A blast furnace smelting method with low iron loss

Abstract

The present invention provides a blast furnace smelting method with low iron loss, which relates to the technical field of vanadium-titanium magnetite smelting, including: step S1: adding raw materials of a specified charge structure to the blast furnace for distribution, and starting smelting; step S2: after the blast furnace condition is stable, adjusting the furnace air volume to a preset air volume range, and adjusting the oxygen enrichment rate to a preset oxygen enrichment rate range; step S3: adjusting the smelting air temperature to a preset temperature range, controlling the coke ratio to a preset coke ratio, controlling the coal ratio to a preset coal ratio range, and controlling the silicon-titanium content to be within a preset first value range; step S4: terminating the smelting after continuous smelting for a preset time length. The present invention increases the furnace air volume, optimizes the charging system and the air supply system, stabilizes the airflow, and improves the gas distribution by optimizing the smelting method; reasonably controls the furnace temperature, reduces the coke ratio, and reduces the iron loss, thereby solving the problem of high iron loss in the existing blast furnace smelting method of vanadium-titanium magnetite.

Description

Technical Field

[0001] The invention relates to the technical field of vanadium-titanium magnetite smelting, and in particular to a blast furnace smelting method with low iron loss. Background Art

[0002] The main method commonly used in smelting vanadium-titanium magnetite is to sinter vanadium-titanium iron concentrate and ordinary powder ore to produce sintered ore, vanadium-titanium iron concentrate balling and bentonite to produce oxidized pellets, and then add sintered ore, pellets and a small amount of lump ore into the blast furnace in a certain proportion with coke, and burn coke in the lower blast furnace to produce reducing gas. The rising reducing gas and the falling charge reduce the ore, which then melts and drips into the furnace to complete the ironmaking process and realize the separation of slag and iron. However, in the conventional smelting process of vanadium-titanium magnetite, there are problems such as poor separation of slag and iron and high iron content in slag. Summary of the invention

[0003] The invention provides a blast furnace smelting method with low iron loss, which is used to solve the defects of poor separation of slag and iron and high iron content in slag in the conventional vanadium-titanium magnetite smelting process in the prior art.

[0004] In one aspect, the present invention provides a blast furnace smelting method with low iron loss, comprising:

[0005] Step S1: adding raw materials of a specified charge structure into a blast furnace for distribution and starting smelting;

[0006] Step S2: After the blast furnace condition is stabilized, the air volume entering the furnace is adjusted to within a preset air volume range, and the oxygen enrichment rate is adjusted to within a preset oxygen enrichment rate range;

[0007] Step S3: adjusting the smelting air temperature to a preset temperature range, controlling the coke ratio to a preset coke ratio, controlling the coal ratio to a preset coal ratio range, and controlling the silicon-titanium content to be within a preset first value range, wherein the silicon-titanium content is the sum of the silicon content and the titanium content in the molten iron;

[0008] Step S4: smelting is continued for a preset time and then terminated;

[0009] Step S4 includes:

[0010] Step S41: obtaining the actual charge structure and obtaining the basic smelting prediction time based on the smelting parameter setting values;

[0011] Step S42: obtaining actual smelting parameters and recording them;

[0012] Step S43: regularly obtaining the remaining smelting time based on the actual smelting parameters;

[0013] Step S44: When the remaining smelting time returns to zero, smelting is terminated;

[0014] Step S41 includes:

[0015] Step S411: obtaining actual charge structure parameters, which include: average particle size of charge, chemical composition ratio of charge, composition uniformity of charge and water content of charge;

[0016] Step S412: Calculate the basic smelting prediction time according to the actual charge structure;

[0017] ;in, Predict time for basic smelting; is the total volume of the charge entering the furnace; is the average smelting intensity under the conditions of smelting parameter setting values; is the average particle size of the charge corresponding to the standard charge structure; is the actual average particle size of the charge; M is the number of chemical components of the charge to be monitored; is the influence ratio of the unit concentration deviation of the i-th chemical component on the smelting intensity; is the actual concentration of the i-th chemical component in the charge; is the standard concentration of the i-th chemical component of the charge corresponding to the standard charge structure; is the actual composition uniformity of the charge; It is the standard composition uniformity corresponding to the standard charge structure; is the actual moisture content of the charge; It is the standard moisture content corresponding to the standard charge structure.

[0018] Preferably, in step S2, the preset air volume range is 3350±50 ; The preset oxygen enrichment rate range is 4.5-5.5%.

[0019] Preferably, in step S3, the preset temperature range is 1200-1230°C; the preset coke ratio range is 385kg / ton iron, the preset coal ratio range is 170~176kg / ton iron, and the first value range is 0.18-0.28%.

[0020] Preferably, step S43 includes:

[0021] Step S431: obtaining current actual smelting parameters;

[0022] Step S432: correcting the remaining smelting time according to actual smelting parameters;

[0023] ;in, is the remaining smelting time; is the basic smelting prediction time; N is the total number of times the remaining smelting time is corrected; The length of time between the jth corrected remaining smelting time and the j-1th corrected remaining smelting time; is the air volume entering the furnace when the remaining smelting time is corrected for the jth time; is the air oxygen enrichment rate when the remaining smelting time is corrected for the jth time; is the smelting air temperature when the remaining smelting time is corrected for the jth time; It is the air volume into the furnace in the smelting parameter setting value; It is the air oxygen enrichment rate in the smelting parameter setting value; It is the smelting air temperature in the smelting parameter setting value; is the basic combustion temperature in the blast furnace; is the heat of combustion of coke; is the coke ratio at the jth correction of the remaining smelting time; is the unit pig iron output; The heat of combustion of coal; is the coal ratio at the jth correction of the remaining smelting time; It is the best smelting combustion temperature; is the current actual air volume entering the furnace; is the current actual air oxygen enrichment rate; is the current actual smelting air temperature; is the current actual focal ratio; is the current actual coal ratio; is the thermal efficiency of combustion; is the total mass of air in the blast furnace; c is the specific heat capacity of air.

[0024] Preferably, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-50% pelletized ore, and 3-5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0025] Preferably, the sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 1-3wt% of dolomite powder, 7.5-12.5wt% of quicklime, 1-3wt% of manganese powder, and 10-13% of blast furnace recycled material.

[0026] Preferably, the compressive strength of the pellets is 2300-2500 N / piece.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention relates to a low iron loss blast furnace charge structure, which reduces the difficulty of separating slag and iron during the vanadium-titanium magnetite smelting process by optimizing the charge structure, thereby reducing the iron loss during the vanadium-titanium magnetite smelting process.

[0029] 2. The present invention relates to a smelting method, which increases the amount of air entering the furnace to activate the furnace, reduce the chemical heat of molten iron, increase the physical heat of molten iron, optimize the charging system and the air supply system, stabilize the airflow, improve the gas distribution, and increase the permeability of the material column to reduce the visible iron carried away by the gas ash; the furnace temperature is reasonably controlled to reduce the coke ratio, so as to reduce the iron loss, thereby solving the problem of high iron loss in the existing method of smelting vanadium-titanium magnetite in blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic flow diagram of the blast furnace smelting method of the present invention;

[0032] Figure 2 This is a diagram of iron loss using different smelting methods corresponding to Example 1 of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] Example 1

[0036] In 2023, in Desheng 3# and 4# blast furnaces, the following Figure 1 The smelting method of the case shown. The smelting method includes the following steps: S1, adding raw materials of a specified charge structure to the blast furnace for distribution, and starting smelting; S2, after the blast furnace condition is stable, adjusting the furnace air volume to a preset air volume range, and adjusting the oxygen enrichment rate to a preset oxygen enrichment rate range; S3, adjusting the smelting air temperature to a preset temperature range, controlling the coke ratio to a preset coke ratio, controlling the coal ratio to a preset coal ratio range, and controlling the silicon-titanium content to be within a preset first value range, the silicon-titanium content being the sum of the silicon content and the titanium content in the molten iron; S4, terminating the smelting after continuing the smelting for a preset time length.

[0037] In S1, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-50% pelletized ore, and 3-5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0038] The sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 1-3wt% of dolomite powder, 7.5-12.5wt% of quicklime, 1-3wt% of manganese powder and 10-13% of blast furnace recycled material.

[0039] In S2, the preset air volume is 3350±50 .

[0040] In S2, the preset oxygen enrichment rate is 4.5-5.5%.

[0041] In S3, the preset temperature is 1200-1230°C.

[0042] In S3, the preset coke ratio is 385 kg / ton iron, the coal ratio is 170 kg / ton iron, and the first value range is controlled to be 0.18-0.28%.

[0043] In 2023, conventional smelting method 1 was used in Desheng 3# and 4# blast furnaces from March to April. The smelting method includes the following steps: S1, adding raw materials of a specified charge structure to the blast furnace for distribution, and starting smelting; S2, after the blast furnace condition is stable, adjusting the furnace air volume to within the preset air volume range, and adjusting the oxygen enrichment rate to within the preset oxygen enrichment rate range; S3, adjusting the smelting air temperature to within the preset temperature range, controlling the coke ratio to within the preset coke ratio, controlling the coal ratio to within the preset coal ratio range, and controlling the silicon-titanium content to within the preset first value range, and the silicon-titanium content is the sum of the silicon content and the titanium content in the molten iron; S4, terminating the smelting after continuing the smelting for a preset time length.

[0044] In S1, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-47% pelletized ore, and 5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0045] The sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 2-3wt% of dolomite powder, 9.5-12.5wt% of quicklime, 2-3wt% of manganese powder and 10-13% of blast furnace recycled material.

[0046] In S2, the preset air volume is 3350±50 The preset oxygen enrichment rate is 4.5-5.5%.

[0047] In S3, the preset temperature is 1200-1230° C. The preset coke ratio is 395 kg / ton iron, the coal ratio is 175 kg / ton iron, and the first value range is controlled to be 0.25-0.45%.

[0048] In 2023, conventional smelting method 2 was used in Desheng 3# and 4# blast furnaces from May to June. The smelting method includes the following steps: S1, adding raw materials of a specified charge structure to the blast furnace for charging, and starting smelting; S2, after the blast furnace condition is stable, adjusting the furnace air volume to within the preset air volume range, and adjusting the oxygen enrichment rate to within the preset oxygen enrichment rate range; S3, adjusting the smelting air temperature to within the preset temperature range, controlling the coke ratio to within the preset coke ratio, controlling the coal ratio to within the preset coal ratio range, and controlling the silicon-titanium content to within the preset first value range, the silicon-titanium content being the sum of the silicon content and the titanium content in the molten iron; S4, terminating the smelting after continuing the smelting for a preset time length.

[0049] In S1, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-47% pelletized ore, and 5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0050] The sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 2-3wt% of dolomite powder, 8.5-12.5wt% of quicklime, 2-2.5wt% of manganese powder and 10-13% of blast furnace recycled material.

[0051] In S2, the preset air volume is 3050±50 .

[0052] In S2, the preset oxygen enrichment rate is 2.5-3.5%.

[0053] In S3, the preset temperature is 1200-1230°C.

[0054] In S3, the preset coke ratio is 390 kg / ton iron, the coal ratio is 170 kg / ton iron, and the first value range is controlled to be 0.25-0.40%.

[0055] In 2023, conventional smelting method 3 was used in Desheng 3# and 4# blast furnaces from July to August. The smelting method includes the following steps: S1, adding raw materials of a specified charge structure to the blast furnace for distribution, and starting smelting; S2, after the blast furnace condition is stable, adjusting the furnace air volume to within the preset air volume range, and adjusting the oxygen enrichment rate to within the preset oxygen enrichment rate range; S3, adjusting the smelting air temperature to within the preset temperature range, controlling the coke ratio to within the preset coke ratio, controlling the coal ratio to within the preset coal ratio range, and controlling the silicon-titanium content within the preset first value range, the silicon-titanium content is the sum of the silicon content and the titanium content in the molten iron; S4, terminating the smelting after continuing the smelting for a preset time length.

[0056] In S1, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-50% pelletized ore, and 3-5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0057] The sintered ore is prepared by weight percentage from 40-50wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 1-3wt% of dolomite powder, 7.5-12.5wt% of quicklime, 2-5wt% of manganese powder and 10-13% of blast furnace recycled material.

[0058] In S2, the preset air volume is 3250±50 .

[0059] In S2, the preset oxygen enrichment rate is 3.5-4.5%.

[0060] In S3, the preset temperature is 1200-1230°C.

[0061] In S3, the preset coke ratio is 385 kg / ton iron, the coal ratio is 180 kg / ton iron, and the first value range is controlled to be 0.22-0.32%.

[0062] The iron loss of different smelting methods is as follows Figure 2 shown.

[0063] In this embodiment, the silicon-titanium content is the sum of the silicon content and the titanium content in the molten iron.

[0064] The beneficial effects of the above technical solution are:

[0065] The present invention optimizes the smelting method, increases the amount of air entering the furnace, activates the furnace, reduces the chemical heat of molten iron, increases the physical heat of molten iron, optimizes the charging system and the air supply system, stabilizes the airflow, improves the gas distribution, and increases the permeability of the material column to reduce the visible iron carried away by the gas ash; the furnace temperature is reasonably controlled, the coke ratio is reduced, and the iron loss is reduced, thereby solving the problem of high iron loss in the existing method of smelting vanadium-titanium magnetite in a blast furnace.

[0066] Example 2

[0067] Based on Example 1, step S4 includes:

[0068] Step S41: obtaining the actual charge structure and obtaining the basic smelting prediction time based on the smelting parameter setting values;

[0069] Step S42: obtaining actual smelting parameters and recording them;

[0070] Step S43: regularly obtaining the remaining smelting time based on the actual smelting parameters;

[0071] Step S44: When the remaining smelting time returns to zero, smelting is terminated.

[0072] Preferably, step S41 includes:

[0073] Step S411: obtaining actual charge structure parameters, which include: average particle size of charge, chemical composition ratio of charge, composition uniformity of charge and water content of charge;

[0074] Step S412: Calculate the basic smelting prediction time according to the actual charge structure;

[0075] ;in, Predict time for basic smelting; is the total volume of the charge entering the furnace; is the average smelting intensity under the conditions of smelting parameter setting values; is the average particle size of the charge corresponding to the standard charge structure; is the actual average particle size of the charge; M is the number of chemical components of the charge to be monitored; is the influence ratio of the unit concentration deviation of the i-th chemical component on the smelting intensity; is the actual concentration of the i-th chemical component in the charge; is the standard concentration of the i-th chemical component of the charge corresponding to the standard charge structure; is the actual composition uniformity of the charge; It is the standard composition uniformity corresponding to the standard charge structure; is the actual moisture content of the charge; It is the standard moisture content corresponding to the standard charge structure.

[0076] Preferably, step S43 includes:

[0077] Step S431: obtaining current actual smelting parameters;

[0078] Step S432: correcting the remaining smelting time according to actual smelting parameters;

[0079] ;in, is the remaining smelting time; is the basic smelting prediction time; N is the total number of times the remaining smelting time is corrected; The length of time between the jth corrected remaining smelting time and the j-1th corrected remaining smelting time; is the air volume entering the furnace when the remaining smelting time is corrected for the jth time; is the air oxygen enrichment rate when the remaining smelting time is corrected for the jth time; is the smelting air temperature when the remaining smelting time is corrected for the jth time; It is the air volume into the furnace in the smelting parameter setting value; It is the air oxygen enrichment rate in the smelting parameter setting value; It is the smelting air temperature in the smelting parameter setting value; is the basic combustion temperature in the blast furnace; is the heat of combustion of coke; is the coke ratio at the jth correction of the remaining smelting time; is the unit pig iron output; The heat of combustion of coal; is the coal ratio at the jth correction of the remaining smelting time; It is the best smelting combustion temperature; is the current actual air volume entering the furnace; is the current actual air oxygen enrichment rate; is the current actual smelting air temperature; is the current actual focal ratio; is the current actual coal ratio; is the thermal efficiency of combustion; is the total mass of air in the blast furnace; c is the specific heat capacity of air.

[0080] In this embodiment, the smelting parameters include: furnace air volume, air oxygen enrichment rate, smelting air temperature, coke ratio, and coal ratio.

[0081] In this embodiment, smelting intensity refers to the amount of charge that can be processed per unit time.

[0082] In this embodiment, the smelting parameter setting value is the set standard value of the smelting parameter during the smelting process.

[0083] In this embodiment, the standard charge structure is a set of pre-set charge structures configured according to a fixed raw material ratio, wherein the chemical composition ratio, composition uniformity, charge moisture content, and average particle size are all fixed values.

[0084] In this embodiment, the influence ratio of the unit concentration deviation of the chemical component on the smelting strength refers to the influence on the smelting strength caused by each unit concentration deviation of the chemical component, and the influence ratio of each chemical component is determined by experiments.

[0085] In this embodiment, the basic combustion temperature is a basic value of the combustion temperature used to calculate the actual combustion temperature in the blast furnace, and the basic combustion temperature is determined based on experiments.

[0086] In this embodiment, the optimal smelting combustion temperature is the combustion temperature with the highest smelting efficiency when smelting vanadium-titanium magnetite under the same other smelting conditions. The optimal smelting combustion temperature is determined based on experiments.

[0087] In this embodiment, the total number of times the remaining smelting time is corrected is the total number of times the remaining smelting time is corrected for the furnace charge (including this correction), and the first correction of the remaining smelting time is used to calculate the basic smelting prediction time.

[0088] In this embodiment, the combustion thermal efficiency indicates what proportion of the heat released by the combustion of the fuel is effectively utilized during the combustion or energy conversion process. The combustion thermal efficiency is derived from experimental measurements and has a value greater than 0 and less than 1.

[0089] The beneficial effects of the above technical solution are:

[0090] Before the start of smelting, the theoretical smelting time (i.e., basic smelting prediction time) under the set values ​​of the smelting parameters is determined through the set values ​​of the smelting parameters and the actual charge structure. As the smelting progresses, the remaining smelting time is corrected regularly based on the actual smelting parameters and the smelting time is adjusted based on the actual smelting conditions, thereby ensuring the stability of the quality of the smelted steel and ensuring low iron loss in the smelting process when there is a difference between the set values ​​and the actual values ​​of the smelting parameters.

[0091] When calculating the basic smelting prediction time, the average smelting intensity under the conditions of the smelting parameter setting values ​​is corrected by the average particle size, chemical composition, composition uniformity and water content of the charge, so as to obtain the theoretical average smelting intensity when using the charge of this furnace. The basic smelting prediction time is calculated according to the theoretical average smelting intensity and the total volume of the charge entering the furnace. The basic smelting prediction time is calculated according to the charge structure parameters of the charge, which improves the accuracy of the calculation results of the basic smelting prediction time. The basic smelting prediction time can be adjusted in a targeted manner according to the conditions of different charges, thereby ensuring the stable quality of the smelted steel.

[0092] When correcting the remaining smelting time, firstly Obtain the smelting progress at that time point (by converting it into the smelting time under the conditions of the smelting parameter setting value), and then The remaining smelting progress (i.e. the remaining smelting time under the set smelting parameter conditions) is obtained, and then the remaining smelting progress is equivalently converted according to the actual furnace air volume, actual air oxygen enrichment rate, actual smelting air temperature, actual coke ratio and actual coal ratio, thereby obtaining the remaining smelting time under the current actual smelting parameter conditions. By applying internal corrections to the remaining smelting multiple times during the smelting process, the accuracy of the remaining smelting time is further improved, thereby ensuring the excellent and stable quality of the smelted steel.

[0093] Example 3

[0094] Based on Example 1, the raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-50% pelletized ore, and 3-5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

[0095] Preferably, the sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 1-3wt% of dolomite powder, 7.5-12.5wt% of quicklime, 1-3wt% of manganese powder, and 10-13% of blast furnace recycled material.

[0096] Preferably, the compressive strength of the pellets is 2300-2500 N / piece.

[0097] The beneficial effects of the above technical solution are:

[0098] The low iron loss blast furnace charge structure involved in the present invention reduces the difficulty of separating slag and iron during the vanadium-titanium magnetite smelting process by optimizing the charge structure, thereby reducing the iron loss during the vanadium-titanium magnetite smelting process.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blast furnace smelting method with low iron loss, characterized in that: include: Step S1: adding raw materials of a specified charge structure into a blast furnace for distribution and starting smelting; Step S2: After the blast furnace condition is stabilized, the air volume entering the furnace is adjusted to within a preset air volume range, and the oxygen enrichment rate is adjusted to within a preset oxygen enrichment rate range; Step S3: adjusting the smelting air temperature to a preset temperature range, controlling the coke ratio to a preset coke ratio, controlling the coal ratio to a preset coal ratio range, and controlling the silicon-titanium content to be within a preset first value range, wherein the silicon-titanium content is the sum of the silicon content and the titanium content in the molten iron; Step S4: smelting is continued for a preset time and then terminated; Step S4 includes: Step S41: obtaining the actual charge structure and obtaining the basic smelting prediction time based on the smelting parameter setting values; Step S42: obtaining actual smelting parameters and recording them; Step S43: regularly obtaining the remaining smelting time based on the actual smelting parameters; Step S44: When the remaining smelting time returns to zero, smelting is terminated; Step S41 includes: Step S411: Acquire actual charge structure parameters, which include: average particle size of charge, chemical composition ratio of charge, composition uniformity of charge and water content of charge; Step S412: Calculate the basic smelting prediction time according to the actual charge structure; ;in, Predict time for basic smelting; is the total volume of the charge entering the furnace; is the average smelting intensity under the conditions of smelting parameter setting values; is the average particle size of the charge corresponding to the standard charge structure; is the actual average particle size of the charge; M is the number of chemical components of the charge to be monitored; is the influence ratio of the unit concentration deviation of the i-th chemical component on the smelting intensity; is the actual concentration of the i-th chemical component in the charge; is the standard concentration of the i-th chemical component of the charge corresponding to the standard charge structure; is the actual composition uniformity of the charge; It is the standard composition uniformity corresponding to the standard charge structure; is the actual moisture content of the charge; It is the standard moisture content corresponding to the standard charge structure.

2. A low iron loss blast furnace smelting method according to claim 1, characterized in that: In step S2, the preset air volume range is 3350±50 ; The preset oxygen enrichment rate range is 4.5-5.5%.

3. A low iron loss blast furnace smelting method according to claim 1, characterized in that: In step S3, the preset temperature range is 1200-1230°C; the preset coke ratio range is 385kg / ton iron, the preset coal ratio range is 170~176kg / ton iron, and the first value range is 0.18-0.28%.

4. A blast furnace smelting method with low iron loss according to claim 1, characterized in that: Step S43 includes: Step S431: obtaining current actual smelting parameters; Step S432: correcting the remaining smelting time according to actual smelting parameters; ;in, is the remaining smelting time; is the basic smelting prediction time; N is the total number of times the remaining smelting time is corrected; The length of time between the jth corrected remaining smelting time and the j-1th corrected remaining smelting time; is the air volume entering the furnace when the remaining smelting time is corrected for the jth time; is the air oxygen enrichment rate when the remaining smelting time is corrected for the jth time; is the smelting air temperature when the remaining smelting time is corrected for the jth time; It is the air volume into the furnace in the smelting parameter setting value; It is the air oxygen enrichment rate in the smelting parameter setting value; It is the smelting air temperature in the smelting parameter setting value; is the basic combustion temperature in the blast furnace; is the heat of combustion of coke; is the coke ratio at the jth correction of the remaining smelting time; is the unit pig iron output; The heat of combustion of coal; is the coal ratio at the jth correction of the remaining smelting time; It is the best smelting combustion temperature; is the current actual air volume entering the furnace; is the current actual air oxygen enrichment rate; is the current actual smelting air temperature; is the current actual focal ratio; is the current actual coal ratio; is the thermal efficiency of combustion; is the total mass of air in the blast furnace; c is the specific heat capacity of air.

5. A blast furnace smelting method with low iron loss according to claim 1, characterized in that: The raw materials of the charge structure include, by weight percentage: 47-50% sintered ore, 45-50% pelletized ore, and 3-5% raw ore. The pelletized ore is prepared by weight percentage from 96-98wt% of vanadium-titanium magnetite concentrate, 1-2wt% of steelmaking sludge, and 1.5-3.0wt% of bentonite.

6. A low iron loss blast furnace smelting method according to claim 5, characterized in that: The sintered ore is prepared by weight percentage from 40-55wt% of vanadium-titanium magnetite concentrate, 10-25wt% of ordinary iron concentrate, 1-3wt% of dolomite powder, 7.5-12.5wt% of quicklime, 1-3wt% of manganese powder and 10-13% of blast furnace recycled material.

7. A low iron loss blast furnace smelting method according to claim 6, characterized in that: The compressive strength of the pellets is 2300-2500 N / piece.

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