Comprehensive evaluation method for cost performance of coke for blast furnace ironmaking

Abstract

The invention discloses a comprehensive evaluation method for the cost performance of coke for blast furnace ironmaking, which comprises the following steps: measuring dry basis ash content, combustible basis volatile component, dry ash-free basis sulfur content and the like of different types of coke, reactivity CRI, post-reaction strength CSR, abrasive strength M10 and crushing strength M25; three new indexes of coke particle size distribution concentration CSS, coke oxidation resistance index RO and time CRI50 required for coke solution loss of 50% are provided, the data and a standard coke are subjected to calculation to obtain a net coke ratio sequence, and the coke performance and cost performance sequence is obtained by combining factors such as price and the like. According to the method, the performance and the cost performance of the coke are more scientifically and comprehensively evaluated by combining the existing indexes of the coke with the new indexes and comprehensively considering the price of the coke, so that the problems that the indexes of part of types of coke are good and the actual effect is relatively poor in the existing evaluation system are solved; and the situation that evaluation is inaccurate only through purchase price and single-dimension evaluation of the performance price of the coke is improved, a coke evaluation system is perfected, and guidance is provided for production and use of the coke for blast furnace ironmaking.

Description

Technical Field

[0001] The invention belongs to the technical field of ironmaking, relates to quality evaluation of coke for blast furnace ironmaking, and specifically is a comprehensive evaluation method for cost performance of coke for blast furnace ironmaking. Background Art

[0002] As the main raw material for blast furnace smelting, coke plays the role of providing heat source, reducing agent, skeleton coke window and carburizing in the blast furnace. At present, the evaluation indicators of coke used in blast furnace smelting mainly include ash content, A d , Volatile matter V daf , moisture Mt, air-dried moisture Mad, reactivity CRI, post-reaction strength CSR, wear resistance M10, crushing strength M25, and proportion of <25mm. Iron and steel enterprises especially use the hot strength of coke as the main assessment indicator. The evaluation of the hot strength of coke mainly refers to the reactivity and post-reaction strength of coke. The reactivity is based on the coke temperature at 1100℃ and CO 2 After 2 hours of reaction, the coke mass loss percentage is used as the percentage of coke mass larger than 10mm after the reaction of the coke after the type I drum test. Although the quality of coke can be roughly ranked according to the current coke quality or cost performance measurement system, many years of practical production experience have shown that the evaluation results of the existing quality system are often inconsistent with the actual blast furnace use effect, especially the top-loading coke with good use effect is often ranked behind the ramming coke, which shows that the existing coke quality evaluation system cannot fully reflect the impact of coke quality on the blast furnace smelting process.

[0003] Practice has proved that the fluctuation of raw material particle size has a significant effect on the permeability index of blast furnace and has an important impact on the stable operation of blast furnace. In the past, the traditional particle size regulations lacked theoretical basis, the regulations were very broad, inaccurate, and weak in guidance, and could not adapt to different blast furnaces or even different periods of the same blast furnace. According to the theoretical relationship of blast furnace permeability or permeability resistance, the coke particle size concentration is an indicator that accurately reflects the impact of raw material particle size on blast furnace. The better the concentration, the more uniform the coke particle size distribution, the better the blast furnace permeability, the smaller the permeability resistance, the smooth operation of blast furnace, the lower the coke ratio and fuel ratio. In addition, coke will deteriorate and degrade inside the blast furnace, causing the particle size concentration or uniformity to decrease, which in turn affects the smooth operation of the blast furnace and deteriorates the blast furnace smelting indicators. The high temperature oxidation resistance of coke and the time taken for 50% dissolution loss rate are important indicators for controlling the deterioration of coke inside the blast furnace and the decrease in particle size concentration.

[0004] The national standard thermal strength of coke is the data of the reaction with carbon dioxide at a fixed time (120 minutes), which is a fixed-time smelting index (CRI, CSR). However, according to the data of coke measurement at the blast furnace tuyere, the coke on the top of the furnace actually dissolves about 50% when it reaches the center line of the blast furnace tuyere. Therefore, the 50% dissolution of coke is used as the smelting index of quantitative dissolution of different types of coke, that is, the time taken for 50% dissolution rate. Coke with the same thermal strength has different contact areas with carbon dioxide during blast furnace smelting due to different porosity. The larger the contact area, the stronger the oxidation resistance. Therefore, the high-temperature oxidation resistance of coke is another important indicator of blast furnace coke.

[0005] In summary, establishing a coke quality evaluation system that takes into account the coke particle size concentration, high-temperature oxidation resistance, and the time required for 50% dissolution loss rate is extremely important for comprehensively and reasonably evaluating coke quality, stabilizing blast furnace production, and controlling blast furnace costs. Summary of the invention

[0006] The purpose of the present invention is to provide a comprehensive evaluation method for the cost performance of coke for blast furnace ironmaking, to achieve comprehensive evaluation of the cost performance of coke for blast furnace ironmaking, and to solve the problem of one-sided and inaccurate cost performance evaluation of coke for blast furnace ironmaking in the prior art.

[0007] To solve the above problems, the technical solution adopted by the present invention is a comprehensive evaluation method for the cost performance of coke for blast furnace ironmaking, comprising the following steps:

[0008] S1. Determine the composition indexes of different cokes, including dry basis ash (Ad), combustible basis volatile matter (Vdaf), dry ash-free basis sulfur (St,d), total moisture (Mt), and air-dried basis moisture (Mad).

[0009] S2. Determine the thermal performance index reactivity CRI and post-reaction strength CSR of different cokes;

[0010] Coke reactivity CRI: Weigh a certain mass of coke sample, place it in a reactor, and react with carbon dioxide at 1100±5℃ for 2h, and the percentage of coke mass loss;

[0011] The post-reaction strength CSR of coke: After the above-mentioned post-reaction coke is tested for a certain number of revolutions of the type I, the mass percentage of coke with a particle size of >10mm in the post-reaction coke is as follows:

[0012]

[0013] Where: g 0 is the total mass of coke, g; g 1 is the mass of coke after the reaction is completed, g; g 2 It is the mass of coke with particle size > 10 mm after drum test, g.

[0014] S3. Determination of cold performance index wear resistance M of different cokes 10 , crushing strength M 25 ;

[0015] The specific steps are as follows: take a 50kg sample of coke with a size larger than 60mm after reaction, place it in a Mikum drum, run it at a constant speed of 25 revolutions per minute for 100 revolutions, and after screening, the percentage of coke with a size larger than 25mm in the drum is taken as the crushing strength M 25 The percentage of coke powder less than 10 mm is taken as the strength M 10 .

[0016] S4. A certain amount of different original cokes or coke samples rotated in a type I drum at a speed of 20r / min for 15min are screened step by step with a round hole sieve and divided into five intervals: <25mm, 25-40mm, 40-60mm, 60-80mm, >80mm, and their respective total mass percentages are obtained, the average particle size is calculated, and the concentration of coke particle size distribution is further obtained. The formula is as follows:

[0017]

[0018] Where: is the average particle size of the coke entering the furnace; is the standard deviation of particle size distribution; CCS is the concentration of particle size distribution of coke entering the furnace; R 1 is the upper limit of a certain particle size range; R 2 is the lower limit of a certain particle size range; w i is the mass fraction of the particle size range; n is the number of particle sizes.

[0019] S5. Determine the oxidation resistance RO of different cokes.

[0020] The specific steps of S5 are:

[0021] S51. Select a certain amount of different types of coke and crush them into sizes of 0.25 mm to 0.3 mm respectively.

[0022] S52, weigh the same mass of coke, place it in the reactor, and introduce 5L / min 100% N 2 Protection, heating to 1100℃ at a rate of 15℃ / min.

[0023] S53, keep the temperature constant for 10 minutes, and after the temperature stabilizes, change to 5L / min CO 2 gas, the reaction time is 40min.

[0024] S54, stop heating, and introduce N during cooling 2 Cool to room temperature. Record the time, mass and other data during cooling, and calculate the weight loss rate in different time periods.

[0025] S55. Calculate the coke dissolution reaction rate, and take the inverse of the average reaction rate as the coke's antioxidant index RO.

[0026] The formula is as follows:

[0027]

[0028] Where: x is the weight loss rate; t is the reaction time; v is the average reaction rate.

[0029] S6. Take a certain amount of different cokes for dissolution test and record the time CRI for the coke conversion rate to reach 50% at 1100℃ 50 .

[0030] The specific steps of S6 are:

[0031] S61, taking a certain amount of coke, and processing the coke into particles with a particle size of 23 to 25 mm;

[0032] S62, weigh 200 ± 0.5 g of the coke sample, put it into the reaction tube, and heat it under N flow rate of 5 L / min. 2 Under protection, the temperature was raised from room temperature to 1100°C at a rate of 10°C / min and kept constant for 10 min.

[0033] S63, switch the gas to CO at a flow rate of 5 L / min 2 Gas, constant temperature until weight loss rate is 50%, record the time CRI 50 .

[0034] S64, stop heating, switch the gas to N with a flow rate of 5L / min 2 The sample is cooled down with the furnace until it is below 100℃, and the N2 supply is stopped. 2 .

[0035] S7, for the data obtained in steps S1 to S6, take the data of one type of coke as the benchmark, add the net coke ratio of other cokes to the benchmark to different degrees, obtain the ranking of the net coke ratios of different types of cokes, compare the net coke ratio with the coke cost, and obtain the ranking of comprehensive cost performance. The specific steps are:

[0036] S71. Randomly select a type of coke as the benchmark coke, and combine the net coke ratio of the benchmark coke with other coke data to obtain the net coke ratio of other cokes. The formula is as follows:

[0037] k 1 =k 0 +(Ad 1 -Ad 0 )*2%*k 0 +(St,d 1 -St,d 0)*1%*10*k 0 +(M10 1 -M10 0 )*1.5%*k 0 -(M25 1 -M25 0 )*0.5%*

[0038] k 0 -(CSR 1 -CSR 0 )*0.35%*k 0 +(Mt 1 -Mt 0 )*0.5%*k 0 +(Vdaf 1 -Vdaf 0 )*1%*k 0 +(CRI 1 -CRI 0 )*0.5%*k 0 *0.5+(Mad 1 -Mad 0 )*1%*k 0 +(RO 1 -RO 0 )*1%*k 0 -(CCS 1 -CCS 0 )*1%*k 0 -(CRI50 1 -CRI50 0 ) / t 0 *k 0 / 2

[0039] Where: k 0 is the net coke ratio of the benchmark coke; k 1 is the net coke ratio of coke.

[0040] S72. Compare the net coke ratio with the coke cost to derive a ranking of overall cost performance.

[0041] Compared with the existing evaluation methods, the present invention has the following beneficial effects:

[0042] 1) Compared with the original evaluation system, this method is more accurate and comprehensive in evaluating the quality of coke, which is conducive to more rational production and use of coke, thereby reducing the cost of coking and blast furnace;

[0043] 2) The test method of the new evaluation index is reliable, has high stability and good repeatability, and can be used as a reliable method for coke quality control;

[0044] 3) The method of the present invention is simple, has good timeliness, can provide guidance for actual production, is suitable for coking enterprises and steel plants, and has wide promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a particle size distribution concentration index table of coke A;

[0046] Figure 2 It is a table showing the coke ratio ranking of six types of coke compared with the benchmark coke, the cost performance ranking of the original coke and the cost performance ranking of the new coke; DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] A comprehensive evaluation method for cost performance of coke for blast furnace ironmaking comprises the following steps:

[0049] S1. Select different types of coke samples and determine their dry basis ash content (Ad), combustible basis volatile matter (Vdaf), dry ash-free basis sulfur content (St,d), total moisture content (Mt), and air-dried basis moisture content (Mad).

[0050] S2. Select the coke sample in S1 and measure the hot performance index reactivity CRI and post-reaction strength CSR respectively.

[0051] The specific steps of S2 are:

[0052] Coke reactivity (CRI): Weigh a certain mass of coke sample g 0 , placed in a high temperature refining furnace, at 100% N 2 The temperature was raised to 1100℃ in an atmosphere of N and then reacted with carbon dioxide at (1100±5)℃ for 2h. 2 Cool to room temperature under the protection of the , and weigh the mass of the coke sample at this time g 1 , the percentage of coke mass loss is taken as CRI;

[0053] Coke strength after reaction (CSR): After the above reaction coke is tested for a certain number of revolutions in type I, the mass of coke with a particle size of >10 mm is g 2 , expressed as a percentage of the mass of the coke after the reaction, the formula is as follows:

[0054]

[0055] Where: g 0 is the total mass of coke, g; g 1is the mass of coke after the reaction is completed, g; g 2 It is the mass of coke with particle size > 10 mm after drum test, g.

[0056] S3. Determination of cold performance index wear resistance M of different cokes 10 , crushing strength M 25 .

[0057] The specific steps of S3 include:

[0058] Take 50kg of coke sample larger than 60mm after reaction, place it in a Mikum drum, run it at a constant speed of 25 rpm for 100 rpm, and after screening, the percentage of coke larger than 25mm in the drum is taken as the crushing strength M 25 The percentage of coke powder less than 10 mm is taken as the strength M 10 .

[0059] S4. The reaction coke is subjected to a drum test to simulate the influence of coke transportation, and is screened and divided into five intervals to obtain the percentage of each interval, calculate the average particle size, and further obtain the coke particle size concentration.

[0060] The specific steps of S4 are as follows: take samples of the same mass of different types of reacted coke, conduct a drum test, and screen them according to five intervals: <25mm, 25-40mm, 40-60mm, 60-80mm, and >80mm. Calculate the percentages of different intervals, and then obtain the average particle size, calculate the standard deviation of the particle size distribution, and its reciprocal is the concentration of the particle size distribution.

[0061] The formula is as follows:

[0062]

[0063] Where: is the average particle size of the coke entering the furnace; is the standard deviation of particle size distribution; CCS is the concentration of particle size distribution of coke entering the furnace; R 1 is the upper limit of a certain particle size range; R 2 is the lower limit of a certain particle size range; w i is the mass fraction of the particle size range; n is the number of particle sizes, Figure 1 The table shows the particle size distribution concentration data of coke A.

[0064] S5. Determine the oxidation resistance RO of coke, the specific steps are:

[0065] S51. Weigh different types of coke and crush them into pieces with a size of 0.25 mm to 0.3 mm.

[0066] S52, weigh (200±0.5)g of coke, place it in the reactor, and introduce 2L / min 100%N 2Protection, heating to 1100℃ at a rate of 15℃ / min.

[0067] S53, keep the temperature constant for 10 minutes, and after the temperature stabilizes, switch to 2L / min CO 2 gas, the reaction time is 60min.

[0068] S54, stop heating, and introduce N during cooling 2 Cool to room temperature. Record the time, mass, weight loss curve and other data, and then calculate the weight loss rate in different time periods.

[0069] S55. Calculate the dissolution reaction rate and take the inverse of the average reaction rate as the antioxidant index of the coke.

[0070] The formula is as follows:

[0071]

[0072] Where: x is the weight loss rate; t is the reaction time; v is the average reaction rate.

[0073] S6, take 200g of different cokes, heat to 1100℃ and introduce CO 2 Carry out dissolution reaction and record the time taken to dissolve 100g CRI 50 , the specific steps are as follows:

[0074] S61. According to the national standard GB / T 1997-2008, the coke is processed into particles with a particle size of 23 to 25 mm.

[0075] S62, weigh (200 ± 0.5) g of coke, put it into the reaction tube, and pass N at a flow rate of 5 L / min. 2 The temperature was raised from room temperature to 1100°C at a rate of 10°C / min and kept constant for 10 min.

[0076] S63, switch the gas to CO at a flow rate of 5 L / min 2 Gas, constant temperature until 100g is dissolved, record the time CRI 50 .

[0077] S64, stop heating, switch the gas to N with a flow rate of 5L / min 2 The sample is cooled down with the furnace until it is below 100℃, and the N2 supply is stopped. 2 .

[0078] S7. For the data obtained from steps S1 to S6, take the data of one type of coke as a benchmark, add the net coke ratio of other cokes to the benchmark to different degrees, and rank the net coke ratios of different types of cokes, that is, rank the coke performance, and then compare the net coke ratio with the coke cost to rank the comprehensive cost performance.

[0079] The specific steps of S7 are:

[0080] S71. Select a type of coke as the benchmark coke, and use the data obtained in step S1, step S2, step S3, step S4, step S5, and step S6 and the net coke ratio as benchmark values.

[0081] S72. The net coke ratio of other cokes is obtained by combining the net coke ratio of the benchmark coke with the data of other cokes. The formula is as follows:

[0082] k 1 =k 0 +(Ad 1 -Ad 0 )*2%*k 0 +(St,d 1 -St,d 0 )*1%*10*k 0 +(M10 1 -M10 0 )*1.5%*k 0 -(M25 1 -M25 0 )*0.5%*

[0083] k 0 -(CSR 1 -CSR 0 )*0.35%*k 0 +(Mt 1 -Mt 0 )*0.5%*k 0 +(Vdaf 1 -Vdaf 0 )*1%*k 0 +(CRI 1 -CRI 0 )*0.5%*k 0 *0.5+(Mad 1 -Mad 0 )*1%*k 0 +(RO 1 -RO 0 )*1%*k 0 -(CCS 1 -CCS 0 )*1%*k 0 -(CRI50 1 -CRI50 0 ) / t 0 *k 0 / 2

[0084] Where: k 0 is the net coke ratio of the benchmark coke; k 1is the net coke ratio of coke.

[0085] S73. Compare the net coke ratio with the coke cost to derive a ranking of overall cost performance.

[0086] pass Figure 2 Comparing the cost-effectiveness ranking table of coke in the new cost-effectiveness ranking, we can see that in the new cost-effectiveness ranking, coke 1 has the highest cost-effectiveness, and coke 6 has the worst. The actual use effect of blast furnace is: coke 1> coke 2> coke 3> coke 4> coke 5> coke 6. The actual result is consistent with the new cost-effectiveness ranking, but inconsistent with the old cost-effectiveness ranking. Therefore, it is recommended to use a new coke evaluation system. Compared with the old cost-effectiveness ranking, the introduction of new indicators has changed the cost-effectiveness ranking. The original performance parameter data of some cokes were good, such as coke 4 and coke 5, but the actual use effect was not as good as those with lower parameters, such as coke 1 and coke 2. The new indicators and new evaluation methods are more in line with production reality. Cokes 1 and 2 have better performance and higher cost-effectiveness in production.

[0087] Regarding the three new indicators, coke particle size distribution concentration CSS: coke particle size is an important performance indicator, which has a significant impact on the permeability of the blast furnace. Traditional particle size regulations often lack theoretical basis, and their regulations are wide, inaccurate and weak in guidance, making it difficult to adapt to the needs of different blast furnaces or the same blast furnace at different times. In contrast, coke particle size concentration is a more accurate indicator that can accurately reflect the impact of raw material particle size on the blast furnace. The higher the concentration, the more uniform the coke particle size distribution, which improves the permeability of the blast furnace, reduces the permeability resistance, and promotes the stable and smooth operation of the blast furnace. This improvement will also lead to a reduction in the coke ratio and fuel ratio. Therefore, optimizing the concentration of coke particle size distribution is crucial to stabilizing the operation of the blast furnace. In summary, through the careful control of coke particle size and its concentration, the permeability of the blast furnace can be significantly improved, the stable operation of the blast furnace can be ensured, and energy consumption can be effectively reduced.

[0088] The RO index of the oxidation resistance of coke: by measuring the porosity of the coke entering the furnace and the coke at the tuyere, the porosity of the coke entering the furnace is about 28%, and it increases to about 50% when it reaches the tuyere. It is found that the internal pore walls of the coke are also oxidized during the descent of the blast furnace. This change shows that the contact area of ​​coke with the same thermal strength with carbon dioxide is different due to the different porosity. The larger the contact area of ​​coke, the stronger its oxidation resistance, thereby improving the thermal performance of coke. Therefore, the oxidation resistance of coke has become another key indicator for measuring the quality of blast furnace coke.

[0089] Time required for 50% loss of coke CRI 50:In the blast furnace smelting process, the quantitative dissolution time of coke is of equal importance to the timed dissolution of the national standard coke thermal reactivity. The national standard thermal strength of coke is defined by the reaction data with carbon dioxide within a fixed time (120 minutes), which is a basic indicator for timed smelting in blast furnaces. However, according to the coke measurement data at the blast furnace tuyere, the coke from the furnace top to the center line of the blast furnace tuyere is actually dissolved by about 50%. Based on this finding, the time point when coke dissolves 50% is used as a new indicator to evaluate the smelting performance of different types of coke in quantitative dissolution, referred to as CRI. 50 This indicator not only reflects the actual performance of coke in the blast furnace, but also provides us with a more accurate way to compare and optimize the quality of different types of coke, ensuring efficient and cost-effective blast furnace operations.

[0090] The new quality evaluation index and method of coke for blast furnace ironmaking has significantly improved the traditional coke evaluation method by introducing three new indicators. This improvement not only enhances the comprehensiveness and accuracy of the evaluation system, but also has a positive impact on guiding the coke procurement process. After applying this system, enterprises can more accurately evaluate the performance of coke to ensure that the coke can meet the strict requirements of blast furnace operation. In terms of cost control, by more accurately evaluating the cost performance of coke, enterprises can effectively reduce the cost of raw materials without sacrificing quality. This cost optimization not only enhances the market competitiveness of enterprises, but also enhances the overall economic benefits. The improvement of the quality evaluation index and method of coke for blast furnace ironmaking marks that the coke evaluation system has entered a new stage of development.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A comprehensive evaluation method for cost performance of coke for blast furnace ironmaking, characterized in that: The following steps are involved: S1. Determine the composition indexes of different cokes, including dry basis ash content Ad, combustible basis volatile matter Vdaf, dry ash-free basis sulfur content St,d, total moisture content Mt, and air-dried basis moisture content Mad; S2. Determine the thermal performance index reactivity CRI and post-reaction strength CSR of different cokes; S3. Determination of cold performance index wear resistance M of different cokes 10 , crushing strength M 25 ; S4, screening a certain amount of different cokes for particle size fractions and determining the proportions of different particle sizes to obtain the coke particle size distribution concentration CCS of different cokes; S5. Determine the RO of the oxidation resistance of different cokes; crush different cokes to less than 0.3 mm, react with carbon dioxide at a constant temperature of 1100°C, and take the reciprocal of the average reaction rate as the oxidation resistance index of the coke. S6. Take a certain amount of different cokes for dissolution loss experiment, record the time taken for the coke conversion rate to reach 50% at 1100℃, and obtain the time required for the coke dissolution loss of 50% (CRI). 50 . S7. For the data obtained in steps S1 to S6, take the data of one type of coke as a benchmark, add the net coke ratios of other cokes to the benchmark to different degrees, and rank the net coke ratios of different types of cokes. Compare the net coke ratios with the coke costs to rank the comprehensive cost performance.

2. The method for comprehensively evaluating the cost performance of coke for blast furnace ironmaking according to claim 1, characterized in that: The specific steps of S4 are: a certain amount of original coke or a coke sample rotated in a type I drum at a speed of 20 r / min for 15 min is screened step by step with a round hole sieve, and divided into five intervals: <25 mm, 25-40 mm, 40-60 mm, 60-80 mm, >80 mm, and the total mass percentages thereof are obtained, the average particle size is calculated, and the coke particle size concentration is obtained; The calculation formula is: Where: is the average particle size of the coke entering the furnace; is the standard deviation of particle size distribution; CCS is the concentration of particle size distribution of coke entering the furnace; R1 is the upper limit of a certain particle size range; R2 is the lower limit of a certain particle size range; w i is the mass fraction of the particle size range; n is the number of particle sizes.

3. The method for comprehensive evaluation of cost performance of coke for blast furnace ironmaking according to claim 1, characterized in that: The specific steps of S5 are: S51, select a certain amount of different types of coke and crush them into sizes of 0.25 mm to 0.3 mm respectively; S52, weigh the same mass of coke, place it in a reaction furnace, introduce 5L / min 100% N2 for protection, and heat to 1100°C at a rate of 15°C / min; S53, keep the temperature constant for 10 minutes, after the temperature stabilizes, change to 5L / min CO2 gas, the reaction time is 40 minutes; S54, stop heating, and introduce N2 protection to cool to room temperature during the cooling process. During the period, the time, mass and other data are recorded to calculate the weight loss rate in different time periods; S55. Calculate the coke dissolution reaction rate, and take the reciprocal of the average reaction rate as the coke's oxidation resistance index RO; the RO calculation formula is: Where: x is the weight loss rate; t is the reaction time; v is the average reaction rate.

4. The method for comprehensive evaluation of cost performance of coke for blast furnace ironmaking according to claim 1, characterized in that: The specific steps of S6 are: S61, taking a certain amount of coke, and processing the coke into particles with a particle size of 23 to 25 mm; S62. Weigh 200±0.5g of the coke sample and put it into a reaction tube. Under the protection of N2 at a flow rate of 5L / min, heat the temperature from room temperature to 1100℃ at a rate of 10℃ / min and keep the temperature constant for 10min. S63, switch the gas to CO2 gas with a flow rate of 5L / min, maintain constant temperature until the weight loss rate is 50%, and record the required time CRI 50 . S64. Stop heating, switch the gas to N2 with a flow rate of 5 L / min, cool the sample to below 100°C with the furnace, and stop passing N2.

5. The method for comprehensive evaluation of cost performance of coke for blast furnace ironmaking according to claim 1, characterized in that: The calculation formula for the net coke ratio of coke in S7 is as follows: k1=k0+(Ad1-Ad0)*2%*k0+(St,d1-St,d0)*1%*10*k0+(M101-M100)*1.5%*k0-(M251-M250)*0.5%*k0-(C SR1-CSR0)*0.35%*k0+(Mt1-Mt0)*0.5%*k0+(Vdaf1-Vdaf0)*1%*k0+(CRI1-CRI0)*0.5%*k0*0 .5+(Mad1-Mad0)*1%*k0+(RO1-RO0)*1%*k0-(CCS1-CCS0)*1%*k0-(CRI501-CRI500) / t0*k0 / 2 In the formula: k0 is the net coke ratio of benchmark coke; k1 is the net coke ratio of coke.

6. The method for comprehensive evaluation of cost performance of coke for blast furnace ironmaking according to claim 1, characterized in that: The comprehensive evaluation index of cost performance of coke for blast furnace ironmaking includes: coke particle size distribution concentration CSS, coke oxidation resistance index RO, coke dissolution loss 50% time CRI 50 .

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