Layered material distribution sintering and cooling method and system

Abstract

The invention discloses a layered material distribution sintering and cooling method. The method comprises the following steps: 1) sequentially and alternately paving sintering raw materials and spacing materials on a sintering trolley to obtain a mixed sintering material layer, wherein the sintering raw materials are separated by at least one spacing material layer from top to bottom to form a plurality of sintering raw material unit layer structures; the sintering machine is started to conduct sintering treatment on the mixed sintering material layer, and at least two sinter unit layers with different temperatures are obtained; and (2) according to different temperatures of all the sinter unit layers, all the sinter unit layers are independently crushed and cooled, and then finished sinter is obtained. According to the layered material distribution sintering and cooling method, the multiple sintering raw material unit layers are arranged for sintering, the interval material layers are arranged, sintered ore at different temperatures obtained after sintering is completed is cooled respectively, the cooling efficiency and the heat energy recovery rate of the sintered ore are improved, meanwhile, the working load of an annular cooler is reduced, and the production cost is reduced. And one-time investment of the circular cooler is saved.

Description

Technical Field

[0001] The invention relates to a sintering and cooling method and system, in particular to a layered material sintering and cooling method and system, belonging to the technical field of iron ore sintering. Background Art

[0002] The general sintering process is one of the main methods for making iron ore blocks in the steel process. At present, the annual output of sintered ore in China exceeds 1 billion tons, and the fuel used for sintering is mainly coke powder. According to the current energy consumption of 40 to 50 kgce per ton of sintered ore, the sintering industry emits more than 100 million tons of CO2 throughout the year, which is an important source of CO2 emissions in the steel industry and even the whole country. In the context of the country's implementation of the dual carbon strategic goals, carbon emission reduction in the sintering process is particularly important. The current mainstream sintering process is exhaust sintering, and the main equipment is belt sintering machine, ignition and holding furnace, distributor, ring cooler, etc. Belt sintering machine has become the absolute mainstream of sintering production in the world due to its high single-shot output and high mechanization and automation.

[0003] Domestic and foreign researchers have conducted a lot of research and attempts on energy saving and low carbon in the sintering process. At present, the most advanced level of energy consumption in the sintering process has reached below 40kgce / ts, but the energy consumption of most sintering machines is still generally between 40 and 50kgce / ts, and there is still room for reduction in the energy consumption of the sintering process.

[0004] The sintering raw materials are mainly composed of iron ore, flux and fuel. The sintering fuel is mainly fossil fuel coke powder, which accounts for about 3-5% of the sintering raw materials. After the various components of the sintering raw materials are fully mixed and granulated, they are evenly spread on the sintering trolley by the distributor. Figure 3 The trolley shown in the figure is moving at a constant speed from left to right. When the trolley moves into the ignition and insulation furnace, gas and air are introduced into the ignition and insulation furnace through the ignition burner for ignition, and the coke powder on the surface of the sintering raw material is ignited. Then, under the action of the exhaust negative pressure under the trolley, the air above the trolley is continuously sucked into the material layer, and the combustion zone in the material layer is transmitted from top to bottom, completing the entire sintering process. The high-temperature flue gas is drawn into the large flue under the trolley by the main exhaust fan, and is discharged into the atmosphere after waste heat utilization and desulfurization and denitrification. When the sintered hot ore is unloaded from the trolley, the average temperature reaches about 750℃, and it is sent to the ring cooler to be cooled to below 150℃. The ring cooler uses air blowing to cool the sintered ore, and the high-temperature exhaust gas generated is used for waste heat utilization. The cooling exhaust gas temperature in the first 40% of the ring cooler reaches 250-500°C, which can generally be used to produce steam for power generation. The cooling air temperature in the second half is lower, and is generally used as combustion air for sintering ignition furnaces, or for hot air sintering.

[0005] From the analysis of the cross-sectional images of the existing sintering machine tail, when the sintered ore reaches the tail of the machine, the sintering process has been basically completed. Due to the heat storage caused by the exhaust at the bottom of the trolley, only the sintered ore at the bottom of the trolley is maintained in a high-temperature red-hot state, while the sintered ore at the upper part is cooled by the inhaled air and the actual temperature is already lower. Figure 4 The figure shows the AA schematic diagram of the tail car section of the sintering machine. The temperature of the sintered ore in the car section will show obvious stratification. Figure 2 Middle III is the red material area (i.e. high temperature area), concentrated in the lower 30% area of ​​the material layer, with a temperature of 700-1200°C and an average temperature of 1000-1050°C; II is the medium-temperature mining area, concentrated in the middle and upper 40% area of ​​the material layer, with a wide temperature distribution of 150-700°C and an average temperature of 350-400°C. The surface layer I, in which the uppermost part of the material layer is the surface layer in contact with the air, is basically close to room temperature, with a temperature range of 50-150°C.

[0006] The current material cooling method is to mix and crush the 70% of medium- and low-temperature black material in the upper middle part and the 30% of high-temperature drying material in the lower part and put them into the ring cooler. This reduces the overall temperature of the sintered ore, increases the workload of the ring cooler, and reduces the quality and utilization efficiency of the waste heat of the sintered ore. Summary of the invention

[0007] In view of the problems of low quality and utilization efficiency of waste heat of sintered ore and high workload of ring cooler in the prior art, the present invention proposes a method and system for layered sintering and cooling. The sintered raw materials are divided into at least two sintered raw material unit layers from top to bottom, and a spacer layer is set between adjacent sintered raw material unit layers. After sintering is completed, different cooling methods are used according to different thermal qualities of sintered ore, and the obtained upper low-temperature sintered ore and lower high-temperature sintered ore are cooled separately to improve the cooling efficiency and sintered ore heat energy recovery rate.

[0008] According to a first embodiment of the present invention, a method for sintering and cooling a layered cloth is provided.

[0009] A method for sintering and cooling layered cloth, the method comprising the following steps:

[0010] 1) laying sintering raw materials and spacer materials alternately on a sintering trolley in sequence to obtain a mixed sintering material layer having a plurality of sintering raw material unit layer structures, in which the sintering raw materials are separated from top to bottom by at least one layer of spacer material; starting a sintering machine to sinter the mixed sintering material layer to obtain at least two sintered ore unit layers with different temperatures;

[0011] 2) According to the different temperatures of each sintered ore unit layer, each sintered ore unit layer is crushed and cooled independently to obtain the finished sintered ore.

[0012] Preferably, in step 1), in the mixed sintering material layer, the number of the spacer material layers is 1 to 5 layers, preferably 2 to 3 layers; and there is a sintering raw material unit layer on the upper side and the lower side of any spacer material layer. Preferably, the layer thickness of each spacer material layer is the same or different. The layer thickness of each sintering raw material unit layer is the same or different.

[0013] Preferably, the spacer material in the spacer material layer is a mixture of any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore.

[0014] Preferably, the thickness of the spacer material layer is 1 to 10 cm, preferably 2 to 8 cm.

[0015] Preferably, the particle size of the spacer material is 5 to 10 mm, preferably 6 to 9 mm.

[0016] Preferably, the spacer material layer is any one of a 3-5 cm thick coal gangue layer, a 5-8 cm thick blast furnace slag layer, a 5-8 cm thick steel slag layer, a 1-3 cm thick limestone layer and a 5-8 cm thick lump ore layer.

[0017] Preferably, fuel is also mixed in the spacer layer; preferably, the fuel is coke; preferably, the amount of fuel mixed in the spacer layer is controlled so that the total carbon content in the gangue layer is 20% to 30%, the total carbon content in the blast furnace slag layer, steel slag layer and lump ore layer is 3% to 5%, and the total carbon content in the limestone layer is 0.5% to 2%; preferably, the carbon content in the lower spacer layer is less than the carbon content in the upper spacer layer.

[0018] Preferably, the cooling of each sintered ore unit layer independently is as follows: each obtained sintered ore unit layer is sent to different ring coolers for cooling according to different temperatures, and waste heat of different qualities collected by different ring coolers is utilized separately.

[0019] Preferably, according to the temperature of each sintered ore unit layer obtained after sintering, different sintered ore unit layers are divided into a medium-temperature layer and a high-temperature layer, and optionally include or exclude a low-temperature layer; the sintered ore in the low-temperature layer is transported to the sintering finished product warehouse, the sintered ore in the medium-temperature layer is sent to a low-temperature ring cooler for cooling, and the sintered ore in the high-temperature layer is sent to a high-temperature ring cooler for cooling.

[0020] Preferably, the temperature of the sintered ore in the low-temperature layer is 50-200°C; the temperature of the sintered ore in the medium-temperature layer is 150-800°C; and the temperature of the sintered ore in the high-temperature layer is 700-1200°C.

[0021] Preferably, the waste heat of different qualities collected by different ring coolers are utilized separately as follows: the low-temperature ring cooler obtains low-temperature cooling exhaust gas; the front section of the high-temperature ring cooler obtains high-temperature cooling exhaust gas, the middle section of the high-temperature ring cooler obtains medium-temperature cooling exhaust gas, and the rear end of the high-temperature ring cooler obtains low-temperature cooling exhaust gas; the obtained low-temperature cooling exhaust gas is used for sintering ignition or hot air sintering, and the high-temperature cooling exhaust gas is used for power generation.

[0022] Preferably, in the mixed sintering material layer, the number of the spacer material layers is 2 layers, and the sintering raw material is separated from top to bottom into an upper unit layer of the sintering raw material, a middle unit layer of the sintering raw material, and a lower unit layer of the sintering raw material by the two spacer material layers; wherein the thickness of the upper unit layer of the sintering raw material is L1,%; the thickness of the middle unit layer of the sintering raw material is L2,%; the thickness of the lower unit layer of the sintering raw material is L3,%; wherein L1, L2, and L3 are all percentages of the thickness of each material layer in the total thickness of the material layer excluding the thickness of the spacer material layer; the percentage of each material layer in the total thickness of the material layer is determined by the following formula:

[0023]

[0024] L2=1-L1-L3……(Formula 3)

[0025] In the formula, r is the average particle size of the sintering raw material, mm; M is the moisture content of the sintering raw material, %; C is the carbon content of the sintering raw material, %; L is the total thickness of the material layer, cm; d is the total thickness of the two separation layers, cm; α, β, γ, and δ are adjustment coefficients, α ranges from 0.2 to 0.8, β ranges from 0.2 to 0.8, γ ranges from 1 to 3, and δ ranges from 2 to 5.

[0026] According to a second embodiment of the present invention, a system for sintering and cooling layered materials is provided.

[0027] A layered material distribution sintering and cooling system, the system includes a sintering machine, a sintering trolley, a material distribution device, an ignition device, a flue gas treatment device, a sintered ore separation device and a ring cooler. The sintering trolley is arranged on the sintering machine, and the material distribution device and the ignition device are both arranged above the sintering trolley. A large flue is arranged below the sintering machine, and the flue gas treatment device is connected to the large flue. According to the movement direction of the sintering trolley, the material distribution device is arranged upstream of the ignition device. The material outlet of the sintering machine is connected to the material inlet of the sintered ore separation device, and the material outlet of the sintered ore separation device is connected to the material inlet of the ring cooler. At least two layers of sintering raw material unit layers are laid on the sintering machine, and a material separation layer is laid between adjacent sintering raw material unit layers. Among them, the system includes 2 to 6 ring coolers in total, and the sintered ore separation device is provided with material outlets of the same number as the number of ring coolers. Preferably, the spacer material in the spacer material layer is any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore. Preferably, the sintering machine is provided with 3 layers of sintering raw material unit layers and 2 layers of spacer material layers, and the sintering raw material unit layers and the spacer material layers are alternately laid. The system also includes a sintered finished product bin. The ring cooler includes a high-temperature ring cooler and a low-temperature ring cooler. The sintered ore separation device is provided with a high-temperature material outlet, a medium-temperature material outlet, and a low-temperature material outlet, the low-temperature material outlet is connected to the sintered finished product bin, the medium-temperature material outlet is connected to the low-temperature ring cooler, and the high-temperature material outlet is connected to the high-temperature ring cooler.

[0028] In the present invention, a plurality of sintering raw material unit layers are arranged from top to bottom in the sintering trolley, and a spacer material layer is arranged between adjacent sintering raw material unit layers to form a mixed sintering material layer. After sintering is completed, a plurality of sintered ore unit layers with different temperatures and not compacted to each other are obtained. The temperature of the lower sintered ore unit layer is higher and the quality of waste heat is relatively higher, while the temperature of the upper sintered ore unit layer is lower and the quality of waste heat is relatively lower. The plurality of sintered ore unit layers are cooled separately, and the high-temperature sintered ore unit layer is cooled to obtain high-quality waste heat, and the low-temperature sintered ore unit layer is cooled to obtain low-quality waste heat. According to different sintered ore thermal qualities, different cooling methods are used to improve the cooling efficiency and the sintered ore heat recovery rate, while reducing the workload of the ring cooler and saving the one-time investment of the ring cooler.

[0029] In the present invention, in order to realize the layered and quality-based cooling of the sintered ore, the sintered ore must be separated according to the different temperature levels before the sintered ore is cooled. Since sintering is the process in which the iron ore produces a liquid phase and condenses into blocks under the joint reaction of coke and flux, the sintering raw materials that were originally in bulk become a whole after sintering. The sintered ore must be crushed as a whole before conventional cooling. Therefore, the effective separation of the sintered raw materials during the sintering process is the key and difficulty in the implementation of the present invention. In order to solve the above-mentioned problems, the spacing material layer must meet the following requirements: 1. It can transmit the combustion zone. Since sintering relies on the bottom suction to form the combustion zone, high temperature is generated where the combustion zone passes, so that the sintered ore is melted and sintered. If the spacing material layer blocks the transmission of the combustion zone, it will cause the sintering to be extinguished, and the sintering below the spacing material layer will not be completed. 2. It can avoid agglomeration. The metal mineral forms a low-temperature eutectic under the action of the flux, and after cooling, it hardens to complete the sintering. However, the spacer layer itself cannot participate in the agglomeration reaction, so that the sintered ore forms an integral sintered ore unit layer above and below the spacer layer, respectively, which is convenient for subsequent separation of the whole block. 3. It has a certain air permeability. The air must be able to efficiently penetrate the spacer layer to provide oxygen for the lower sintered material. 4. It has a certain mechanical strength. Due to the relatively large density and weight of the sintered ore, the spacer layer is located below the sintered ore and is squeezed by the sintered ore above. It must be able to withstand the pressure from the sintered ore to avoid collapse. 5. Try not to add additional materials that are not required for the steel process. Because the spacer layer will inevitably enter the blast furnace with the sintered ore, if there are too many useless materials, the smelting energy consumption of the blast furnace will inevitably increase. 6. Low cost and wide source of materials.

[0030] In the present invention, according to the requirements for the spacer layer, several spacer layer materials are proposed, and according to the characteristics of the spacer layer materials, specific requirements are proposed for the thickness of the spacer layer corresponding to each material: 1. Coal gangue. Coal gangue is a solid waste generated in the process of coal mining and coal preparation. Coal gangue contains a certain amount of carbon, which can effectively transfer the sintering combustion zone. The carbon content of coal gangue used as a spacer material should not be less than 20%, the particle size of coal gangue is 5 to 10 mm, and the thickness of the material in the material layer is 3 to 5 cm. Too low carbon content will lead to failure of sintering ignition, too small particle size will affect sintering permeability, and too large particle size will lead to too large gaps in the spacer layer, and the sintering material will penetrate into the gaps, and the adjacent sintering raw material unit layers cannot be effectively separated. 2. Blast furnace slag and steel slag. Blast furnace slag and steel slag come from the steel process itself, and their own output is large and the supply is stable, without adding additional material procurement costs. The iron content in steel slag is 10% to 20%. By sintering and returning to the blast furnace, a part of the iron can be recovered. The particle size of blast furnace slag and steel slag used as the interval material layer is 5 to 10 mm, and the thickness of the material layer is 5 to 8 cm. Since the steel slag still contains a certain amount of iron, in order to avoid the melting and sintering of this part of iron, which will cause difficulties in subsequent separation, the thickness of the material layer needs to be slightly thicker than that of coal gangue. Since the thickness of the material layer is relatively thick, in order to prevent the combustion zone from penetrating the interval material zone, it is necessary to add 3% to 5% of coke to the lump ore as an ignition medium for transmitting combustion. 3. Limestone. The main component of limestone is calcium carbonate, which decomposes into lime (CaO) and carbon dioxide under the conditions of sintering combustion zone temperature (1100 to 1300 ° C). Carbon dioxide enters the flue with the sintering flue gas, and lime enters the blast furnace together with the sintered ore, which can be used as a slag-making agent for the blast furnace. Using limestone as a paving medium does not add any unnecessary materials to the steel process, does not increase the energy consumption of the blast furnace, and has a wide range of sources. It is an ideal material separation medium. When using limestone as a material separation medium, the particle size is 5 to 10 mm, and the thickness of the material in the material layer is 1 to 3 cm. Since limestone does not contain carbon and limestone decomposes and absorbs heat, if the paving thickness is too thick, it may cause the sintering combustion zone to extinguish, so the paving thickness must be controlled within a reasonable range. 4. Lump ore. Lump ore is one of the three major iron raw materials entering the blast furnace (sintering, pelletizing, and lump ore). Using lump ore as a material separation medium does not require additional material flow in the steel process, and does not increase the additional medium procurement cost. The particle size of the lump ore as a material separation medium is 5 to 10 mm, and the thickness of the material in the material layer is 5 to 8 cm. When using lump ore as a material separation medium, due to the relatively thick material layer, in order to prevent the combustion zone from penetrating the material separation zone, it is necessary to add 3% to 5% coke to the lump ore as an ignition medium for transmitting combustion. The present invention specifically limits the laying thickness of each material according to the properties of each spacer layer material, and also limits the carbon content in the spacer layer to achieve the best spacer effect.

[0031] In the present invention, in the mixed sintering material layer, when the number of interval material layers is 2 layers, the material layer is divided into the upper unit layer of sintering raw materials, the middle unit layer of sintering raw materials and the lower unit layer of sintering raw materials. The thickness of each layer is affected by the characteristics of the sintering raw materials. When the particle size of the sintering raw materials is larger and the humidity is smaller, the air permeability is better, the corresponding upper layer is better cooled by air, and the heat is taken away more smoothly by the flue gas, then L1 is larger and L3 is smaller; when the carbon content in the sintering material layer is larger, the sintering heat storage effect is more obvious and L3 is larger. The thickness of each material layer is determined by the following formula:

[0032]

[0033] L2=1-L1-L3

[0034] In the above formula, the thickness of the upper, middle and lower layers are L1, L2, and L3 respectively, and the unit is %, that is, the thickness of each layer accounts for the percentage of the total thickness of the material layer excluding the thickness of the barrier layer; r is the average particle size of the sintering raw material, mm; M is the moisture content of the sintering raw material, %; C is the carbon content of the sintering raw material, %; L is the total thickness of the material layer, cm; d is the total thickness of the two barrier layers, cm; α, β, γ, and δ are adjustment coefficients, α ranges from 0.2 to 0.8, β ranges from 0.2 to 0.8, γ ranges from 1 to 3, and δ ranges from 2 to 5.

[0035] The following are several sets of values ​​calculated according to the above formula. In the table, the total thickness D of the material layer is 100 cm, and the total thickness of the spacer layer is 8 cm.

[0036] r / mm C M α β γ δ <![CDATA[L1 / %]]> <![CDATA[L2 / %]]> <![CDATA[L3 / %]]> 5 3.5％ 8％ 0.4 0.3 1.8 2.8 21.5 34.3 44.2 5 4.5 8％ 0.4 0.3 1.8 2.8 19.4 30.2 50.4 10 3.5 8％ 0.4 0.3 1.8 2.8 26.5 33.2 40.3 5 3.5 12％ 0.4 0.3 1.8 2.8 17.4 48.5 34.0

[0037] In the present invention, the actual number of layers of the sintering raw material unit layer is comprehensively considered according to factors such as the material layer thickness and the quality of the sintered ore during the production process. When there are 3 sintering raw material unit layers and 2 spacer material layers, they are A, B, C, D, and E from top to bottom, respectively, wherein A, C, and E are sintering raw material unit layers, and B and D are spacer material layers. After sintering, the sintered ore of the A layer is a low-temperature sintered ore (50-150°C), the sintered ore of the C layer is a medium-temperature sintered ore (150-700°C), and the sintered ore of the E layer is a high-temperature sintered ore (700-1200°C). After the surface sintered ore is ignited by the ignition furnace, the sintering material begins to sinter from top to bottom, and the combustion zone penetrates the isolation zone and continues to sinter downward. Before the sintered ore is unloaded from the trolley, the three layers of sintered ore A / C / E are separated by a special separation device and crushed separately. After the sintering ore is separated and crushed, the A-layer sintering ore is close to the sintering surface and has a lower temperature of only 50-150°C. Its thickness accounts for 20%-30% of the sintering raw material unit layer. This part of the sintering ore is close to room temperature, and the waste heat utilization value is low. It has reached the temperature conditions of conventional belt transportation and can be directly transported to the sintering finished product warehouse by conventional transportation belt for standby. The C-layer sintering ore is a medium-temperature sintering ore with a wide temperature distribution range of 150-700°C and an average temperature of 350-400°C. This part of the sintering ore enters the low-temperature ring cooler for cooling alone. After the sintering ore is cooled to below 150°C, the sintering ore is transported to the sintering finished product warehouse by belt. The cooling exhaust gas temperature is about 200-300°C, which can be used for sintering ignition or hot air sintering. The E-layer sintered ore is a high-temperature sintered ore with a relatively high temperature of 700-1200°C and an average temperature of 1000-1050°C. The quality of waste heat utilization is relatively high. After crushing, this part of the sintered ore enters the high-temperature ring cooler for cooling alone. The first 30% of the ring cooling area can generate high-temperature steam above 600°C for high-parameter power generation, and its heat recovery efficiency is higher than that of traditional technology; the middle 40% of the ring cooler area can generate 400-600°C steam for conventional power generation; the last 30% of the ring cooler still generates cooling waste gas at 200-300°C for sintering ignition or hot air sintering.

[0038] In the present invention, since the second spacer material layer is at the bottom and has a heat storage effect during sintering, the carbon content required for the lower layer material can be less, and the carbon content of the second spacer material layer is less than that of the first spacer material layer.

[0039] In the present invention, experiments show that it is completely infeasible to use a physical partition with holes to replace the spacer material layer, because sintering is a process of exhausting air from top to bottom, and heat and mass transfer are required downward. Even if the partition has holes, hot air and flue gas can be transferred downward through the small holes, but it is far from meeting the sintering needs of the lower layer of materials. Therefore, if a partition is used, the only advantage is that the separation effect is good, and the sintering material layers of each layer can be easily separated in the later stage, but the sintering material below the partition will almost fail to sinter, and the combustion zone cannot move downward. The middle and lower layers are almost equivalent to no sintering, which seriously affects the main sintering process; and the sintering combustion zone temperature is 1200-1400℃. For a long time at such a high temperature, it is also necessary to bear hundreds of tons of sintering raw materials on it. Such a partition, no matter what material it is made of, will generally be crushed, so it is actually completely infeasible to place a partition in the raw material. The finished sintered ore, high temperature or low temperature exhaust gas mentioned later basically do not exist.

[0040] In the present invention, it should be noted that if the sintering raw material unit layer is more finely layered, the more layers there are, the more accurate the control of heating and cooling of the material layer will be, but too many layers will also increase the difficulty and cost of material distribution. Therefore, in the actual production process, the number of layers needs to be comprehensively considered based on factors such as material layer thickness, sinter ore quality and sintering raw material characteristics.

[0041] In the present invention, all formulas in the present invention are obtained by fitting by the inventors based on experiments and engineering applications, and all calculations are numerical values ​​converted according to prescribed units, which are obtained by substituting the converted numerical values ​​into the formulas for calculation (after converting the units of each parameter, only the numerical values ​​are substituted into the formulas for calculation without substituting the units, and the units are only used to adjust the size of the numerical values).

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The present invention provides a method and system for layered material distribution sintering and cooling, which sets multiple sintering raw material unit layers for sintering, and sets interval material layers, and cools the sintered ores at different temperatures obtained after sintering separately, thereby improving the cooling efficiency and the heat energy recovery rate of the sintered ores, while reducing the workload of the ring cooler and saving the primary investment of the ring cooler.

[0044] 2. The present invention provides a method and system for sintering and cooling layered materials. According to the performance requirements for the spacer material layer, several spacer materials are proposed, and the laying thickness of each material is specifically limited according to the properties of different materials. In addition, parameters such as the carbon content in the spacer material layer are specifically limited to achieve the best spacer effect without affecting sintering. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1A schematic structural diagram of a system for sintering and cooling layered materials provided by the present invention.

[0046] Figure 2 This is the cross-sectional view of the sintered ore layer at BB.

[0047] Figure 3 It is a structural schematic diagram of a sintering system in the prior art.

[0048] Figure 4 This is the cross-section of the sintered ore at AA.

[0049] Figure numerals: 1: sintering machine; 2: sintering trolley; 3: material distribution device; 4: ignition device; 5: flue gas treatment device; 6: sintered ore separation device; 7: ring cooler; 701: high-temperature ring cooler; 702: low-temperature ring cooler; 8: large flue; 9: sintered finished product warehouse. DETAILED DESCRIPTION

[0050] The technical solution of the present invention is illustrated below by way of example, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0051] According to a first embodiment of the present invention, a method for sintering and cooling a layered cloth is provided.

[0052] A method for sintering and cooling layered cloth, the method comprising the following steps:

[0053] 1) laying sintering raw materials and spacer materials alternately on a sintering trolley in sequence to obtain a mixed sintering material layer having a plurality of sintering raw material unit layer structures, in which the sintering raw materials are separated from top to bottom by at least one layer of spacer material; starting a sintering machine to sinter the mixed sintering material layer to obtain at least two sintered ore unit layers with different temperatures;

[0054] 2) According to the different temperatures of each sintered ore unit layer, each sintered ore unit layer is crushed and cooled independently to obtain the finished sintered ore.

[0055] Preferably, in step 1), in the mixed sintering material layer, the number of the spacer material layers is 1 to 5 layers, preferably 2 to 3 layers; and there is a sintering raw material unit layer on the upper side and the lower side of any spacer material layer. Preferably, the layer thickness of each spacer material layer is the same or different. The layer thickness of each sintering raw material unit layer is the same or different.

[0056] Preferably, in the mixed sintering material layer, the number of spacer layers is 2, and the sintering raw material is separated from top to bottom into an upper unit layer of sintering raw material, a middle unit layer of sintering raw material and a lower unit layer of sintering raw material by the two spacer layers; wherein, the upper unit layer of sintering raw material accounts for 25-35% of the total amount of sintering raw material, the middle unit layer of sintering raw material accounts for 30-50% of the total amount of sintering raw material, and the lower unit layer of sintering raw material accounts for 25-35% of the total amount of sintering raw material.

[0057] Preferably, the spacer material in the spacer material layer is a mixture of any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore.

[0058] Preferably, the thickness of the spacer material layer is 1 to 10 cm, preferably 2 to 8 cm.

[0059] Preferably, the particle size of the spacer material is 5 to 10 mm, preferably 6 to 9 mm.

[0060] Preferably, the spacer material layer is any one of a 3-5 cm thick coal gangue layer, a 5-8 cm thick blast furnace slag layer, a 5-8 cm thick steel slag layer, a 1-3 cm thick limestone layer and a 5-8 cm thick lump ore layer.

[0061] Preferably, fuel is also mixed in the spacer layer; preferably, the fuel is coke; preferably, the amount of fuel mixed in the spacer layer is controlled so that the total carbon content in the gangue layer is 20% to 30%, the total carbon content in the blast furnace slag layer, steel slag layer and lump ore layer is 3% to 5%, and the total carbon content in the limestone layer is 0.5% to 2%; preferably, the carbon content in the lower spacer layer is less than the carbon content in the upper spacer layer.

[0062] Preferably, the cooling of each sintered ore unit layer independently is as follows: each obtained sintered ore unit layer is sent to different ring coolers for cooling according to different temperatures, and waste heat of different qualities collected by different ring coolers is utilized separately.

[0063] Preferably, according to the temperature of each sintered ore unit layer obtained after sintering, different sintered ore unit layers are divided into a medium-temperature layer and a high-temperature layer, and optionally include or exclude a low-temperature layer; the sintered ore in the low-temperature layer is transported to the sintering finished product warehouse, the sintered ore in the medium-temperature layer is sent to a low-temperature ring cooler for cooling, and the sintered ore in the high-temperature layer is sent to a high-temperature ring cooler for cooling.

[0064] Preferably, the temperature of the sintered ore in the low-temperature layer is 50-200°C; the temperature of the sintered ore in the medium-temperature layer is 150-800°C; and the temperature of the sintered ore in the high-temperature layer is 700-1200°C.

[0065] Preferably, the waste heat of different qualities collected by different ring coolers are utilized separately as follows: the low-temperature ring cooler obtains low-temperature cooling exhaust gas; the front section of the high-temperature ring cooler obtains high-temperature cooling exhaust gas, the middle section of the high-temperature ring cooler obtains medium-temperature cooling exhaust gas, and the rear end of the high-temperature ring cooler obtains low-temperature cooling exhaust gas; the obtained low-temperature cooling exhaust gas is used for sintering ignition or hot air sintering, and the high-temperature cooling exhaust gas is used for power generation.

[0066] Preferably, in the mixed sintering material layer, the number of the spacer material layers is 2 layers, and the sintering raw material is separated from top to bottom into an upper unit layer of the sintering raw material, a middle unit layer of the sintering raw material, and a lower unit layer of the sintering raw material by the two spacer material layers; wherein the thickness of the upper unit layer of the sintering raw material is L1,%; the thickness of the middle unit layer of the sintering raw material is L2,%; the thickness of the lower unit layer of the sintering raw material is L3,%; wherein L1, L2, and L3 are all percentages of the thickness of each material layer in the total thickness of the material layer excluding the thickness of the spacer material layer; the percentage of each material layer in the total thickness of the material layer is determined by the following formula:

[0067]

[0068] L2=1-L1-L3……(Formula 3)

[0069] In the formula, r is the average particle size of the sintering raw material, mm; M is the moisture content of the sintering raw material, %; C is the carbon content of the sintering raw material, %; L is the total thickness of the material layer, cm; d is the total thickness of the two separation layers, cm; α, β, γ, and δ are adjustment coefficients, α ranges from 0.2 to 0.8, β ranges from 0.2 to 0.8, γ ranges from 1 to 3, and δ ranges from 2 to 5.

[0070] According to a second embodiment of the present invention, a system for sintering and cooling layered materials is provided.

[0071] A layered material distribution sintering and cooling system, the system comprises a sintering machine 1, a sintering trolley 2, a material distribution device 3, an ignition device 4, a flue gas treatment device 5, a sintered ore separation device 6 and a ring cooler 7. The sintering trolley 2 is arranged on the sintering machine 1, and the material distribution device 3 and the ignition device 4 are both arranged above the sintering trolley 2. A large flue 8 is arranged below the sintering machine 1, and the flue gas treatment device 5 is connected to the large flue 8. According to the movement direction of the sintering trolley 2, the material distribution device 3 is arranged upstream of the ignition device 4. The material outlet of the sintering machine 1 is connected to the material inlet of the sintered ore separation device 6, and the material outlet of the sintered ore separation device 6 is connected to the material inlet of the ring cooler 7. At least two layers of sintering raw material unit layers are laid on the sintering machine 1, and a material separation layer is laid between adjacent sintering raw material unit layers. Among them, the system comprises 2 to 6 ring coolers 7 in total, and the sintered ore separation device 6 is provided with the same number of material outlets as the number of the ring coolers 7. Preferably, the spacer material in the spacer material layer is any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore.

[0072] Preferably, three layers of sintering raw material unit layers and two layers of spacer material layers are laid on the sintering machine 1, and the sintering raw material unit layers and the spacer material layers are laid alternately. The system also includes a sintered finished product bin 9. The annular cooler 7 includes a high-temperature annular cooler 701 and a low-temperature annular cooler 702. The sintered ore separation device 6 is provided with a high-temperature material outlet, a medium-temperature material outlet and a low-temperature material outlet, the low-temperature material outlet is connected to the sintered finished product bin 9, the medium-temperature material outlet is connected to the low-temperature annular cooler 702, and the high-temperature material outlet is connected to the high-temperature annular cooler 701.

[0073] Example 1

[0074] A layered material distribution sintering and cooling system, the system comprises a sintering machine 1, a sintering trolley 2, a material distribution device 3, an ignition device 4, a flue gas treatment device 5, a sintered ore separation device 6 and a ring cooler 7. The sintering trolley 2 is arranged on the sintering machine 1, and the material distribution device 3 and the ignition device 4 are both arranged above the sintering trolley 2. A large flue 8 is arranged below the sintering machine 1, and the flue gas treatment device 5 is connected to the large flue 8. According to the movement direction of the sintering trolley 2, the material distribution device 3 is arranged upstream of the ignition device 4. The material outlet of the sintering machine 1 is connected to the material inlet of the sintered ore separation device 6, and the material outlet of the sintered ore separation device 6 is connected to the material inlet of the ring cooler 7. At least two layers of sintering raw material unit layers are laid on the sintering machine 1, and a material separation layer is laid between adjacent sintering raw material unit layers. Among them, the system comprises two ring coolers 7 in total, and the sintered ore separation device 6 is provided with the same number of material outlets as the ring coolers 7. The spacer material in the spacer material layer is coal gangue.

[0075] Example 2

[0076] Example 1 is repeated, except that the system further includes a sintered finished product bin 9. The two ring coolers 7 are a high-temperature ring cooler 701 and a low-temperature ring cooler 702. The sintered ore separation device 6 is provided with a high-temperature material outlet, a medium-temperature material outlet and a low-temperature material outlet, the low-temperature material outlet is connected to the sintered finished product bin 9, the medium-temperature material outlet is connected to the low-temperature ring cooler 702, and the high-temperature material outlet is connected to the high-temperature ring cooler 701.

[0077] Application Example 1

[0078] A method for sintering and cooling layered cloth is performed using the system described in Example 2, and the method comprises the following steps:

[0079] 1) The sintering raw materials and the spacer materials are alternately laid on the sintering trolley in sequence to obtain a mixed sintering material layer having a sintering raw material unit layer structure formed by two layers of spacer material layers from top to bottom, which are an upper unit layer of sintering raw materials, a first spacer material layer, a middle unit layer of sintering raw materials, a second spacer material layer and a lower unit layer of sintering raw materials from top to bottom; the sintering machine is started to sinter the mixed sintering material layer to obtain an upper unit layer of sintered ore, a first spacer material layer, a middle unit layer of sintered ore, a second spacer material layer and a lower unit layer of sintered ore from top to bottom.

[0080] 2) The average temperature of the upper unit layer of sintered ore is 85℃, the average temperature of the middle unit layer of sintered ore is 402℃, and the average temperature of the lower unit layer of sintered ore is 1037℃. After each unit layer of sintered ore is crushed independently, the upper unit layer of sintered ore is transported to the sintered finished product warehouse, the middle unit layer of sintered ore is sent to the low-temperature ring cooler, and the lower unit layer of sintered ore is sent to the high-temperature ring cooler. After cooling, 650t / h of finished sintered ore is obtained. The low-temperature ring cooler obtains 1811Nm 3 / h low temperature exhaust gas with a temperature of 265℃, high temperature ring cooler to obtain 1321Nm 3 / h high temperature exhaust gas with a temperature of 718℃, 2241Nm 3 / h medium temperature exhaust gas with a temperature of 530℃ and 2514Nm 3 / h low-temperature exhaust gas with a temperature of 252°C. The low-temperature exhaust gas is used for sintering ignition, the medium-temperature exhaust gas is used for hot air sintering, and the high-temperature exhaust gas is used for power generation.

[0081] Among them, the spacer material in the first spacer layer and the second spacer layer is coal gangue, the particle size of the coal gangue is 7mm, and the first spacer layer and the second spacer layer are both mixed with coke. The thickness of the first spacer layer is 4cm and the carbon content is 27%, and the thickness of the second spacer layer is 4cm and the carbon content is 23%.

[0082] According to formula 1 to formula 3, calculate the percentage of each material layer in the total material layer thickness:

[0083]

[0084] L2=1-L1-L3=41.43%

[0085] In the formula, r is the average particle size of the sintering raw material, which is 5mm; M is the moisture content of the sintering raw material, which is 9.6%; C is the carbon content of the sintering raw material, which is 3.5%; L is the total thickness of the material layer, which is 100cm; d is the total thickness of the two separation layers, which is 8cm; α, β, γ, and δ are adjustment coefficients, α is 0.4, β is 0.3, γ is 1.8, and δ is 2.8.

[0086] The thickness of the upper unit layer of the sintered raw material is 18 cm; the thickness of the middle unit layer of the sintered raw material is 36 cm; and the thickness of the lower unit layer of the sintered raw material is 38 cm.

[0087] Example 1 was applied repeatedly, except that the thickness of the first spacer material layer and the second spacer material layer and the carbon content therein were changed. The specific parameters are shown in Table 1.

[0088] Table 1

[0089]

[0090]

[0091] Application Example 14

[0092] Example 1 is applied repeatedly, except that the spacer materials in the first spacer layer and the second spacer layer are replaced with blast furnace slag. The particle size of the blast furnace slag is 8 mm, and the first spacer layer and the second spacer layer are both mixed with coke. The thickness of the first spacer layer is 6 cm, and the carbon content is 4.5%. The thickness of the second spacer layer is 7 cm, and the carbon content is 3.5%.

[0093] Example 14 was applied repeatedly, except that the thickness of the first spacer material layer and the second spacer material layer and the carbon content therein were changed. The specific parameters are shown in Table 2.

[0094] Table 2

[0095]

[0096] Application Example 23

[0097] Example 1 was repeated, except that the spacer material in the first spacer material layer was changed to limestone, and the spacer material in the second spacer material layer was changed to lump ore, and the average particle size of the limestone and the lump ore was 8 mm. The thickness of the first spacer material layer was 2 cm, and the carbon content was 1%. The thickness of the second spacer material layer was 7 cm, and the carbon content was 3.5%.

[0098] Example 23 was repeated except that the thickness of the first spacer material layer and the second spacer material layer and the carbon content therein were changed. The specific parameters are shown in Table 3.

[0099] Table 3

[0100]

[0101] Application Example 32

[0102] Example 1 was applied repeatedly, except that the thickness of the upper unit layer of the sintered raw material, the middle unit layer of the sintered raw material and the lower unit layer of the sintered raw material were changed. The specific parameters are shown in Table 4.

[0103] Table 4

[0104]

[0105]

[0106] Comparative Example 1

[0107] A sintering and cooling method, the method comprising the following steps:

[0108] 1) Laying the sintering raw materials on a sintering trolley to obtain a sintering material layer; starting a sintering machine to sinter the mixed sintering material layer to obtain a sintered ore unit layer.

[0109] 2) The average temperature of the sintered ore layer is 750℃. The sintered ore unit layer is sent to the ring cooler. After cooling, 650t / h of finished sintered ore is obtained. The ring cooler obtains 2328Nm 3 / h medium temperature exhaust gas with temperature of 351℃ and 3519Nm 3 / h low-temperature exhaust gas with a temperature of 179°C. The low-temperature exhaust gas is used for sintering ignition, and the medium-temperature exhaust gas is used for hot air sintering.

[0110] Comparative Example 2

[0111] A method for sintering and cooling layered cloth, the method comprising the following steps:

[0112] 1) The sintering material is divided into three layers and laid on a sintering trolley, and adjacent sintering raw material unit layers are separated by partitions to obtain a mixed sintering material layer including a three-layer sintering raw material unit layer structure, which are an upper unit layer of sintering raw material, a middle unit layer of sintering raw material and a lower unit layer of sintering raw material from top to bottom; the sintering machine is started to sinter the mixed sintering material layer to obtain the upper unit layer of sintered ore on the top, but the middle unit layer of sintering raw material and the lower unit layer of sintering raw material are almost not sintered, and the sintering fails.

[0113] 2) The average temperature of the upper unit layer of the sintered ore is 93°C. After the upper unit layer of the sintered ore is crushed, 281t / h of finished sintered ore is obtained.

[0114] The thickness of the partition is 3 cm, and there are air holes on the partition. The thickness of the upper unit layer of the sintered raw material is 22 cm; the thickness of the middle unit layer of the sintered raw material is 28 cm; and the thickness of the lower unit layer of the sintered raw material is 33 cm.

[0115] The sintering energy consumption, waste heat power generation and ring cooler load of application examples 1 to 27 and comparative examples 1 and 2 are statistically analyzed. The results are shown in Table 4.

[0116] Table 4

[0117]

[0118]

[0119]

[0120] According to the above experimental data, the present invention provides a layered material distribution sintering and cooling method, which sets multiple sintering raw material unit layers for sintering, sets spacer material layers, and limits the carbon content in the spacer material layers. The thickness of the spacer material layers is limited according to different spacer materials, and the sintered ores at different temperatures obtained after sintering are cooled separately, which improves the cooling efficiency and the heat energy recovery rate of the sintered ore, while reducing the workload of the ring cooler and saving the one-time investment of the ring cooler.

Claims

1. A method for sintering and cooling layered cloth, characterized in that: The method comprises the following steps: 1) laying sintering raw materials and spacer materials alternately on a sintering trolley in sequence to obtain a mixed sintering material layer having a plurality of sintering raw material unit layer structures, in which the sintering raw materials are separated from top to bottom by at least one layer of spacer material; starting a sintering machine to sinter the mixed sintering material layer to obtain at least two sintered ore unit layers with different temperatures; 2) According to the different temperatures of each sintered ore unit layer, each sintered ore unit layer is crushed and cooled independently to obtain the finished sintered ore.

2. The method according to claim 1, characterized in that: In step 1), in the mixed sintering material layer, the number of spacer material layers is 1 to 5 layers, preferably 2 to 3 layers; there is a sintering raw material unit layer on the upper and lower sides of any spacer material layer; preferably, the thickness of each spacer material layer is the same or different; the thickness of each sintering raw material unit layer is the same or different.

3. The method according to claim 1 or 2, characterized in that: The spacer material in the spacer material layer is a mixture of any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore; Preferably, the thickness of the spacer layer is 1 to 10 cm, preferably 2 to 8 cm; and / or The particle size of the spacer material is 5 to 10 mm, preferably 6 to 9 mm.

4. The method according to claim 3, characterized in that: The spacer material layer is any one of a 3-5 cm thick coal gangue layer, a 5-8 cm thick blast furnace slag layer, a 5-8 cm thick steel slag layer, a 1-3 cm thick limestone layer and a 5-8 cm thick lump ore layer.

5. The method according to any one of claims 1 to 4, characterized in that: Fuel is also mixed in the spacer layer; preferably, the fuel is coke; preferably, the amount of fuel mixed in the spacer layer is controlled so that the total carbon content in the gangue layer is 20% to 30%, the total carbon content in the blast furnace slag layer, steel slag layer, and lump ore layer is 3% to 5%, and the total carbon content in the limestone layer is 0.5% to 2%; preferably, the carbon content in the lower spacer layer is less than the carbon content in the upper spacer layer.

6. The method according to any one of claims 1 to 5, characterized in that: The cooling of each sintered ore unit layer independently comprises: sending each sintered ore unit layer obtained into different ring coolers for cooling according to different temperatures, and utilizing the waste heat of different qualities collected by the different ring coolers separately; Preferably, according to the temperature of each sintered ore unit layer obtained after sintering, different sintered ore unit layers are divided into a medium temperature layer and a high temperature layer, and optionally include or exclude a low temperature layer; the sintered ore in the low temperature layer is transported to a sintered finished product warehouse, the sintered ore in the medium temperature layer is sent to a low temperature ring cooler for cooling, and the sintered ore in the high temperature layer is sent to a high temperature ring cooler for cooling; Preferably, the temperature of the sintered ore in the low-temperature layer is 50-200°C; the temperature of the sintered ore in the medium-temperature layer is 150-800°C; and the temperature of the sintered ore in the high-temperature layer is 700-1200°C.

7. The method according to claim 6, characterized in that: The waste heat of different qualities collected by different ring coolers is utilized separately as follows: the low-temperature ring cooler obtains low-temperature cooling exhaust gas; the front section of the high-temperature ring cooler obtains high-temperature cooling exhaust gas, the middle section of the high-temperature ring cooler obtains medium-temperature cooling exhaust gas, and the rear end of the high-temperature ring cooler obtains low-temperature cooling exhaust gas; the obtained low-temperature cooling exhaust gas is used for sintering ignition or hot air sintering, and the high-temperature cooling exhaust gas is used for power generation.

8. The method according to any one of claims 1 to 7, characterized in that: In the mixed sintering material layer, the number of the spacer material layers is 2, and the sintering raw material is divided from top to bottom into an upper unit layer of sintering raw material, a middle unit layer of sintering raw material and a lower unit layer of sintering raw material by the two spacer material layers; wherein the thickness of the upper unit layer of sintering raw material is L1,%; the thickness of the middle unit layer of sintering raw material is L2,%; the thickness of the lower unit layer of sintering raw material is L3,%; wherein L1, L2, L3 are all percentages of the thickness of each material layer in the total thickness of the material layer excluding the thickness of the spacer material layer; the percentage of each material layer in the total thickness of the material layer is determined by the following formula: L2=1-L1-L3……(Formula 3) In the formula, r is the average particle size of the sintering raw material, mm; M is the moisture content of the sintering raw material, %; C is the carbon content of the sintering raw material, %; L is the total thickness of the material layer, cm; d is the total thickness of the two separation layers, cm; α, β, γ, and δ are adjustment coefficients, α ranges from 0.2 to 0.8, β ranges from 0.2 to 0.8, γ ranges from 1 to 3, and δ ranges from 2 to 5.

9. A system for layered material sintering and cooling or a system for the method according to any one of claims 1 to 8, characterized in that: The system comprises a sintering machine (1), a sintering trolley (2), a material distribution device (3), an ignition device (4), a flue gas treatment device (5), a sintered ore separation device (6) and a ring cooler (7); the sintering trolley (2) is arranged on the sintering machine (1), and the material distribution device (3) and the ignition device (4) are both arranged above the sintering trolley (2); a large flue (8) is arranged below the sintering machine (1), and the flue gas treatment device (5) is connected to the large flue (8); according to the movement direction of the sintering trolley (2), the material distribution device (3) is arranged upstream of the ignition device (4); the sintering machine (1) is provided with a plurality of sintering devices, each of which is connected to the sintering device (1). The material outlet of (1) is connected to the material inlet of the sintered ore separation device (6), and the material outlet of the sintered ore separation device (6) is connected to the material inlet of the ring cooler (7); at least two layers of sintered raw material unit layers are laid on the sintering machine (1), and a spacer layer is laid between adjacent sintered raw material unit layers; wherein the system comprises 2 to 6 ring coolers (7) in total, and the sintered ore separation device (6) is provided with the same number of material outlets as the ring coolers (7); preferably, the spacer material in the spacer material layer is any one or more of coal gangue, blast furnace slag, steel slag, limestone, and lump ore.

10. The system according to claim 9, characterized in that: The sintering machine (1) is provided with three layers of sintering raw material unit layers and two layers of spacer material layers, and the sintering raw material unit layers and the spacer material layers are alternately provided; the system further comprises a sintering finished product bin (9); the ring cooler (7) comprises a high-temperature ring cooler (701) and a low-temperature ring cooler (702); the sintered ore separation device (6) is provided with a high-temperature material outlet, a medium-temperature material outlet and a low-temperature material outlet, the low-temperature material outlet is connected to the sintering finished product bin (9), the medium-temperature material outlet is connected to the low-temperature ring cooler (702), and the high-temperature material outlet is connected to the high-temperature ring cooler (701).

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