Oil-based drill cuttings and red mud waste co-treatment system and method

Abstract

The present invention relates to the technical field of waste treatment, and provides a co-treatment system and method for oil-based drill cuttings and red mud waste, mainly including: a mixing device, a forming device, a pyrolysis device, a coke quenching device and a screening device connected in sequence. The mixing device is used to obtain a mixture of oil-based drill cuttings and red mud; the forming device is used to form the mixture into pyrolysis raw materials; the pyrolysis device is used to pyrolyze the pyrolysis raw materials to generate pyrolysis solid-phase products; the coke quenching device is used to cool down the pyrolysis solid-phase products; the screening device is used to screen the cooled pyrolysis solid-phase products to obtain granular pyrolysis solid-phase products, and the pyrolysis solid-phase products are red mud drill cuttings-based iron-carbon materials. The present invention realizes the co-treatment of two kinds of wastes, namely oil-based drill cuttings and red mud, achieves the purpose of treating waste with waste, and has the characteristics of simple operation, stable and reliable, energy-saving and environmental protection, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of waste treatment, and particularly relates to a co-treatment system and method for oil-based drill cuttings and red mud waste. Background Art

[0002] At present, during the process of shale gas exploitation, oil-based mud is used for drilling. The drill bit cuts the rock in the formation to generate a large amount of drill cuttings, thus forming oil-based drill cuttings. The oil-based drill cuttings contain pollutants such as petroleum hydrocarbons, heavy metals, and organic substances. If directly discharged without treatment, it will cause serious harm to the surrounding ecological environment. Emission standards in many regions of the world stipulate that the mass percentage of total petroleum hydrocarbons (TPH) in oil-based drill cuttings should be less than 1% for discharge; and red mud is the waste with the largest production volume and the most serious pollution during the production process of alumina. Currently, when producing 1 ton of alumina, nearly 2 tons of red mud are generated simultaneously, and the annual national red mud discharge is over 7 million tons. The stacking of red mud not only occupies a large amount of land, but also causes land alkalization, pollutes groundwater, and endangers people's health. Therefore, there is an urgent need for a treatment system that can effectively treat the above-mentioned waste. Summary of the Invention

[0003] The present invention provides a co-treatment system and method for oil-based drill cuttings and red mud waste, realizing the co-treatment of the two wastes of oil-based drill cuttings and red mud, achieving the purpose of treating waste with waste, and having the characteristics of simple operation, stable and reliable performance, energy conservation and environmental protection, etc.

[0004] The present invention provides a co-treatment system for oil-based drill cuttings and red mud waste, including: a mixing device for obtaining a mixture of oil-based drill cuttings and red mud; a forming device connected to the mixing device for forming the mixture into pyrolysis raw materials; a pyrolysis device, the inlet of which is connected to the forming device for pyrolyzing the pyrolysis raw materials to generate pyrolysis solid-phase products; a coke quenching device, the inlet of which is connected to the outlet of the pyrolysis device for cooling the pyrolysis solid-phase products; a screening device connected to the outlet of the coke quenching device for screening the cooled pyrolysis solid-phase products to obtain granular pyrolysis solid-phase products, and the pyrolysis solid-phase products are red mud drill cuttings-based iron-carbon materials.

[0005] According to a co-treatment system for oil-based drill cuttings and red mud waste provided by the present invention, it further includes a pyrolysis oil and gas treatment unit connected to the pyrolysis device for separating and treating the pyrolysis oil and gas generated by pyrolysis, and returning the treated pyrolysis gas and heavy oil to the pyrolysis device.

[0006] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, the pyrolysis oil - gas treatment unit includes: an oil - gas condensation and separation device, an oil - water separation device, and a residue - oil separation device. The inlet of the oil - gas condensation and separation device is connected to the pyrolysis oil - gas outlet of the pyrolysis device, and the pyrolysis gas outlet of the oil - gas condensation and separation device is connected to the fuel inlet of the pyrolysis device; the inlet of the oil - water separation device is connected to the pyrolysis oil - water outlet of the oil - gas condensation and separation device; the inlet of the residue - oil separation device is connected to the pyrolysis oil outlet of the oil - water separation device, and the heavy - oil outlet of the residue - oil separation device is connected to the fuel inlet of the pyrolysis device.

[0007] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, a heat - exchange pipeline is provided in the coke quenching device for introducing normal - temperature combustion - supporting gas. The heat - exchange pipeline is externally connected to a first heat exchanger, and the first heat exchanger is respectively connected to the fuel inlet and the flue - gas outlet of the pyrolysis device.

[0008] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, a second heat exchanger is further included, and the second heat exchanger is connected to the first heat exchanger.

[0009] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, a dust collector, a desulfurization and denitration device, and a smoke exhaust device are further included and are connected in sequence, and the dust collector is connected to the second heat exchanger.

[0010] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, an oil - based drill - cuttings pretreatment device and a red - mud crushing and preheating device are further included, and the oil - based drill - cuttings pretreatment device and the red - mud crushing and preheating device are respectively connected to the mixing device.

[0011] According to a co - processing system for oil - based drill cuttings and red mud waste provided by the present invention, the pyrolysis device is a settling - furnace reactor.

[0012] The present invention also provides a co - processing method for oil - based drill cuttings and red mud waste, including the following steps:

[0013] S1. Mix the oil - based drill cuttings with the red mud to obtain a mixture;

[0014] S2. Mold the mixture into pyrolysis raw materials;

[0015] S3. Pyrolyze the pyrolysis raw materials to generate pyrolysis solid - phase products;

[0016] S4. Cool down the pyrolysis solid - phase products;

[0017] S5. Screen the cooled - down pyrolysis solid - phase products to obtain granular pyrolysis solid - phase products, and the pyrolysis solid - phase products are red - mud drill - cuttings - based iron - carbon materials.

[0018] A method for co - treating oil - based drill cuttings and red mud waste provided by the present invention further includes the steps of:

[0019] Separating and treating the pyrolysis oil and gas generated by pyrolysis, and using the treated pyrolysis gas and heavy oil as fuels for pyrolysis;

[0020] Purifying the flue gas generated by pyrolysis.

[0021] The co - treatment system and method for oil - based drill cuttings and red mud waste provided by the present invention obtain a mixture of oil - based drill cuttings and red mud through a mixing device; form the mixture into pyrolysis raw materials through a forming device; pyrolyze the pyrolysis raw materials through a pyrolysis device to generate pyrolysis solid - phase products; cool the pyrolysis solid - phase products through a quenching device; screen the cooled pyrolysis solid - phase products through a screening device to obtain granular pyrolysis solid - phase products, which can be used as adsorbents for wastewater treatment, realizing the resource utilization of pyrolysis solid - phase products. Among them, the pyrolysis solid - phase product is a red - mud drill - cuttings - based iron - carbon material, which has a high specific surface area and high Cr(VI) selectivity. Therefore, by co - treating the two wastes of oil - based drill cuttings and red mud, the product obtained by the present invention is a valuable adsorption material, without pollutant emissions, achieving the purpose of treating waste with waste, and having the characteristics of simple operation, stable reliability, energy conservation and environmental protection.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 is a structural block diagram of the co - treatment system for oil - based drill cuttings and red mud waste provided by the present invention;

[0025] Figure 2 is a flow schematic diagram of the co - treatment method for oil - based drill cuttings and red mud waste provided by the present invention;

[0026] Reference numerals:

[0027] 1: mixing device; 2: forming device; 3: pyrolysis device; 4: quenching device;

[0028] 5: screening device; 6: oil - gas condensation and separation device; 7: oil - water separation device;

[0029] 8: Residual oil separation device; 9: Heat exchange pipeline; 10: First heat exchanger;

[0030] 11: Second heat exchanger; 12: Dust collector; 13: Desulfurization and denitrification device;

[0031] 14: Exhaust device; 15: Oil-based drill cuttings pretreatment device;

[0032] 16: Red mud crushing and preheating device. Detailed implementation mode

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0034] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention. In addition, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0036] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is at a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is at a lower horizontal height than the second feature.

[0037] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0038] The following will describe Figure 1 the co-processing system for oil-based drill cuttings and red mud waste of the present invention.

[0039] According to an embodiment of the present invention, as Figure 1 shown, the co-processing system for oil-based drill cuttings and red mud waste provided by the present invention mainly includes: a mixing device 1, a forming device 2, a pyrolysis device 3, a coke quenching device 4, and a screening device 5 connected in sequence. Among them, two kinds of wastes, oil-based drill cuttings and red mud, are introduced into the mixing device 1 and mixed to obtain a mixture of oil-based drill cuttings and red mud. At this time, the mixture is an unformed pyrolysis raw material; the feeding port of the forming device 2 is connected to the discharging port of the mixing device 1, and the unformed pyrolysis raw material is introduced into the forming device 2 for treatment to form a formed pyrolysis raw material; the feeding port of the pyrolysis device 3 is connected to the discharging port of the forming device 2, and the formed pyrolysis raw material is introduced into the pyrolysis device 3 for pyrolysis activation to generate a pyrolysis solid-phase product; the feeding port of the coke quenching device 4 is connected to the discharging port of the pyrolysis device 3, and the pyrolysis solid-phase product is introduced into the coke quenching device 4 for cooling; the feeding port of the screening device 5 is connected to the discharging port of the coke quenching device 4, and the cooled pyrolysis solid-phase product is introduced into the screening device 5 for screening to obtain granular and powdery pyrolysis solid-phase products. The pyrolysis solid-phase product is a red mud drill cuttings-based iron-carbon material with a high specific surface area and high Cr(VI) selectivity. Among them, the granular pyrolysis solid-phase product can be used as an adsorbent, and the powdery pyrolysis solid-phase product can be formed into granules again through the forming device and then used as an adsorbent to achieve zero pollutant emissions.

[0040] Therefore, in the present invention, oil-based drill cuttings and red mud, two types of waste, are pyrolyzed, and finally a granular pyrolysis solid-phase product is obtained as an adsorbent for wastewater treatment, realizing the resource utilization of the pyrolysis solid-phase product. That is, in the present invention, oil-based drill cuttings and red mud, two types of waste, are co-treated, and the obtained product is a valuable adsorbent material without pollutant emissions, achieving the purpose of treating waste with waste, and having the characteristics of simple operation, stability and reliability, energy conservation and environmental protection; moreover, the present invention makes full use of the inherent characteristics of the raw materials and products. Specifically: during the pyrolysis process, the alkalinity of the red mud is neutralized by the acidity of pyrolysis gases such as CO2, H2S, and SO2, reducing the environmental impact of the high alkalinity of the pyrolysis solid-phase product, and at the same time reducing the corrosion of the subsequent connecting pipelines by the high acidity of the pyrolysis oil and gas, thereby ensuring the stability and reliability of the entire treatment system.

[0041] It should be understood that during the catalytic pyrolysis of oil-based drill cuttings and red mud, the synergistic effect of iron and carbon generates a high-quality adsorbent material, that is, the pyrolysis solid-phase product. Specifically: the reducing pyrolysis oil and gas and the carbon element in the oil-based drill cuttings reduce the Fe in the red mud 3+ to FeO with Cr(Ⅵ) adsorption activity. At the same time, the iron element and its oxides in the red mud are highly efficient catalysts for catalytic cracking during the pyrolysis process, having catalytic active sites. During the pyrolysis, porous activated carbon grows on its surface, so that the final pyrolysis solid-phase product becomes an adsorbent material with a high specific surface area (up to 1000 m 2 / g) and high Cr(Ⅵ) selectivity, that is, the red mud drill cuttings-based iron-carbon material. Therefore, the red mud drill cuttings-based iron-carbon material of the present invention can be understood as a composite material generated from two types of waste, oil-based drill cuttings and red mud, including FeO with Cr(Ⅵ) adsorption activity and porous activated carbon.

[0042] In an embodiment of the present invention, the forming device 2 includes, but is not limited to, devices such as an extrusion machine and a pressing machine.

[0043] According to the embodiment of the present invention, the treatment system of the present invention further includes a pyrolysis oil and gas treatment unit, which is connected to the pyrolysis device 3 and is used for separating and treating the pyrolysis oil and gas generated by pyrolysis, and returning the treated pyrolysis gas and heavy oil to the pyrolysis device 3 as fuel to participate in combustion, reducing the consumption of natural gas fuel in the entire system, and realizing the recycling and reuse of resources.

[0044] In an embodiment of the present invention, as Figure 1As shown in the figure, the pyrolysis oil and gas treatment unit includes: an oil and gas condensation and separation device 6, an oil-water separation device 7, and a residue oil separation device 8. The inlet of the oil and gas condensation and separation device 6 is connected to the pyrolysis oil and gas outlet of the pyrolysis device 3, and the pyrolysis gas outlet of the oil and gas condensation and separation device 6 is connected to the fuel inlet of the pyrolysis device 3. The pyrolysis oil and gas generated by the pyrolysis of the pyrolysis device 3 are introduced into the oil and gas condensation and separation device 6 for condensation and separation treatment to obtain pyrolysis gas and pyrolysis oil-water. The pyrolysis gas is returned to the pyrolysis device 3 to participate in combustion as fuel; the inlet of the oil-water separation device 7 is connected to the pyrolysis oil-water outlet of the oil and gas condensation and separation device 6. The pyrolysis oil-water is introduced into the oil-water separation device 7, and the oil-water separation device 7 separates and treats the pyrolysis oil-water to obtain pyrolysis water and pyrolysis oil; the inlet of the residue oil separation device 8 is connected to the pyrolysis oil outlet of the oil-water separation device 7, and the heavy oil outlet of the residue oil separation device 8 is connected to the fuel inlet of the pyrolysis device 3. The pyrolysis oil is introduced into the residue oil separation device 8 for separation treatment to obtain light oil with high fluidity and heavy oil with low fluidity. The light oil is low-sulfur high-quality clean oil with high economic value and can be recycled. The heavy oil is high-sulfur low-quality oil and is returned to the pyrolysis device 3 to participate in combustion as fuel.

[0045] Therefore, through the reinjection combustion of pyrolysis gas and heavy oil, the present invention not only reduces the energy consumption of the entire system but also centrally controls the pollutants of the entire system. Specifically: during the pyrolysis process, heteroatoms such as sulfur and nitrogen tend to crack to form pyrolysis gas, and at the same time, a large amount of pollutants such as polycyclic aromatic hydrocarbons accumulate in the heavy oil. Injecting the pyrolysis gas and heavy oil back into the combustion can centrally treat the pollutants generated during the entire process, and the generated sulfur and nitrogen oxides can be centrally treated in the subsequent desulfurization and denitrification device 13, reducing the dispersion of pollutants in the entire process and improving the environmental friendliness of the process.

[0046] According to an embodiment of the present invention, as Figure 1 shown, a heat exchange pipeline 9 is provided in the coke quenching device 4 for introducing normal-temperature auxiliary combustion gas. The heat exchange pipeline 9 is externally connected to a first heat exchanger 10, and the first heat exchanger 10 is respectively connected to the fuel inlet and the flue gas outlet of the pyrolysis device 3. By introducing normal-temperature auxiliary combustion gas through the heat exchange pipeline 9, the normal-temperature auxiliary combustion gas exchanges heat with the pyrolysis solid-phase product in the coke quenching device 4 to reduce the temperature of the pyrolysis solid-phase product, and at the same time, the normal-temperature auxiliary combustion gas is preheated once to obtain medium-temperature auxiliary combustion gas at 70 - 100 °C, and then introduced into the first heat exchanger 10 to exchange heat with the 500 - 700 °C high-temperature flue gas discharged from the flue gas outlet of the pyrolysis device 3 for secondary preheating to form high-temperature auxiliary combustion gas at 300 - 500 °C, and at the same time, the high-temperature flue gas is cooled to obtain low-temperature flue gas at 100 - 200 °C. Finally, the high-temperature auxiliary combustion gas is introduced into the pyrolysis device 3 through the fuel inlet of the pyrolysis device 3 to assist combustion. The present invention uses the waste heat of the pyrolysis solid-phase product to preheat the normal-temperature auxiliary combustion gas once, and then uses the high-temperature flue gas for secondary preheating. The entire process utilizes energy in a stepped manner, improving the energy utilization rate of the entire process.

[0047] According to an embodiment of the present invention, as Figure 1 shown, the treatment system of the present invention further includes a second heat exchanger 11. The second heat exchanger 11 is connected to the first heat exchanger 10. The low-temperature flue gas cooled by the first heat exchanger 10 is introduced into the second heat exchanger 11 for further cooling to obtain normal-temperature flue gas.

[0048] There is no particular limitation on the specific types of the first heat exchanger 10 and the second heat exchanger 11 of the present invention, as long as heat exchange can be achieved. In an example of the present invention, the second heat exchanger 11 is a regenerative heat exchanger.

[0049] According to an embodiment of the present invention, as Figure 1 shown, the treatment system of the present invention further includes a dust collector 12, a desulfurization and denitration device 13, and a smoke exhaust device 14 connected in sequence. The dust collector 12 is connected to the second heat exchanger 11. The normal-temperature flue gas after cooling is subjected to dust removal, desulfurization, and denitration purification treatment in sequence, and is discharged through the smoke exhaust device 14 after reaching the standard.

[0050] In an example of the present invention, the smoke exhaust device 14 is a chimney.

[0051] According to an embodiment of the present invention, as Figure 1 shown, the treatment system of the present invention further includes an oil-based drill cuttings pretreatment device 15 and a red mud crushing and preheating device 16. The oil-based drill cuttings pretreatment device 15 and the red mud crushing and preheating device 16 are respectively connected to the feeding port of the mixing device 1. The oil-based drill cuttings are subjected to centrifugal dewatering and screening treatment by the oil-based drill cuttings pretreatment device 15 to obtain oil-based drill cuttings particles. The red mud is crushed and preheated by the red mud crushing and preheating device 16 to obtain heated red mud powder. Then, the oil-based drill cuttings particles and the heated red mud powder are introduced into the mixing device 1 for mixing to obtain a mixture of the two.

[0052] In an embodiment of the present invention, the pyrolysis device 3 is a settling furnace reactor. A regenerative radiant tube is provided in the settling furnace reactor, and heating is carried out through the regenerative radiant tube. It can be understood that the regenerative radiant tube has a flue gas outlet and a fuel inlet.

[0053] According to an embodiment of the present invention, the present invention also provides a method for co-processing oil-based drill cuttings and red mud waste. The processing method described below can be mutually corresponding and referred to the processing system described above. As Figure 2 shown, it mainly includes the following steps.

[0054] S1. Mix the oil-based drill cuttings with the red mud to obtain a mixture.

[0055] S2. Mold the mixture into pyrolysis raw materials.

[0056] S3. Pyrolyze the pyrolysis raw materials to generate pyrolysis solid-phase products.

[0057] S4. Cool down the pyrolysis solid product.

[0058] S5. Screen the pyrolysis solid product after cooling to obtain granular pyrolysis solid product, which can be used as an adsorbent. Among them, the pyrolysis solid product is a red mud drill cuttings-based iron-carbon material with a high specific surface area and high Cr(VI) selectivity.

[0059] According to the embodiments of the present invention, the treatment method of the present invention further includes the steps of: separating and treating the pyrolysis oil and gas generated by pyrolysis, using the treated pyrolysis gas and heavy oil as fuels for pyrolysis, and purifying the flue gas generated by pyrolysis.

[0060] In a specific example, as Figure 1 shown, the oil-based drill cuttings are dehydrated and screened by the oil-based drill cuttings pretreatment device 15 to obtain oil-based drill cuttings particles with a particle size of 5-30 mm. The red mud is crushed by the red mud crushing and preheating device 16 and preheated to a set temperature of 100-300 °C to obtain heated red mud powder. Then, the oil-based drill cuttings particles and the heated red mud powder are fed into the mixing device 1 for mixing, and the mixing mass ratio of the two is set between 3:7 and 7:3. At the same time, a binder is added and stirred evenly. The types of binders include, but are not limited to, one or more of carboxymethyl cellulose (CMC), phenolic resin (PR), and polyvinyl butyral (PVB). The addition ratio is controlled at 10% to 20% of the total material mass to obtain a mixture of the two. At this time, the mixture is an unformed pyrolysis raw material. The unformed pyrolysis raw material is processed by the forming device 2 to form a formed pyrolysis raw material. The formed pyrolysis raw material is pyrolytically activated in the pyrolysis device 3 in the temperature range of 500-800 °C to generate a pyrolysis solid product. The pyrolysis solid product is cooled by the heat exchange pipe 9 of the coke quenching device 4 and then sent to the screening device 5 for screening. The obtained granular pyrolysis solid product can be used as an adsorbent, and the powdered pyrolysis solid product can be formed into granules again by the forming device and used as an adsorbent.

[0061] The pyrolysis oil and gas generated by the pyrolysis device 3 are fed into the oil and gas condensation and separation device 6 for condensation and separation treatment to obtain pyrolysis gas and pyrolysis oil and water. The pyrolysis gas is sent back to the pyrolysis device 3 as fuel to participate in combustion. The pyrolysis oil and water are fed into the oil and water separation device 7, and the oil and water separation device 7 separates and treats the pyrolysis oil and water to obtain pyrolysis water and pyrolysis oil. The pyrolysis oil is fed into the residue oil separation device 8 for separation treatment to obtain light oil and heavy oil. The light oil can be recycled, and the heavy oil is sent back to the pyrolysis device 3 as fuel to participate in combustion.

[0062] The normal-temperature combustion-supporting gas is introduced through the heat exchange pipeline 9, and exchanges heat with the pyrolysis solid-phase products in the coke quenching device 4 to reduce the temperature of the pyrolysis solid-phase products. At the same time, the normal-temperature combustion-supporting gas is preheated for the first time, and then introduced into the first heat exchanger 10 to exchange heat with the high-temperature flue gas discharged from the pyrolysis device 3 for the second preheating to form the high-temperature combustion-supporting gas. At the same time, the high-temperature flue gas is cooled down. Finally, the high-temperature combustion-supporting gas is introduced into the pyrolysis device 3 for combustion support.

[0063] The low-temperature flue gas cooled by the first heat exchanger 10 is introduced into the second heat exchanger 11 for further cooling to normal temperature, and then passes through the dust collector 12, the desulfurization and denitrification device 13 and the smoke exhaust device 14 in sequence for dust removal, desulfurization and denitrification purification treatment, and is discharged after reaching the standard.

[0064] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oil-based drill cuttings and red mud waste co-treatment system, characterized in that, Comprising: A mixing device for obtaining a mixture of oil-based drill cuttings and red mud; An oil-based drill cuttings pretreatment device and a red mud crushing and preheating device, the oil-based drill cuttings pretreatment device and the red mud crushing and preheating device are respectively connected to the mixing device. The oil-based drill cuttings are dried and screened by the oil-based drill cuttings pretreatment device to obtain oil-based drill cuttings particles, and the red mud is crushed and preheated by the red mud crushing and preheating device to obtain heated red mud powder. Then, the oil-based drill cuttings particles and the heated red mud powder are fed into the mixing device for mixing; A forming device, the forming device is connected to the mixing device for forming the mixture into a pyrolysis raw material; A pyrolysis device, the inlet of the pyrolysis device is connected to the forming device for pyrolyzing the pyrolysis raw material to generate a pyrolysis solid-phase product; A coke quenching device, the inlet of the coke quenching device is connected to the outlet of the pyrolysis device for cooling the pyrolysis solid-phase product; A screening device, the screening device is connected to the outlet of the coke quenching device for screening the cooled pyrolysis solid-phase product to obtain granular pyrolysis solid-phase product, and the granular pyrolysis solid-phase product can be used as an adsorbent; The pyrolysis solid-phase product is a red mud drill cuttings-based iron-carbon material, specifically a composite material including FeO with Cr(Ⅵ) adsorption activity and activated carbon with loose pores, which is generated from two wastes, oil-based drill cuttings and red mud.

2. The co-processing system for oil-based drill cuttings and red mud waste according to claim 1, wherein It further includes a pyrolysis oil and gas treatment unit, the pyrolysis oil and gas treatment unit is connected to the pyrolysis device for separating and treating the pyrolysis oil and gas generated by pyrolysis, and returning the treated pyrolysis gas and heavy oil to the pyrolysis device.

3. The co-treatment system for oil-based drill cuttings and red mud waste according to claim 2, wherein, The pyrolysis oil and gas treatment unit includes: an oil and gas condensation and separation device, an oil-water separation device and a residue oil separation device. The inlet of the oil and gas condensation and separation device is connected to the pyrolysis oil and gas outlet of the pyrolysis device, and the pyrolysis gas outlet of the oil and gas condensation and separation device is connected to the fuel inlet of the pyrolysis device; the inlet of the oil-water separation device is connected to the pyrolysis oil and water outlet of the oil and gas condensation and separation device; the inlet of the residue oil separation device is connected to the pyrolysis oil outlet of the oil-water separation device, and the heavy oil outlet of the residue oil separation device is connected to the fuel inlet of the pyrolysis device.

4. The oil-based drill cuttings and red mud waste co-treatment system according to claim 1, wherein There is a heat exchange pipeline in the coke quenching device for introducing normal temperature auxiliary combustion gas, the heat exchange pipeline is externally connected to a first heat exchanger, and the first heat exchanger is respectively connected to the fuel inlet and the flue gas outlet of the pyrolysis device.

5. The oil-based drill cuttings and red mud waste collaborative treatment system according to claim 4, wherein It further includes a second heat exchanger, and the second heat exchanger is connected to the first heat exchanger.

6. The oil-based drill cuttings and red mud waste co-treatment system according to claim 5, characterized in that It further includes a dust collector, a desulfurization and denitration device and a smoke exhaust device connected in sequence, and the dust collector is connected to the second heat exchanger.

7. The co-treatment system for oil-based drill cuttings and red mud waste according to claim 1, characterized in that, The pyrolysis device is a settling furnace reactor.

8. A method for co - treating oil - based drill cuttings and red mud waste, used to control the co - treatment system of oil - based drill cuttings and red mud waste as described in any one of claims 1 to 7, characterized in that, Including the following steps: S1. Mix the oil-based drill cuttings and red mud to obtain a mixture; S2. Form the mixture into a pyrolysis raw material; S3. Pyrolyze the pyrolysis raw material to generate a pyrolysis solid-phase product; S4. Cool the pyrolysis solid-phase product; S5. Screen the cooled pyrolysis solid-phase product to obtain granular pyrolysis solid-phase product, and the pyrolysis solid-phase product is a red mud drill cuttings-based iron-carbon material.

9. The co-treatment method of oil-based drill cuttings and red mud waste according to claim 8, wherein It also includes the steps of: Separating the pyrolysis oil and gas generated by pyrolysis, and using the pyrolysis gas and heavy oil obtained from the treatment as the fuel for pyrolysis; Purifying the flue gas generated by pyrolysis.

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