Method for measuring and calculating cost performance of composite ferrocoke

Abstract

The invention discloses a method for measuring and calculating the cost performance of composite ferro-coke, which comprises the following steps: when the composite ferro-coke is adopted to replace part of coke, calculating the converted price P1Fe of the composite ferro-coke under the conditions of chemical component balance and physical property balance; calculating the converted price P2Fe of the composite ferrocoke under the conditions of chemical component balance and physical performance balance when the composite ferrocoke is adopted to replace part of the pellets; when the current purchase price of the composite iron coke is lower than the converted price P1Fe of the composite iron coke, replacing part of the coke with the composite iron coke, and when the current purchase price of the composite iron coke is lower than the converted price P2Fe of the composite iron coke, replacing part of the pellet ore with the composite iron coke. By measuring and calculating the converted price of the composite iron coke meeting the conditions of chemical component balance and physical performance balance, when the purchase price of the composite iron coke is lower than the corresponding converted price, the composite iron coke is purchased to replace part of coke or pellets, and the chemical component balance and the physical performance balance are met before and after replacement. And certain economic benefits can be generated.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite ferro-coke evaluation, and more specifically, the present invention relates to a method for calculating the cost performance of composite ferro-coke. Background Art

[0002] Composite iron coke is a product obtained by hot-pressing iron ore powder, bituminous coal and anthracite into flat balls and then roasting them in a carbonization shaft furnace. It is a new type of raw fuel for blast furnaces.

[0003] As a highly active composite material, composite iron coke can lower the initial gasification temperature of coke in a blast furnace. This reduces the temperature of the heat storage zone, heat loss in the high-temperature zone, and total fuel consumption per ton of iron, significantly contributing to energy conservation and emission reduction.

[0004] However, when composite iron coke is used to replace part of the coke or part of the pellets, it is not certain whether the current alternatives are cost-effective. Summary of the Invention

[0005] The present invention provides a method for calculating the cost performance of composite iron-coke, aiming to improve at least one of the above problems.

[0006] The present invention is achieved by providing a method for calculating the cost performance of composite iron-coke, the method comprising:

[0007] (1) When composite iron coke is used to replace part of the coke, the conversion price of composite iron coke that meets the conditions of chemical composition balance and physical property balance is calculated.

[0008] (2) Calculate the conversion price of composite iron coke when replacing part of the pellets, which satisfies the chemical composition balance and physical property balance conditions.

[0009] (3) The current purchase price of composite iron coke is lower than the conversion price of composite iron coke When the current purchase price of composite iron coke is lower than the conversion price of composite iron coke, the composite iron coke is used to replace part of the coke. When the sintering process is completed, composite iron coke is used to replace part of the pellets.

[0010] Furthermore, the conversion price of composite iron coke The formation process is as follows:

[0011] When composite iron coke is used to replace part of the coke, calculate the basic conversion price of composite iron coke to meet the carbon balance When composite iron coke is used to replace part of the coke, calculate the change in pig iron cost when the slag balance is met The molten iron benefits generated by satisfying the iron balance And the change in pig iron cost when physical properties balance is met The conversion price of composite coke is

[0012] Furthermore, the basic conversion price of composite coke The formation process is as follows:

[0013]

[0014] Among them, P C is the current price of coke, X is the replacement amount of composite iron coke, Q Fe The total amount of composite iron coke required to meet the carbon balance, where the total amount of composite iron coke required to meet the carbon balance is Q Fe The formation process is as follows:

[0015] Calculate the carbon content Q per ton of molten iron after the composite iron coke replaces part of the coke c , in, is the coke consumption per ton of molten iron, is the carbon content in coke, is the carbon content in the composite iron coke;

[0016] Calculate the amount of composite iron coke replenishment required to maintain carbon balance The total amount of composite iron coke required to meet carbon balance

[0017] Furthermore, the change in pig iron cost The calculation process is as follows:

[0018] Calculation of the comprehensive effective SiO2 content of coke and composite iron coke after composite iron coke replaces part of the coke The calculation formula is as follows:

[0019]

[0020] in, Respectively represent the SiO2 content in coke and composite iron coke; They represent the CaO content in coke and composite iron coke respectively, and ALK is the set blast furnace slag basicity.

[0021] Based on effective SiO2 content Calculate the change in pig iron cost The calculation formula is as follows:

[0022]

[0023] in, Indicates the effective SiO2 content in coke, It means that 1kg SiO2 affects the coke ratio.

[0024] Furthermore, the benefits of producing molten iron under iron balance The formation process is as follows:

[0025] Calculate the molten iron output after replacing part of the coke with composite iron-coke in, Indicates the iron content after composite iron coke replaces part of the coke; M Fe Indicates the mass fraction of iron in molten iron;

[0026] Iron content The calculation formula is as follows:

[0027]

[0028] in, The iron content in coke and composite iron coke are shown respectively;

[0029] Calculate current molten iron production The amount of coke consumed

[0030] Calculate the benefits of producing molten iron under iron balance Among them, P Fe Indicates the current cost price of pig iron.

[0031] Furthermore, the change in pig iron cost The calculation formula is as follows:

[0032]

[0033] Among them, I Fe , I C Respectively represent the drum strength of composite iron coke and coke; B jb It represents the increase in blast furnace coke ratio caused by a 1% decrease in drum strength, and x represents the replacement ratio of composite iron coke.

[0034] Furthermore, the conversion price of composite iron coke The acquisition process is as follows:

[0035] When composite iron coke is used to replace part of the pellets, calculate the basic conversion price of composite coke iron when the iron balance is met

[0036] When composite iron coke is used to replace part of the pellets, calculate the change in pig iron cost when the slag balance is met Reduce fuel costs while meeting carbon neutrality Change in pig iron cost when physical property balance is met Conversion price of composite coke

[0037] Furthermore, the basic conversion price of composite coke The acquisition process is as follows:

[0038] Calculate the output of hot metal per ton after composite iron coke replaces part of the pellets The calculation formula is as follows:

[0039]

[0040] Among them, Q pel The amount of pellets Q required to produce one ton of molten iron pel , Respectively represent the iron content in pellets and composite iron coke; M Fe Indicates the mass fraction of iron in molten iron;

[0041] Calculate the additional amount of composite iron coke to be The calculation formula is as follows:

[0042]

[0043] Basic conversion price of composite coke The calculation formula is as follows:

[0044]

[0045] Furthermore, the change in pig iron cost The calculation formula is as follows:

[0046]

[0047] in, Indicates the effective SiO2 content in the pellets, It indicates the comprehensive effective SiO2 content of pellets and composite iron coke after replacement;

[0048] Comprehensive effective SiO2 content of pellets and composite iron coke after replacement The calculation formula is as follows:

[0049]

[0050] in, Specifically indicates the SiO2 content in pellets and composite iron coke; They represent the CaO content in pellets and composite iron coke respectively, and ALK is the set blast furnace slag basicity.

[0051] Further reducing fuel costs The calculation formula is as follows:

[0052] Calculate the carbon content per ton of molten iron after replacing part of the pellets with composite iron coke in, is the carbon content in the composite iron coke;

[0053] Reduce fuel costs per ton of hot metal in, is the carbon content in coke, P C is the current price of coke.

[0054] Furthermore, the change in pig iron cost The formation process is as follows:

[0055]

[0056] Among them, C jb is the increase in blast furnace coke ratio caused by a 100N decrease in compressive strength, and x represents the replacement ratio of composite iron coke.

[0057] The present invention calculates the converted price of composite ferro-coke that meets the conditions of chemical composition balance and physical property balance. When the purchase price of the composite ferro-coke is lower than the corresponding converted price, the composite ferro-coke is purchased to replace part of the coke or pellets, so as to achieve the chemical composition balance and physical property balance before and after the replacement, and generate certain economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 Flowchart of a method for calculating the cost-effectiveness of composite iron-coke provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The specific implementation methods of the present invention will be further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0060] Figure 1 A flow chart of a method for calculating the cost performance of composite iron-coke provided in an embodiment of the present invention, the method is specifically as follows:

[0061] (1) Calculate the conversion price of composite iron coke when replacing part of the coke with composite iron coke, which satisfies the chemical composition balance and physical property balance conditions. (2) Calculate the conversion price of composite iron coke when replacing part of the pellets, which satisfies the chemical composition balance and physical property balance conditions. (3) The current purchase price of composite iron coke is lower than the conversion price of composite iron coke When the current purchase price of composite iron coke is lower than the conversion price of composite iron coke, the composite iron coke is used to replace part of the coke. When the sintering process is completed, composite iron coke is used to replace part of the pellets.

[0062] In the embodiment of the present invention, the conversion price of composite coke used for partial coke replacement is The specific process of determining is as follows:

[0063] (11) Calculate the basic conversion price of composite coke iron when replacing part of the coke with composite coke iron to meet the carbon balance

[0064] In the embodiment of the present invention, the basic conversion price of composite iron coke is The details are as follows:

[0065]

[0066] Among them, P C is the current price of coke per ton, X is the replacement amount of composite iron coke, in kg, Q Fe The total amount of composite iron coke required to meet carbon balance, in kg, where the total amount of composite iron coke Q Fe The acquisition process is as follows:

[0067] Calculate the carbon content Q per ton of molten iron after the composite iron coke replaces part of the coke c , the unit is kg, and the calculation formula is as follows:

[0068]

[0069] in, is the coke consumption per ton of molten iron, in kg, is the carbon content in coke, is the carbon content in the composite iron coke. Then calculate the amount of composite iron coke required to maintain carbon balance The unit is kg, Among them, the total amount of composite iron coke

[0070] (12) Calculate the change in pig iron cost required to meet the slag balance condition when replacing part of the coke with composite iron coke Change in pig iron cost The calculation process is as follows:

[0071] Calculation of the comprehensive effective SiO2 content of coke and composite iron coke after composite iron coke replaces part of the coke The calculation formula is as follows:

[0072]

[0073] in, Respectively represent the SiO2 content in coke and composite iron coke; They represent the CaO content in coke and composite iron coke respectively, and ALK is the set blast furnace slag basicity.

[0074] The change in pig iron cost is The calculation formula is as follows:

[0075]

[0076] in, Indicates the effective SiO2 content in coke; Indicates that 1kg SiO2 affects the coke ratio. (13) Calculate the molten iron benefit generated by satisfying the iron balance condition when composite iron coke is used to replace part of the coke. The acquisition process is as follows:

[0077] Calculate the hot metal production after replacing part of the coke with composite iron coke The unit is tons, and the calculation formula is as follows:

[0078]

[0079] in, Indicates the iron content in molten iron after composite iron coke replaces part of the coke; M Fe Indicates the mass fraction of iron in molten iron, where the iron content The calculation formula is as follows:

[0080]

[0081] in, The iron contents in coke and composite iron coke are shown respectively.

[0082] Calculate current iron production The amount of coke consumed The unit is kg, and the calculation formula is as follows:

[0083]

[0084] Then calculate the benefits of producing molten iron under iron balance conditions The calculation formula is as follows:

[0085]

[0086] Among them, P Fe Indicates the current cost price per ton of pig iron.

[0087] (14) Calculate the change in pig iron cost when replacing part of the coke with composite iron coke to meet the physical property balance

[0088] The drum strength of composite iron coke is 82.79%, while the drum strength of coke is 88.13%. According to experience, a 1% reduction in drum strength will increase the blast furnace coke ratio by 0.75%. When the coke ratio per ton of iron is 370kg / t, the coke price is 2091 yuan / ton, and the replacement amount is 10%, the pig iron cost change after replacing part of the coke with composite iron coke is The calculation formula is as follows:

[0089]

[0090] Among them, I Fe , I C Respectively represent the drum strength of composite iron coke and coke; B jb = represents the increase in blast furnace coke ratio caused by a 1% decrease in drum strength, and x represents the replacement ratio of composite iron coke. (15) Composite coke iron conversion price

[0091] In the embodiment of the present invention, the composite iron coke conversion price The acquisition process is as follows:

[0092] (21) Calculate the basic conversion price of composite coke iron when composite iron coke is used to replace part of the pellets to meet the iron balance

[0093] Calculate the output of hot metal per ton after composite iron coke replaces part of the pellets The calculation formula is as follows:

[0094]

[0095] Among them, Q pel Indicates the amount of pellets required to produce one ton of molten iron. Respectively represent the iron content in pellets and composite iron coke, M Fe Indicates the mass fraction of iron in molten iron;

[0096] Since the iron content in pellets is higher than that in composite iron coke, in order to ensure the iron yield per ton of molten iron before and after replacement To achieve iron balance, it is necessary to supplement part of the composite iron coke based on the replacement amount X in the composite iron coke. The additional amount of composite iron coke is The unit is kg, and the calculation formula is as follows:

[0097]

[0098] Basic conversion price of composite coke The calculation formula is as follows:

[0099]

[0100] (22) Calculate the change in pig iron cost when slag balance is met when composite iron coke is used to replace part of the pellets The calculation formula is as follows:

[0101]

[0102] in, Indicates the effective SiO2 content in the pellets, It represents the comprehensive effective SiO2 content of the pellets and the composite iron coke after replacement. The calculation formula of the comprehensive effective SiO2 content of the pellets and the composite iron coke after replacement is as follows:

[0103]

[0104] in, Specifically indicates the SiO2 content in pellets and composite iron coke; They represent the CaO content in pellets and composite iron coke respectively, and ALK is the set blast furnace slag basicity.

[0105] (23) Calculate the fuel cost reduction when using composite iron coke to replace part of the pellets to meet the carbon balance The calculation formula is as follows:

[0106] Calculate the carbon content per ton of molten iron after replacing part of the pellets with composite iron coke in, is the carbon content in the composite iron coke;

[0107] Reduced fuel cost per ton of hot metal in, is the carbon content in coke, P C is the current price of coke per ton.

[0108] (24) Calculate the change in pig iron cost when composite iron coke is used to replace part of the pellets to meet the physical property balance

[0109] The compressive strength of composite iron coke is 2309N, while that of pellets is 2606N. According to the empirical formula, when the compressive strength is in the range of 1000N-2000N, a 100N reduction in compressive strength will increase the blast furnace coke ratio by 1%. When the compressive strength is in the range of 2000N-2500N, a 100N reduction in compressive strength will increase the blast furnace coke ratio by 0.5%. When the compressive strength is in the range of 2500N-3000N, a 100N reduction in compressive strength will hardly affect the coke ratio. The coke ratio per ton of iron is 370kg / t, the coke price is RMB 2091 / ton, and the replacement amount is 10%. Then, when the composite iron coke replaces pellets, the following will be achieved:

[0110]

[0111] Among them, C jb is the increase in blast furnace coke ratio caused by a 100N decrease in compressive strength, and x represents the replacement ratio of composite iron coke;

[0112] (25) Conversion price of composite coke

[0113] The following is a calculation of the cost-effectiveness of composite ferro-coke replacing coke and pellets based on the chemical composition and physical properties of composite ferro-coke, coke, and pellets. The specific process is as follows:

[0114] Table 1 Chemical composition and physical and chemical properties of a batch of production

[0115]

[0116] Table 2 Chemical composition and physical and chemical properties of coke

[0117]

[0118]

[0119] Table 3 Chemical composition and physical properties of pellets

[0120]

[0121] When replacing 10% of coke with composite iron coke, the cost-effectiveness calculation process of this replacement scheme is as follows:

[0122] (1) Chemical composition analysis

[0123] 1. Carbon (C) balance

[0124] Before replacement: Taking the actual production of a blast furnace as an example, the coke consumption per ton of molten iron 370kg, C content in coke is 85.57%, the coke price P C It is 2091 yuan / ton, and it can be calculated that the amount of C brought into each ton of molten iron = 370×85.57% = 316.61kg.

[0125] Replacement amount (composite iron coke): the amount of composite iron coke consumed per ton of molten iron is X = 370 × 10% = 37 kg. After testing, the C content in the composite iron coke is It is 35.60%, and it can be calculated that the amount of C brought into each ton of molten iron = 37×35.60% = 13.172 kg.

[0126] After replacement (coke + composite iron coke): coke consumption per ton of molten iron The carbon content of each ton of hot metal is 333 kg, and the amount of composite iron coke consumed per ton of hot metal is X, which is 37 kg. The amount of carbon carried into each ton of hot metal after replacement can be calculated as = 333 × 85.57% + 37 × 35.60% = 298.12 kg. In order to ensure that the amount of carbon carried into each ton of hot metal before and after replacement remains unchanged, an additional 18.49 kg of carbon needs to be added, that is, an additional amount of composite iron coke needs to be added. The chemical composition balance and physical property balance conditions are met.

[0127] 2. Slag balance

[0128] Before replacement (coke): Taking the actual production of a blast furnace as an example, the coke consumption per ton of molten iron The CaO content in the coke is 370kg. The SiO2 content in coke is 0.64%. The slag basicity ALK is set to 1.2, and the amount of SiO2 balanced by 1.2 times the basicity is 0.53%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If it is 0.5kg, then the SiO2-affected coke ratio = 370×5.22%×0.5=9.65kg / t.

[0129] Replacement amount (composite iron coke): iron consumption per ton of composite iron coke amount X = 370 × 10% = 37 kg, after testing the CaO content in the composite iron coke The SiO2 content in composite iron coke is 3.35%. The slag basicity ALK is set to 1.2, and the amount of SiO2 balanced by 1.2 times the basicity is 2.79%. The effective SiO2 content = 16.03% - 2.79% = 13.24%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If it is 0.5kg, then the SiO2 impact on coke ratio = 37×13.24%×0.5=2.45kg / t.

[0130] After replacement (coke + composite iron coke): coke consumption per ton of molten iron The composite iron coke amount X consumed per ton of molten iron is 333kg, and the CaO content per ton of molten iron after replacement is (333×0.64%+37×3.35%) / 370=0.91%. The SiO2 content per ton of molten iron after replacement is (333×5.75%+37×16.03%) / 370=6.78%. The blast furnace slag basicity ALK is set to 1.2, and 1.2 times the basicity balances the SiO2 amount to 0.76%. The effective SiO2 content is 6.78%-0.76%=6.02%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If the content of SiO2 in the coke ratio is 0.5kg, then the coke ratio affected by SiO2 = 370×6.02%×0.5=11.13kg / t. After replacement, the coke ratio increases by 1.48kg / t. The coke price is 2091 yuan / ton, and the pig iron cost increases by 3.09 yuan / ton.

[0131] 3. Iron balance

[0132] Before replacement (coke): Taking the actual production of a blast furnace as an example, the coke consumption per ton of molten iron 370kg, Fe content in coke It is 0%, and the iron production is 0 tons.

[0133] Replacement amount (composite iron coke): The amount of composite iron coke consumed per ton of molten iron is X, which is 37 kg. The Fe content in the composite iron coke is is 26.02%,

[0134] After replacement (coke + composite iron coke): coke consumption per ton of molten iron The composite iron coke consumption per ton of molten iron is 333kg, and the amount of composite iron coke consumed per ton of molten iron is X is 37kg. After replacement, the Fe content in each ton of molten iron = (333×0%+37×26.02%) / 370=2.60%. Calculate current current Assuming that the cost of pig iron is RMB 2606.70 / ton, after replacement

[0135] (2) Physical properties analysis

[0136] The drum strength of the composite iron-coke is 82.79%, while the drum strength of the coke is 88.13%. According to the empirical formula, a 1% decrease in drum strength will increase the blast furnace coke ratio by 0.75%. The coke ratio per ton of iron is 370kg / t, the coke price is 2091 yuan / ton, and the replacement amount is 10%. When the composite iron-coke is used to replace coke, the pig iron cost increases by (88.13%-82.79%)×0.75%×370×10%×2091 / 1000=3.1 yuan / ton.

[0137] After replacement, the slag, iron balance and physical properties analysis show that the total molten iron benefit is RMB 18.82-3.09-3.1=12.63 / ton, which is the basic conversion price of composite coke iron. Increment but Conclusion: When the current purchase price of composite ferrocoke is less than RMB 1,211.28 / ton, it is cost-effective to use composite ferrocoke to replace part of the coke.

[0138] When replacing 10% of pellets with composite iron coke, the cost-effectiveness calculation process of this replacement solution is as follows:

[0139] (1) Chemical composition analysis

[0140] 1. Iron balance

[0141] Before replacement (pellet): After testing, the Fe content of a pellet is 60.75%, Assume that the price of pellets is 921.70 yuan / ton.

[0142] Replacement amount (composite iron coke): the amount of composite iron coke consumed per ton of molten iron X = the amount of pellets consumed per ton of molten iron Q pel ×10%=1556×10%=156kg (approximate value), Fe content in composite iron coke is 26.02%,

[0143] After replacement (pellet ore + composite iron coke): the amount of pellet ore consumed per ton of molten iron after replacement (Q pel -X) is 1400kg (approximate value), the amount of composite iron coke consumed per ton of molten iron X is 156kg, the Fe content in each ton of molten iron = (1400×60.75%+156×26.02%) / 1400+156=57.28%, then the iron production per ton of molten iron = (amount of pellets consumed per ton of iron + amount of composite iron coke consumed per ton of iron) × Fe content after replacement / mass fraction of Fe in molten iron / 1000 = 1556×57.28% / 0.945 / 1000 = 0.943 ton.

[0144] To ensure that the molten iron output remains unchanged at 1 ton before and after replacement, an additional 0.057 tons of iron is required. but

[0145] 2. Slag balance

[0146] Before replacement (pellet ore): Pellet ore consumption per ton of molten iron Q pel It is 1556kg (approximate value). The CaO content in the pellets was tested. 0.66%, measuring the SiO2 content in pellets The blast furnace slag basicity ALK is set to 1.2, and the 1.2 times basicity balances the SiO2 amount to 0.55%, then the effective SiO2 content = 9.12% - 0.55% = 8.57%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If it is 0.5kg, then the SiO2 influence on coke ratio = 1556×8.57%×0.5=66.66kg / t.

[0147] Replacement amount (composite iron coke): the consumption of composite iron coke per ton of molten iron is X = 1556 × 10% = 156 kg (approximate value). The CaO content in the composite iron coke is tested. The SiO2 content in composite iron coke is 3.35%. The slag basicity ALK is set to 1.2, and the amount of SiO2 balanced by 1.2 times the basicity is 2.79%. The effective SiO2 content = 16.03% - 2.79% = 13.24%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If it is 0.5kg, then the SiO2 influence on coke ratio = 156×13.24%×0.5=10.3kg / t.

[0148] After replacement (pellet ore + composite iron coke): pellet ore consumption per ton of molten iron (Q pel -X) is 1400kg (approximate value), the composite iron coke consumption per ton of iron X is 156kg, Assuming the blast furnace slag basicity ALK is 1.2, 1.2 times the basicity balances the SiO2 amount to 0.77%, then the effective SiO2 content = 9.81% - 0.77% = 9.04%. According to the conclusion drawn by experts and scholars: 1kgSiO2 affects the coke ratio If the content of SiO2 in the coke ratio is 0.5kg, then the coke ratio affected by SiO2 = 1556×9.04%×0.5 = 70.29kg / t. After replacement, the coke ratio increases by 3.63kg / t. The coke price is 2091 yuan / ton, and the pig iron cost increases by 7.59 yuan / ton.

[0149] 3. Carbon (C) balance

[0150] Before replacement (pellet ore): ton iron consumption pellet ore quantity Q pel It is 1556kg (approximate value). The C content in the pellets was tested. It is 0%, and the amount of C brought in per ton of molten iron is 0 kg.

[0151] Replacement amount (composite iron coke): the consumption of composite iron coke per ton of molten iron is X = 1556 × 10% = 156 kg (approximate value). After testing, the C content in composite iron coke is It is 35.60%, and it can be calculated that the amount of C brought into each ton of molten iron = 156×35.60% = 55.378 kg.

[0152] After replacement (pellet + composite iron coke): pellet consumption per ton of molten iron (Q pel -X) is 1400kg (approximate value), the consumption of composite iron coke per ton of molten iron is X is 156kg, The amount of C carried into each ton of molten iron can be calculated as follows: 1400 × 0% + 156 × 35.60% = 55.378 kg. The price of coke is 2091 yuan / ton, and the carbon content of coke is 85.57%. After the replacement, the cost of pig iron dropped by 135.32 yuan / ton.

[0153] (2) Physical properties analysis

[0154] The compressive strength of composite iron coke is 2309N, while that of pellets is 2606N. According to the empirical formula, when the compressive strength is in the range of 1000N-2000N, a 100N reduction in compressive strength will increase the blast furnace coke ratio by 1%. When the compressive strength is in the range of 2000N-2500N, a 100N reduction in compressive strength will increase the blast furnace coke ratio by 0.5%. When the compressive strength is in the range of 2500N-3000N, a 100N reduction in compressive strength will hardly affect the coke ratio. The coke ratio per ton of iron is 370kg / t, the coke price is 2091 yuan / ton, and the replacement amount is 10%. When the composite iron coke is used to replace pellets, the cost of pig iron increases by (2500-2309)×0.5% / 100×370×10%×2091 / 1000=0.74 yuan / ton.

[0155] After the replacement, the slag, C balance and physical properties analysis reduced the total molten iron cost by RMB 135.32-7.59-0.74=126.99 / ton, the basic conversion price of composite coke iron Increment The conversion price of composite coke is Conclusion: The current purchase price of composite ferrocoke is less than RMB 1,208.82 / ton, which is cost-effective in replacing pellets.

[0156] 10% and 20% composite iron-coke were used in blast furnaces to replace coke. The theoretically calculated price of composite iron-coke was 1,211.28 yuan / ton, representing the critical value for cost-effectiveness. Cost analysis was conducted to verify the cost-effectiveness of composite iron-coke. A blast furnace with relatively stable raw material and fuel conditions and a fixed operator was selected. The quality of composite iron-coke, coke, and pellets is shown in Tables 1, 2, and 3.

[0157] Table 4 Pig iron cost when composite iron coke is used to replace part of the coke in blast furnace

[0158]

[0159] When 10% composite iron coke is added to replace coke, the temperature of the heat reserve zone in the blast furnace decreases, indirect reduction develops, carbon utilization increases, and the pig iron cost decreases by 3.34 yuan / t compared to when it is not added. When 20% composite iron coke is added to replace coke, the temperature of the heat reserve zone in the blast furnace decreases, indirect reduction develops, and carbon utilization increases. However, because the physical properties of composite iron coke are inferior to those of coke, more powder is generated in the furnace, affecting the permeability of the blast furnace and causing a certain degree of reduction in gas utilization. The pig iron cost decreases by 2.18 yuan / t compared to when it is not added, and the pig iron cost increases by 1.16 yuan / t compared to when it is added at 10%.

[0160] Table 5 Pig iron cost when composite iron coke is used in blast furnace instead of pellets

[0161]

[0162]

[0163] When 10% composite iron coke is added to replace pellets, the temperature of the heat reserve zone in the blast furnace decreases, indirect reduction develops, carbon utilization increases, and the pig iron cost decreases by 0.97 yuan / t compared to when it is not added. When 20% composite iron coke is added to replace pellets, the temperature of the heat reserve zone in the blast furnace decreases, indirect reduction develops, and carbon utilization increases. However, because the physical properties of composite iron coke are inferior to those of pellets and coke, more powder is generated in the furnace, affecting the permeability of the blast furnace and causing a certain degree of reduction in gas utilization. The pig iron cost increases by 1.95 yuan / t compared to when it is not added, and the pig iron cost increases by 2.92 yuan / t compared to when it is added at 10%.

[0164] The present invention has been described exemplarily. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A method for calculating the cost performance of composite iron-coke, characterized in that: The method is specifically as follows: (1) When composite iron coke is used to replace part of the coke, calculate the composite iron coke conversion price P1 that meets the chemical composition balance and physical property balance conditions. Fe ; (2) Calculate the conversion price of composite iron coke when replacing part of the pellets, which satisfies the chemical composition balance and physical property balance conditions. (3) When the current purchase price of composite iron coke is lower than the converted price of composite iron coke P1 Fe When the current purchase price of composite iron coke is lower than the conversion price of composite iron coke, the composite iron coke is used to replace part of the coke. When the sintering process is completed, composite iron coke is used to replace part of the pellets.

2. The method for calculating the cost performance of composite iron-coke according to claim 1, wherein: Composite iron coke conversion price P1 Fe The formation process is as follows: When composite iron coke is used to replace part of the coke, calculate the basic conversion price of composite iron coke to meet the carbon balance When composite iron coke is used to replace part of the coke, calculate the pig iron cost change P3 when the slag balance is met Fe , the molten iron benefits generated by satisfying iron balance And the change in pig iron cost when physical properties balance is met The conversion price of composite coke is 3. The method for calculating the cost performance of composite iron-coke according to claim 2, wherein: Basic conversion price of composite coke The formation process is as follows: Among them, P C is the current price of coke, X is the replacement amount of composite iron coke, Q Fe The total amount of composite iron coke required to meet the carbon balance, where the total amount of composite iron coke required to meet the carbon balance is Q Fe The formation process is as follows: Calculate the carbon content Q per ton of molten iron after the composite iron coke replaces part of the coke c , in, is the coke consumption per ton of molten iron, is the carbon content in coke, is the carbon content in the composite iron coke; Calculate the amount of composite iron coke replenishment required to maintain carbon balance The total amount of composite iron coke required to meet carbon balance 4. The method for calculating the cost performance of composite iron-coke according to claim 2, wherein: Pig iron cost change P3 Fe The calculation process is as follows: Calculation of the comprehensive effective SiO2 content of coke and composite iron coke after composite iron coke replaces part of the coke The calculation formula is as follows: in, Respectively represent the SiO2 content in coke and composite iron coke; Respectively represent the CaO content in coke and composite iron coke, ALK is the set high furnace slag basicity; Based on effective SiO2 content Calculate the pig iron cost change P3 Fe , the calculation formula is as follows: in, Indicates the effective SiO2 content in coke, It means that 1kg SiO2 affects the coke ratio.

5. The method for calculating the cost performance of composite iron-coke according to claim 2, wherein: Benefits of producing molten iron under iron balance The formation process is as follows: Calculate the molten iron output after replacing part of the coke with composite iron-coke in, Indicates the iron content after composite iron coke replaces part of the coke; M Fe Indicates the mass fraction of iron in molten iron; Iron content The calculation formula is as follows: in, The iron content in coke and composite iron coke are shown respectively; Calculate current molten iron production The amount of coke consumed Calculate the benefits of producing molten iron under iron balance Among them, P Fe Indicates the current cost price of pig iron.

6. The method for calculating the cost performance of composite iron-coke according to claim 2, wherein: Change in pig iron cost The calculation formula is as follows: Among them, I Fe , I C Respectively represent the drum strength of composite iron coke and coke; B jb It represents the increase in blast furnace coke ratio caused by a 1% decrease in drum strength, and x represents the replacement ratio of composite iron coke.

7. The method for calculating the cost performance of composite iron-coke according to claim 1, wherein: Composite iron coke conversion price The acquisition process is as follows: When composite iron coke is used to replace part of the pellets, calculate the basic conversion price of composite coke iron when the iron balance is met When composite iron coke is used to replace part of the pellets, calculate the change in pig iron cost when the slag balance is met Reduce fuel costs while meeting carbon neutrality Change in pig iron cost when physical property balance is met Conversion price of composite coke 8. The method for calculating the cost performance of composite iron-coke according to claim 7, wherein: Basic conversion price of composite coke The acquisition process is as follows: Calculate the output of hot metal per ton after composite iron coke replaces part of the pellets The calculation formula is as follows: Among them, Q pel The amount of pellets Q required to produce one ton of molten iron pel , Respectively represent the iron content in pellets and composite iron coke; M Fe Indicates the mass fraction of iron in molten iron; Calculate the additional amount of composite iron coke to be The calculation formula is as follows: Basic conversion price of composite coke The calculation formula is as follows:

9. The method for calculating the cost performance of composite iron-coke according to claim 7, wherein: Change in pig iron cost The calculation formula is as follows: in, Indicates the effective SiO2 content in the pellets, It indicates the comprehensive effective SiO2 content of pellets and composite iron coke after replacement; Comprehensive effective SiO2 content of pellets and composite iron coke after replacement The calculation formula is as follows: in, Specifically indicates the SiO2 content in pellets and composite iron coke; They represent the CaO content in pellets and composite iron coke respectively, and ALK is the set blast furnace slag basicity.

10. The method for calculating the cost performance of composite iron-coke according to claim 7, wherein: Reduce fuel costs The calculation formula is as follows: Calculate the carbon content per ton of molten iron after replacing part of the pellets with composite iron coke in, is the carbon content in the composite iron coke; Reduce fuel costs per ton of hot metal in, is the carbon content in coke, P C is the current price of coke; Change in pig iron cost The formation process is as follows: Among them, C jb is the increase in blast furnace coke ratio caused by a 100N decrease in compressive strength, and x represents the replacement ratio of composite iron coke.

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