A sinter stock replacement method

Abstract

The application discloses a sinter pile changing method. The method is to analyze and measure the compositions of upper and lower material piles before pile changing, and to analyze the sintered sinter in a sintering cup, to obtain a SiO2 change correction value according to the measurement and analysis results, and to determine the pile changing mode and pile changing control time according to the SiO2 change correction value and the material pile ratio change. The method adopts different material pile changing methods according to the adjustment of the upper and lower mixed uniform material pile ratios, stabilizes the sinter quality, and especially improves the stability rate of the alkalinity. The method is simple in operation, and provides a relatively convenient and fast method for sinter material pile changing. After the method is used, the stability rate of the sinter alkalinity is improved by 1.29% under the condition that the material pile ratio fluctuates greatly, and the effect is obvious.

Description

Technical Field

[0001] This invention belongs to the field of sintering technology, specifically relating to a method for sintering ore stacking. Background Technology

[0002] In my country's steel production process, iron ore sintering is a crucial method for providing blast furnaces with high-quality raw materials for ironmaking. As steel companies continuously strive for higher blast furnace output, better quality, and improved economic efficiency, the quality of sinter directly impacts the effective control of blast furnace production costs. As inland steel enterprises are subject to significant fluctuations in imported iron ore prices, the stockpile ratio may be frequently adjusted to efficiently control ore costs and maximize ironmaking profits. Sometimes, the adjustment between two stockpiles exceeds 50%, leading to fluctuations in sinter quality during stockpile changes. This, in turn, affects the stability and efficiency of the blast furnace. Therefore, providing a practical and feasible stockpile replacement method is extremely important to reduce sinter quality fluctuations during stockpile changes. Summary of the Invention

[0003] The purpose of this invention is to provide a method for sintering ore.

[0004] The objective of this invention is achieved as follows: a method for switching sinter piles, specifically, involves calculating and analyzing the composition of the upper and lower piles and conducting sinter test analysis in the sintering cup before switching piles. The SiO2 change correction value is obtained by combining the calculation and test analysis results, and the switching pile method and switching pile control time are determined based on the SiO2 change correction value.

[0005] The formula for calculating the SiO2 change correction value is shown in equation (I):

[0006] |SiO 2（变化修正值） | = (Y1 + Y2) / 2 - SiO 2（上一在用料堆实际生产值） (I)

[0007] Where Y1 = (a*X) 测算（SiO2） +b); Y2 = (c*X) 试验（SiO2） +d); a and b are obtained by regression analysis of the SiO2 values ​​of the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile; c and d are obtained by regression analysis of the SiO2 values ​​of the sinter produced by the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile.

[0008] Substituting the theoretically calculated SiO2 value of the material to be replaced into the Y1 formula, we obtain the theoretical predicted value Y1 of the material to be replaced; substituting the SiO2 value of the sintering cup of the material to be replaced into the Y2 formula, we obtain the predicted value Y2 of the test results of the sintering cup.

[0009] The beneficial effects of this invention are as follows:

[0010] 1. This invention adopts different material pile replacement methods according to the adjustment of the ratio of the upper and lower mixed material piles, so as to stabilize the quality of sintered ore, especially improve the stability rate of alkalinity.

[0011] 2. The method of this invention is simple to operate and provides a convenient and quick way to replace sinter stockpiles. After using the method of this invention, the basicity stability rate of sintered ore increases by up to 1.29% even when the stockpile ratio fluctuates significantly, demonstrating a significant effect. Attached Figure Description

[0012] Figure 1 The formula for the regression correlation between the theoretical calculation of SiO2 and actual production in Example 1;

[0013] Figure 2 The regression correlation formula between the experimental results of the SiO2 sintering cup in Example 1 and actual production is shown.

[0014] Figure 3 The formula for the regression correlation between the theoretical calculation of SiO2 and actual production in Example 2;

[0015] Figure 4 The regression correlation formula between the experimental results of the SiO2 sintering cup in Example 2 and actual production is shown.

[0016] Figure 5 The formula for the regression correlation between the theoretical calculation of SiO2 and actual production in Example 3;

[0017] Figure 6 The regression correlation formula between the experimental results of the SiO2 sintering cup in Example 3 and actual production is given. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0019] This invention discloses a method for switching sintered ore piles. Specifically, before switching piles, the composition of the upper and lower piles is calculated and analyzed, and the sintered ore in the sintering cup is tested and analyzed. The SiO2 change correction value is obtained by combining the calculation and test analysis results. Based on the SiO2 change correction value, the switching pile method and switching pile control time are determined.

[0020] The formula for calculating the SiO2 change correction value is shown in equation (I):

[0021] |SiO 2（变化修正值） | = (Y1 + Y2) / 2 - SiO 2（上一在用料堆实际生产值） (I)

[0022] Where Y1 = (a*X) 测算（SiO2） +b); Y2 = (c*X)试验（SiO2） +d); a and b are obtained by regression analysis of the SiO2 values ​​of the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile; c and d are obtained by regression analysis of the SiO2 values ​​of the sinter produced by the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile.

[0023] Substituting the theoretically calculated SiO2 value of the material to be replaced into the Y1 formula, we obtain the theoretical predicted value Y1 of the material to be replaced; substituting the SiO2 value of the sintering cup of the material to be replaced into the Y2 formula, we obtain the predicted value Y2 of the test results of the sintering cup.

[0024] The specific regression analysis method is as follows: Collect relevant data, select data in an Excel spreadsheet, select data analysis, select regression analysis, select Y-value input area data, select X-value input data, select linear fitting graph, confirm, select add trend line, select formula display. According to the relevant formula on the regression analysis graph, the values ​​of a and b can be obtained. According to the theoretically calculated SiO2 value, substitute it into formula (I) to obtain the theoretically calculated SiO2 prediction value of the material pile to be replaced. Similarly, according to the SiO2 value detected by the sintering cup test results, substitute it into the formula obtained by the regression analysis of the SiO2 value detected by the sintering cup test results and the actual production SiO2 (this formula can obtain the values ​​of c and d) to obtain the SiO2 prediction value of the sintering cup of the material pile to be replaced. Add the two values, divide by 2, and subtract the actual production SiO2 value of the previous material pile to get the change correction value of the material pile (SiO2) to be replaced.

[0025] The method of this invention selects data from 5 to 10 stockpiles before replacement for relevant predictions mainly to avoid sampling and detection errors of individual stockpiles in theoretical calculations and chemical analysis of sintering cups.

[0026] The specific replacement method is as follows: When the change in the stockpile ratio is ≤20% and the SiO2 change correction value is 0.0~0.5, the replacement method is to directly replace the stockpile after the first layer is used up, the replacement control time is <24~36h, and the fuel particle size is coarsened by 2%~5% during the replacement period;

[0027] When the change in the stockpile ratio is ≤20% and the SiO2 change correction value is >0.5, the stockpile replacement method is to replace it after the previous stockpile is used up. The stockpile replacement control time is <8~10h, and the fuel particle size is coarsened by 2%~5% during the stockpile replacement period.

[0028] When the feed stock ratio changes by more than 20% and the SiO2 change correction value is 0.0~0.5, the feed stock replacement method is to replace it directly after the first layer is used up, with a feed stock replacement control time of less than 24~36 hours, and the fuel particle size coarsening by 5%~7% during the feed stock replacement period;

[0029] When the change in the stockpile ratio is greater than 20% and the SiO2 change correction value is greater than 0.5, the stockpile replacement method is to replace it only after the previous stockpile is used up. The stockpile replacement control time is less than 8 to 10 hours. During the stockpile replacement period, the fuel particle size is coarsened by 5% to 7%, as shown in Table 1.

[0030] Table 1. Stack replacement methods with different SiO2 correction values

[0031]

[0032] Example 1

[0033] The two sintering stockpiles, D6# and D5#, at the Kunming Iron and Steel Group Honghe Base were replaced. The stockpiling ratios of D6# and D5# are shown in Table 2.

[0034] Table 2. Mix proportions of D6# and D5# stockpiles

[0035]

[0036] First, calculations and analyses were performed on the replaced material piles d1-d5, relevant sintering cup tests were organized, and the composition of the sintered ore in the sintering cups was fully analyzed. The theoretical SiO2 values ​​of the d1-d5 material piles, the test analysis values ​​of the sintered ore in the sintering cups, and the actual production values ​​were obtained, as shown in Table 3. Calculations and analyses were performed on the feedstock d6 to be replaced, relevant sintering cup tests were organized, and a full analysis of the sinter composition in the sintering cups was conducted. The theoretical SiO2 value of the feedstocks d1-d5 was 5.75%, and the experimental analysis value of the sinter in the sintering cups was 5.11%. The theoretical SiO2 values ​​of the five feedstocks preceding d6 (d1, d2, d3, d4, d5) were 5.46%, 5.57%, 5.76%, 5.24%, and 5.35%, respectively; the SiO2 values ​​in the sintering cups were 5.35%, 5.65%, 5.87%, 5.61%, and 5.17%, respectively; and the actual production SiO2 values ​​were 5.72%, 5.44%, 5.68%, 5.30%, and 5.51%, respectively.

[0037] Formula 1 is obtained by using Excel to calculate the theoretical SiO2 values ​​of the five stockpiles, the SiO2 values ​​of the sintering cup, and the actual SiO2 values ​​produced. Figure 1 ):Y1 （生） =0.5449X （理） +2.5462 and formula 2 ( Figure 2 ):Y2 （生） =-0.0174X （烧）+5.6264, (a=0.5449, b=2.5462; c=-0.0174, d=5.6264) Substituting the theoretically calculated SiO2 value of d6 (5.75%) into Formula 1, we get Y1=5.679%. Substituting the SiO2 value of d6 sintering cup (5.11%) into Formula 2, we get Y2=5.537%. Therefore, the corrected (estimated) SiO2 for d6 is (5.679% + 5.537%) / 2 = 5.61%. The SiO2 change correction value (compared to the previous in-use stockpile) is 5.61 - 5.51 = |0.10| (the specific calculation results are shown in Table 3). The ratio of D6# to D5# stockpile changes by 14%. Finally, the stockpile replacement operation is carried out according to Table 1. The ratio of D6# to D5# stockpiles changed by 14%. According to the formula, the SiO2 correction value changed by 0.10%. After the first layer of D5# was used up, the first layer of D6# stockpiles was directly used in combination. The fuel particle size <3mm was adjusted from 78% to 74%. The sinter quality remained stable throughout the entire stockpile replacement process, and the alkalinity stability rate did not exceed the control value.

[0038] Note: Y1 （生） and Y2 （生） The two formulas are related to the number of stockpiles and the change in SiO2 value selected earlier, so they need to be obtained using Excel regression analysis before each stockpile change based on the actual situation.

[0039] Table 3. SiO2 values ​​of the d1-d6 stockpile in Example 1

[0040]

[0041] Example 2

[0042] The two sintering stockpiles, D16# and D15#, at the Kunming Iron and Steel Group Honghe Base were replaced. The stockpiling ratios of D16# and D15# are shown in Table 4.

[0043] Table 4. Mix proportions of D16# and D15# stockpiles

[0044]

[0045] First, calculations and analyses were performed on the replaced material piles d10-d15, relevant sintering cup tests were organized, and a full analysis of the sinter composition in the sintering cups was conducted. The theoretical calculation value of SiO2 in the d10-d15 material piles, the test analysis value of the sinter in the sintering cups, and the actual production value were obtained, as shown in Table 5. Calculations and analyses were performed on the feedstock d16 to be replaced, relevant sintering cup tests were organized, and a full analysis of the sinter composition in the sintering cups was conducted. The theoretical SiO2 value for feedstocks d10-d15 was 5.47%, and the experimental analysis value of the sinter in the sintering cups was 5.38%. The theoretical SiO2 values ​​for the six feedstocks preceding d16 (d10, d11, d12, d13, d14, and d15) were 5.82%, 6.10%, 5.97%, 5.86%, 5.49%, and 5.54%, respectively; the SiO2 values ​​for the sintering cups were 5.74%, 6.01%, 5.49%, 6.01%, 5.66%, and 5.29%, respectively; and the actual SiO2 values ​​produced were 5.69%, 5.84%, 5.72%, 5.69%, 5.51%, and 5.72%, respectively.

[0046] Formula 3 is obtained by using Excel to calculate the theoretical SiO2 values ​​of the above six stockpiles, the SiO2 values ​​of the sintering cup, and the actual SiO2 values ​​produced. Figure 3 ):Y1 （生） =-0.5846X （理） +2.2614 and formula 4 ( Figure 4 ):Y2 （生） =0.3577X （烧） +3.6111 (a=0.5846, b=2.2614; c=0.3577, d=3.6111), substituting the theoretical SiO2 value of 5.47% for d16 into Formula 3, we get Y1=5.459%. Substituting the SiO2 sintering cup value of 5.30% for d16 into Formula 4, we get Y2=5.507%. Therefore, the corrected (estimated) SiO2 for d16 is (5.459% + 5.507%) / 2 = 5.48%. The SiO2 change correction value (compared to the previous in-use stockpile) is 5.48 - 5.72 = |0.24| (the specific calculation results are shown in Table 5). Finally, the stockpile replacement operation is performed according to Table 1.

[0047] The ratio of D16# to D15# feedstock changed by 24%. According to the formula, the SiO2 correction value changed by 0.24%. After the first layer of D15# was used up, the first layer of D16# feedstock was directly used in combination. The proportion of fuel particles <3mm was adjusted from 76% to 70%. The sinter quality remained stable throughout the entire feedstock replacement process, and the alkalinity stability rate did not exceed the control value.

[0048] Note: Y1 （生） and Y2 （生）The two formulas are related to the number of stockpiles and the change in SiO2 value selected earlier, so they need to be obtained using Excel regression analysis before each stockpile change based on the actual situation.

[0049] Table 5. SiO2 values ​​of d10-d16 stockpile in Example 2

[0050]

[0051] Example 3

[0052] The two sintering stockpiles, D27# and D26#, at the Kunming Iron and Steel Group Honghe Base were replaced. The stockpiling ratios of D27# and D26# are shown in Table 6.

[0053] Table 6. Mix proportions of D27# and D26# stockpiles

[0054]

[0055] First, calculations and analyses were performed on the d21-d27 stockpiles of the base that had been replaced. Related sintering cup tests were organized, and a full analysis of the composition of the sintered ore in the sintering cups was conducted. The theoretical calculation value of SiO2 in the d21-d27 stockpiles, the test analysis value of the sintered ore in the sintering cups, and the actual production value were obtained, as shown in Table 7. Calculations and analyses were performed on the feedstock d27, relevant sintering cup tests were organized, and a full analysis of the sinter composition in the sintering cups was conducted. The theoretical SiO2 value of the d27 feedstock was 5.39%, and the experimental analysis value of the sinter in the sintering cups was 4.81%. The theoretical SiO2 values ​​for the preceding six feedstocks (d21, d22, d23, d24, d25, and d26) were 5.15%, 5.27%, 5.10%, 4.85%, 4.76%, and 4.95%, respectively; the SiO2 values ​​in the sintering cups were 4.98%, 5.41%, 4.88%, 5.04%, 5.24%, and 4.81%, respectively; and the actual production SiO2 values ​​were 5.01%, 5.22%, 5.17%, 5.05%, 4.96%, and 4.85%, respectively.

[0056] Formula 5 is obtained by using Excel regression analysis of the theoretically calculated SiO2 values ​​of the six stockpiles, the SiO2 values ​​of the sintering cup, and the actual SiO2 values ​​produced, respectively, for the above six stockpiles. Figure 5 ):Y1 （生） =0.3614X （理） +3.2746 and formula 6 ( Figure 6 ):Y2 （生） =0.0386X （烧）+4.8914, substituting the theoretical SiO2 value of 5.42% for d27 into Formula 5, we get Y1 = 5.233%. Substituting the SiO2 sintering cup value of 4.85% for d27 into Formula 6, we get Y2 = 5.079%. Therefore, the corrected (estimated) SiO2 for d27 is (5.233% + 5.079%) / 2 = 5.16%. The SiO2 change correction value (compared to the previous in-use stockpile) is 5.16 - 4.65 = |0.51| (the specific calculation results are shown in Table 7). Finally, the stockpile replacement operation is performed according to Table 1.

[0057] The ratio of D27# to D26# fuel changed by 60%. According to the formula, the SiO2 correction value changed by 0.51%. D26# was completely used up before being replaced. The fuel particle size <3mm was adjusted from 78% to 72%. The sinter quality remained stable throughout the entire replacement process, and the alkalinity stability rate did not exceed the control value.

[0058] Note: Y1 （生） and Y2 （生） The two formulas are related to the number of stockpiles and the change in SiO2 value selected earlier, so they need to be obtained using Excel regression analysis before each stockpile change based on the actual situation.

[0059] Table 7. SiO2 values ​​of the d21-d27 stockpile in Example 2

[0060]

[0061] Randomly selected samples were used to track the basicity stability of sinter during stockpile replacement periods six months before and after using the method of this invention. Before using the method, the basicity R exceeded ±0.1 an average of 3-5 times, but these occurrences were not necessarily continuous and mainly concentrated within 48 hours before and after stockpile replacement. After using the method, the R exceeded ±0.1 an average of 0-2 times, a significant reduction compared to before, demonstrating a clear effect. The sinter quality fluctuated less, especially in terms of basicity stability.

[0062] Experimental Example 1

[0063] After the withdrawal of major mineral types such as Guisha Mine in October 2019, the ore structure used by Kunming Iron and Steel Group's Honghe Base increased from 4-5 varieties to more than 10 varieties, with a single stockpile containing more than 15 varieties at its peak. This posed a significant challenge to the stability of sinter quality, especially the basicity stability rate. However, since the use of the method of this invention in 2020, the basicity stability rate M±0.1 of the sinter at this base has remained stable and has even improved. Specific performance is shown in Table 5.

[0064] Table 8. Stability of Sintered Ore at Kunming Iron & Steel Group Honghe Base

[0065]

[0066] Results analysis: The lowest basicity stability rate of sintered ore was 98.56% in 2018, which was 1.29% lower than that in 2020. Before using the method of this invention, the best basicity stability rate of sintered ore was in 2019, when the proportion of the main mineral type in the Guisha mine was over 60%, and the basicity stability rate of sintered ore was 99.39% throughout the year, which was 0.46% lower than the 99.85% in 2020 when the method of this invention was used and there was no main mineral type. The effect is significant.

[0067] From January to June 2021, the basicity stability rate of sintered ore at Kunming Iron & Steel Group's Honghe Base declined. This was mainly due to the significant increase in international ore prices in 2021, which led to frequent changes in the ore usage structure and a further increase in the types of ore used in order to reduce ore usage costs. Multiple production stockpiles were being built and used simultaneously, and the stockpiling time could not be effectively guaranteed, resulting in a decline in the basicity stability rate of sintered ore. However, the basicity stability rate of sintered ore remained above 99%, and the basicity stability rate M±0.05 in 2021 also continuously broke records, remaining stable above 85%.

Claims

1. A method for sintering stockpile, characterized in that, This method involves calculating and analyzing the composition of the upper and lower stockpiles and conducting sintering cup tests before the stockpile swap. The SiO2 variation correction value is then derived by combining the calculation and test results. Based on this SiO2 variation correction value, the stockpile swapping method and control time are determined. The formula for calculating the SiO2 variation correction value is shown in equation (I). |SiO 2（变化修正值） |=(Y1+Y2) / 2- SiO 2（上一在用料堆实际生产值） ; (I) Where Y1 = (a*X) 测算（SiO2） +b); Y2 = (c*X) 试验（SiO2） +d); a and b are obtained by regression analysis of the SiO2 values ​​of the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile; c and d are obtained by regression analysis of the SiO2 values ​​of the sinter produced by the first 5-10 stockpiles of the stockpile to be replaced and the SiO2 values ​​of the sinter produced by the actual stockpile. Substituting the theoretically calculated SiO2 value of the material to be replaced into the Y1 formula, we obtain the theoretical predicted value Y1 of the material to be replaced; substituting the SiO2 value of the sintering cup of the material to be replaced into the Y2 formula, we obtain the predicted value Y2 of the test results of the sintering cup.

2. The sinter replacement method according to claim 1, characterized in that, The specific replacement method is as follows: When the change in the stockpile ratio is ≤20% and the SiO2 change correction value is 0.0~0.5, the replacement method is to directly replace the stockpile after the first layer is used up, the replacement control time is <24~36h, and the fuel particle size is coarsened by 2%~5% during the replacement period; When the change in the stockpile mix ratio is ≤20% and the SiO2 change correction value is >0.5, the stockpile replacement method is to replace it only after the previous stockpile is used up, the stockpile replacement control time is <8~10h, and the fuel particle size is coarsened by 2%~5% during the stockpile replacement period; When the feed stock ratio changes by more than 20% and the SiO2 change correction value is 0.0~0.5, the feed stock replacement method is to replace it directly after the first layer is used up, with a feed stock replacement control time of less than 24~36 hours, and the fuel particle size coarsening by 5%~7% during the feed stock replacement period; When the change in the stockpile ratio is greater than 20% and the SiO2 change correction value is greater than 0.5, the replacement method is to replace the previous stockpile after it is used up. The replacement control time is less than 8 to 10 hours, and the fuel particle size is coarsened by 5% to 7% during the replacement period.

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