Method for evaluating cost performance of blast furnace injection coal

Abstract

The invention discloses a method for evaluating the cost performance of blast furnace injection coal. The method comprises the following steps: step 1, establishing a single coal database for blast furnace injection; 2, selecting a value index, a heat value, an ash content, a grindability index and an S content of blast furnace injection coal instead of coke, and respectively calculating values generated by a single coal quality index; 3, calculating the comprehensive value of the single injection coal; 4, calculating the effective value rate of the single injection coal by taking the effective value rate as a basis for evaluating the cost performance of the pulverized coal; 5, according to the calculation result of the effective value rate of each single coal, carrying out cost performance sorting on the available single coal; and 6, according to the cost performance sequence of the single coals, the single coals with high cost performance are preferentially selected for coal blending. The invention aims to solve the problem of how to reasonably match and use each single coal for injection, and after the coal blending is optimized, not only can the quality of the injection coal meet the production requirement of a blast furnace be ensured, but also the lowest cost of the injection coal can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of optimized coal blending for blast furnace ironmaking pulverized coal, and in particular relates to a method for evaluating the cost performance of blast furnace pulverized coal injection. Background Art

[0002] The pulverized coal injection process is to inject the ground and mixed pulverized coal into the furnace through the blast furnace tuyere gun at a fixed pressure and flow rate. After entering the front end of the tuyere, it burns instantly and generates heat, thereby replacing and substituting a certain amount of coke. With the increasing scarcity of coke resources and rising prices, how to effectively utilize the price difference between pulverized coal injection and coke, improve the coal-coke replacement ratio, and achieve a reduction in pig iron costs is one of the necessary means for blast furnaces in the industry to be competitive.

[0003] In order to improve the economic efficiency of pulverized coal injection, it is necessary to optimize the combination of existing pulverized coal resources. Conventional pulverized coal inspection indicators include: calorific value, ignition point, combustibility, reactivity, fluidity, grindability and explosiveness. Therefore, in the design of the coal blending scheme, it is necessary to fully consider the physical and chemical properties of the coal and its economic efficiency. At present, most pulverized coal injection structures use anthracite + bituminous coal. When the ratio of bituminous coal is higher, its ignition temperature is lower and the pulverized coal combustion rate is higher. The increase in the ratio of bituminous coal can enhance the reducing atmosphere in the blast furnace and provide more hydrogen for the blast furnace to reduce iron. However, its flammability and explosiveness also bring safety risks. For this reason, nitrogen inerting technology and other methods will be selected in the process for safety protection to ensure the stable operation of the system.

[0004] Overall, PCI cost-effectiveness evaluation and optimization of coal blending technology is a systematic project that covers multiple factors such as coal type characteristics, blast furnace smelting requirements, and equipment adaptability. Establishing a blast furnace PCI cost-effectiveness evaluation system to determine the PCI blending plan is an effective and scientific method. Technical personnel can set an optimized coal blending plan based on the PCI cost-effectiveness evaluation results to achieve efficient and stable operation of blast furnace smelting, bringing significant economic benefits to the enterprise. Summary of the invention

[0005] The purpose of the present invention is to provide a method for evaluating the cost performance of blast furnace coal injection, aiming to solve the problem of how to reasonably match and use each type of coal for blast furnace injection. After optimizing the coal blending, the quality of the blast furnace coal injection can be guaranteed to meet the production requirements of the blast furnace and the cost of the blast furnace coal injection can be minimized. This method can solve the problem that there are many parameters for the quality and cost indicators of blast furnace coal injection and its cost performance cannot be quantitatively evaluated.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for evaluating the cost performance of blast furnace coal injection, comprising the following steps:

[0008] Step 1: first establish a single coal database for blast furnace injection;

[0009] Step 2: Select the value indicators of blast furnace pulverized coal replacing coke, calorific value, ash content, grindability index, and S content, and calculate the value generated by the quality indicators of each type of coal. The specific calculation formula is as follows:

[0010] Calorific value of pulverized coal:

[0011] High calorific value of pulverized coal × coke price / high calorific value of coke;

[0012] Negative value of ash content of coal powder:

[0013] - Ash content of coal powder × coke price × 0.935;

[0014] Negative value of sulfur content in coal powder: -S content of coal powder × coke price × 6.6;

[0015] Negative value of grindability index of coal powder:

[0016] The additional cost of pulverizing = (coal pulverized grindability index - standard grindability index) * power consumption * electricity price / standard grindability index;

[0017] Step 3: Calculate the comprehensive value of a single type of PCI coal. The specific formula is as follows:

[0018] The comprehensive value of coal powder = the calorific value of coal powder + the negative value of ash content of coal powder + the negative value of S content of coal powder - the additional cost value of coal powder making;

[0019] Step 4: Use the effective value rate as the basis for evaluating the cost performance of pulverized coal and calculate the effective value rate of a single type of PCI coal. The specific formula is as follows:

[0020] Coal powder effective value rate = (coal powder comprehensive value - coal powder dry basis price) / coal powder dry basis price;

[0021] Step 5: Based on the calculation results of the effective value rate of each single type of coal, the available single types of coal are ranked by cost performance;

[0022] Step 6: Sort by cost performance of individual coals and give priority to single coals with high cost performance.

[0023] Furthermore, the database includes at least the following single coal performance indicators: industrial analysis, elemental analysis, grindability index, explosiveness analysis, and jet characteristics analysis.

[0024] Furthermore, the dry basis price of the single type of coal is calculated based on the purchase price and moisture content of the PCI coal.

[0025] Furthermore, according to this method, the available pulverized coal is ranked according to its cost-effectiveness, and a single type of coal with high cost-effectiveness is preferentially selected according to the resource quantity in the coal blending design, which can effectively reduce the cost of pulverized coal injection and bring significant economic benefits to the enterprise.

[0026] Furthermore, according to this method, when objective conditions such as market conditions change, the cost performance of each type of coal can be calculated in a timely and accurate manner, and corresponding production adjustment plans can be given in a timely manner.

[0027] Compared with the prior art, the beneficial technical effects of the present invention are:

[0028] 1) According to this method, the available pulverized coal is ranked according to its cost performance. In the coal blending design, a single type of coal with high cost performance is selected according to the resource quantity, which can effectively reduce the cost of pulverized coal injection and bring significant economic benefits to the enterprise.

[0029] 2) When market conditions and other objective conditions change, the cost performance of each type of coal can be calculated in a timely and accurate manner, and corresponding production adjustment plans can be given in a timely manner.

[0030] 3) It can save the complicated manual calculations and laboratory tests of engineering technicians. DETAILED DESCRIPTION

[0031] A method for evaluating the cost performance of blast furnace coal injection comprises the following steps:

[0032] Step 1: First, establish a single coal database for blast furnace injection; the database includes the performance indicators of each single coal (industrial analysis, elemental analysis, grindability index, explosiveness analysis, jet characteristics analysis, etc.). Calculate the dry basis price of the single coal based on the purchase price and moisture content of the injection coal.

[0033] Step 2: Select the value indicators of blast furnace coal injection to replace coke, calorific value, ash content, grindability index, S content, and calculate the value of each coal quality indicator. The specific calculation formula is as follows:

[0034] Calorific value of pulverized coal:

[0035] High calorific value of pulverized coal × coke price / high calorific value of coke

[0036] Negative value of ash content of coal powder: (increase in ash content of coal powder leads to increase in coke ratio)

[0037] - Ash content of coal powder × coke price × 0.935

[0038] Negative value of sulfur content in pulverized coal: (increased sulfur content in pulverized coal leads to increased coke ratio)

[0039] -S content of coal powder × coke price × 6.6

[0040] Negative value of the grindability index of coal powder: (low grindability index of coal powder leads to increased coal production cost)

[0041] Increased cost of pulverizing = (coal pulverized grindability index - standard grindability index) * power consumption * electricity price / standard grindability index

[0042] Step 3: Calculate the comprehensive value of a single type of PCI coal. The specific formula is as follows:

[0043] The comprehensive value of coal powder = the calorific value of coal powder + the negative value of ash content of coal powder + the negative value of S content of coal powder - the additional cost value of coal powder making.

[0044] Step 4: Use the effective value rate as the basis for evaluating the cost performance of pulverized coal and calculate the effective value rate of a single type of PCI coal. The specific formula is as follows:

[0045] Effective value rate of coal powder = (comprehensive value of coal powder - dry basis price of coal powder) / dry basis price of coal powder.

[0046] Step 5: Based on the calculation results of the effective value rate of each single type of coal, rank the cost-effectiveness of the available single types of coal.

[0047] Step 6: Sort by cost performance of individual coals and give priority to single coals with high cost performance.

[0048] Application examples:

[0049] 1) Based on the current production data of a steel enterprise, the coal resources in the purchase order are tested and analyzed. The specific data are shown in Table 1:

[0050] Table 1 Industrial analysis of pulverized coal injection (%)

[0051] Pulverized coal product name price Moisture Ash Volatile Matter Fixed Carbon S content Grindability Index Calorific value Yankuang Energy 748 18.37 6.21 33.9 61.8 0.4 69 23.41 Haohua Clean Coal 688 20 5.6 37.4 59 0.36 81.64 22.8 Guoneng Ningmei Bituminous Coal 826.04 18 7.5 28.7 63.5 0.32 58.01 22.7 Lu'an Xinjiang 808 12.48 8.64 30.7 62.4 0.08 59 24.9 Anthracite average 1300 9.1 10.7 8.9 81 0.64 28 Lu'an, Shanxi 1270 7.42 10.37 7.39 80 0.87 46.2 27.78 Baotou Steel Industry 1280 8.79 11.21 9.62 80.05 0.97 62.91 27.72 Luyang, Shanxi 1280 10.35 11.18 9.8 80.05 0.94 62.97 27.54 Handan Jizhong 1303 12.57 11.1 10.08 80.32 0.53 49 25.4 Shanxi Coking Coal 1315 8.31 10.85 8.42 81.46 0.44 53 28.91 Shanxi Huayang 1310 8 12.26 7.91 80.29 0.82 52.64 27.88 Yangquan Coal Industry 1310 9.64 11.05 9.7 80.49 0.95 59 27.95 Jinneng Holdings 1337 7.72 10.47 9.33 82.83 0.37 60 28.81 National Energy Ningmei 1320 9.1 10.11 9.64 81.51 0.12 59.08 28.27 Shanxi Coking Coal (Fire) 1345 8.31 10.85 8.38 81.46 0.44 53 28.91 Shanxi Luyang(Fire) 1310 9.1 11.18 9.55 80.5 0.91 62.97 27.78

[0052] 2) Calculate the value corresponding to each single type of coal quality index:

[0053] Table 2 Industrial analysis of pulverized coal injection (%)

[0054] Coal Type Purchase price Purchase dry basis price Calorific value Negative value of ash, V ash Negative sulfur value Grindability Value Comprehensive value of coal powder Yankuang Energy 748.0 916.3 1752 -145 -66 -16 1525 Haohua Clean Coal 688.0 860.0 1707 -131 -59 2 1519 Guoneng Ningmei Bituminous Coal 826.0 1007.4 1699 -175 -53 -32 1439 Lu'an Xinjiang 808.0 923.2 1864 -202 -13 -30 1618 Anthracite average 1300.0 1430.1 2096 -250 -106 -116 1624 Lu'an, Shanxi 1270.0 1371.8 2079 -242 -144 -49 1644 Baotou Steel Mining 1280.0 1403.4 2075 -262 -160 -25 1628 Luyang, Shanxi 1280.0 1427.8 2061 -261 -155 -25 1620 Handan Jizhong 1303.0 1490.3 1901 -259 -87 -45 1509 Shanxi Coking Coal 1315.0 1434.2 2164 -254 -73 -39 1798 Shanxi Huayang 1310.0 1423.9 2087 -287 -135 -40 1625 Yangquan Coal Industry 1310.0 1449.8 2092 -258 -157 -30 1647 Jinneng Holdings 1337.0 1448.9 2156 -245 -61 -29 1822 National Energy Ningmei 1320.0 1452.1 2116 -236 -20 -30 1830 Shanxi Coking Coal (Fire) 1345.0 1466.9 2164 -254 -73 -39 1798 Shanxi Luyang(Fire) 1310.0 1441.1 2079 -261 -155 -25 1638

[0055] 3) Calculate the comprehensive value and effective value rate of each type of coal, and rank them by cost performance based on the effective value rate

[0056] Coal Type Purchase price Purchase dry basis price Comprehensive value of coal powder Effective value rate Cost-effectiveness ranking Yankuang Energy 748.0 916.3 1525 66.4 3 Haohua Clean Coal 688.0 860.0 1519 76.6 1 Guoneng Ningmei Bituminous Coal 826.0 1007.4 1439 42.9 4 Lu'an Xinjiang 808.0 923.2 1618 75.3 2 Anthracite average 1300.0 1430.1 1624 13.6 14 Lu'an, Shanxi 1270.0 1371.8 1644 19.9 9 Baotou Steel Mining 1280.0 1403.4 1628 16.0 10 Luyang, Shanxi 1280.0 1427.8 1620 13.5 15 Handan Jizhong 1303.0 1490.3 1509 1.3 16 Shanxi Coking Coal 1315.0 1434.2 1798 25.4 7 Shanxi Huayang 1310.0 1423.9 1625 14.1 11 Yangquan Coal Industry 1310.0 1449.8 1647 13.6 13 Jinneng Holdings 1337.0 1448.9 1822 25.7 6 National Energy Ningmei 1320.0 1452.1 1830 26.0 5 Shanxi Coking Coal (Fire) 1345.0 1466.9 1798 22.6 8 Shanxi Luyang(Fire) 1310.0 1441.1 1638 13.7 12

[0057] 4) Classify single types of coal into bituminous coal and anthracite based on their volatile content, and rank them by cost-effectiveness.

[0058]

[0059] 5) According to the cost-effectiveness ranking of bituminous coal and anthracite, formulate the coal blending plan for PCI. Haohua bituminous coal should be the first choice for bituminous coal, and Guoneng Ningmei, Jinneng Holdings, and Shanxi Coking Coal should be selected in turn for anthracite. The coal blending plan is set according to the resource volume:

[0060] Haohua Bituminous Coal: Guoneng Ningmei: Jinneng Holdings: Shanxi Coking Coal = 40:20:20:10

[0061] 4) Comparison of blast furnace economic and technical indicators and molten iron costs before and after optimization:

[0062] Table 5 Comparison of coal quality and blast furnace economic and technical indicators before and after optimization of coal blending

[0063]

[0064] From the perspective of blast furnace economic and technical indicators, after the optimization of the coal blending structure of PCI, the coke ratio of the blast furnace decreased by 4.35kg / t and the coal ratio increased by 4.22kg / t. According to the current coke price of 2,639 yuan / ton and the mixed coal cost of 1,065.2 yuan / ton, after the replacement of coal and coke, the fuel cost of the blast furnace decreased by 7.05 yuan / ton. According to the daily iron production of 18,000 tons, the fuel cost can be reduced by 126,900 yuan / day, and the annual fuel cost can be reduced by 44.415 million yuan / year. At the same time, the gray iron ratio of the blast furnace decreased by 1.4kg / t, and the C content of gas ash decreased by 3.82 percentage points. It can be seen that with the increase of the bituminous coal ratio, the gray iron ratio and the C content of gas ash both showed a downward trend, indicating that after increasing the bituminous coal ratio, the unburned coal powder in the blast furnace dust removal ash decreased and the combustion rate of PCI increased.

[0065] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for evaluating the cost performance of blast furnace coal injection, characterized in that: The steps include: Step 1: first establish a single coal database for blast furnace injection; Step 2: Select the value indicators of blast furnace pulverized coal replacing coke, calorific value, ash content, grindability index, and S content, and calculate the value generated by the quality indicators of each type of coal. The specific calculation formula is as follows: Calorific value of pulverized coal: High calorific value of pulverized coal × coke price / high calorific value of coke; Negative value of ash content of coal powder: - Ash content of coal powder × coke price × 0.935; Negative value of sulfur content in coal powder: -S content of coal powder × coke price × 6.6; Negative value of grindability index of coal powder: The additional cost of pulverizing = (coal pulverized grindability index - standard grindability index) * power consumption * electricity price / standard grindability index; Step 3: Calculate the comprehensive value of a single type of PCI coal. The specific formula is as follows: The comprehensive value of coal powder = the calorific value of coal powder + the negative value of ash content of coal powder + the negative value of S content of coal powder - the additional cost value of coal powder making; Step 4: Use the effective value rate as the basis for evaluating the cost performance of pulverized coal and calculate the effective value rate of a single type of PCI coal. The specific formula is as follows: Coal powder effective value rate = (coal powder comprehensive value - coal powder dry basis price) / coal powder dry basis price; Step 5: Based on the calculation results of the effective value rate of each single type of coal, the available single types of coal are ranked by cost performance; Step 6: Sort by cost performance of individual coals and give priority to single coals with high cost performance.

2. The method for evaluating the cost performance of blast furnace coal injection according to claim 1, characterized in that: The database includes at least the following single coal performance indicators: industrial analysis, elemental analysis, grindability index, explosiveness analysis, and jet characteristics analysis.

3. The method for evaluating the cost performance of blast furnace coal injection according to claim 1, characterized in that: The dry basis price of this single type of coal is calculated based on the purchase price and moisture content of the PCI coal.

4. The method for evaluating the cost performance of blast furnace coal injection according to claim 1, characterized in that: According to this method, the available pulverized coal is ranked according to its cost-effectiveness. In the coal blending design, a single type of coal with high cost-effectiveness is given priority according to the resource quantity. This can effectively reduce the cost of pulverized coal injection and bring significant economic benefits to the enterprise.

5. The method for evaluating the cost performance of blast furnace coal injection according to claim 1, characterized in that: According to this method, when objective conditions such as market conditions change, the cost performance of each type of coal can be calculated in a timely and accurate manner, and corresponding production adjustment plans can be given in a timely manner.

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