A cold rolling oil sludge co-treatment system and method

Abstract

This application relates to a co-processing system and method for cold-rolled sludge. The system includes: a pretreatment unit for performing heating-fluidization, solid-liquid separation, and dehydration treatments on the cold-rolled sludge; a quantitative distribution unit including an intermediate storage tank, a transfer pump, a flow regulating valve, and a fully electrically heated pipeline; and a multi-process co-processing unit including receiving points for the coking, sintering, cold solidification, and auxiliary combustion processes. The pretreatment unit first "unlocks" the viscosity, the quantitative distribution unit then "locks" it to low viscosity, and the multi-process co-processing unit finally "resets" the viscosity to zero. These three processes are sequentially linked, forming a complete technical chain of "viscosity reduction—stable transportation—full utilization," transforming cold-rolled sludge from high-viscosity hazardous waste into a cryogenic fluid fuel / raw material that can be transported over long distances via pipelines, accurately measured, and utilized as a resource.

Description

Technical Field

[0001] This application belongs to the field of hazardous waste resource utilization technology, and in particular relates to a co-processing system and method for cold-rolled oil sludge. Background Technology

[0002] Cold-rolled sludge is a hazardous waste generated from the rolling, leveling, and degreasing sections of cold-rolling mills in steel enterprises. Cold-rolled sludge contains 30–60 wt% mineral oil, has a hydrocarbon mass ratio ≥6, a calorific value ≥28 MJ / kg, and also contains metal oxide particles <200 µm in diameter and emulsifiers. It is characterized by high viscosity, easy solidification, and large fluctuations in moisture content.

[0003] Existing technologies mainly employ incineration, solvent extraction, cement kiln co-processing, or single sintering blending methods for treatment. However, none of these methods can simultaneously solve the problems of high viscosity flow obstacles in cold-rolled sludge, precise control of multi-process synergistic ratios, and odor sealing throughout the entire process. Furthermore, they have not formed a closed-loop, fully quantified, and harmless resource utilization route within steel enterprises. Summary of the Invention

[0004] This application provides a system and method for the co-processing of cold-rolled sludge to solve the following technical problem: how to reduce the viscosity of cold-rolled sludge for easy transport.

[0005] In a first aspect, embodiments of this application provide a cold-rolled sludge co-processing system, comprising: The pretreatment unit is used to perform heating-fluidization treatment, solid-liquid separation treatment and dehydration treatment on cold rolling sludge to output fluidized cold rolling sludge with a water content ≤5wt%, a solid impurity content ≤3wt% and a particle size ≤50µm. The quantitative distribution unit includes an intermediate storage tank, a transfer pump, a flow regulating valve, and a fully electric heat tracing pipeline. The transfer pump pumps the fluidized cold-rolled sludge from the intermediate storage tank. The flow regulating valve adjusts the mass flow rate online according to the demand signal of the downstream process. The fully electric heat tracing pipeline maintains the fluidized cold-rolled sludge at 60-80°C and transports it to the downstream receiving point. The multi-process co-processing unit includes a coking process receiving point, a sintering process receiving point, a cold solidification process receiving point, and an auxiliary combustion process receiving point. The coking process receiving point receives 0.05-0.1 wt% of the fluidized cold-rolled sludge, the sintering process receiving point receives 0.05-0.1 wt% of the total dust and 0.5-1 wt% of the total mixture, the cold solidification process receiving point receives 0.1-1 wt% of the total mixture, and the auxiliary combustion process receiving point receives 10-20 wt% of the total mixed fuel.

[0006] Optionally, the preprocessing unit includes: A stirred steam jacketed storage tank is used to introduce 0.2-0.4 MPa saturated steam into cold-rolled sludge to heat the sludge to 60-120°C. A filtration-adsorption module is used to remove solid particles with a particle size >50µm from the cold-rolled sludge after heating. A vacuum dehydration module is used to reduce the moisture content of filtered cold-rolled sludge to 2-5 wt%.

[0007] Optionally, the outer wall temperature sensor of the fully electric heat tracing pipeline is interlocked with the flow regulating valve. When the inner wall temperature of the pipeline is <60℃, the flow regulating valve automatically increases its opening to compensate for the flow resistance.

[0008] Optionally, the receiving point of the coking process is located downstream of the main belt scale of the coke oven coal, and the flow regulating valve is interlocked with the coal quantity signal of the main belt scale to achieve online blending of 0.05-0.1wt%.

[0009] Secondly, embodiments of this application provide a method for the co-treatment of cold-rolled sludge, comprising the following steps: The cold-rolled sludge is subjected to a heating-fluidization treatment to make the temperature of the cold-rolled sludge ≥60℃ and the kinematic viscosity ≤300cSt; The cold-rolled sludge after the heating-fluidization process was filtered to remove solid particles with a diameter >50µm; The filtered cold-rolled sludge is subjected to dehydration treatment to obtain fluidized cold-rolled sludge with a water content of 2-5 wt% and a solid impurity content of 1-3 wt%. The fluidized cold-rolled sludge is distributed to the coking process, sintering process, cold solidification process, and auxiliary combustion process via a fully electrically heated pipeline, wherein: In the coking process, the fluidized cold-rolled sludge is mixed with the blended coal at a ratio of 0.05-0.1 wt% and then charged into the coking oven carbonization chamber. In the sintering process, the fluidized cold-rolled sludge is first premixed with dust at a ratio of 0.05-0.1 wt%, and then mixed with iron ore powder, flux and fuel at a ratio of 0.5-1 wt% before being fed into the sintering machine. In the cold solidification process, the fluidized cold-rolled sludge is mixed with iron-containing dust and sludge and binder at a ratio of 0.1-1wt%, briquetting and drying to obtain cold solidified balls for converter slag formation; In the auxiliary combustion process, the fluidized cold-rolled sludge is heated to ≥120°C and then mixed with kerosene, heavy oil or pulverized coal at a ratio of 10-20wt% and injected into the burner.

[0010] Optionally, the heating-fluidization process is completed in a stirred steam jacketed tank, wherein the steam pressure of the stirred steam jacketed tank is 0.2-0.4 MPa, the stirring paddle speed is 20-40 rpm, and a ribbon stirring paddle is used.

[0011] Optionally, the heat tracing power of the entire electric heat tracing pipeline is 40-80W / m, and the temperature of the outer wall of the pipeline is maintained at 60-100℃.

[0012] Optionally, the carbonization temperature of the coking process is 1000-1100℃, and the carbonization time is 16-20h; the hydrocarbon components of the fluidized cold-rolled sludge in the coking process are converted into coke oven gas and tar during the carbonization process.

[0013] Optionally, the ignition temperature of the sintering machine in the sintering process is 1050-1150℃; the hydrocarbon components of the fluidized cold-rolled sludge in the sintering process are burned in the sintering bed to provide heat and reduce solid fuel consumption by 3-5 kg / t of sintered ore.

[0014] Optionally, the briquetting pressure of the cold consolidation process is 10-15 MPa, the drying temperature is 100-120℃, and the compressive strength of the dried cold-consolidated briquette is ≥800 N / piece.

[0015] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a cold-rolled sludge co-processing system that transforms highly viscous hazardous waste into a cryogenic fluid that can be transported via pipelines. 1. Pretreatment Unit: This unit is primarily responsible for transforming cold-rolled sludge from a "high-viscosity plastic body" to a "low-viscosity pumpable fluid." Its principle is as follows: Heating-Fluidization: The cold-rolled sludge is heated in a closed system to approximately 80°C, causing the oil components to change from a glassy state to a viscous flow state, resulting in an exponential decrease in apparent viscosity. Supplemented with appropriate amounts of steam or hot water, a "water-in-oil" emulsion is constructed, disrupting the original high-viscosity network framework and achieving initial viscosity reduction. Solid-Liquid Separation-Deep Dehydration: A combination of cyclone and centrifugation is used to remove hard phases such as metal shavings and oxide scale with a particle size >50μm, eliminating the potential for subsequent "solid bridging." Simultaneously, free water is reduced to below 5wt% to prevent emulsion reversal and viscosity rebound. The resulting cold-rolled sludge has a particle size ≤50μm, water content ≤5wt%, impurities ≤3wt%, and viscosity reduced from >100Pa·s to below 300mPa·s, completing the fundamental phase transition from a "solid paste" to a "homogeneous flow."

[0016] 2. Quantitative Delivery Unit: The unit's mission is to maintain the low viscosity state obtained from pretreatment and achieve long-distance, steady-state, and metered transportation. Its principle is as follows: The intermediate storage tank is equipped with slow-speed stirring to prevent particle deposition and resulting localized increases in yield stress; the entire pipeline is electrically heated to maintain a constant temperature within the 60–80℃ range, completely eliminating the risk of blockage caused by heat dissipation along the pipeline, leading to "temperature drop → viscosity rebound"; a gear pump and mass flow valve form a closed-loop control system, using a constant shear rate to disrupt any potentially recoverable thixotropic structure, and adjusting the flow rate in real time according to downstream demand to avoid pressure peaks caused by high yield stress when restarting the pump. Therefore, the cold-rolled sludge remains within the Newtonian plateau region within the pipeline, with apparent viscosity fluctuations of less than 10%, achieving stable transportation over kilometers.

[0017] 3. Multi-process Collaborative Unit: This unit is responsible for the final disposal of low-viscosity cold-rolled sludge, ensuring that it does not revert to a high-viscosity state upon cooling. The principle is as follows: Fluidized cold-rolled sludge, still carrying residual heat, is injected in trace amounts (0.05–20 wt%) into four high-temperature processes: coking, sintering, cold solidification, and auxiliary combustion. In coking and sintering, the material layer temperature is >1000℃, causing the cold-rolled sludge to vaporize and burn within milliseconds upon entering the furnace, instantly eliminating the viscosity problem. In cold solidification, the pellets harden at around 200℃, and the cold-rolled sludge acts as an organic binder, solidifying into the matrix, converting residual viscosity into strength. In the auxiliary burner, the cold-rolled sludge is atomized and sprayed in, burning instantly as liquid fuel, directly converting viscosity energy into calorific value. Due to the small dispersion amount and the large thermal inertia of the furnace, the cold-rolled sludge is completely utilized before cooling, eliminating the risk of high-viscosity accumulation at the end of the system, thus completing the final stage of "viscosity control" in a closed loop.

[0018] In summary, the pretreatment unit first "unlocks" the viscosity reduction, the quantitative distribution unit then "locks" the low viscosity, and the multi-process collaborative unit finally "resets" the viscosity to zero. The three are connected in sequence to form a complete technology chain of "viscosity reduction - stable transportation - full consumption", which transforms cold-rolled sludge from high-viscosity hazardous waste into a low-temperature fluid fuel / raw material that can be transported over long distances through pipelines, accurately measured, and utilized as a resource. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" and "contains" as used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0021] In a first aspect, embodiments of this application provide a cold-rolled sludge co-processing system, comprising: The pretreatment unit is used to perform heating-fluidization treatment, solid-liquid separation treatment and dehydration treatment on cold rolling sludge to output fluidized cold rolling sludge with a water content ≤5wt%, a solid impurity content ≤3wt% and a particle size ≤50µm. The quantitative distribution unit includes an intermediate storage tank, a transfer pump, a flow regulating valve, and a fully electric heat tracing pipeline. The transfer pump pumps the fluidized cold-rolled sludge from the intermediate storage tank. The flow regulating valve adjusts the mass flow rate online according to the demand signal of the downstream process. The fully electric heat tracing pipeline maintains the fluidized cold-rolled sludge at 60-80°C and transports it to the downstream receiving point. The multi-process co-processing unit includes a coking process receiving point, a sintering process receiving point, a cold solidification process receiving point, and an auxiliary combustion process receiving point. The coking process receiving point receives 0.05-0.1 wt% of the fluidized cold-rolled sludge, the sintering process receiving point receives 0.05-0.1 wt% of the total dust and 0.5-1 wt% of the total mixture, the cold solidification process receiving point receives 0.1-1 wt% of the total mixture, and the auxiliary combustion process receiving point receives 10-20 wt% of the total mixed fuel.

[0022] The pretreatment unit performs a heating-fluidization process on the cold-rolled sludge: heating causes the oil components in the cold-rolled sludge to change from a glassy state to a viscous state, and the apparent viscosity decreases exponentially with increasing temperature; simultaneously, steam is introduced to form a water-in-oil emulsion, disrupting the original high-viscosity network skeleton. For every 10°C increase in temperature, the apparent viscosity of the cold-rolled sludge decreases by approximately 30%, thereby reducing the initial viscosity of the cold-rolled sludge (>100 Pa·s) to below 300 mPa·s, thus enabling the cold-rolled sludge to achieve fluidity and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity".

[0023] The pretreatment unit performs solid-liquid separation on the cold-rolled sludge: removing solid particles with a diameter >50µm and eliminating the "solid bridge" network between particles. For every 1wt% reduction in solid impurities, the yield stress of the cold-rolled sludge decreases by approximately 8%, thereby further reducing the flow resistance of the cold-rolled sludge and enabling it to maintain a continuous low-viscosity state within the pipeline, thus solving the technical problem of "facilitating the transport of cold-rolled sludge with sufficient viscosity".

[0024] The pretreatment unit performs dehydration treatment on the cold-rolled sludge, reducing the moisture content to ≤5wt% to prevent free water from forming a "continuous aqueous phase" that could lead to emulsion reversal. When the moisture content is reduced from 10wt% to 5wt%, the apparent viscosity of the cold-rolled sludge decreases by 40%, ensuring that the cold-rolled sludge maintains a viscosity below 300 mPa·s at 60–80℃. This gives the cold-rolled sludge a pumpable viscosity, solving the technical problem of "making the viscosity of cold-rolled sludge easy to transport."

[0025] The pretreatment unit outputs fluidized cold-rolling sludge with a moisture content ≤5wt%, solid impurity content ≤3wt%, and particle size ≤50µm. These three parameters work together to maintain the fluidized cold-rolling sludge in a "fine-particle suspension" rheological model, with a yield stress <20Pa. This ensures the fluidized cold-rolling sludge can withstand temperatures of 60–80℃ and a shear rate of 100s. -1 Under certain conditions, the apparent viscosity is below 300 mPa·s, thus enabling the fluidized cold-rolled sludge to meet the upper limit of viscosity of 1 Pa·s for pipeline transportation, thereby solving the technical problem of "the viscosity of cold-rolled sludge is suitable for easy transportation".

[0026] The entire process of electrically heated pipeline maintains the fluidized cold-rolled sludge at 60–80℃: when the temperature is below 60℃, the crystallinity of the grease increases sharply, and the apparent viscosity rises exponentially. The entire process of electrically heated pipeline keeps the temperature of the fluidized cold-rolled sludge constant at 60℃, 65℃, 70℃, 75℃, and 80℃, thereby controlling the viscosity fluctuation within ±10%, eliminating pipeline blockage caused by sudden viscosity increases, and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity".

[0027] In some embodiments, the preprocessing unit includes: A stirred steam jacketed storage tank is used to introduce 0.2-0.4 MPa saturated steam into cold-rolled sludge to heat the sludge to 60-120°C. A filtration-adsorption module is used to remove solid particles with a particle size >50µm from the cold-rolled sludge after heating. A vacuum dehydration module is used to reduce the moisture content of filtered cold-rolled sludge to 2-5 wt%.

[0028] A steam-jacketed mixing tank is used to introduce saturated steam at 0.2–0.4 MPa into the cold-rolled sludge. Steam pressures of 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, and 0.4 MPa correspond to saturation temperatures of 120–143 °C, rapidly raising the temperature of the cold-rolled sludge to 60–120 °C. This reduces the apparent viscosity of the cold-rolled sludge from >100 Pa·s to below 300 mPa·s, thereby giving the sludge initial fluidity and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity."

[0029] The filtration-adsorption module removes solid particles with a diameter >50µm, reducing inter-particle friction and the formation of a "solid bridging" network. When solid impurities are reduced from 5wt% to 3wt%, the yield stress of cold-rolled sludge decreases by 16%, thereby reducing pipeline start-up pressure and solving the technical problem of "facilitating the transport of cold-rolled sludge with sufficient viscosity".

[0030] The vacuum dehydration module reduces the moisture content of filtered cold-rolled sludge to 2–5 wt%. Under a vacuum of -0.08 MPa, the boiling point of water drops to 60°C, and low-temperature dehydration prevents oil oxidation. Moisture contents of 2 wt%, 3 wt%, 4 wt%, and 5 wt% correspond to an apparent viscosity below 300 mPa·s, thus ensuring that the cold-rolled sludge maintains low viscosity at pumping temperatures and solving the technical problem of "making the viscosity of cold-rolled sludge easy to transport".

[0031] In some embodiments, the outer wall temperature sensor of the fully electrically heated pipeline is interlocked with the flow regulating valve. When the inner wall temperature of the pipeline is <60°C, the flow regulating valve automatically increases its opening to compensate for the flow resistance.

[0032] When the temperature is below 60℃, the flow regulating valve automatically increases its opening to improve the shear rate and compensate for the viscosity rebound. This controls the viscosity increase caused by the temperature drop to within +15%, thereby maintaining the average viscosity of the fluidized cold-rolled sludge in the pipeline at <1 Pa·s, thus solving the technical problem of "the viscosity of cold-rolled sludge is easy to transport".

[0033] In some embodiments, the receiving point of the coking process is located downstream of the main belt scale of the coke oven coal, and the flow regulating valve is interlocked with the coal quantity signal of the main belt scale to achieve online blending of 0.05-0.1wt%.

[0034] The flow regulating valve is interlocked with the main belt conveyor's coal quantity signal to achieve online proportional blending of 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, and 0.1wt%. This ensures a constant instantaneous dosage of fluidized cold-rolled sludge, thereby avoiding changes in pipeline back pressure caused by batch fluctuations and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity".

[0035] Secondly, embodiments of this application provide a method for the co-treatment of cold-rolled sludge, comprising the following steps: The cold-rolled sludge is subjected to a heating-fluidization treatment to make the temperature of the cold-rolled sludge ≥60℃ and the kinematic viscosity ≤300cSt; The cold-rolled sludge after the heating-fluidization process was filtered to remove solid particles with a diameter >50µm; The filtered cold-rolled sludge is subjected to dehydration treatment to obtain fluidized cold-rolled sludge with a water content of 2-5 wt% and a solid impurity content of 1-3 wt%. The fluidized cold-rolled sludge is distributed to the coking process, sintering process, cold solidification process, and auxiliary combustion process via a fully electrically heated pipeline, wherein: In the coking process, the fluidized cold-rolled sludge is mixed with the blended coal at a ratio of 0.05-0.1 wt% and then charged into the coking oven carbonization chamber. In the sintering process, the fluidized cold-rolled sludge is first premixed with dust at a ratio of 0.05-0.1 wt%, and then mixed with iron ore powder, flux and fuel at a ratio of 0.5-1 wt% before being fed into the sintering machine. In the cold solidification process, the fluidized cold-rolled sludge is mixed with iron-containing dust and sludge and binder at a ratio of 0.1-1wt%, briquetting and drying to obtain cold solidified balls for converter slag formation; In the auxiliary combustion process, the fluidized cold-rolled sludge is heated to ≥120°C and then mixed with kerosene, heavy oil or pulverized coal at a ratio of 10-20wt% and injected into the burner.

[0036] Heating-fluidization treatment ensures that the temperature of the cold-rolled sludge is ≥60℃ and the kinematic viscosity is ≤300cSt: Kinematic viscosity 300cSt corresponds to 3×10 -4 m 2 / s, which is equivalent to 0.3 Pa·s at the pumping shear rate. This reduces the viscosity of cold-rolled sludge to below 1 Pa·s, the upper limit acceptable for pipeline centrifugal pumps, thereby enabling continuous pumping of cold-rolled sludge and solving the technical problem of "the viscosity of cold-rolled sludge is easy to transport".

[0037] The entire process of electrically heated pipelines is distributed to the coking, sintering, cold solidification, and auxiliary combustion processes: multiple outlets for decentralized heat dissipation, low flow rate at each point, flow velocity within the pipeline >0.5m / s, maintaining turbulence, and shear rate >100s. -1 This prevents the fluidized cold-rolled sludge from stagnating and cooling down in the pipeline, thus ensuring that the viscosity of the fluidized cold-rolled sludge is <1 Pa·s throughout the process, solving the technical problem of "the viscosity of cold-rolled sludge is suitable for easy transportation".

[0038] In some embodiments, the heating-fluidization process is completed in a stirred steam jacketed tank with a steam pressure of 0.2-0.4 MPa and a stirring paddle speed of 20-40 rpm.

[0039] The stirring paddle operates at speeds of 20 rpm, 25 rpm, 30 rpm, 35 rpm, and 40 rpm, providing a linear velocity of 0.3–0.6 m / s, creating a dual field of macroscopic eddies and microscopic shears. This reduces the internal temperature non-uniformity of the cold-rolled sludge to less than 2°C, thereby preventing sudden increases in viscosity in localized low-temperature zones and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity."

[0040] In some embodiments, the heat tracing power of the entire electric heat tracing pipeline is 40-80W / m, and the temperature of the outer wall of the pipeline is maintained at 60-80℃.

[0041] The electric heating power of the entire pipeline, at 30W / m, 35W / m, 40W / m, 45W / m, and 50W / m, can compensate for heat loss within an ambient temperature range of -10℃ to 40℃. This keeps the outer wall temperature of the pipeline constant at 60℃, 65℃, 70℃, 75℃, and 80℃, resulting in a temperature drop of <2℃ / 100m and a viscosity increase of <5% for fluidized cold-rolled sludge, thus solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity."

[0042] In some embodiments, the carbonization temperature of the coking process is 1000-1100℃ and the carbonization time is 16-20h; the hydrocarbon components of the fluidized cold-rolled sludge in the coking process are converted into coke oven gas and tar during the carbonization process.

[0043] At a high temperature of 1000-1100℃, the hydrocarbon components of the oil sludge instantly pyrolyze into coke oven gas and tar, and the viscosity immediately returns to zero. This ensures that the fluidized cold-rolled oil sludge no longer has viscosity issues after entering the coke oven carbonization chamber, thus eliminating the need for upstream pipelines to consider end-point viscosity recovery and solving the technical problem of "easy transportation of cold-rolled oil sludge with low viscosity".

[0044] In some embodiments, the ignition temperature of the sintering machine in the sintering process is 1050-1150℃; the hydrocarbon components of the fluidized cold-rolled sludge in the sintering process are burned in the sintering bed to provide heat and reduce solid fuel consumption by 3-5 kg / t of sintered ore.

[0045] The ignition temperature of the sintering machine is 1050–1150℃, resulting in a combustion wave velocity of 0.8–1.2 m / min for the material layer. The sludge burns out within 10 seconds, releasing heat and reducing solid fuel consumption by 3–5 kg / t of sinter. This reduces the viscosity of the fluidized cold-rolled sludge to zero at the front end of the sintering machine, eliminating the need for a viscosity buffer at the rear end during pipeline transportation and solving the technical problem of "facilitating the transportation of cold-rolled sludge with appropriate viscosity".

[0046] In some embodiments, the briquetting pressure of the cold consolidation process is 10-15 MPa, the drying temperature is 100-120°C, and the compressive strength of the dried cold-consolidated briquette is ≥800 N / piece.

[0047] High pressure of 10-15 MPa forces the spheres to expel pore moisture. After drying at 100-120℃, the moisture content is <1 wt%, and the viscosity solidifies into strength. This transforms fluidized cold-rolled sludge from a viscous flow state into solid spheres, thereby eliminating the risk of viscosity recovery at the end and solving the technical problem of "facilitating the transport of cold-rolled sludge with appropriate viscosity".

[0048] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0049] I. Implementation Examples Example 1 1. The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 60 ℃; 2. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; 3. The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 5 wt%, a solid impurity content of 3 wt%, and a particle size of 50 µm. 4. The entire process of electrically heated pipeline maintains the fluidized cold-rolled sludge at 60°C and transports it to the receiving point of the coking process; 5. At the feeding point of the coking process, fluidized cold-rolled sludge is mixed with blended coal at a ratio of 0.05 wt% and then loaded into the coking oven carbonization chamber. The carbonization temperature is 1000 ℃ and the carbonization time is 16 h.

[0050] Example 2 The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 70 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 4 wt%, a solid impurity content of 2.5 wt%, and a particle size of 45 µm. The entire process is electrically heated pipeline to maintain the fluidized cold-rolled sludge at 65 ℃ and transport it to the receiving point of the sintering process; At the sintering process receiving point, fluidized cold-rolled sludge and dust are premixed at a ratio of 0.07 wt%, and then mixed with iron ore powder, flux, and fuel at a ratio of 0.7 wt%. The ignition temperature of the sintering machine is 1100 ℃.

[0051] Example 3 The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 80 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold rolling sludge after solid-liquid separation to obtain fluidized cold rolling sludge with a water content of 3 wt%, a solid impurity content of 2 wt%, and a particle size of 40 µm. The entire process uses electrically heated pipelines to maintain the fluidized cold-rolled sludge at 70°C and transport it to the receiving point of the cold solidification process. At the material receiving point of the cold consolidation process, fluidized cold-rolled sludge, iron-containing dust, and binder are mixed at a ratio of 0.5 wt%, briquetting pressure is 12 MPa, drying temperature is 110 ℃, and drying time is 2 h.

[0052] Example 4 The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 90 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 2 wt%, a solid impurity content of 1.5 wt%, and a particle size of 35 µm. The entire process is electrically heated pipeline to maintain the fluidized cold-rolled sludge at 75 ℃ and transport it to the receiving point of the auxiliary combustion process; In the auxiliary combustion process, the fluidized cold-rolled sludge is heated to 120 °C at the receiving point and then mixed with kerosene at a ratio of 15 wt% and injected into the burner.

[0053] Example 5 The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 100 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 2 wt%, a solid impurity content of 1 wt%, and a particle size of 30 µm. The entire process is electrically heated pipeline, which maintains the fluidized cold-rolled sludge at 80°C and transports it to the receiving point of the coking process. At the coking process receiving point, fluidized cold-rolled sludge is mixed with blended coal at a ratio of 0.1 wt% and then loaded into the coke oven carbonization chamber. The carbonization temperature is 1100 ℃ and the carbonization time is 20 h.

[0054] Example 6 The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 110 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 2 wt%, a solid impurity content of 1 wt%, and a particle size of 25 µm. The entire process uses electrically heated pipelines to maintain the fluidized cold-rolled sludge at 80°C and transport it to the receiving point of the auxiliary combustion process. In the auxiliary combustion process, the fluidized cold-rolled sludge is heated to 130 °C at the receiving point and then mixed with heavy oil at a ratio of 20 wt% and injected into the burner.

[0055] II. Comparative Example Comparative Example 1 (without heating) The pretreatment unit directly performs solid-liquid separation on cold-rolled sludge at 25 °C to remove solid particles with a particle size >50 µm. The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain cold-rolled sludge with a water content of 5 wt%, a solid impurity content of 3 wt%, and a particle size of 50 µm. The entire process of electrically heated pipelines maintains the cold-rolled sludge at 25°C and transports it to the receiving point of the coking process. At the coking process receiving point, cold-rolled sludge is mixed with blended coal at a ratio of 0.05 wt% and then loaded into the coke oven carbonization chamber. The carbonization temperature is 1000 ℃ and the carbonization time is 16 h.

[0056] Comparative Example 2 (undehydrated) The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 60 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit did not perform dehydration treatment on the cold-rolled sludge after solid-liquid separation, resulting in cold-rolled sludge with a water content of 12 wt%, a solid impurity content of 3 wt%, and a particle size of 50 µm. The entire process of electrically heated pipelines maintains the cold-rolled sludge at 60°C and transports it to the receiving point of the coking process. At the coking process receiving point, cold-rolled sludge is mixed with blended coal at a ratio of 0.05 wt% and then loaded into the coke oven carbonization chamber. The carbonization temperature is 1000 ℃ and the carbonization time is 16 h.

[0057] Comparative Example 3 (without solid-liquid separation) The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 60 ℃. The pretreatment unit did not perform solid-liquid separation treatment on the heated cold-rolled sludge; The pretreatment unit performs dehydration treatment on the cold-rolled sludge to obtain cold-rolled sludge with a water content of 5 wt%, a solid impurity content of 8 wt%, and a particle size of 80 µm. The entire process of electrically heated pipelines maintains the cold-rolled sludge at 60°C and transports it to the receiving point of the coking process. At the coking process receiving point, cold-rolled sludge is mixed with blended coal at a ratio of 0.05 wt% and then loaded into the coke oven carbonization chamber. The carbonization temperature is 1000 ℃ and the carbonization time is 16 h.

[0058] Comparative Example 4 (without electric heating) The pretreatment unit performs a heating-fluidization treatment on the cold-rolled sludge to bring the temperature of the cold-rolled sludge to 60 ℃. The pretreatment unit performs solid-liquid separation on the heated cold-rolled sludge to remove solid particles with a diameter >50 µm; The pretreatment unit performs dehydration treatment on the cold-rolled sludge after solid-liquid separation to obtain fluidized cold-rolled sludge with a water content of 5 wt%, a solid impurity content of 3 wt%, and a particle size of 50 µm. The fluidized cold-rolled sludge is transported to the coking process receiving point in a natural environment through a pipeline without electric heating, and the temperature drops to 30 ℃ along the way. At the coking process receiving point, fluidized cold-rolled sludge is mixed with blended coal at a ratio of 0.05 wt% and then loaded into the coke oven carbonization chamber. The carbonization temperature is 1000 ℃ and the carbonization time is 16 h.

[0059] III. Results Data Experimental methods for evaluating results: Average viscosity of the pipeline: measured using a rotational viscometer at 100 s⁻¹. -1 Online sampling was performed at the shear rate, with one sample taken every 100 m, and the arithmetic mean was taken.

[0060] Pipeline start-up pressure: Install a 0.5-class pressure transmitter at the outlet of the delivery pump and record the maximum pressure at the instant the valve is fully closed to fully open.

[0061] 1000 m pressure drop: Install a 0.5 class pressure transmitter at the beginning and end of the pipeline, and read the difference after 30 minutes of steady-state transmission.

[0062] Congestion status: If the flow rate drops to zero within 30 seconds within 8 hours of continuous operation, it is considered "yes".

[0063] Coke crush resistance strength M40 and abrasion resistance strength M10: Sampling and testing were conducted according to the methods specified in GB / T 1996-2017 "Metallurgical Coke".

[0064] Table 1. Results data for both the examples and comparative examples.

[0065] As shown in Table 1, the inventiveness of this application's technical solution compared to the prior art is mainly reflected in: 1. Examples 1-6 all achieved an average pipeline viscosity of ≤0.8 Pa·s, which is two orders of magnitude lower than Comparative Example 1 (120 Pa·s). This enables cold-rolled sludge to be transported over long distances in 60-80 ℃ without diluent for the first time, solving the common industry problem of "high viscosity and difficult transportation".

[0066] 2. The starting pressure of Examples 1-6 is ≤0.35 MPa and the pressure drop at 1000 m is ≤0.28 MPa, which is ≥90% lower than that of Comparative Example 1. Thus, the complex configuration of the traditional "high-pressure plunger pump + pipe wall heating jacket" is eliminated, while still ensuring continuous and stable operation, significantly reducing engineering investment and operating energy consumption.

[0067] 3. Examples 1-6 ran continuously for 8 hours without clogging, while Comparative Examples 1-4 all showed flow rates dropping to zero after more than 30 seconds; thus proving that the combination of “heating-fluidization + solid-liquid separation + dehydration + full-process electric heating” forms a viscosity locking chain at the principle level, achieving “zero clogging” in cold-rolled sludge conveying for the first time.

[0068] 4. The coke crushing strength M40 of Examples 1, 2, and 5 is ≥86.2% and the abrasion resistance M10 is ≤6.1%, which is better than that of Comparative Example 1 (M40 82.0% and M10 7.5%). This shows that the trace amount of fluidized cold rolling sludge (0.05-0.1 wt%) is transformed into high-quality coke oven gas and tar in the high-temperature field of the coke oven. It not only does not damage the quality of coke, but also improves the microstructure of coke by supplementing trace hydrocarbon components, thus breaking through the technical prejudice that "adding sludge will reduce strength".

[0069] 5. Table 1 covers all endpoints and medians for moisture content of 2-5 wt%, solid impurities of 1-3 wt%, particle size of 25-50 µm, temperature of 60-110 ℃, and dosage of 0.05-20 wt%, all of which yielded stable results with viscosity <1 Pa·s, no clogging, and qualified product indicators; thus proving that the full range of values ​​given in the claims is not a simple patchwork, but has repeatable and predictable inventive boundaries.

[0070] In summary, this application, through a three-level viscosity control chain of "pretreatment-quantitative delivery-multi-process collaboration", achieves for the first time, simultaneously at both the principle and engineering levels, the triple effects of "low-viscosity conveying-high calorific value utilization-product quality improvement" for cold-rolled sludge.

[0071] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A system for the co-processing of cold-rolled sludge, characterized in that, include: The pretreatment unit is used to perform heating-fluidization treatment, solid-liquid separation treatment and dehydration treatment on cold rolling sludge to output fluidized cold rolling sludge with a water content ≤5wt%, a solid impurity content ≤3wt% and a particle size ≤50µm. The quantitative distribution unit includes an intermediate storage tank, a transfer pump, a flow regulating valve, and a fully electric heat tracing pipeline. The transfer pump pumps the fluidized cold-rolled sludge from the intermediate storage tank. The flow regulating valve adjusts the mass flow rate online according to the demand signal of the downstream process. The fully electric heat tracing pipeline maintains the fluidized cold-rolled sludge at 60-80°C and transports it to the downstream receiving point. The multi-process co-processing unit includes a coking process receiving point, a sintering process receiving point, a cold solidification process receiving point, and an auxiliary combustion process receiving point. The coking process receiving point receives 0.05-0.1 wt% of the fluidized cold-rolled sludge, the sintering process receiving point receives 0.05-0.1 wt% of the total dust and 0.5-1 wt% of the total mixture, the cold solidification process receiving point receives 0.1-1 wt% of the total mixture, and the auxiliary combustion process receiving point receives 10-20 wt% of the total mixed fuel.

2. The cold-rolled sludge co-processing system according to claim 1, characterized in that, The preprocessing unit includes: A stirred steam jacketed storage tank is used to introduce 0.2-0.4 MPa saturated steam into cold-rolled sludge to heat the sludge to 60-120°C. A filtration-adsorption module is used to remove solid particles with a particle size >50µm from the cold-rolled sludge after heating. A vacuum dehydration module is used to reduce the moisture content of filtered cold-rolled sludge to 2-5 wt%.

3. The cold-rolled sludge co-processing system according to claim 1, characterized in that, The external wall temperature sensor of the entire electric heat tracing pipeline is interlocked with the flow regulating valve. When the inner wall temperature of the pipeline is <60℃, the flow regulating valve automatically increases its opening to compensate for the flow resistance and automatically increases the electric heat tracing temperature.

4. The cold-rolled sludge co-processing system according to claim 1, characterized in that, The receiving point for the coking process is located downstream of the main belt scale for coke oven coal. The flow regulating valve is interlocked with the coal quantity signal of the main belt scale to achieve online blending of 0.05-0.1wt%.

5. A method for co-processing cold-rolled sludge, characterized in that, Includes the following steps: The cold-rolled sludge is subjected to a heating-fluidization treatment to make the temperature of the cold-rolled sludge ≥60℃ and the kinematic viscosity ≤300cSt; The cold-rolled sludge after the heating-fluidization process was filtered to remove solid particles with a diameter >50µm; The filtered cold-rolled sludge is subjected to dehydration treatment to obtain fluidized cold-rolled sludge with a water content of 2-5 wt% and a solid impurity content of 1-3 wt%. The fluidized cold-rolled sludge is distributed to the coking process, sintering process, cold solidification process, and auxiliary combustion process via a fully electrically heated pipeline, wherein: In the coking process, the fluidized cold-rolled sludge is mixed with the blended coal at a ratio of 0.05-0.1 wt% and then charged into the coking oven carbonization chamber. In the sintering process, the fluidized cold-rolled sludge is first premixed with dust at a ratio of 0.05-0.1 wt%, and then mixed with iron ore powder, flux and fuel at a ratio of 0.5-1 wt% before being fed into the sintering machine. In the cold solidification process, the fluidized cold-rolled sludge is mixed with iron-containing dust and sludge and binder at a ratio of 0.1-1wt%, briquetting and drying to obtain cold solidified balls for converter slag formation; In the auxiliary combustion process, the fluidized cold-rolled sludge is heated to ≥120°C and then mixed with kerosene, heavy oil or pulverized coal at a ratio of 10-20wt% and injected into the burner.

6. The method for co-processing cold-rolled sludge according to claim 5, characterized in that, The heating-fluidization process is completed in a stirred steam jacketed tank with a steam pressure of 0.2-0.4 MPa and a stirring paddle speed of 20-40 rpm, using a ribbon-type stirring paddle.

7. The method for co-processing cold-rolled sludge according to claim 5, characterized in that, The heat tracing power of the entire electric heat tracing pipeline is 40-80W / m, and the temperature of the outer wall of the pipeline is maintained at 60-100℃.

8. The method for co-processing cold-rolled sludge according to claim 5, characterized in that, The carbonization temperature of the coking process is 1000-1100℃, and the carbonization time is 16-20h; the hydrocarbon components of the fluidized cold-rolled sludge in the coking process are converted into coke oven gas and tar during the carbonization process.

9. The method for co-processing cold-rolled sludge according to claim 5, characterized in that, The ignition temperature of the sintering machine in the sintering process is 1050-1150℃; the hydrocarbon components of the fluidized cold-rolled sludge in the sintering process are burned in the sintering bed to provide heat and reduce solid fuel consumption by 3-5 kg / t of sintered ore.

10. The method for co-processing cold-rolled sludge according to claim 5, characterized in that, The briquetting pressure of the cold consolidation process is 10-15 MPa, the drying temperature is 100-120℃, and the compressive strength of the dried cold-consolidated briquette is ≥800 N / piece.

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