temperature and high pressure conditions, which can easily lead to C-C breakage, destroy the main chain structure, reduce the performance of the recycled rubber, and cause pollution to the environment. For example, waste load-bearing tire rubber generally adopts high temperature and high pressure dynamic desulfurization tank technology to prepare solid recycled rubber. This technology has the problems of uncontrollable de-crosslinking, high energy consumption due to long-term high temperature and high pressure, and difficult treatment of waste gas and wastewater during the production process. For this reason, it is very necessary to develop a method for green recycling of waste tire rubber. Summary of the invention

[0003] The purpose of the present invention is to provide a method for green regeneration of rubber from waste tires. The method is more environmentally friendly than the prior art, can improve the quality of regenerated rubber, promote the desulfurization process, reduce costs, and improve resource utilization.

[0004] The object of the present invention is achieved by comprising the following steps: S1, crushing the cleaned waste tires, wherein the cleaned waste tires are free of impurities such as soil, metal, etc. to obtain rubber fragments; S2, adding petroleum sulfoxide to the rubber fragments and mixing them evenly, and then performing high-temperature desulfurization; S3. The desulfurized rubber material is processed (such as extrusion, calendering, etc.) to obtain recycled rubber.

[0005] Preferably, in step S2, the mass ratio of petroleum sulfoxide to waste tires is controlled at 1:5-10.

[0006] Preferably, the high-temperature desulfurization temperature in step S2 is controlled at 200°C to 300°C.

[0007] Preferably, the high-temperature desulfurization treatment time in step S2 is 3h~5h.

[0008] Preferably, the pH value of the high temperature desulfurization process in step S2 is controlled at 7-8.

[0009] Beneficial effects of the present invention: 1. The petroleum sulfoxide in the method of the present invention can destroy the cross-linking structure in the waste tire rubber, break the sulfur cross-linking bond, and achieve de-crosslinking; after de-crosslinking, the viscosity of the waste rubber is reduced, becoming softer and more plastic, regaining processing performance, and the prepared recycled rubber material can be used to manufacture new rubber products; 2. The present invention utilizes chemical regeneration method to produce higher quality recycled rubber, whose performance is closer to that of original rubber, so that it can be used in a wider range of application fields; it can make fuller use of the rubber components in waste tires, reduce resource waste, and improve resource utilization; 3. Compared with the traditional recycled rubber processing technology, the method of the present invention is simple in process, easy to operate, low in energy consumption, less polluting, and realizes efficient and green production, and has broad application prospects; petroleum sulfoxide itself is non-toxic, non-corrosive, and friendly to the environment and human body. DETAILED DESCRIPTION

[0010] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0011] Example 1 The waste tires are all-season passenger car tires. The method for green recycling of waste tire rubber according to this embodiment includes the following steps: S1, crushing the cleaned waste tires to obtain rubber fragments; S2, adding petroleum sulfoxide to the rubber fragments and mixing them evenly, the mass ratio of petroleum sulfoxide to waste tires is controlled at 1:10, and then high-temperature desulfurization is performed, the temperature is controlled at 200°C, the treatment time is 3h, and the pH is controlled at 7; S3, the desulfurized rubber material is processed to obtain recycled rubber; The processing method of step S3 is carried out according to the traditional method; after testing, the ash content of the recycled rubber is 9.56wt%, the acetone extract is 24.42wt%, the tensile strength is 9.37 MPa, the elongation at break is 372%, and the Mooney viscosity is 73, indicating that the method of the present invention is ideal for recycling rubber from waste tires.

[0012] Example 2 The waste tires are all-terrain waste tires of off-road vehicles. The method for green recycling of waste tire rubber in this embodiment is based on the method in Example 1. The difference from Example 1 is that the mass ratio of petroleum sulfoxide to waste tires is controlled at 13:100, the temperature of high-temperature desulfurization is controlled at 230°C, the treatment time is 4h, and the pH is controlled at 8; After testing, the ash content of the recycled rubber was 11.22 wt%, the acetone extract was 23.56 wt%, the tensile strength was 8.44 MPa, the elongation at break was 381%, and the Mooney viscosity was 72, indicating that the method of the present invention has an ideal effect on recycling rubber from waste tires.

[0013] Example 3 The waste tires are passenger truck tires, which are specially designed to bear heavier loads. The tires usually use thicker and more durable rubber compounds and have a reinforced carcass structure to withstand long-term wear. The method of green recycled rubber from waste tires in this embodiment is based on the method in Example 1, and the difference from Example 1 is that the mass ratio of petroleum sulfoxide to waste tires is controlled at 1:5, the temperature of high-temperature desulfurization is controlled at 250°C, the treatment time is 4h, and the pH is controlled at 8. After testing, the ash content of the recycled rubber was 10.48 wt%, the acetone extract was 21.19 wt%, the tensile strength was 9.31 MPa, the elongation at break was 369%, and the Mooney viscosity was 72, indicating that the method of the present invention has an ideal effect on recycling rubber from waste tires.

[0014] Example 4 The waste tires are trailer tires, which usually have a reinforced carcass and tread structure. The method for green recycling of waste tire rubber in this embodiment is based on the method in Example 1, and the difference from Example 1 is that the mass ratio of petroleum sulfoxide to waste tires is controlled at 9:50, the temperature of high-temperature desulfurization is controlled at 280°C, the treatment time is 5h, and the pH is controlled at 8. After testing, the ash content of the recycled rubber was 10.93 wt%, the acetone extract was 23.75 wt%, the tensile strength was 8.74 MPa, the elongation at break was 373%, and the Mooney viscosity was 74, indicating that the method of the present invention has an ideal effect on recycling rubber from waste tires.

[0015] Example 5 The method for green recycling rubber from waste tires in this embodiment is based on the method in Example 1, and is different from Example 1 in that the mass ratio of petroleum sulfoxide to waste tires is controlled at 1:7.5, the temperature of high-temperature desulfurization is controlled at 250°C, the processing time is 4 hours, and the pH is controlled at 7.5.

Claims

1. A method for green recycling of rubber from waste tires, characterized in that The following steps are involved: S1, crushing the cleaned waste tires to obtain rubber fragments; S2, adding petroleum sulfoxide to the rubber fragments and mixing them evenly, and then performing high-temperature desulfurization; S3. The desulfurized rubber material is processed to obtain recycled rubber.

2. The method for green recycling of rubber from waste tires according to claim 1, characterized in that In step S2, the mass ratio of petroleum sulfoxide to waste tire is controlled at 1:5-10.

3. The method for green recycling of rubber from waste tires according to claim 1, characterized in that The high-temperature desulfurization temperature in step S2 is controlled at 200°C~300°C.

4. The method for green recycling of rubber from waste tires according to claim 1, characterized in that The high-temperature desulfurization treatment time in step S2 is 3h~5h.

5. The method for green recycling of rubber from waste tires according to claim 1, characterized in that The pH value of the high temperature desulfurization process in step S2 is controlled at 7~8.