JPWO2018110521A1 - Blast furnace operation method - Google Patents

Abstract

Provided is a blast furnace operating method capable of controlling the component concentration of a blast furnace raw material to a target component concentration even if the component concentration of the sintered raw material varies. A blast furnace operation method in which a blast furnace raw material including a sintered product ore, lump iron ore and auxiliary materials is charged into a blast furnace, and a sintering process comprising sintering a sintered raw material to form a sintered cake, A crushing step for crushing to sinter, a cooling step for cooling the sinter, a sieving step for sieving the cooled sinter into product sinter and return ore, and cooling A measurement step for measuring the concentration of at least one component of the sintered ore, the product sintered ore, and the return ore; and an adjustment step for adjusting the blending amount of the product sintered ore, the massive iron ore and the auxiliary material contained in the blast furnace raw material; In the adjustment step, the blending amount of the blast furnace raw material is adjusted using the component concentration measured in the measurement step.

Description

  The present invention relates to a blast furnace operation method for adjusting the blending amount of a blast furnace raw material, specifically, measuring the component concentration of sintered ore as a blast furnace raw material, and using the component concentration, the blending amount of the blast furnace raw material The present invention relates to a method of operating a blast furnace.

In the blast furnace iron manufacturing method, iron-containing raw materials such as sintered ore, lump iron ore, and pellets are mainly used as blast furnace raw materials at present. Here, the sintered ore is composed of iron ore having a particle size of 10 mm or less, various iron sources such as various kinds of dust generated in the steel mill, CaO-containing raw materials such as limestone, quicklime, and slag, and quartzite and serpentine. , A secondary material as a SiO ₂ source and MgO source made of dolomite, refined nickel slag, etc. and a solid fuel (carbon material) that is a coagulation material made of powdered coke or anthracite while mixing moisture with a drum mixer -It is a kind of agglomerated minerals that have been granulated and fired.

In recent years, the concentration of iron contained in sintered raw materials, which are raw materials for sintered ores, has decreased, and the concentration of gangue components such as SiO ₂ and Al ₂ O ₃ has increased. The component concentration of the ore produced becomes more unstable as the concentration of components may differ from ship to ship.

  The variation in the component concentration in the sintered raw material leads to the variation in the component concentration of the sintered ore that is the product. In general, the component concentration of the raw material charged in the blast furnace is always controlled for reasons such as management of slag quality. If a certain component concentration becomes high, it is necessary to add another component as a secondary raw material in order to dilute it, so it is necessary to quickly detect changes in the component concentration of sintered ore, massive iron ore, and pellets. Since the lump ore and pellets themselves are products, the component concentration is analyzed at the time of unloading, etc., but the online component concentration analysis on the current sintered ore is not performed, The fact is that the component concentration is analyzed only at a very low frequency.

  If the component concentration of the blast furnace raw material fluctuates due to fluctuations in the component concentration of the sinter and greatly deviates from the target component concentration, and this causes the slag viscosity to deteriorate, the hot metal temperature is set to maintain the slag viscosity. It needs to be raised. The worsening of slag viscosity leads to worsening of slag discharge at the bottom of the blast furnace, which hinders gas flow and deteriorates air permeability, increasing the amount of coke added to compensate for hot metal temperature and air permeability. It may be necessary to make it happen. As described above, when the component concentration of the blast furnace raw material greatly deviates from the target component concentration, the blast furnace operation becomes unstable, and various measures are required.

  As a technique for grasping the quality of sintered ore, for example, Patent Document 1 predicts the reducibility and reduced powdering property of the product sintered ore from the filling state of the sintered raw material, and adjusts the blending ratio of the blast furnace raw material Instead, a technique for adjusting the blast furnace raw material by adjusting the composition of the sintered raw material is disclosed.

  Patent Document 2 discloses a technique for measuring the FeO of a product sintered ore and adjusting the coagulation material, granulated moisture, and exhaust air amount of the sintered raw material from the difference from the target value. Patent Document 3 discloses a technique for measuring FeO of a sintered product ore and adjusting the amount of city gas blown by a sintering machine based on a difference from a target value.

  Patent Document 4 discloses a technique for estimating a component of a product sintered ore from components of a surface layer of a sintered raw material obtained by a laser type component measuring machine installed on a sintering machine and reflecting the component in the composition of the sintered raw material. Has been.

Japanese Patent Laid-Open No. 10-324929 JP-A-57-149433 JP 2011-038735 A JP-A-60-262926

  However, Patent Documents 1 to 4 disclose a technique for measuring a certain component concentration in a sintered ore and adjusting a sintering raw material using the measured component concentration, or a sintered ore. This is a technique for adjusting the manufacturing conditions. Patent Documents 1 to 4 do not disclose any adjustment of the blending amount of the blast furnace raw material charged into the blast furnace using the measured component concentration of the sintered ore. Since the component concentration of the sinter can change depending on the heat level during the sintering reaction, even if the variation of the component concentration of the sintering raw material is suppressed, the variation of the component concentration of the sinter cannot necessarily be suppressed. Absent. For this reason, the subject that the component density | concentration of the blast furnace raw material charged into a blast furnace cannot be controlled to the target component density | concentration occurred. The present invention has been made in view of such problems of the prior art, and the purpose thereof is to control the component concentration of the blast furnace raw material to the target component concentration even if the component concentration of the sintered raw material fluctuates. It is to provide a blast furnace operation method.

The features of the present invention that solve such problems are as follows.
(1) A blast furnace operating method for charging a blast furnace raw material containing a product sintered ore, massive iron ore and auxiliary raw materials into a blast furnace, and sintering the sintered raw material into a sintered cake; A crushing step for crushing the sintered cake to form a sintered ore, a cooling step for cooling the sintered ore, and sieving the cooled sintered ore into a product sintered ore and return ore A measurement step of measuring at least one component concentration of the cooled sintered ore, the product sintered ore and the return ore, the product sintered ore contained in the blast furnace raw material, the block iron ore, and An adjusting step for adjusting the blending amount of the auxiliary raw material, and in the adjusting step, the blending amount of the blast furnace raw material is adjusted using the component concentration measured in the measuring step.
(2) The blast furnace raw material further includes pellets, and in the adjusting step, the blending amounts of the product sintered ore, the pellets, the massive iron ore and the auxiliary raw materials included in the blast furnace raw material are adjusted. ) Blast furnace operation method.
(3) In the measurement step, at least one component concentration of the cooled sintered ore, the product sintered ore and the returned ore that is conveyed on a conveyor is continuously measured. (1) or (2) The blast furnace operating method described.
(4) The blast furnace operating method according to any one of (1) to (3), wherein in the measurement step, the concentration of at least one component of the product sintered ore and the return ore is measured.
(5) The blast furnace operating method according to any one of (1) to (3), wherein in the measurement step, the component concentration of the product sintered ore is measured.
(6) The blast furnace operation according to any one of (1) to (5), wherein in the measurement step, the concentration of at least one component of total CaO, SiO ₂ , MgO, Al ₂ O ₃ , and FeO is measured. Method.

  By carrying out the blast furnace operating method of the present invention, the component concentration of the blast furnace raw material can be controlled to a target component concentration. Thereby, the fluctuation | variation of the viscosity of a blast furnace slag, etc. can be suppressed, and it can contribute to the stable operation of a blast furnace.

FIG. 1 is a schematic diagram showing an example of a sintered ore manufacturing apparatus 10 that can implement the blast furnace operating method according to the present embodiment. FIG. 2 is a graph showing changes in basicity of blast furnace slag. FIG. 3 is a graph showing fluctuations in the coke ratio. FIG. 4 is a graph showing fluctuations in basicity of the blast furnace raw material and fluctuations in the coke ratio. FIG. 5 is a graph showing measured values of FeO concentration in Invention Example 3, Invention Example 4 and Comparative Example 3. FIG. 6 is a graph showing the reduction amount of the coke ratio in Invention Example 3, Invention Example 4 and Comparative Example 3.

  In this invention, the measurement process which measures the component density | concentration of a sintered ore is provided, and the component density | concentration of a sintered ore is measured by the said measurement process. Using this component concentration, the blending amount of the smelter ore, pellets, massive iron ore and auxiliary materials, which are blast furnace raw materials, is adjusted. As a result, it was possible to control the component concentration of the blast furnace raw material to be a target component concentration, and as a result, it was found that blast furnace operation could be stabilized, and the present invention was completed. Hereinafter, the present invention will be described through embodiments of the present invention.

  FIG. 1 is a schematic diagram showing an example of a sintered ore manufacturing apparatus 10 that can implement the blast furnace operating method according to the present embodiment. The sintered ore manufacturing apparatus 10 includes a sintering machine 12, a primary crusher 14, a cooler 16, a secondary crusher 18, a plurality of sieving devices 20, 22, 24, and 26, and an infrared analyzer 28. And a product line 30 and a return ore line 32.

  In the sintering machine 12, a sintering process is performed. The sintering machine 12 is, for example, a downward suction type Dwightroid sintering machine. The sintering machine 12 includes a sintering raw material supply device, an endless moving pallet, an ignition furnace, and a wind box. A sintering raw material is charged into the pallet from the sintering raw material supply device, and a charging layer of the sintering raw material is formed. The charging layer is ignited in an ignition furnace, and the air in the charging layer is sucked downward through the windbox, thereby moving the combustion / melting zone in the charging layer below the charging layer. Thereby, the charging layer is sintered and a sintered cake is formed. When the air in the charging layer is sucked downward through the wind box, air enriched with gaseous fuel and / or oxygen gas may be supplied from above the charging layer. The gaseous fuel is any flammable gas selected from blast furnace gas, coke oven gas, blast furnace / coke oven mixed gas, converter gas, city gas, natural gas, methane gas, ethane gas, propane gas and mixed gas thereof. It is.

  In the primary crusher 14, a crushing process is performed, and the sintered cake is crushed by the primary crusher 14 into a sintered ore. In the cooler 16, a cooling process is performed, and the sintered ore is cooled by the cooler 16 and becomes a cooled sintered ore.

  In the sieving devices 20, 22, 24, and 26, a sieving step is performed. In the sieving device 20, the cooled sintered ore is sieved into a sintered ore having a particle size of more than 75 mm and a sintered ore having a particle size of 75 mm or less. In this embodiment, the particle size means a particle size that is sieved by a sieve. For example, a sintered ore having a particle size of more than 75 mm is a particle size that is sieved on a sieve using a sieve having an opening of 75 mm. The sintered ore having a particle diameter of 75 mm or less means a particle diameter that is sieved under a sieve using a sieve having an opening of 75 mm.

  The sintered ore having a particle size of more than 75 mm that has been sieved on the sieve by the sieving device 20 is pulverized by the secondary crusher 18 so that the particle size becomes 50 mm or less. The pulverized sintered ore is mixed under a sieve and sieved by a sieving device 22. Thereby, the upper limit of the particle size of the product sintered ore can be made 75 mm or less.

  The sintered ore having a particle size of 75 mm or less that has been screened under the sieve by the sieving device 20 is then converted into a product sintered ore having a particle size of more than 5 mm by the sieving devices 22, 24, and 26, Sieve into return ore. The product sintered ore screened by the sieving devices 22, 24 and 26 is conveyed to the blast furnace 34 by a belt conveyor which is a product line 30. On the other hand, the return ore screened by the screening devices 22, 24 and 26 is conveyed again to the sintering material supply device of the sintering machine 12 by the belt conveyor which is the return ore line 32. Each value of the particle size of the sintered ore, the particle size of the product sintered ore and the particle size of the return ore to be screened using the sieving devices 20, 22, 24, and 26 is merely an example, and is limited to this value. It is not a thing.

An infrared analyzer 28 is provided on the belt conveyor of the product line 30. In the infrared analyzer 28, a measurement process is performed. In the measurement step, the concentration of one or more components of total CaO, SiO ₂ , MgO, Al ₂ O ₃ and FeO contained in the product sintered ore is measured. The infrared analyzer 28 irradiates the sintered ore with infrared rays having a wavelength in the range of 0.5 μm to 50.0 μm, and receives reflected light from the sintered ore. Each molecular vibration of total CaO, SiO ₂ , MgO, Al ₂ O ₃ , and FeO contained in the sintered ore absorbs the specific wavelength components of the irradiated infrared rays, so these components are unique to the reflected infrared rays. A wavelength component is added. Therefore, it is possible to measure the total _{CaO, SiO 2, MgO, Al} 2 O 3, component concentration of FeO by analyzing the illumination light and the reflected light in the finished product sintered ore. Total CaO is obtained by converting Ca in all compounds having Ca and O such as CaO, CaCO ₃ , Ca (OH) _2, and Fe ₂ CaO ₄ into CaO.

  The infrared analyzer 28 irradiates infrared rays having a wavelength of 20 or more at a frequency of 128 times per minute, for example, and receives reflected light reflected by the product sintered ore. By irradiating infrared rays in such a short time, the infrared analyzer 28 can continuously measure the component concentration of the product sintered ore conveyed on the belt conveyor of the product line 30 online. The infrared analyzer 28 is an example of a component analyzer, and is not limited to a system that divides reflected light but may use a system that scatters transmitted light. Further, instead of the infrared analyzer 28, a laser analyzer that irradiates the measurement target with a laser, a neutron analyzer that irradiates the measurement target with neutrons, or a microwave analyzer that irradiates the measurement target with microwaves may be used. Good.

The product sintered ore whose component concentration has been measured is conveyed to the blast furnace 34, and an adjustment step is performed to adjust the blending amount of the blast furnace raw material composed of the product sintered ore, pellets, massive iron ore and auxiliary materials. The blast furnace raw material may include raw materials other than those described above, and may not include pellets. In the adjustment process, the total component amount of the blast furnace raw material is calculated using the component concentration of the sintered product ore measured using the infrared analyzer 28 and the component concentration of pellets, massive iron ore, and auxiliary raw materials measured in advance. Then, using the calculated value, feedforward control is performed on the blending amount of the blast furnace raw material so as to achieve a target component concentration. For example, in order to control the basicity (CaO / SiO ₂ ) of the blast furnace raw material to a target component concentration, the amount of the auxiliary raw material contained in the blast furnace raw material may be adjusted.

  If the FeO concentration of the product sintered ore becomes high and the FeO concentration of the blast furnace raw material becomes high, the reducibility of the blast furnace raw material deteriorates. When the reducibility of the blast furnace raw material deteriorates, indirect reduction, which is an exothermic reaction, decreases, direct reduction, which is an endothermic reaction, increases, and the inside of the blast furnace becomes short of heat. In order to eliminate this heat shortage, the reducing material is further charged into the blast furnace, and the coke ratio in blast furnace operation increases. For this reason, by controlling the FeO concentration of the blast furnace raw material to a target component concentration, an increase in the coke ratio of the blast furnace operation can be suppressed, and it can contribute to the stable operation of the blast furnace. For example, in order to control the target concentration of FeO of the blast furnace raw material, the blending amount of the lump ore contained in the blast furnace raw material may be adjusted.

  In this way, the blending amount of the blast furnace raw material is adjusted so that the component concentration of the blast furnace raw material becomes a target component concentration. In this embodiment, the measurement frequency of the component concentration by the infrared analyzer 28 is 128 times per minute, the average value of the component concentration of 128 times is calculated once per minute, and the calculated average value of the component concentration Was used to adjust the blending amount of the blast furnace raw material every minute.

  As described above, the blast furnace operating method according to the present embodiment measures the component concentration of the product sintered ore conveyed through the product line 30 using the infrared analyzer 28, and uses the component concentration as a target component. The blending amount of the blast furnace raw material is adjusted so as to obtain a concentration. Thereby, even if the component concentration of the sintering raw material fluctuates and the component concentration of the product sintered ore fluctuates, the component concentration of the blast furnace raw material can be controlled to the target component concentration, and the blast furnace raw material is charged into the blast furnace. As a result, blast furnace operation is stabilized, and an increase in the coke ratio during blast furnace operation can be suppressed.

  In the present embodiment, an example in which the infrared analyzer 28 is provided on the belt conveyor of the product line 30 and the component concentration of the product sintered ore is measured has been shown. It may be provided at any one of the positions 10 and the concentration of at least one component of the cooled sinter, the product sinter and the return ore may be measured.

  In the charging layer in which the sintering raw material is charged into the pallet, the component concentration in the surface layer and the component concentration in the lower layer are greatly different, and the component concentration depends on the moisture content of the sintering raw material and / or the state of the sintering raw material supply device. Fluctuates depending on. Infrared analysis can only analyze the surface layer to be analyzed due to its nature. For this reason, the component concentration of the surface layer is different from the component concentration of the lower layer, and even if the charged layer in which the component concentration varies is measured with the infrared analyzer 28, the component concentration of the entire charged layer cannot be measured with high accuracy. On the other hand, after the cooling step, since the sintered raw material is sintered, pulverized, cooled and mixed to some extent, the component concentration in the surface layer and the component concentration in the lower layer do not differ greatly. For this reason, in the measurement process of this embodiment, the concentration of at least one component of the sintered ore, the product sintered ore and the return ore after the cooling process is measured. Thereby, even if it is the infrared analyzer 28 which can analyze only the surface layer of analysis object, a component density | concentration can be measured with high precision.

  In a state where the particle size distribution of the sinter is wide, for example, infrared rays are irradiated to only a part of the sinter, such as inability to irradiate the sinter with a small particle size hidden in the sinter with a large particle size. The reflected light from the sintered ore is not stable. On the other hand, after the sieving step, since the sinter is divided into a product sintered ore having a particle size of more than 5 mm and a return ore having a particle size of 5 mm or less, the particle size distribution of the sintered ore is narrow. For this reason, in the measurement process, it is preferable to measure the concentration of at least one component of the product sintered ore and the return ore after the sieving process. Thereby, since the infrared analyzer 28 can irradiate infrared rays uniformly to the sintered ore and the reflected light from the sintered ore is stabilized, the component concentration can be measured with higher accuracy.

  After the sieving step, the component concentration of the product sinter or return ore is measured in the measurement step. However, measuring the product sinter ore is one of the blast furnace raw materials rather than measuring the return ore. This is more preferable because the component concentration of the sintered product ore used as a material can be directly measured.

Using the sinter production apparatus 10 provided with the infrared analyzer 28 in the product line 30, the component concentration of total CaO, SiO ₂ , MgO, Al ₂ O ₃ and FeO contained in the product sinter is set to 1 per minute. Measured at the frequency of times. Invention Example 1 is an operation example in which the amount of the auxiliary raw material of the blast furnace raw material is adjusted once per minute using the measurement result. Comparative Example 1 is an operation example in which the blending amount of the auxiliary raw material of the blast furnace raw material is not adjusted. The variation in basicity of the blast furnace slag and the coke ratio of the blast furnace in Comparative Example 1 and Invention Example 1 were measured.

FIG. 2 is a graph showing changes in basicity of blast furnace slag. FIG. 2A shows the change in basicity of Comparative Example 1, and FIG. 2B shows the change in basicity of Invention Example 1. In FIG. 2, the horizontal axis represents time (days), and the vertical axis represents total CaO / SiO ₂ (−). The basicity values shown in FIG. 2 are values obtained by conducting offline chemical analysis on the components of the hot metal and blast furnace slag discharged from the blast furnace.

  As shown in FIG. 2, in the first comparative example, the basicity greatly fluctuated near the target value. On the other hand, in Invention Example 1, the component concentration of the sintered sinter is measured at a frequency of once per minute, and the composition of the blast furnace raw material is adjusted so that the component concentration of the blast furnace raw material becomes the target value using the component concentration. As a result, the deviation of the basicity from the target value became smaller. Thus, it was confirmed that the deviation from the target value of the basicity in the blast furnace slag can be reduced by carrying out the blast furnace operating method according to the present embodiment.

  FIG. 3 is a graph showing fluctuations in the coke ratio. In FIG. 3, the horizontal axis represents time (days) and the vertical axis represents the coke ratio (kg / t-pig). From 0 to 19 days is the coke ratio of Comparative Example 1 in which the blast furnace raw material whose blending amount was not adjusted was charged and the blast furnace operation was performed, and until 20 to 39 days, the frequency was once per minute. It is a coke ratio of the invention example 1 which charged the blast furnace raw material which adjusted the compounding quantity, and performed blast furnace operation.

  As shown in FIG. 3, compared to Comparative Example 1, Invention Example 1 had a lower coke ratio in blast furnace operation. Thus, by implementing the blast furnace operation method according to the present embodiment, it was confirmed that the blast furnace operation was stabilized, and as a result, an increase in the coke ratio of the blast furnace operation could be suppressed.

FIG. 4 is a graph showing fluctuations in basicity of the blast furnace raw material and fluctuations in the coke ratio. FIG. 4A shows the change in basicity of the blast furnace raw materials of Comparative Example 2 and Invention Example 2. FIG. In FIG. 4A, the horizontal axis represents time (hours), and the vertical axis represents total blast furnace raw material total CaO / SiO ₂ (−). FIG. 4 (b) shows the variation of the coke ratio in the blast furnace operation of Comparative Example 2 and Invention Example 2. In FIG.4 (b), a horizontal axis is time (hour) and a vertical axis | shaft is coke ratio (kg / t-pig).

In FIG. 4, in Comparative Example 2, the total CaO and SiO ₂ of the sintered product ore is measured at a frequency of once every 2 hours using fluorescent X-rays, and the blast furnace raw material is measured at the same frequency using the measurement results. It is the operation example which adjusted the compounding quantity of the auxiliary material of. Inventive Example 2, as in Inventive Example 1, uses the infrared analyzer 28 provided in the product line 30 to determine the total CaO and SiO ₂ component concentrations of the product sintered ore at a frequency of once per minute. It is the operation example which adjusted the compounding quantity of the auxiliary material of a blast furnace raw material with the same frequency using a measurement result.

  In the example shown in FIG. 4, the blast furnace operation was performed under the conditions of Comparative Example 2 from 0 to 6 o'clock, and the blast furnace operation was performed under the conditions of Invention Example 2 from 6 o'clock to 19 o'clock. As shown in FIG. 4 (a), in Comparative Example 2, the amount of the auxiliary raw material is adjusted at a frequency of once every two hours. Therefore, in the measurement once every two hours, the basicity of the blast furnace raw material is Variations appear to be suppressed. However, instead of Comparative Example 2 to Invention Example 2, when the blending amount of the auxiliary raw material of the blast furnace raw material was adjusted once per minute, the blending amount was adjusted as shown in FIG. 4B. The coke ratio of blast furnace operation decreased from the time zone when the blast furnace raw material was thought to be charged into the blast furnace. In general, the sinter discharged from the sintering machine is cooled by a cooling machine, sized, and then charged into a blast furnace through a blast furnace storage tank. Although depending on the size of the storage tank, the residence time of the raw material in the storage tank used in this example is about 8 hours, and it can be inferred that the effect gradually appeared in the blast furnace after 8 hours.

From this, the basicity of the blast furnace material fluctuates during the measurement once every 2 hours, but the basicity of the blast furnace raw material fluctuates during that time. It is thought that became higher. On the other hand, in Inventive Example 2, an infrared analyzer 28 is provided in the product line 30 and the total CaO and SiO ₂ of the product sintered ore is measured at a frequency of once per minute, and the blast furnace raw material is measured using the measurement result. Since the amount of the auxiliary raw material was adjusted so that the basicity became the target value, the fluctuation of the basicity of the blast furnace raw material was suppressed even during 2 hours, and as a result, the increase in the coke ratio of the blast furnace operation could be suppressed. Conceivable.

  FIG. 5 is a graph showing measured values of FeO concentration in Invention Example 3, Invention Example 4 and Comparative Example 3. In FIG. 5, the vertical axis represents the measured value (mass%) of the FeO concentration at a specific time.

Inventive Example 3 provides an infrared analyzer 28 in the product line 30 to measure the total CaO, SiO ₂ , MgO, Al ₂ O ₃ and FeO component concentrations of the product sintered ore at a frequency of once per minute. This is an operation example in which the blending amount of the auxiliary raw material of the blast furnace raw material is adjusted once per minute using the measurement result. Inventive Example 4 provides an infrared analyzer 28 in the return ore line 32 and measures the total CaO, SiO ₂ , MgO, Al ₂ O ₃ and FeO component concentrations of the sintered product ore once per minute. And, it is an operation example in which the blending amount of the auxiliary raw material of the blast furnace raw material is adjusted once per minute using the measurement result. In Comparative Example 3, the infrared analyzer 28 is provided at a position where the sintered cake surface of the sintering machine 12 can be measured, and the total CaO, SiO ₂ , MgO, Al _{2 on the} sintered cake surface is once per minute. This is an operation example in which the component concentrations of O ₃ and FeO are measured, and the blending amount of the auxiliary raw material of the blast furnace raw material is adjusted once a minute using the measurement result.

  As shown in FIG. 5, the FeO concentration in the case of measuring the product sintered ore was 7.1% by mass, whereas the FeO concentration in the case of measuring the return ore produced from the same sintered raw material was 6%. It was 9 mass%. From this result, there was no big difference between the result of measuring the FeO concentration of the return ore using an infrared analyzer and the result of measuring the FeO concentration of the product sintered ore. On the other hand, the FeO concentration when measuring the surface of the sintered cake obtained by sintering the same sintering raw material using the infrared analyzer 28 is 5.6% by mass, and the FeO concentration when measuring the product sintered ore. It was very different.

  Infrared analyzers, by their nature, can only measure the component concentration of the surface irradiated with infrared rays. Sintered product ore and sinter are crushed and mixed to some extent in the process, so that the average component of the whole can be obtained by irradiating the surface with infrared rays. On the other hand, since the component concentration of the sintering raw material charged in the pallet is different between the upper layer and the lower layer, and the heat level of the upper layer and the lower layer during sintering is different, the component is different between the upper layer and the lower layer of the sintered cake. Large differences in density occur. For this reason, as shown in FIG. 5, the component concentration of Comparative Example 3 in which the surface of the sintered cake was measured with an infrared analyzer was considered to be significantly different from the component concentration of Invention Example 3 in which the surface of the product sintered ore was measured. It is done.

  FIG. 6 is a graph showing the reduction amount of the coke ratio in Invention Example 3, Invention Example 4 and Comparative Example 3. In FIG. 6, the vertical axis represents the coke ratio reduction amount (kg / t-pig). The amount of coke reduction shown in FIG. 6 is affected by operational fluctuations before adjusting the blending amount of the blast furnace raw material and after adjusting the blending amount of the blast furnace raw material according to Invention Example 3, Invention Example 4, and Comparative Example 3. It is the amount of coke ratio reduction after the elapse of 120 hours, which is estimated to have been settled and operated under steady conditions.

  Invention Example 3 in which the component amount of the smelting raw material charged into the blast furnace as the blast furnace raw material was used to adjust the blending amount of the auxiliary raw material of the blast furnace raw material, In Invention Example 4 in which the blending amount of the auxiliary raw material of the blast furnace raw material was adjusted using the component concentration, the coke ratio at the time after 120 hours had decreased. On the other hand, in the comparative example 3 which adjusted the compounding quantity of the auxiliary raw material of a blast furnace raw material using the measured value of the sintered cake with a big difference of a component density | concentration with the product sintered ore charged in a blast furnace, after 120 hours passed The coke ratio at the time increased conversely. This is considered to reflect the result that the component concentration of the blast furnace raw material charged into the blast furnace was not adjusted to the target component concentration in Comparative Example 3.

DESCRIPTION OF SYMBOLS 10 Sinter production apparatus 12 Sintering machine 14 Primary crusher 16 Cooling machine 18 Secondary crusher 20 Sieving equipment 22 Sieving equipment 24 Sieving equipment 26 Sieving equipment 28 Infrared analyzer 30 Product line 32 Return line 34 Blast furnace

Claims (6)

A blast furnace operation method for charging a blast furnace raw material including a sintered product ore, massive iron ore and auxiliary materials into the blast furnace,
A sintering step of sintering the sintering raw material to form a sintered cake;
Crushing step of crushing the sintered cake to form a sintered ore;
A cooling step for cooling the sintered ore;
A sieving step of sieving the cooled sinter into a product sinter and return ore;
A measuring step for measuring a concentration of at least one component of the cooled sinter, the product sinter and the return ore;
An adjustment step of adjusting the amount of the product sintered ore contained in the blast furnace raw material, the massive iron ore and the auxiliary raw material,
In the adjustment step, a blast furnace operation method in which the blending amount of the blast furnace raw material is adjusted using the component concentration measured in the measurement step. The blast furnace raw material further includes pellets,
2. The blast furnace operation method according to claim 1, wherein in the adjustment step, a blending amount of the product sintered ore, the pellets, the block iron ore, and the auxiliary raw materials included in the blast furnace raw material is adjusted.   The blast furnace operation according to claim 1 or 2, wherein in the measurement step, the concentration of at least one component of the cooled sintered ore, the product sintered ore and the returned ore conveyed on a conveyor is continuously measured. Method.   The blast furnace operating method according to any one of claims 1 to 3, wherein in the measurement step, the concentration of at least one component of the product sintered ore and the return ore is measured.   The blast furnace operating method according to any one of claims 1 to 3, wherein in the measurement step, the component concentration of the product sintered ore is measured. Wherein the measuring step, the total _CaO, SiO 2, _MgO, measuring the _Al 2 O 3, 1 or more component concentration FeO, blast furnace operation method according to any one of claims 1 to 5.

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