A method for improving the sintering process ultra-low internal rejection rate

Abstract

The application discloses a kind of sintering process ultra-low internal return rate improvement method, the method is as follows specifically: a, adjusting batching structure, b, accurately control the error of blanking, c, using ultra-thick layer low water low carbon production process, adjust sintering material layer, so that sintering material layer reaches 910~950mm;D, establish internal return rate intelligent analysis system, e, improve the change of process operation and sieve shaker screening mode, two rows of multiple blind grate bars are respectively arranged on the both sides of pallet, 90 ° turning is carried out to edge wind flow, according to the trajectory of mixed material in cylinder and the coverage of spray head, so that each spray head spraying surface slightly overlaps, the sintering process ultra-low internal return rate improvement method of the application, by improving the grain size composition of mixed material, strengthening the crushing operation of fuel, strict batching operation, improve the thickness of material layer to realize low water thick material layer low carbon sintering, prolong cooling time and air system air leakage treatment, find out the related influencing factors of sintering internal return rate, and take corresponding measures to reduce internal return rate, realize internal return rate reduction 3%.

Description

TECHNICAL FIELD

[0001] The present application relates to a sintering process ultra-low internal return rate improvement method, belonging to the technical field of sinter ore internal return rate reduction method. BACKGROUND

[0002] With the development of iron-making concentrate technology, the quality requirements of blast furnace for sinter ore are becoming more and more strict, not only the grade and alkalinity are required to be stable, but also the strength and particle size composition are required to be higher and higher; in recent years, with the increase of sinter ore grade, the strength of finished ore is reduced and the proportion of fine particle size is increased, which has caused different degrees of influence on sintering and iron-making production; according to the past experience, if the return ore rate increases by 1%, the fuel ratio increases by 0.5%~1%, and the output decreases by 1%; the corresponding increase of return ore rate is not conducive to reducing sintering cost and processing fee; in recent years, steel plants are trying to reduce the cost of sinter ore, and are developing various cost reduction and efficiency improvement methods to find a breakthrough in reducing internal return rate; but the effect is not ideal, the internal return rate is high, which causes rework and increases controllable cost, therefore, reducing the return rate of sinter ore has become a technical problem to be solved in our work. SUMMARY

[0003] In order to solve the above problems, the present application provides a sintering process ultra-low internal return rate improvement method, which improves the particle size composition of the mixture, strengthens the crushing operation of the fuel, strictly controls the batching operation, increases the layer thickness to realize low-water thick-layer low-carbon sintering, prolongs the cooling time and handles the air leakage of the air system, finds out the related influencing factors of sintering internal return rate, and takes corresponding measures to reduce the internal return rate, so that the internal return rate is reduced by 3% on the basis of the existing.

[0004] The sintering process ultra-low internal return rate improvement method of the present application comprises the following specific steps:

[0005] a. Adjust the batching structure, match the proportion of limonite and magnetite concentrate, so that the proportion of limonite powder is less than 55%, and the proportion of magnetite concentrate is increased to 6.21%;

[0006] b. Accurately control the unloading error, display the real-time data and curve of the silo unloading on the industrial internet platform, and automatically calculate the unloading amount according to the silo weight, the unloading error is within 1%;

[0007] c. Adopt the ultra-thick layer low-water low-carbon production process, adjust the sintering layer, so that the sintering layer reaches 910~950mm;

[0008] d. Establishing an internal return rate intelligent analysis system, by automatically acquiring and / or manually importing the sintering process data into the analysis system, the correlation, regression and / or clustering analysis algorithm is built in the intelligent analysis system, the actual production process data and the internal return rate result data are analyzed and the law is found through correlation, regression and / or clustering, and the correlation of the internal return data under the process parameter condition is maximized; and the process parameters of the historical optimal internal return rate are output, and the process parameters of the predicted optimal internal return rate are output by using the prediction model;

[0009] e. Improve the change of process operation and the vibration screen screening mode, two rows of multiple blind grate bars are arranged on both sides of the pallet, the edge air flow is turned by 90 degrees, according to the trajectory of the mixed material in the cylinder and the coverage of the nozzle, each nozzle spraying surface slightly overlaps, and the mixed water is 80℃ hot water, the outlet cover establishes a water curtain dust removal, in the secondary mixing machine, due to the friction between the mixed material and the inner wall of the cylinder and the mixed material, the mixed material is repeatedly circulated, and the mixed material is granulated in multiple such movements; the mixed material is rolled to form small balls through the above movement process.

[0010] Further, the sintering material layer adopts a trapezoidal distribution mode, and the sintering material layer is 910-930mm.

[0011] Further, the method further comprises improving the fuel particle size crushing structure, first, the gap between the four rollers on both sides is sealed with an old belt, then a flexible material guiding cylinder is arranged at the discharge port of the four roller buffer bin; the particle size of the four rollers 1 / 2 / 3# is detected at regular intervals, and the gasket is adjusted according to the crushing result of the four rollers every day, so that the crushing particle size meets the requirements.

[0012] Further, the method further comprises replacing the air bellow spacing plate with a spring pair sealing plate. Ignition generally has an "edge effect", that is, under the condition of lower temperature, the material on both sides of the pallet often cannot be ignited, yellow material appears, and this part becomes return ore. Therefore, the air bellow spacing plate is replaced with a spring pair sealing plate during maintenance to reduce the ignition negative pressure and ensure that there is no yellow material on the surface of the material layer, thereby reducing the internal return rate.

[0013] Compared with the prior art, the sintering process ultra-low internal return rate improvement method has the advantages that: through performance comparison and optimization of the burden structure, the return ore rate is greatly reduced through cooperation of process operation and screening; under the condition of the same basicity, the sinter drum strength is significantly improved; through experiments, the fuel ratio is finally reduced, the combustion of solid fuel is promoted, the generation of FeO is reduced, and the solid fuel consumption is reduced; the maximum thickness can reach 950mm during production, the sintering machine speed can be reduced by about 8%, the vertical sintering speed is reduced, the heat storage effect is strengthened, the solid fuel consumption is reduced, the surface layer cold return rate is reduced, the finished product rate of the sinter is increased by about 2%, the sinter drum strength is correspondingly increased by 1%, and the return ore rate is reduced by 1-2%. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The sintering burden calculation schematic diagram for the first test burden of the application.

[0015] Figure 2 The mixing burden calculation schematic diagram for the first test burden of the application.

[0016] Figure 3 The sintering burden calculation schematic diagram for the second test burden of the application.

[0017] Figure 4 The mixing burden calculation schematic diagram for the second test burden of the application.

[0018] Figure 5 The cold return rate change curve schematic diagram for the first and second burden test of the application.

[0019] Figure 6 The first stage tracking different layer thickness schematic diagram of the application.

[0020] Figure 7 The second stage tracking different layer thickness schematic diagram of the application.

[0021] Figure 8 The third stage tracking different layer thickness schematic diagram of the application.

[0022] Figure 9 The fourth stage tracking different layer thickness schematic diagram of the application.

[0023] Figure 10 The fifth stage tracking different layer thickness schematic diagram of the application.

[0024] Figure 11 The sixth stage tracking different layer thickness schematic diagram of the application.

[0025] Figure 12 The seventh stage tracking different layer thickness schematic diagram of the application.

[0026] Figure 13 The first to seventh stage average bed thickness diagram of the present application.

[0027] Figure 14 The first to seventh stage bed thickness corresponding to the cold return rate curve diagram of the present application.

[0028] Figure 15 The cold return rate curve diagram under the improved process operation of the present application. DETAILED DESCRIPTION

[0029] Example 1:

[0030] The sintering process ultra-low internal return rate improvement method of the present application, the sintering process ultra-low internal return rate improvement method of the present application, including the method is as follows:

[0031] a, adjust the burden structure, optimize the burden structure under the condition of optimal material cost, adjust the burden ratio, reduce the return ore rate; by using a large amount of low-cost limonite as the main material for sintering, how to make good use of high proportion of limonite, reasonable ore matching is very important, find out the optimal matching ratio of different materials, and carry out sintering cup test in advance, and obtain the best burden structure, reduce the cost while reducing the sintering internal return rate, by matching limonite with magnetite concentrate, the proportion of limonite powder is less than 55%, and the proportion of magnetite concentrate is increased to 6.21%;

[0032] b, accurately control the error of discharging, display the real-time data and curve of the silo discharging on the industrial internet platform, and automatically calculate the discharging amount according to the silo weight, the discharging error is within 1%;

[0033] c, adopt the ultra-thick bed low-water low-carbon production process, adjust the sintering bed, and make the sintering bed reach 910-950mm;

[0034] d, establish an internal return rate intelligent analysis system, by automatically acquiring and / or manually importing the sintering process data into the analysis system, the internal intelligent analysis system is internally provided with correlation, regression and / or clustering analysis algorithm, the actual production process data and internal return rate result data are analyzed and regularity is found by correlation, regression and / or clustering method, the correlation of internal return data under the process parameter condition is maximized; and output the process parameters of the historical optimal internal return rate, and output the process parameters of the predicted optimal internal return rate by using the prediction model;

[0035] e. Improve the process operation and the vibrating screen screening method. Set two rows of multiple blind grates on both sides of the trolley to turn the edge airflow 90°. According to the trajectory of the mixture in the cylinder and the coverage of the nozzle, make the spray surface of each nozzle slightly overlap, and then spray it completely onto the material surface. The mixing water is 80℃ hot water. A water curtain is set up at the outlet to remove dust. In the secondary mixer, due to the friction between the mixture and the inner wall of the drum, and between the mixtures, the mixture is repeatedly circulated. The mixture is granulated in this repeated movement. The mixture rolls through the above movement process to form small balls.

[0036] The sintering material layer adopts a trapezoidal material distribution method, and the sintering material layer is 910~930mm. The method also includes improving the fuel particle size crushing structure. First, the gap between the two sides of the four rollers is sealed with old belts. Then, a flexible guide cylinder is installed at the feed inlet of the four roller buffer chamber. Particle size testing is performed on rollers 1 / 2 / 3 of the four rollers at regular intervals. During the shift, shims are adjusted based on the daily crushing results of the four rollers to ensure the crushed particle size meets the requirements. During maintenance, marked air leakage points are welded and repaired to reduce air leakage in the ventilation system.

[0037] The thick-layer sintering production plan adopts a trapezoidal material distribution method, increasing the material thickness by 50mm based on the trolley sideboard, and by 30mm compared to the same industry standard. This increases the yield of sintered ore by approximately 2%, and correspondingly improves the drum strength of sintered ore by 1%. The reduced carbon content in the sintering mixture leads to a predicted decrease of approximately 3% in the solid fuel consumption of the sintered ore, and a decrease in the FeO content, improving the reducibility of the sintered ore. This is beneficial for reducing the coke ratio during ironmaking, resulting in considerable economic benefits. The ultra-thick material layer low-water, low-carbon production method further enhances the sintering process. The thick material layer method can reduce the fuel ratio, promote the combustion of solid fuel, reduce FeO formation, and reduce solid fuel consumption. During production, the maximum thickness can reach 950mm, which can reduce the sintering machine speed by about 8%, reduce the vertical sintering speed, and the thick material layer sintering can improve the yield of sintered ore, that is, reduce the return rate, and reduce the energy consumption of sintering. The thick material layer has a strong automatic heat storage effect, which can increase the heat required by the combustion layer by 40%. It is beneficial to reduce solid fuel consumption, reduce the surface cold return rate, and improve the yield of sintered ore.

[0038] The method also includes replacing the wind box partition plate with a spring-loaded sealing plate. Ignition generally has an "edge effect," meaning that at low temperatures, the material on both sides of the trolley often cannot be ignited, resulting in yellow material. This part then becomes return ore. Therefore, during maintenance, the wind box partition plate is replaced with a spring-loaded sealing plate to reduce the ignition negative pressure, ensure that no yellow material appears on the surface of the material layer, and reduce the internal return rate.

[0039] The improved method for ultra-low internal return rate in the sintering process of this invention can reduce the internal return rate by about 3%. After the implementation of this method, the drum index of sintered ore is increased by at least 1%, and the yield of sintered ore is increased by at least 2%, which better meets the production needs of blast furnace, lays a raw material foundation for the smooth operation of blast furnace production, and achieves good economic benefits. The increase in the strength of sintered ore also helps to reduce dust generation and improve the on-site environment.

[0040] The improved method for ultra-low internal return rate in the sintering process of the present invention involves adjusting the ingredient structure as follows:

[0041] The experiment was conducted under a basic alkalinity of 1.8. The feed composition was changed every three days. After adjustment, the production status was observed and recorded for one week, and the change in the return ore rate was observed. Figure 1 and Figure 2 The shown ingredient structure is the ratio from September 25th to 28th, using a mixture of 31.3% mixed powder and 26.3% super-fine powder with 2.94% Jinshan concentrate. This ratio is limonite mixed with some magnetite concentrate. As the ingredient structure for the experiment, the change in cold return rate was observed.

[0042] like Figure 3 and Figure 4 The shown ingredient structure is the ratio from September 29 to October 1, using a mixture of 32.54% bleached powder and 25.74% superfine powder, combined with 6.21% Fushan concentrate. This ratio is a mixture of limonite and some magnetite concentrate. The ratio of magnetite concentrate was increased to form the ingredient structure for the experiment.

[0043] like Figure 5 As shown, under the condition of constant basicity, through this adjustment of the feed structure, when the proportion of mixed powder and super-fine powder (such as limonite powder) reaches more than 55%, the sintering internal return rate is high, the limonite burn-off is large, the material layer shrinkage is large, the ore formation rate is low, and the liquid phase production is poor. When the proportion of magnetite concentrate is increased from 2.94% to 6.21%, the sintering internal return rate decreases, but there is still a slight increase in the content. However, the average internal return rate is decreasing. When the proportion of limonite is high, the combination with magnetite concentrate often complements the materials in the sintering process. When the liquid phase production capacity is strong, adding magnetite powder with a higher assimilation temperature and moderate liquid phase flow as a supplement can effectively improve the strength of the sinter and reduce the internal return rate.

[0044] The improved method for ultra-low internal return rate in the sintering process of the present invention involves the following experiment to adjust the material layer thickness:

[0045] The experiment was conducted with the basic alkalinity remaining constant at 1.8. The production status was observed after each adjustment of the material layer thickness and during the shift, and the change in the return ore rate was observed.

[0046] Track different material layer thicknesses daily and follow... Figures 6 to 12The different cloth thicknesses of the cloth are tracked to observe the change of the internal return rate; the average value of the internal return rate of each day is as follows Figure 13 As shown in the figure, Figure 14 As shown in the figure, with the increase of the material layer thickness, the sintered ore return rate shows a downward trend, and the decrease is relatively large, so the sintered ore return rate decreases by 0.2-0.8% when the sintered material layer thickness increases by 10mm; with the increase of the material layer thickness, the automatic heat storage capacity of the material layer is strengthened, more heat is gathered at the lower part, the strength of the sintered ore at the lower part of the material layer is improved, and the return rate is reduced accordingly; the increase of the material layer thickness has a great influence on the strength of the sintered ore.

[0047] The sintering process ultra-low internal return rate improvement method of the present application, the sintering process ultra-low internal return rate improvement method of the present application, the change of process operation and the adjustment experiment of the vibration screen screening effect are as follows:

[0048] Under the condition of basicity of 1.8, after the change of process operation and the adjustment of the vibration screen screening effect, the production status of one week is observed and recorded, and the change of the return rate is observed.

[0049] (1) The edge effect of the pallet is considered, in order to reduce the edge effect, there are two rows of 12 blind bars on both sides of the pallet, at the same time, the edge air flow is turned by 90°, the edge air flow is weakened, and the edge effect is inhibited;

[0050] (2) According to the trajectory of the mixed material in the cylinder and the coverage of the nozzle, it is ensured that each nozzle spraying surface slightly overlaps, and is completely sprayed on the material surface, to ensure continuous and effective spraying; the mixing machine uses 80 DEG C hot water, and the outlet cover establishes a water curtain for dust removal, to ensure that the steam can be smoothly discharged; in the secondary mixing machine, due to the friction between the mixed material and the inner wall of the roller and the mixed material, the mixed material is repeatedly circulated and granulated in multiple movements;

[0051] (3) After the maintenance of the grate bar, the permeability of the mixed material is obviously enhanced, the wind tunnel phenomenon is eliminated, the air suction of the sintering machine is uniform, the negative pressure is reduced from an average of 19kPa to 18.2kPa, the sintered ore output is increased from 14500 tons to more than 15000 tons, the ore output rate is increased from 79.5% to 81.1%, and the sintered ore cold return rate is obviously reduced;

[0052] (4) The speed of the eleven rollers is increased from 12HZ to 19HZ, the particle size of the mixed material is more reasonable in the direction of the pallet height, the upper fine particle material is increased, the particle size of the mixed material at the lower part of the pallet is coarser, the fuel particle size is reasonable, the sintering process is more uniform, the material layer thickness is increased from 900mm to 920mm, and the sintered ore internal return rate is reduced;

[0053] (5) When the sintering machine is distributing material, the eleven-roller lower side beam limits the distribution height, and the material layer is only 910 mm high. When overhauling, the two-centimeter-wide flat material plate at the bottom of the eleven-roller is cut off, so that the distribution thickness is increased by 20 mm on the basis of the original, and the sintering ore yield is improved;

[0054] (6) One set of sieve nets of the first and second sieves and the third sieve are replaced during overhauling, and the >5 mm particle level in the cold return ore is reduced from 11.74% before overhauling to 4.93% after overhauling, and the total amount of >5 mm in the cold return is reduced, thereby reducing the internal return rate;

[0055] As shown in Figure 15 , with the strict implementation and improvement of each measure, the sintering ore cold return rate is obviously reduced, the ore yield is increased from 79.5% to 81.1%; and the sintering ore yield is increased from 14,500 tons to more than 15,000 tons.

[0056] The above examples are only the preferred embodiments of the present application, so equivalent changes or modifications made according to the structure, features and principles described in the patent application range of the present application are included in the patent application range of the present application.

Claims

1. A method for improving the sintering process with ultra-low internal rejection rate, characterized in that, The method is as follows: a. Adjust the ingredient structure, match the limonite with the magnetite concentrate, so that the proportion of limonite powder is less than 55%, and the proportion of magnetite concentrate is increased to 6.21%; b. Accurately control the unloading error, display the real-time data and curve of the silo unloading on the industrial internet platform, and automatically calculate the unloading amount according to the silo weight, with an unloading error of 1% or less; c. Adopt the ultra-thick layer low-water low-carbon production process, adjust the sintering material layer, so that the sintering material layer is 910-950 mm; specifically, the sintering material layer adopts a trapezoidal distribution manner, and the sintering material layer is 910-930 mm; d. Establish an intelligent analysis system for internal return rate, automatically acquire and / or manually import the sintering process data into the analysis system, and internally embed correlation, regression and / or clustering analysis algorithms in the intelligent analysis system, analyze and find the law of actual production process data and internal return rate result data through correlation, regression and / or clustering, and maximize the correlation of internal return data under the condition of process parameters; and output the process parameters of the historical optimal internal return rate, and use the prediction model to output the process parameters of the predicted optimal internal return rate; e. Improve the change of process operation and the vibration screen screening method, set two rows of multiple blind grating strips on both sides of the pallet, turn the edge air flow by 90°, according to the trajectory of the mixed material in the cylinder and the coverage of the spray head, so that each spray head slightly overlaps the spray surface, and completely sprays onto the material surface, the mixed water is 80°C hot water, the outlet cover establishes a water curtain dust removal, in the secondary mixing machine, due to the friction between the mixed material and the inner wall of the cylinder, and the friction between the mixed material and the mixed material, the mixed material is repeatedly circulated in this way, and the mixed material is granulated in multiple such movements; the mixed material is rolled to form small balls through the above movement process.

2. The sintering process ultra-low internal reject improvement method according to claim 1, characterized in that: The method also includes improving the fuel particle size crushing structure, first, the four-roller gap between the two sides is sealed with an old belt, then a flexible guide cylinder is arranged at the discharge port of the four-roller buffer bin; the particle size of the four-roller 1 / 2 / 3# rollers is detected at regular intervals, and the gasket is adjusted according to the four-roller crushing result every day, so that the crushing particle size meets the requirements.

3. The sintering process ultra-low internal reject improvement method of claim 1, wherein: The method also includes replacing the air bellow spacing plate with a spring pair sealing plate.

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