A method for building a multi-functional ore blending model for pellet ore

Abstract

The present invention discloses a method for building a multi-functional ore blending model for pellet ore, which relates to the technical field of sintering pellets. The method for building a multi-functional ore blending model for pellet ore is characterized in that the specific operations are as follows: S1. Calculate the weight gain rate of the oxidation reaction of the FeO content in magnetite concentrate. Based on the oxidation roasting theory of magnetite concentrate pellets, the method for building a multi-functional ore blending model for pellet ore designs a multi-functional ore blending model for pellet ore. In addition to calculating several main components of pellet ore and the raw material consumption cost, it also improves the adaptability of the pellet ore blending model to magnetite concentrates with different FeO contents, different proportions of raw materials passing through -200 mesh, different S contents of raw materials, and different alkali metal contents, and improves the comprehensiveness and accuracy of the pellet ore blending model for predicting the quality of pellet ore, and evaluates the pellet ore blending structure from multiple perspectives and functions such as pellet ore quality, single consumption of bentonite, process energy consumption, environmental protection, and cost.

Description

Technical Field

[0001] The invention relates to the technical field of sintering pellets, and in particular to a method for building a multifunctional ore blending model for pellets. Background Art

[0002] Compared with the sintering process, the pelletizing process has obvious advantages in energy saving, low carbon and waste gas emission. 1. The energy consumption of the pelletizing process is more than 40% lower than that of the sintering process; 2. Its flue gas emission is only about 75% of that of sintering, and the SO2 and NO per ton of pelletized ore are x The emissions are only 1 / 2 and 1 / 3 respectively, so the environmental protection investment and operating cost of pellet production are lower than those of sintering; 3. Sintered ore relies on liquid phase bonding, and ideal material permeability is the key to the smooth sintering process, and an appropriate proportion of internal carbon is essential; while pellets are solid-phase roasting and consolidation, and the process can completely use no coke or coal, and there is a higher selectivity for clean fuel types that meet the needs of emission reduction control; 4. Compared with sintered ore, pellets have the characteristics of high grade and uniform particle size, which can easily meet the requirements of blast furnace production for low carbon emissions. Since the grade of pellets is generally higher than that of sintered ore, the use of a high proportion of pellets can improve the grade of the ore entering the furnace, reduce the slag ratio, reduce the erosion of the blast furnace lining by the slag flow through the coke layer, and reduce the impact on soft melt dripping and permeability, which is beneficial to blast furnace strengthening and optimization of blast furnace technical and economic indicators. The preparation of high-quality metallurgical pellets and the smelting of high-proportion pellets in blast furnaces will be the best measures to crack the long process of China's steel industry to reduce pollutant emissions and achieve low-carbon smelting and sustainable development.

[0003] There are many ore matching models for sintering, but there are few ore matching models for pelletizing. Most of the ore matching models for pelletizing are inversely deduced based on the raw materials and the composition of the pellet ore, without rigorous calculation according to the pelletizing theory. There is often a large error between the theoretical composition value of the pellet ore and the actual value, resulting in poor adaptability of the ore matching model for pelletizing. Since most of the raw materials for pelletizing are magnetite concentrate, the magnetite concentrate increases in weight due to FeO oxidation during roasting. Preliminary calculations show that the dry-based pellets increase in weight by about 2% after roasting, and the weight gain has a very large impact on the calculation of the theoretical composition of the pellet ore. In addition, the previous ore matching targets were relatively simple, generally based on the pellet ore components TFe, SiO2, Al2O3, etc. In order to increase the adaptability of the ore matching model, the ore matching model is strictly established according to the pellet roasting theory, and the ore matching targets should include the calculation of harmful elements (S, P, Zn, alkali metals, TiO2), the FeO content of the mixture (oxidation heat release during roasting), etc. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the shortcomings of the prior art, the present invention provides a method for building a multifunctional ore blending model for pellets, which solves the problem that in the prior art, the ore blending model for pellets is mostly inferred based on the raw materials and the composition of the pellets, and is not strictly calculated according to the pellet theory. There is often a large error between the theoretical composition value of the pellets and the actual value, resulting in poor adaptability of the ore blending model for pellets. Since most of the raw materials for pellets are magnetite concentrates, the magnetite concentrates gain weight due to FeO oxidation during roasting. Preliminary calculations show that the dry-based pellets gain weight by about 2% after firing, and the weight gain has a very large impact on the calculation of the theoretical composition of the pellets. In addition, the previous ore blending targets were relatively single, generally based on the pellet components TFe, SiO2, Al2O3, etc., and had poor adaptability.

[0006] (II) Technical solution

[0007] To achieve the above purpose, the present invention is implemented by the following technical scheme: a method for building a multifunctional ore blending model for pelletized ore, the specific operation is as follows:

[0008] S1. Calculate the weight gain rate of FeO content in magnetite concentrate by oxidation reaction. FeO oxidation reaction formula:

[0009] 144 16 160;

[0011] The oxidation of FeO content in magnetite is a weight-increasing process, and the FeO weight-increasing rate is B = 16÷144×100% = 11.1%; S2. Calculate the desulfurization efficiency of magnetite concentrate. The oxidation reaction of S in iron concentrate:

[0012] 4FeS2+11O2↑=2Fe2O3+8SO2↑

[0013] 4FeS+7O2↑=2Fe2O3+4SO2↑

[0014] It can be seen that the oxidation of sulfur in magnetite concentrate is a weightless process. The above reaction requires a temperature of ~600°C, while the pelletized ore

[0015] The roasting temperature is ~1250℃, so only a small part of the pellets remain. The pellets usually contain about 0.005% S. If the sulfur content of the concentrate is 0.080%, the desulfurization efficiency of the pellets = (0.080-0.005) ÷ 0.080 × 100% = 93.74%;

[0016] S3. Determine the burning loss value of bentonite.

[0017] Experiments and data show that the burning rate of bentonite is ~16%;

[0018] S4. Calculation of dry ratio of various raw materials.

[0019] The raw material ratios of the on-site production line are generally wet-based ratios. When calculating the ratios, they need to be converted to dry-based ratios:

[0020] In the formula, P i is the dry-based ratio of the i-th raw material, J i is the wet-based ratio of the i-th raw material, S i is the moisture content of the i-th raw material, is the sum of the wet-based ratios of each raw material multiplied by (1 - moisture content);

[0021] S5. Calculation of the fired amount of pellet ore.

[0022] The weight gain coefficient Z of each concentrate powder 精矿 =[P i ×B×FeO content of concentrate powder]-[S content of concentrate × desulfurization efficiency of pellet ore]

[0023] The weight gain coefficient Z of pellet ore 球团 =(∑Z 精粉 )-(dry-based ratio of bentonite × burn-off rate)

[0024] In the formula, P i is the dry-based ratio of the i-th raw material, B is the FeO weight gain rate (11.1%), the pellet desulfurization efficiency is 93.74% calculated in step S2, and the bentonite burn-off rate is 16% set in step S3;

[0025] The fired amount of pellet ore Q = 1 + Z 球团 ;

[0026] S6. Calculation of the theoretical composition of pellet ore.

[0027] TFe of pellet ore = ∑ TFe amounts of various raw materials brought into the pellet ore / fired amount of pellet ore Q

[0028] The remaining components (such as SiO2, Al2O3, Zn, TiO2, alkali metals, etc.) are calculated in the same way;

[0029] S7. Calculation of the -200 mesh ratio of the pelletizing mixture

[0030] L i =P i ×A i

[0031] The -200 mesh ratio of the pelletizing mixture

[0032] In the formula, P i is the dry-based ratio of the i-th raw material, A iis the ratio of the -200 mesh of the i-th raw material, and L is the ratio of the -200 mesh of the pelletizing mixture, that is, L is the sum of the dry basis ratios of all materials multiplied by their -200 mesh ratios. Similarly, the FeO content of the pelletizing mixture can be obtained;

[0033] S8. Prediction and calculation of the sulfur content in the dry basis of the pelletizing mixture and the SO2 concentration in the flue gas

[0034] ③ Calculation of the sulfur content in the dry basis of the pelletizing mixture

[0035] S i =P i ×s i

[0036] Sulfur content in the dry basis of the pelletizing mixture

[0037] In the formula, P i is the dry basis ratio of the i-th raw material, s i is the sulfur content of the i-th raw material, and S is the sulfur content in the dry basis of the pelletizing mixture, that is, S is the sum of the dry basis ratios of all materials multiplied by their sulfur contents.

[0038] ④ Prediction and calculation of the SO2 concentration in the flue gas

[0039] The SO2 in the pellet flue gas mainly comes from the concentrate powder, and a small part comes from the solid fuel - coal. The following calculates the SO2 concentration in the flue gas of the pelletizing process with full gas, and almost 100% of the SO2 in the discharged flue gas comes from the oxidation of the sulfur in the concentrate powder.

[0040] The amount of sulfur oxidized per hour W S = Dry basis pellet amount per hour (t / h) × Sulfur content in the dry basis of the pelletizing mixture = W × S. According to the relationship between the molecular weights of S and SO2, the relative molecular weight of S is 32, and the relative molecular weight of SO2 is 64. It is calculated that for each

[0041] hour's flue gas SO2 amount

[0042] In the formula, M so2 is the relative molecular weight of SO2, M s is the relative molecular weight of S, and W S is the amount of sulfur oxidized per hour W S Then the SO2 concentration in the pellet flue gas

[0043] In the formula, Q flue gas volume is the total volume of the pellet flue gas per hour, and N so2 is the predicted SO2 concentration in the pellet flue gas, with the unit of mg / m 3 ;

[0044] S9. Calculation of the unit consumption of each raw material.

[0045]

[0046] where D i is the specific consumption of the i-th raw material, and P i is the dry basis ratio of the i-th raw material;

[0047] S10. Calculation of raw material cost.

[0048] C i = specific consumption of a certain raw material × its raw material unit price = D i × X i

[0049]

[0050] (III) Beneficial effects

[0051] The present invention provides a method for building a multi-functional ore blending model for pellet ore. It has the following beneficial effects:

[0052] (1). This method for building a multi-functional ore blending model for pellet ore, based on the oxidation roasting theory of magnetite concentrate pellets, designs a multi-functional ore blending model for pellet ore. In addition to calculating several main components of pellet ore and the raw material consumption cost, it also improves the adaptability of the pellet ore blending model to magnetite concentrates with different FeO contents, different ratios of raw materials passing through -200 mesh, different S contents of raw materials, and different alkali metal contents, and improves the comprehensiveness and accuracy of the pellet ore blending model for predicting the quality of pellet ore. It evaluates the pellet ore blending structure from multiple perspectives and functions such as pellet ore quality, specific consumption of bentonite, process energy consumption, environmental protection, and cost.

[0053] (2). This method for building a multi-functional ore blending model for pellet ore, based on the oxidation chemical reaction of magnetite concentrate pellets, calculates the heat release of the oxidation reaction corresponding to magnetite concentrates with different FeO contents and the weight gain rate of the finished pellet ore, clarifies the influence of the FeO content of magnetite concentrate pellets on the composition of pellet ore and process energy consumption, and improves the adaptability of the pellet ore blending model to magnetite concentrates with different FeO contents and the accuracy of cost prediction.

[0054] (3). This method for building a multi-functional ore blending model for pellet ore reads the ratio of each raw material passing through -200 mesh in the pellet ore, calculates the ratio of the pelletizing mixture passing through -200 mesh, increases the analysis function of the pellet ore blending model for bentonite consumption, and improves the adaptability of the pellet ore blending model to different ratios of raw materials passing through -200 mesh and the accuracy of cost prediction.

[0055] (4) The method for establishing the multi-functional ore blending model of pellet calculates the S content of each raw material of the pellet, calculates the S content of the pelletizing mixture, and then predicts the SO2 concentration in the pellet flue gas based on the flue gas volume and the oxidation reaction of sulfides during the pellet roasting process, providing a basis for the ultra-low emission of the flue gas in pellet production, avoiding the occurrence of environmental protection accidents, improving the adaptability of the pellet batching model to the S content of different raw materials, calculating the alkali metal content of the pellet ore by reading the alkali metal content of each raw material of the pellet, predicting the change of the reduction swelling rate of the pellet ore, and improving the comprehensiveness and accuracy of the pellet batching model for predicting the quality of the pellet ore. Description of the Drawings

[0056] Figure 1 Schematic diagram of the EXCEL table input item settings of the batching model of the embodiment of the present invention;

[0057] Figure 2 Schematic diagram of the EXCEL table output item settings of the batching model of the embodiment of the present invention. Detailed Embodiments

[0058] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0059] Please refer to Figure 1-2 , the present invention provides a technical solution: a method for establishing a multi-functional ore blending model of pellet, and the specific operation is as follows:

[0060] S1. Calculate the weight gain rate of the oxidation reaction of the FeO content in the magnetite concentrate. The oxidation reaction formula of FeO:

[0061] 144 16 160;

[0063] Among them, the oxidation of the FeO content in the magnetite is a weight gain process, and the FeO weight gain rate B = 16 ÷ 144 × 100% = 11.1%;

[0064] S2. Calculate the desulfurization efficiency of the magnetite concentrate. The oxidation reaction of S in the iron concentrate:

[0065] 4FeS2 + 11O2↑ = 2Fe2O3 + 8SO2↑

[0066] 4FeS + 7O2↑ = 2Fe2O3 + 4SO2↑

[0067] It can be seen from this that the oxidation of sulfur in magnetite concentrate is a weight-loss process. The above reaction requires ~600 °C, while the roasting temperature of pellet is ~1250 °C. Therefore, only a very small part remains in the pellet. The pellet usually contains about 0.005% S. Assuming the sulfur content in the concentrate powder is 0.080%, the desulfurization efficiency of the pellet = (0.080 - 0.005) ÷ 0.080 × 100% = 93.74%;

[0068] S3. Determine the burn-off value of bentonite.

[0069] Experiments and data research show that the burn-off rate of bentonite is ~16%;

[0070] S4. Calculate the dry ratio of various raw materials.

[0071] The ratio of each raw material in the on-site production line is generally the wet basis ratio. When calculating the ratio, it needs to be converted to the dry basis ratio:

[0072] Where P i is the dry basis ratio of the i-th raw material, J i is the wet basis ratio of the i-th raw material, S i is the moisture content of the i-th raw material, is the sum of the wet basis ratios of each raw material multiplied by (1 - moisture content);

[0073] S5. Calculate the firing yield of pellets.

[0074] The weight gain coefficient Z of each concentrate powder 精矿 = [P i × B × FeO content of concentrate powder] - [sulfur content of concentrate × desulfurization efficiency of pellet]

[0075] The weight gain coefficient Z of pellets 球团 = (∑Z 精粉 ) - (dry basis ratio of bentonite × burn-off rate)

[0076] Where P i is the dry basis ratio of the i-th raw material, B is the FeO weight gain rate (11.1%), the pellet desulfurization efficiency is 93.74% calculated in step S2, and the bentonite burn-off rate is 16% set in step S3;

[0077] The firing yield of pellets Q = 1 + Z 球团 ;

[0078] S6. Calculate the theoretical composition of pellets.

[0079] The TFe of pellets = ∑TFe amounts of various raw materials brought into the pellets / the firing yield of pellets Q

[0080] The remaining components (SiO2, Al2O3, Zn, TiO2, alkali metals, etc.) are calculated in the same way;

[0081] S7. Calculation of the proportion of -200 mesh in the pelletizing mixture

[0082] L i = P i × A i

[0083] Proportion of -200 mesh in the pelletizing mixture

[0084] In the formula, P i is the dry basis ratio of the i-th raw material, A i is the proportion of -200 mesh of the i-th raw material, and L is the proportion of -200 mesh in the pelletizing mixture, that is, L is the sum of the dry basis ratios of all materials multiplied by their proportions of -200 mesh. Similarly, the FeO content of the pelletizing mixture can be obtained;

[0085] S8. Prediction calculation of the dry basis sulfur content and flue gas SO2 concentration of the pelletizing mixture

[0086] ⑤ Calculation of the dry basis sulfur content of the pelletizing mixture

[0087] S i = P i × s i

[0088] Dry basis sulfur content in the pelletizing mixture

[0089] In the formula, P i is the dry basis ratio of the i-th raw material, s i is the sulfur content of the i-th material, and S is the dry basis sulfur content of the pelletizing mixture, that is, S is the sum of the dry basis ratios of all materials multiplied by their sulfur contents.

[0090] ⑥ Prediction calculation of flue gas SO2 concentration

[0091] The SO2 in the pellet flue gas mainly comes from the concentrate powder, and a small part comes from the solid fuel - coal. The following calculates the flue gas SO2 concentration in the pelletizing process of full coal gas. Almost 100% of the SO2 in the discharged flue gas comes from the oxidation of sulfur in the concentrate powder.

[0092] Sulfur oxidation amount per hour W S = Dry basis pellet amount per hour (t / h) × Dry basis sulfur content of the pelletizing mixture = W × S. According to the relationship between the molecular weights of S and SO2, the relative molecular weight of S is 32, and the relative molecular weight of SO2 is 64. Calculate the amount of flue gas SO2 per hour

[0093] In the formula, M so2 is the relative molecular weight of SO2, M s is the relative molecular weight of S, W S is the sulfur oxidation amount per hour W S Then the flue gas SO2 concentration of the pellet Where Q flue gas volume is the total pellet flue gas volume per hour, N so2 is the predicted SO2 concentration of pellet flue gas, with the unit of mg / m 3 ;

[0094] S9. Calculation of single consumption of each raw material.

[0095]

[0096] Where D i is the single consumption of the i-th raw material, and P i is the dry basis ratio of the i-th raw material;

[0097] S10. Calculation of raw material cost.

[0098] C i = single consumption of a certain raw material × its raw material unit price = D i × X i

[0099]

[0100] Example:

[0101] 1. Calculate the weight gain rate of the oxidation reaction of the FeO content in magnetite concentrate. The FeO oxidation reaction formula:

[0102] 2FeO + O2↑ = Fe2O3 144 16 160

[0104] The oxidation of the FeO content in magnetite is a weight gain process. The FeO weight gain rate = 16 ÷ 144 × 100% = 11.1%.

[0105] 2. Open the EXCEL table.

[0106] 3. As Figure 1 shown, input the wet ratio of each raw material, the physical and chemical indexes of the raw material, the unit price, the FeO weight gain rate (11.11%), the burn loss value of bentonite (generally set at about 16%), and the dry basis pellet quantity per hour. The physical and chemical indexes of the raw material mainly include: H2O, TFe, SiO2, Al2O3, S, FeO, P, TiO2, Na2O + K2O, Zn, -200 mesh ratio, etc.

[0107] 4. As Figure 2 shown, set the output item formula of each batching model in the EXCEL table

[0108] 4.1 Set the formula for converting the wet basis ratio of each raw material to the dry basis ratio in the EXCEL table.

[0109]

[0110] Where P i is the dry basis ratio of the i-th raw material, and J i is the wet basis ratio of the i-th raw material, and S i is the moisture content of the i-th raw material. is the sum of the wet basis ratios of each raw material multiplied by (1 - moisture content).

[0111] 4.2 Set the formula for the fired amount of pellet ore

[0112] The weight gain coefficient Z of each concentrate powder 精矿 = [P i × B × FeO content of concentrate powder] - [S content of concentrate × desulfurization efficiency of pellet ore]

[0113] The weight gain coefficient Z of pellet ore 球团 = (∑Z 精粉 ) - (dry basis ratio of bentonite × burn-off rate)

[0114] Where P i is the dry basis ratio of the i-th raw material, B is the FeO weight gain rate (11.1%), the pellet desulfurization efficiency is 93.74% calculated in step S2, and the bentonite burn-off rate is 16% set in step S3;

[0115] The fired amount Q of pellet ore = 1 + Z 球团 ;

[0116] 4.3 Set the formula for calculating the theoretical composition of pellet ore.

[0117] The TFe of pellet ore = ∑ the amount of TFe brought into the pellet ore by various raw materials / the fired amount Q of pellet ore

[0118] The same applies to the remaining components (SiO2, Al2O3, Zn, TiO2, alkali metals, etc.).

[0119] 4.4 Set the prediction calculation formulas for the dry basis sulfur content of the pelletizing mixture and the SO2 concentration in the flue gas

[0120] ① Calculation of the dry basis sulfur content of the pelletizing mixture

[0121] S i = P i × s i

[0122] The dry basis S content of the pelletizing mixture

[0123] Where P i is the dry basis ratio of the i-th raw material, s i is the sulfur content of the i-th raw material, and S is the dry basis sulfur content of the pelletizing mixture, that is, S is the sum of the dry basis ratios of all materials multiplied by their sulfur contents.

[0124] ② Prediction and calculation of flue gas SO2 concentration

[0125] Sulfur oxidation amount W per hour S = Dry basis pellet amount per hour (t / h) × Dry basis sulfur content in pelletizing mixture = W × S Flue gas SO2 amount per hour

[0126] In the formula, M so2 Is the relative molecular mass of SO2, M s Is the relative molecular mass of S, W S Is the sulfur oxidation amount W per hour S Pellet flue gas SO2 concentration

[0127] In the formula, Q flue gas volume is the total pellet flue gas volume per hour, N so2 Is the predicted pellet flue gas SO2 concentration, with the unit of mg / m 3 .

[0128] 4.5 Compile the calculation of the -200 mesh ratio of pelletizing mixture

[0129] L i = P i × A i

[0130] -200 mesh ratio of pelletizing mixture

[0131] In the formula, P i Is the dry basis ratio of the i-th raw material, A i Is the -200 mesh ratio of the i-th raw material, L is the -200 mesh ratio of the pelletizing mixture, that is, L is the sum of the dry basis ratios of all materials multiplied by their -200 mesh ratios. Similarly, the calculation formula for the FeO content of the pelletizing mixture is compiled

[0132] 4.6 Compile the calculation formula for the unit consumption of each raw material.

[0133]

[0134] In the formula, D i Is the unit consumption of the i-th raw material, P i Is the dry basis ratio of the i-th raw material.

[0135] 4.7 Compile the calculation formula for raw material cost.

[0136] C i = Unit consumption of a certain raw material × Its raw material unit price = D i × X i

[0137]

[0138] In the formula, D iis the unit consumption of the i-th raw material, X i is the unit price of the i-th raw material.

[0139] 4.8 Change the proportion of each raw material and the raw material composition, and calculate the theoretical composition of pellet ore, the proportion of -200 mesh in the pelletizing mixture, the FeO content in the pelletizing mixture (affecting the process energy consumption), the SO2 concentration in the flue gas, the cost, etc. output by the ore blending model. Evaluate the pellet ore blending structure from multiple perspectives and functions such as pellet ore quality, bentonite unit consumption, process energy consumption, environmental protection, and cost.

[0140] In summary, the method for building the multi-functional ore blending model of pellet ore is based on the oxidation roasting theory of magnetite concentrate pellets. A multi-functional ore blending model of pellet ore is designed. In addition to calculating several main components of pellet ore and the raw material consumption cost, it also improves the adaptability of the pellet ore blending model to magnetite concentrates with different FeO contents, different raw material -200 mesh ratios, different raw material S contents, and different alkali metal contents, and improves the comprehensiveness and accuracy of the pellet ore blending model for predicting the quality of pellet ore. Evaluate the pellet ore blending structure from multiple perspectives and functions such as pellet ore quality, bentonite unit consumption, process energy consumption, environmental protection, and cost.

[0141] The method for building the multi-functional ore blending model of pellet ore is based on the oxidation chemical reaction of magnetite concentrate pellets, calculates the heat release of the oxidation reaction corresponding to magnetite concentrates with different FeO contents and the weight gain rate of the finished pellet ore, clarifies the influence of the FeO content of magnetite concentrate pellets on the composition of pellet ore and the process energy consumption, and improves the adaptability of the pellet ore blending model to magnetite concentrates with different FeO contents and the accuracy of cost prediction.

[0142] The method for building the multi-functional ore blending model of pellet ore reads the proportion of -200 mesh of each raw material of the pellet, calculates the proportion of -200 mesh of the pelletizing mixture, increases the analysis function of the pellet ore blending model for bentonite consumption, and improves the adaptability of the pellet ore blending model to different raw material -200 mesh ratios and the accuracy of cost prediction.

[0143] The method for building the multi-functional ore blending model of pellet ore reads the S content of each raw material of the pellet, calculates the S content of the pelletizing mixture, and then predicts the SO2 concentration in the pellet flue gas based on the flue gas volume and the oxidation reaction of sulfides during the pellet roasting process, provides a basis for the ultra-low emission of flue gas in pellet production, avoids the occurrence of environmental protection accidents, improves the adaptability of the pellet ore blending model to different raw material S contents, calculates the alkali metal content of the pellet ore by reading the alkali metal content of each raw material of the pellet, and predicts the change of the reduction swelling rate of the pellet ore, improving the comprehensiveness and accuracy of the pellet ore blending model for predicting the quality of pellet ore.

[0144] It should be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0145] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for building a multi-functional ore blending model for pellet ore, characterized in that: The specific operations are as follows: S1. Calculate the weight gain rate of the oxidation reaction of the FeO content in magnetite concentrate. The oxidation reaction formula of FeO is: Among them, the oxidation of the FeO content in magnetite is a weight gain process. The weight gain rate B of FeO = 16÷144×100% = 11.1%; S2. Calculate the desulfurization efficiency of magnetite concentrate. The oxidation reaction of S in iron concentrate is: 4FeS2 + 11O2↑ = 2Fe2O3 + 8SO2↑ 4FeS + 7O2↑ = 2Fe2O3 + 4SO2↑ It can be seen from this that the oxidation of sulfur in magnetite concentrate is a weight loss process. The above reactions require 600°C, while the roasting temperature of pellets is 1250°C. Therefore, only a very small part remains in the pellets. Pellets usually contain about 0.005% S. Assuming that the sulfur content in the concentrate powder is 0.080%, the desulfurization efficiency of pellets = (0.080 - 0.005)÷0.080×100% = 93.74%; S3. Determine the burn-off value of bentonite; Experiments and data research show that the burn-off rate of bentonite is 16%; S4. Calculate the dry ratio of various raw materials; The raw material ratios of the on-site production line are generally wet basis ratios, and need to be converted to dry basis ratios when calculating the ratios: where P i is the dry basis ratio of the i-th raw material, J i is the wet basis ratio of the i-th raw material, S i is the moisture content of the i-th raw material, is the sum of the wet basis ratios of each raw material multiplied by (1 - moisture content); S5. Calculate the firing output of pellets; Weight gain coefficient Z of each concentrate powder 精矿 = [P i × B × FeO content of concentrate powder] - [S content of concentrate × desulfurization efficiency of pellet Pellet weight gain coefficient Z 球团 =(∑Z 精粉 ) - (dry basis ratio of bentonite × burn-off rate) where P i is the dry basis ratio of the i-th raw material, B is the FeO weight gain rate, the pellet desulfurization efficiency is 93.74% calculated in step S2, and the bentonite burn-off rate is 16% set in step S3; The fired amount Q of pellet ore = 1 + Z 球团 ; S6. Calculate the theoretical composition of pellets; TFe of pellets = ∑TFe amounts of various raw materials brought into the pellets / firing output Q of pellets For the remaining components, and so on; S7. Calculate the proportion of -200 mesh in the pelletizing mixture L i = P i × A i Proportion of -200 mesh in pelletizing mixture Where P i is the dry basis ratio of the i-th raw material, A i is the proportion of -200 mesh of the i-th raw material, and L is the proportion of -200 mesh in the pelletizing mixture, that is, L is the sum of the dry basis ratios of all materials multiplied by their -200 mesh proportions; similarly, the FeO content of the pelletizing mixture can be obtained; S8. Predict and calculate the sulfur content on dry basis of the pelletizing mixture and the SO2 concentration in the flue gas ① Calculate the sulfur content on dry basis of the pelletizing mixture S i = P i × s i S content of the pelletizing mixture on dry basis where P i is the dry basis ratio of the i-th raw material, s i is the sulfur content of the i-th material, and S is the sulfur content of the pelletizing mixture on dry basis, that is, S is the sum of the dry basis ratios of all materials multiplied by their sulfur contents; ② Predict and calculate the SO2 concentration in the flue gas SO2 in the pellet flue gas mainly comes from the concentrate powder, and a small part comes from the solid fuel - coal. The following calculates the SO2 concentration in the flue gas of the pellet process using all gas. Almost 100% of the SO2 in the discharged flue gas comes from the oxidation of S in the concentrate powder; Sulfur oxidation amount per hour W S = Dry basis pellet amount per unit time (t / h) × Sulfur content in dry basis of pelletizing mixture = W × S. According to the relationship between the molecular weights of S and SO2, the relative molecular weight of S is 32, and the relative molecular weight of SO2 is 64. The SO2 amount in flue gas per hour is calculated as follows In the formula, M so2 is the relative molecular weight of SO2, M s is the relative molecular weight of S, W S is the sulfur oxidation amount per hour W S Then the SO2 concentration in the pellet flue gas In the formula, Q is the total amount of pellet flue gas per hour, N so2 is the predicted SO2 concentration in the pellet flue gas, with the unit of mg / m 3 ; S9. Calculate the unit consumption of each raw material; where D i is the unit consumption of the i-th raw material, and P i is the dry basis ratio of the i-th raw material; S10. Calculate the raw material cost; C i = Unit consumption of a certain raw material × its raw material unit price = D i × X i

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