A method and system for utilizing oil-containing iron oxide scale

Abstract

This invention provides a method and system for utilizing oil-containing iron oxide scale. The method includes the following steps: during the sintering process, a base layer is first laid on the sintering machine, followed by a first-stage layer on top of the base layer, and then ignition. After the sintering machine has traveled a certain distance, a second-stage layer is laid on top of the first-stage layer, and then ignition is performed again. The sintering mixture in the first-stage layer does not contain oil-containing iron oxide scale, while the sintering mixture in the second-stage layer does contain oil-containing iron oxide scale. This invention eliminates the adverse effects of oily substances in the added oil-containing iron oxide scale on the sintering ventilation system; it also avoids the explosion risk caused by the low-flash-point oil decomposition products formed by the oily substances, ensuring the safety of the sintering system. This invention effectively recovers oil-containing iron oxide scale resources that enterprises cannot effectively utilize, and utilizes the potential combustion heat of the oily substances in the oil-containing iron oxide scale, reducing the fuel consumption in the sintering mixture and achieving full reuse of valuable resources in the oil-containing iron oxide scale.

Description

Technical Field

[0001] This invention belongs to the field of oil-containing iron oxide scale resource processing technology in the iron and steel metallurgy industry, and more specifically, it relates to a method and system for utilizing oil-containing iron oxide scale. Background Technology

[0002] Oily iron oxide scale is a byproduct generated during the hot working of steel billets that is difficult to recycle and reuse. During hot working, continuous heating furnaces typically heat steel billets to above 1200℃, causing oxidation and the formation of iron oxide scale. This scale is generally removed mechanically and hydraulically. During this removal process, the oil and grease used to lubricate the rolls and rollers mix with the cooling water from the mill stand, forming oily iron oxide scale. The oil content varies considerably depending on the hot rolling production line and processing technology.

[0003] Over the past few decades, a large amount of this oily iron oxide scale has accumulated. After dehydration, the iron content of this scale averages 65%–70%. Due to its high iron content, recycling this scale through further melting or reduction is economically viable. Because it contains varying amounts of oil, this scale cannot be directly added to the top of converters or blast furnaces. Currently, most companies outsource its disposal, leading to the loss of ferrous resources. To recover these resources, companies have conducted numerous studies and trials, including direct use as sintering raw material, briquetting in rotary kilns, rotary kiln distillation, roasting, and high-temperature reduction.

[0004] One method, directly using oil-containing iron oxide scale as a raw material in sintering, seems simple and feasible, but its large-scale use in current sintering processes poses significant safety risks. This is because the oil adsorbed by the iron oxide scale will desorb and distill at temperatures of 400-500℃ or lower. 400-500℃ is the drying and preheating stage of the sintering process, where the oxygen content in the sintering exhaust gas is generally low. Under high negative pressure, there is a lack of conditions for oil combustion, causing the oil to enter the sintering exhaust gas as oil gas. The oil fumes easily condense and adhere to dust collectors, main exhaust fan rotors, etc. Furthermore, large quantities or prolonged use of oil-containing iron oxide scale in the sintering machine can lead to localized concentrations of low-flash-point oil decomposition products, potentially causing an explosion risk. Many domestic enterprises have experienced accidents such as spontaneous combustion and even flue explosions due to the use of oil-containing iron oxide scale to reduce raw material costs. Currently, oil-containing iron oxide scale is rarely used directly in ordinary sintering processes.

[0005] For the briquetting rotary kiln method, some companies utilize OG coarse particles and iron oxide scale produced during steelmaking, adding a special binder in a certain proportion, and thoroughly mixing them in a high-pressure mixer before extruding them into pellets. The finished product is then returned to the steel mill for use. This method also has the following disadvantages: firstly, the processing cost is high; secondly, the oil evaporates when heated during use, emitting an unpleasant odor, polluting the working environment and endangering the health of workers.

[0006] The rotary kiln distillation method involves first dehydrating the hot-rolled sludge, then using a flame-retardant heated rotary kiln to remove the oil. The hot oil vapor is condensed to obtain recovered oil, and the iron scale remaining after oil removal can be recycled. This method is environmentally friendly, but it has high investment and operating costs.

[0007] Methods such as roasting and high-temperature reduction for treating oily iron oxide scale also suffer from problems such as high investment and high operating costs, making them unsustainable in terms of economic viability. Summary of the Invention

[0008] The purpose of this invention is to provide a very economical, efficient and safe method and system for utilizing oily iron oxide scale, so as to achieve the goal of keeping oily iron oxide scale solid waste out of the factory, and to achieve sustainable recycling and economical utilization.

[0009] To achieve the above objectives, a first aspect of the present invention provides a method for utilizing oil-containing iron oxide scale, comprising the following steps:

[0010] In the sintering production process, a base layer is first laid on the sintering machine, then the first layer is laid on the base layer, and then the ignition is performed.

[0011] After the sintering machine has run a certain distance, a second layer of material is laid on the first layer of material that has been laid and ignited, and then ignited again.

[0012] The sintering mixture of the first layer does not contain oil-containing iron oxide scale, while the sintering mixture of the second layer contains oil-containing iron oxide scale.

[0013] Furthermore, the thickness of the first fabric layer accounts for 65-70% of the total fabric layer thickness, the thickness of the second fabric layer accounts for 30-35% of the total fabric layer thickness, and the total fabric layer thickness is the sum of the thicknesses of the first fabric layer and the second fabric layer.

[0014] Furthermore, the thickness of the first fabric layer is 400-700 mm, and the thickness of the second fabric layer is 200-400 mm.

[0015] Furthermore, the amount of oil-containing iron oxide scale added to the sintering mixture of the secondary fabric layer is 1wt to 15wt%.

[0016] Furthermore, both the sintering mixture of the first layer and the sintering mixture of the second layer contain iron-containing materials, flux, and fuel.

[0017] A second aspect of the present invention provides a system for utilizing oil-containing iron oxide scale, comprising:

[0018] The exhaust sintering unit includes a sintering machine and a negative pressure exhaust device;

[0019] A base material silo is used to lay the base material layer for the sintering machine;

[0020] The initial mixing material distribution unit includes an initial mixing material batching device, a first mixing device, and an initial mixing material silo; the initial mixing material distribution unit is used to distribute the initial material layer;

[0021] A secondary mixing material distribution unit includes a secondary mixing material batching device, a second mixing device, and a secondary mixing material silo; the secondary mixing material distribution unit is used to distribute a secondary material layer; and

[0022] The ignition unit includes a primary fabric ignition system and a secondary fabric ignition system; the primary fabric ignition system is used to ignite the primary fabric layer, and the secondary fabric ignition system is used to ignite the secondary fabric layer.

[0023] Furthermore, it also includes a material distribution device, wherein the primary mixing material batching device includes a main line batching bin system and a main line batching belt located below it; the first mixing device includes a main line primary mixer, a main line primary mixing belt and a main line secondary mixer;

[0024] The main line feeding belt transports the sintered mixture of the first feeding layer to the main line primary mixer for primary mixing. After that, it enters the material distribution device and is divided into two parts. One part is transported by the main line primary mixing belt to the main line secondary mixer for further mixing, and then enters the primary mixing silo.

[0025] Furthermore, the secondary mixing and batching device includes an auxiliary line batching bin system and an auxiliary line batching belt located below it; the second mixing device includes an auxiliary line primary mixing belt, an auxiliary line primary mixer, and an auxiliary line secondary mixer.

[0026] The auxiliary line feeding belt transports the sintered mixture from the secondary feeding layer to the auxiliary line primary mixing belt. At the same time, another part of the sintered mixture from the primary feeding layer from the distribution device also enters the auxiliary line primary mixing belt. The auxiliary line primary mixing belt transports the material on it to the auxiliary line primary mixer for primary mixing, then enters the auxiliary line secondary mixer for further mixing, and then enters the secondary mixing silo.

[0027] Furthermore, it also includes a material layer oxygen replenishment device for replenishing oxygen to the primary material layer and / or the secondary material layer.

[0028] Furthermore, both the main line batching bin system and the auxiliary line batching bin system include multiple parallel conical storage bins.

[0029] Compared with the prior art, the present invention has the following technical effects:

[0030] This invention discloses a method for utilizing oil-containing iron oxide scale. First, a sintering mixture without oil-containing iron oxide scale is initially fed and ignited on a sintering machine. After a certain distance, the mixed sintering material containing oil-containing iron oxide scale is then fed and ignited again on the previously fed and ignited sintering layer, creating two combustion zones on the same sintering cross-section simultaneously. In this way, the distillation and decomposition products formed by the oily substances in the upper layer of the sintering mixture's oil-containing iron oxide scale after drying and preheating pass through the lower combustion zone, where the high temperature achieves complete combustion of the oily substances. This avoids the oil fumes condensing and adhering to dust in subsequent dust collectors, main exhaust fan rotors, and other equipment, eliminating the adverse effects of oily substances on the sintering ventilation system. Furthermore, it avoids the explosion risk caused by the low flash point oil decomposition products formed by the oily substances, ensuring the safety of the sintering system. Furthermore, the method of this invention effectively recovers oil-containing iron oxide scale from enterprises, and the recovery effect is not affected by the oil content, enabling large-scale and highly economical recovery. In addition, the method of this invention can utilize the combustion heat of oily substances in the oil-containing iron oxide scale to reduce the fuel demand in the sintering mixture, thereby achieving full reuse of valuable resources in the oil-containing iron oxide scale and turning waste into treasure.

[0031] This invention discloses a system for utilizing oil-containing iron oxide scale. A primary mixing unit and a secondary mixing unit are used to lay out a primary and secondary material layers, respectively. Then, the materials are ignited twice, sequentially by a primary material ignition system and a secondary material ignition system, resulting in two simultaneous combustion zones on the same sintering cross-section. In this way, the distillation and decomposition products formed by the oily substances in the secondary material layer after drying and preheating pass through the combustion zone of the first material layer, achieving complete combustion of the oily substances through the high-temperature combustion of the primary material layer. This avoids the condensation of oil fumes and their adhesion to dust collectors, main exhaust fan rotors, and other equipment, reducing or even eliminating the adverse effects of oily substances on the sintering ventilation system. Furthermore, it avoids the explosion risk caused by the low flash point oil decomposition products formed by the oily substances, ensuring the safety of the sintering system. Furthermore, the system of this invention effectively recovers oil-containing iron oxide scale from enterprises, and the recovery effect is not affected by the oil content, enabling large-scale and highly economical recovery. The system of this invention can also utilize the combustion heat of oily substances in the oil-containing iron oxide scale to reduce the fuel demand in the sintering mixture, realizing the full reuse of valuable resources in the oil-containing iron oxide scale and turning waste into treasure. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a system for utilizing oil-containing iron oxide scale according to an embodiment of the present invention;

[0034] Figure 2 This is a process flow diagram of a method for utilizing oil-containing iron oxide scale provided in an embodiment of the present invention.

[0035] The following are the labeling elements in the figure:

[0036] 1. Sintering machine; 2. Bottom material silo; 3. Primary mixing silo; 4. Primary material surface ignition system; 5. Material layer oxygen supply device; 6. Secondary mixing silo; 7. Secondary material surface ignition system; 8. Bottom material layer; 9. Primary material layer; 10. Secondary material layer; 11. Main line batching silo system; 12. Main line batching belt; 13. Main line primary mixer; 14. Main line primary mixing belt; 15. Main line secondary mixer; 16. Material distribution device; 17. Auxiliary line primary mixing belt; 18. Auxiliary line primary mixer; 19. Auxiliary line batching silo system; 20. Auxiliary line secondary mixer; 21. Auxiliary line batching belt. Detailed Implementation

[0037] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0038] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0039] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0040] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0041] In a first aspect, embodiments of the present invention provide a system for utilizing oil-containing iron oxide scale, the structure of which is as follows: Figure 1As shown, the system includes a sintering unit with exhaust ventilation, a bottom material silo 2, a primary mixing material placement unit, a secondary mixing material placement unit, and an ignition unit. The sintering unit with exhaust ventilation includes a sintering machine 1 and a negative pressure exhaust system (not shown in the figure). The negative pressure exhaust system provides a top-down airflow to the sintering machine 1 to provide the oxygen required for sintering. The bottom material silo 2 is used to place the bottom material layer 8 on the sintering machine 1. The primary mixing material placement unit includes a primary mixing material batching device, a first mixing device, and a primary mixing silo 3. The sintering mixture is batched by the primary mixing material batching device, mixed and granulated by the first mixing device, and then enters the primary mixing silo 3. The primary mixing material placement unit is used to place the primary material layer 9. The secondary mixing material placement unit includes a secondary mixing material batching device, a second mixing device, and a secondary mixing silo 6. The sintering mixture is batched by the secondary mixing material batching device, mixed and granulated by the second mixing device, and then enters the secondary mixing silo 6. The secondary mixing material placement unit is used to place the secondary material layer 10. The ignition unit includes a primary fabric ignition system 4 and a secondary fabric ignition system 7. The primary fabric ignition system 4 is used to ignite the primary fabric layer 9, and the secondary fabric ignition system 7 is used to ignite the secondary fabric layer 10.

[0042] The sintering mixture of the first layer 9 does not contain oil-containing iron oxide scale, while the sintering mixture of the second layer 10 contains oil-containing iron oxide scale.

[0043] During normal production, sintering machine 1 operates from left to right. The bottom material hopper 2, storing 10-20mm particle size bottom material, first lays the bottom material layer 8, approximately 50mm thick, to protect the lower grate bars of sintering machine 1 and prevent material leakage. Next, the primary mixing hopper 3 lays the primary material layer 9 on top of the bottom material layer 8, and it is ignited by the primary material surface ignition system 4. After sintering machine 1 has been running for a period of time, the secondary mixing hopper 6 lays the secondary material layer 10 on the already ignited platform, and it is ignited by the secondary material surface ignition system 7. The thickness of the primary material layer 9 and the secondary material layer 10 is adjusted according to actual conditions to ensure the completion of the double-layer sintering endpoint temperature and the sintering process.

[0044] An embodiment of the present invention provides a system for utilizing oily iron oxide scale. A primary mixing layer 9 and a secondary mixing layer 10 are laid out in a primary mixing layer unit and a secondary mixing layer unit, respectively. Then, the system undergoes two ignition processes: a primary material ignition system 4 and a secondary material ignition system 7, resulting in two simultaneous combustion zones on the same sintering cross-section. In this way, the distillation and decomposition products formed by the oily substances in the secondary mixing layer 10 after drying and preheating pass through the combustion zone of the first ignited mixing layer 9. The high-temperature combustion in the primary mixing layer 9 achieves complete combustion of the oily substances. This avoids the condensation of oil fumes and their adhesion to dust in subsequent dust collectors, main exhaust fan rotors, and other equipment, eliminating the adverse effects of oily substances on the sintering ventilation system. Furthermore, it avoids the explosion risk caused by the low flash point oil decomposition products formed by the oily substances, ensuring the safety of the sintering system. Furthermore, the system of this invention effectively recovers oil-containing iron oxide scale from enterprises, and the recovery effect is not affected by the oil content, enabling large-scale and highly economical recovery. The system of this invention can also utilize the combustion heat of oily substances in the oil-containing iron oxide scale to reduce the fuel consumption in the sintering mixture, thereby achieving full reuse of valuable resources in the oil-containing iron oxide scale and turning waste into treasure.

[0045] Furthermore, the system for utilizing oil-containing iron oxide scale according to an embodiment of the present invention also includes a material distribution device 16. The primary mixing material batching device includes a main line batching bin system 11 and a main line batching belt 12 disposed below it; the first mixing device includes a main line primary mixer 13, a main line secondary mixing belt 14, and a main line secondary mixer 15. The main line batching belt 12 transports the sintered mixture of the first material layer 9 to the main line primary mixer 13 for primary mixing, and then enters the material distribution device 16 to be divided into two parts. One part is transported to the main line secondary mixer 15 via the main line secondary mixing belt 14 for further mixing and granulation, and then enters the primary mixing bin 3.

[0046] Furthermore, the secondary mixing and batching device of this embodiment includes an auxiliary line batching bin system 19 and an auxiliary line batching belt 21 disposed below it. The second mixing device includes an auxiliary line primary mixing belt 17, an auxiliary line primary mixer 18, and an auxiliary line secondary mixer 20. The auxiliary line batching belt 21 transports the sintered mixture from the secondary feeding layer 10 to the auxiliary line primary mixing belt 17. At the same time, another portion of the sintered mixture from the primary feeding layer 9 from the distribution device 16 also enters the auxiliary line primary mixing belt 17. The auxiliary line primary mixing belt 17 transports the material on it to the auxiliary line primary mixer 18 for primary mixing, and then it enters the auxiliary line secondary mixer 20 for further mixing and granulation, and then enters the secondary mixing bin 6.

[0047] Furthermore, the system for utilizing oil-containing iron oxide scale according to an embodiment of the present invention also includes a material layer oxygen replenishment device 5, which is used to replenish oxygen to the first material layer 9 and / or the second material layer 10 so that the sintering material on the first material layer 9 and the second material layer 10 can have sufficient oxygen for combustion.

[0048] Furthermore, both the main line batching bin system 11 and the auxiliary line batching bin system 19 of this embodiment of the invention include multiple parallel conical storage bins, which can store different raw materials to meet the batching requirements of multiple raw materials.

[0049] Secondly, embodiments of the present invention also provide a method for utilizing oily iron oxide scale, which is implemented using the above-described utilization system and includes the following steps:

[0050] In the sintering production process, the bottom material layer 8 is first laid on the sintering machine 1, and then the first material layer 9 is laid on the bottom material layer 8 and ignited.

[0051] After the sintering machine 1 has traveled a certain distance, a secondary material layer 10 is laid on the primary material layer 9 that has been laid and ignited, and then ignited.

[0052] The sintering mixture of the first layer 9 does not contain oil-containing iron oxide scale, while the sintering mixture of the second layer 10 contains oil-containing iron oxide scale.

[0053] In one embodiment of the present invention, a method for utilizing oil-containing iron oxide scale involves first feeding and igniting a sintering mixture without oil-containing iron oxide scale on a sintering machine 1. After a certain distance, the mixed sintering material containing oil-containing iron oxide scale is then fed and ignited again on the material layer of the sintering machine 1 that has already been fed and ignited, resulting in two combustion zones operating simultaneously on the same sintering cross-section. In this way, the distillation and decomposition products formed by the oily substances in the upper sintering mixture (i.e., the secondary feeding layer 10) after drying and preheating will pass through the lower combustion zone, which is ignited first. The high-temperature combustion in the lower combustion zone achieves complete combustion of the oily substances. This avoids the oil fumes condensing and adhering to dust, sticking to subsequent dust collectors, main exhaust fan rotors, and other equipment, thus eliminating the adverse effects of oily substances on the sintering ventilation system. Furthermore, it avoids the explosion risk caused by the low flash point oil decomposition products formed by the oily substances, ensuring the safety of the sintering system. Furthermore, the method of this invention effectively recovers oil-containing iron oxide scale from enterprises, and the recovery effect is not affected by the oil content, enabling large-scale and highly economical recovery. The method of this invention can also utilize the combustion heat of oily substances in the oil-containing iron oxide scale to reduce the fuel consumption in the sintering mixture, thereby achieving full reuse of valuable resources in the oil-containing iron oxide scale and turning waste into treasure.

[0054] Furthermore, the thickness of the first layer 9 accounts for 65-70% of the total layer thickness, and the thickness of the second layer 10 accounts for 30-35% of the total layer thickness. The total layer thickness is the sum of the thicknesses of the first layer 9 and the second layer 10. By controlling the thickness of each layer, the oily substances can be fully combusted while ensuring the completion of the double-layer sintering endpoint temperature and the sintering process. For example, the thickness of the first layer 9 is 400-700 mm, and the thickness of the second layer 10 is 200-400 mm.

[0055] Furthermore, the particle size of the oil-containing iron oxide scale does not exceed 10 mm, and the amount of oil-containing iron oxide scale added to the sintering mixture of the secondary fabric layer 10 is 1 wt to 15 wt% to ensure that the oily substances can be fully burned.

[0056] In this embodiment of the invention, the sintering mixture of the first layer 9 and the sintering mixture of the second layer 10 can both adopt conventional sintering material formulas. The sintering materials include iron-containing materials, flux and fuel, and may also include other recycled auxiliary materials.

[0057] This invention also provides a process flow diagram for utilizing oil-containing iron oxide scale, as shown in the embodiment of the invention. Figure 2 As shown, this exhaust sintering system, by setting up a separable batching, mixing, and granulation system and a separable material distribution and ignition system in the sintering batching system, can achieve the preparation of two mixtures and multiple material distribution and ignition processes. The main batching system contains all normal batching raw materials (i.e., all sintering raw materials), including iron-containing materials, flux, fuel, and other recycled auxiliary materials, but excluding oil-containing iron oxide scale. The auxiliary batching system includes an oil-containing iron oxide scale silo, etc. The main batching line feeds materials according to a preset ratio and enters the mixing system A for mixing. Specifically, the materials first enter the primary mixer for water addition and mixing. After mixing, the material is divided into two parts according to metering requirements by a material distribution device. One part continues to enter the secondary mixer of the main line for enhanced mixing and granulation to form the main line mixture. The main line generally adopts a two-stage mixer mode. The other part of the mixed material is combined with the oil-containing iron oxide scale from the auxiliary line batching and then enters the mixing system B for mixing and granulation to form the auxiliary line mixture. The two mixtures are fed into different feeding systems (feeding system A and feeding system B, respectively) and ignition systems (ignition system A and ignition system B, respectively) on the sintering machine. The auxiliary line generally adopts a high-intensity mixer plus a first-stage mixer configuration. The main line mixture without oil-containing iron oxide scale enters the primary mixing bin first, while the auxiliary line mixture with oil-containing iron oxide scale enters the secondary mixing bin later.

[0058] The following two specific embodiments illustrate a method and system for utilizing oil-containing iron oxide scale according to the present invention.

[0059] Example 1

[0060] use Figure 1 The system for utilizing oily iron oxide scale shown includes a sintering machine 1, a 300㎡ sintering machine system with a feeding capacity of 650t / h. The secondary feeding layer 10 of the auxiliary line batching bin system 19 contains the following mass percentage components in its sintering mixture: 44.7% blended ore, 4.4% limestone powder, 5.0% dolomite, 3.5% metallurgical lime powder, 4.0% fuel, 1% oily iron oxide scale, 1% steel slag, 0.9% dust collector ash, 1.5% blast furnace gas ash, 18% internal return powder, and 16% external return powder.

[0061] 11 is the main batching silo system, which prepares the raw materials for production preparation, excluding oily iron oxide scale. 19 is the auxiliary batching silo system, which prepares the sintering mixture, including the recovered oily iron oxide scale. Each raw material is quantitatively fed into the main batching silo system 11 and the auxiliary batching silo system 19 according to the computer-designed proportions. The main batching materials are collected by the main batching belt 12 and then enter the main primary mixer 13 for thorough mixing and water addition. The online material distribution device 16 distributes the material according to the production ratio requirements. 70% of the main mixture enters the main line, and after being further mixed and granulated by the main secondary mixer 15, it is conveyed to the primary mixing silo 3 above the sintering machine 1. 30% of the main mixture, along with the oily iron oxide scale from the auxiliary line, is successively fed into the auxiliary primary mixer 18 and the auxiliary secondary mixer 20 for mixing and granulation, and then conveyed to the secondary mixing silo 6.

[0062] During normal production, sintering machine 1 operates from left to right. The bottom material hopper 2, storing 10-20mm particle size bottom material, first lays the bottom material layer 8, approximately 50mm thick, to protect the lower grate bars and prevent material leakage. The initial mixing hopper 3 then lays the initial material layer 9, accounting for 70% of the total material layer height, via the material laying system, and is ignited for the first time by the initial material surface ignition system 4. After a period of time, the secondary mixing hopper 6 continues to lay the secondary material layer 10, accounting for 30% of the total material layer height, on the already ignited platform, and is ignited by the secondary material surface ignition system 7.

[0063] Example 2

[0064] use Figure 1 The system for utilizing oily iron oxide scale shown includes a sintering machine 1, a 300㎡ sintering machine system with a feeding capacity of 650t / h. The sintering mixture of the secondary feeding layer 10 prepared by the auxiliary line batching bin system 19 contains the following mass percentage components: 43.7% blended ore, 4.4% limestone powder, 5.0% dolomite, 3.5% metallurgical lime powder, 4.0% fuel, 2% oily iron oxide scale, 1% steel slag, 0.9% dust collector ash, 1.5% blast furnace gas ash, 18% internal return powder, and 16% external return powder.

[0065] 11 is the main batching silo system, which prepares all raw materials for production preparation except for oily iron oxide scale. 19 is the auxiliary batching silo system, which prepares the sintering mixture including the recovered oily iron oxide scale. Each raw material is quantitatively fed into the main batching silo system 11 and the auxiliary batching silo system 19 according to the computer-designed proportions. The main batching materials are collected by the main batching belt 12 and then enter the main primary mixer 13 for thorough mixing and water addition. The online material distribution device 16 distributes the material according to the production ratio requirements. 65% of the main mixture enters the main line, and after being further mixed and granulated by the main secondary mixer 15, it is conveyed into the primary mixing silo 3 above the sintering machine 1. 35% of the main mixture, along with the oily iron oxide scale from the auxiliary line, is successively fed into the auxiliary primary mixer 18 and the auxiliary secondary mixer 20 for mixing and granulation, and then conveyed to the secondary mixing silo 6.

[0066] During normal production, sintering machine 1 operates from left to right. The bottom material hopper 2, storing 10-20mm particle size bottom material, first lays the bottom material layer 8, approximately 50mm thick, to protect the lower grate bars and prevent material leakage. The initial mixing hopper 3 then lays the initial material layer 9, accounting for 65% of the total material layer height, via the material laying system, and is ignited for the first time by the initial material surface ignition system 4. After a period of time, the secondary mixing hopper 6 continues to lay the secondary material layer 10, accounting for 35% of the total material layer height, on the already ignited platform, and is ignited by the secondary material surface ignition system 7.

[0067] Based on an annual processing capacity of 50,000 tons of oily iron oxide scale, and an estimated profit increase of 200 yuan per ton of oily iron oxide scale, the annual profit increase would be 10 million yuan.

[0068] The method and system for utilizing oily iron oxide scale in this invention solves the problem of resource recovery and utilization of large amounts of oily iron oxide scale in steel enterprises. The process route is economical and safe. Utilizing high-iron-content iron oxide scale can also improve the grade of sintered ore and reduce solid fuel consumption in sintered materials, thereby reducing the cost of sintered raw materials.

[0069] The method and system for utilizing oily iron oxide scale in this invention solves the long-standing problem of how to economically, efficiently, and safely dispose of oily iron oxide scale resources. It can effectively address the current issues of high difficulty and high operating costs in disposing of oily iron oxide scale, turning waste into treasure, achieving resource utilization and harmlessness, ensuring that solid waste does not leave the factory, promoting green production, and driving the construction of "zero-waste enterprises" and "zero-waste cities".

[0070] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for utilizing oil-containing iron oxide scale, characterized in that, Includes the following steps: In the sintering production process, a base layer is first laid on the sintering machine, then the first layer is laid on the base layer, and then the ignition is performed. After the sintering machine has run a certain distance, a second layer of material is laid on the first layer of material that has been laid and ignited, and then ignited again. The sintering mixture of the first layer does not contain oil-containing iron oxide scale, while the sintering mixture of the second layer contains oil-containing iron oxide scale. The thickness of the first layer accounts for 65-70% of the total layer thickness, and the thickness of the second layer accounts for 30-35% of the total layer thickness. The total layer thickness is the sum of the thicknesses of the first and second layers. The amount of oil-containing iron oxide scale added to the sintering mixture of the second layer is 1-15 wt%.

2. The method for utilizing oil-containing iron oxide scale as described in claim 1, characterized in that, The thickness of the first fabric layer is 400~700 mm, and the thickness of the second fabric layer is 200~400 mm.

3. A method for utilizing oil-containing iron oxide scale as described in claim 1 or 2, characterized in that, Both the sintering mixture of the first layer and the sintering mixture of the second layer contain iron-containing materials, flux, and fuel.

4. A system for utilizing oil-containing iron oxide scale, characterized in that, include: The exhaust sintering unit includes a sintering machine and a negative pressure exhaust device; A base material silo is used to lay the base material layer for the sintering machine; The initial mixing material distribution unit includes an initial mixing material batching device, a first mixing device, and an initial mixing material silo; the initial mixing material distribution unit is used to distribute the initial material layer; A secondary mixing material distribution unit includes a secondary mixing material batching device, a second mixing device, and a secondary mixing material silo; the secondary mixing material distribution unit is used to distribute a secondary material layer. as well as The ignition unit includes a primary material surface ignition system and a secondary material surface ignition system; the primary material surface ignition system is used to ignite the primary material layer, and the secondary material surface ignition system is used to ignite the secondary material layer. It also includes a material distribution device. The primary mixing material batching device includes a main line batching bin system and a main line batching belt located below it. The first mixing device includes a main line primary mixer, a main line primary mixing belt, and a main line secondary mixer. The main line batching belt transports the sintered mixture of the first material layer to the main line primary mixer for primary mixing, and then enters the material distribution device to be divided into two parts. One part is transported by the main line primary mixing belt to the main line secondary mixer for further mixing, and then enters the primary mixing bin. The main line batching bin system does not contain an oil-containing iron oxide scale bin. The secondary mixing and batching device includes an auxiliary line batching bin system and an auxiliary line batching belt located below it; the second mixing device includes an auxiliary line primary mixing belt, an auxiliary line primary mixer, and an auxiliary line secondary mixer; the auxiliary line batching belt transports the sintered mixture from the secondary feeding layer to the auxiliary line primary mixing belt, while another portion of the sintered mixture from the initial feeding layer of the distribution device also enters the auxiliary line primary mixing belt; the auxiliary line primary mixing belt transports the material on it to the auxiliary line primary mixer for primary mixing, then enters the auxiliary line secondary mixer for further mixing, and then enters the secondary mixing bin; the auxiliary line batching bin system includes an oil-containing iron oxide scale bin.

5. The system for utilizing oil-containing iron oxide scale as described in claim 4, characterized in that, It also includes a material layer oxygenation device for supplying oxygen to the first fabric layer and / or the second fabric layer.

6. The system for utilizing oil-containing iron oxide scale as described in claim 4, characterized in that, Both the main line batching silo system and the auxiliary line batching silo system include multiple parallel conical storage silos.

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