Method for judging high-titanium vanadium titano-magnetite blast furnace smelting hearth accumulation

Abstract

The invention provides a method for judging hearth accumulation of a high-titanium vanadium titano-magnetite blast furnace smelting furnace, which comprises the following steps: monitoring the temperature of a part 300-1000mm below the center of a tap hole to obtain temperature data T; the difference value between the air supply volume and the air supply pressure value is calculated, and difference value data X is obtained; and according to the temperature T and the difference X data, the hearth stacking degree is judged. According to the method, the problem that the hearth accumulation cannot be judged in time in blast furnace smelting of the high-titanium vanadium titano-magnetite is solved by utilizing matching and change of the air volume and the air pressure and the temperature below the center of the tap hole, and compared with a method for judging the hearth accumulation by utilizing Ti, Si, C and the like in molten iron in the prior art, the method disclosed by the invention is intuitive, higher in timeliness and higher in practicability. And technical support is provided for subsequent elimination of hearth accumulation.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel metallurgy technology, and particularly relates to a method for determining the accumulation of blast furnace hearth in the smelting of high-titanium vanadium-titanium magnetite. Background Technology

[0002] In blast furnace smelting, the hearth is the primary area for heat introduction and generation, and the driving force for the downward flow and reduction of the furnace charge. Therefore, the working condition of the hearth is fundamental to stable and efficient blast furnace production. Hearth buildup is often caused by abnormal distribution of the temperature or gas flow field within the blast furnace. In areas where heat and gas flow cannot effectively reach, the slag-iron and coke mixture mixes together and cannot melt effectively in time, forming clumps. This leads to an inactive hearth and loss of thermal stability, causing blast furnace malfunctions and disrupted smelting processes. Improper handling of hearth buildup can result in difficulties in slag and iron discharge, poor blast capacity, low output, high fuel consumption, and increased pig iron costs. In China, multiple sensors for detecting temperature and flow are typically installed at the bottom of the hearth in large blast furnaces. However, due to the large amount of data and the presence of a dead iron layer at the bottom, heat transfer to the sensing area is delayed, making it difficult to accurately diagnose hearth buildup in a short time.

[0003] To address these issues, steel companies have explored numerous methods in practice. These include using models to assess the amount of residual slag and iron in the hearth, thereby ensuring its normal operation; the application of inverse heat transfer boundary solutions in blast furnace hearth erosion diagnosis; and the use of mathematical models to manage the working state of the blast furnace hearth, constructing mathematical models to ensure hearth buildup and stability. Some companies also assess blast furnace hearth buildup based on water temperature difference and heat load, but these methods cannot directly determine the hearth's operational status.

[0004] In the blast furnace smelting of high-titanium vanadium-titanium magnetite at Panzhihua Iron and Steel Group, the TiO2 content in the blast furnace slag is 20-25%. During the smelting process, TiO2 in the slag is easily reduced to form high-melting-point phases such as TiC, TiN, and their solid solutions Ti(C,N), resulting in viscous slag. If these high-melting-point substances are not removed in time, they accumulate in the center of the hearth, forming a viscous mixture. This accumulation leads to abnormal temperature field and airflow distribution within the furnace, resulting in slag and iron separation and severely affecting the normal blast furnace smelting process. Summary of the Invention

[0005] The purpose of this invention is to provide a method for judging the accumulation of blast furnace hearth in the smelting of high-titanium vanadium-titanium magnetite. The method of this invention uses changes in parameters such as air volume and air pressure to judge the working status of the hearth in a timely manner, which is highly timely and provides support for the rapid elimination of hearth accumulation.

[0006] This invention provides a method for determining the accumulation of material in the hearth of a blast furnace for smelting high-titanium vanadium-titanium magnetite, comprising the following steps:

[0007] The temperature at a depth of 300-1000 mm below the center of the taphole was monitored, and the temperature data T was obtained.

[0008] Calculate the difference between the supply air volume and the supply air pressure to obtain the difference data X;

[0009] The degree of buildup in the furnace hearth is determined by using temperature T and the difference X data.

[0010] Preferably, the temperature at a depth of 400-600mm below the taphole is monitored to obtain temperature data T.

[0011] Preferably, a thermocouple is pre-embedded 300-1000mm below the center of the iron outlet to detect the temperature.

[0012] Preferably, the difference data X is calculated using formula I:

[0013] X = QH formula I;

[0014] In Formula I, Q represents the air supply volume, expressed in m³ / s. 3 The calculation is performed per minute, where H represents the supply air pressure, expressed in units of 10⁻⁶. 2 pa calculation.

[0015] Preferably, the degree of accumulation in the furnace hearth is specifically divided into four levels: normal state, general accumulation, medium accumulation, and severe accumulation.

[0016] Preferably, the furnace hearth under normal conditions satisfies: 500℃<T≤600℃, 5<X≤150;

[0017] The generally stacked hearth satisfies the following conditions: 470℃<T≤500℃, -10<X≤5;

[0018] The furnace hearth with medium stacking satisfies: 440℃<T≤470℃, -60<X≤-10;

[0019] The severely accumulated furnace hearth satisfies the following conditions: 400℃<T≤440℃, -100<X≤-60.

[0020] Preferably, the degree of buildup in the furnace hearth is determined by monitoring the average temperature T over 24 hours and the average difference X over 24 hours.

[0021] Preferably, the slag from the smelting of high-titanium vanadium-titanium magnetite has a TiO2 mass fraction of 20-26%.

[0022] Preferably, in the blast furnace smelting of high-titanium vanadium-titanium magnetite, the mass fraction of Ti in the molten iron is 0.05~0.60%, and the mass fraction of Si is 0.05~0.70%.

[0023] Preferably, in the blast furnace smelting of the high-titanium vanadium-titanium magnetite, the blast furnace coke ratio is 380~450 kg / tp, and the blast furnace coal ratio is 100~150 kg / tp.

[0024] This invention provides a method for determining hearth buildup in blast furnaces smelting high-titanium vanadium-titanium magnetite, comprising the following steps: monitoring the temperature 300-1000 mm below the center of the taphole to obtain temperature data T; calculating the difference between the air volume and air pressure to obtain difference data X; and determining the degree of hearth buildup using temperature T and difference X. This invention utilizes the matching and variation of air volume and pressure, along with the temperature below the center of the taphole, to address the problem of timely hearth buildup detection in blast furnaces smelting high-titanium vanadium-titanium magnetite. Compared to existing methods that use Ti, Si, and C in molten iron to determine hearth buildup, this invention's method is more intuitive and timely, providing technical support for subsequent measures to eliminate hearth buildup. Detailed Implementation

[0025] This invention provides a method for determining the accumulation of material in the hearth of a blast furnace for smelting high-titanium vanadium-titanium magnetite, comprising the following steps:

[0026] The temperature at a depth of 300-1000 mm below the center of the taphole was monitored, and the temperature data T was obtained.

[0027] Calculate the difference between the supply air volume and the supply air pressure to obtain the difference data X;

[0028] The degree of buildup in the furnace hearth is determined by using temperature T and the difference X data.

[0029] This invention obtains temperature data T by detecting the temperature at a specific location below the center of the taphole.

[0030] In this invention, the temperature T is preferably the temperature at 300-1000 mm below the center of the tap hole, more preferably the temperature at 400-600 mm, such as 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, and preferably a range of values ​​with any of the above values ​​as the upper or lower limit.

[0031] The present invention preferably obtains the temperature T by pre-embedding a thermocouple at a specific position below the center of the tap hole.

[0032] This invention preferably monitors the temperature T over 24 hours and takes its average value to determine the buildup status of the hearth in a blast furnace for smelting high-titanium vanadium-titanium magnetite. For example, the temperature at 500mm below the center of the taphole is recorded every 2 hours, and the average of the recorded temperature values ​​is taken to obtain the temperature parameter T.

[0033] This invention obtains the difference data X by calculating the numerical difference between the supply air volume and the supply air pressure. Preferably, the calculation can be performed with reference to the following formula:

[0034] X = QH formula I;

[0035] In Formula I, Q represents the air supply volume, expressed in m³ / s. 3 The calculation is performed per minute, where H represents the supply air pressure, expressed in units of 10⁻⁶. 2 pa calculation.

[0036] The present invention preferably calculates the numerical difference between the air supply volume and air supply pressure over 24 hours and takes the average value to determine the packing condition of the hearth of a blast furnace for smelting high-titanium vanadium-titanium magnetite. For example, the air supply volume and air supply pressure are recorded every hour, the numerical difference between the air supply volume and air supply pressure at that time is calculated, and then the average of the calculated differences is taken to obtain the difference parameter X.

[0037] After obtaining the temperature parameter T and the difference parameter X, this invention uses the relationship between the two to determine the packing status of the hearth in a blast furnace for smelting high-titanium vanadium-titanium magnetite.

[0038] In this invention, the stacking state of high-titanium vanadium-titanium magnetite in the hearth can be divided into four levels: normal state, general stacking, medium stacking, and severe stacking, as shown in Table 1.

[0039] Table 1. Relationship between the packing state, temperature T, and difference X in the hearth of high-titanium vanadium-titanium magnetite ore.

[0040]

[0041] Note: Air volume is measured in meters (m). 3 / min, unit of wind pressure, 10 2 pa.

[0042] According to Table 1, the furnace hearth under normal conditions satisfies: 500℃<T≤600℃, 5<X≤150;

[0043] The generally stacked hearth satisfies the following conditions: 470℃<T≤500℃, -10<X≤5;

[0044] The furnace hearth with medium stacking satisfies: 440℃<T≤470℃, -60<X≤-10;

[0045] The severely accumulated furnace hearth satisfies the following conditions: 400℃<T≤440℃, -100<X≤-60.

[0046] In this invention, the mass fraction of TiO2 in the slag from the smelting of high-titanium vanadium-titanium magnetite is 20-26%.

[0047] In this invention, during the blast furnace smelting of high-titanium vanadium-titanium magnetite, the mass fraction of Ti in the molten iron is 0.05~0.60%, and the mass fraction of Si is 0.05~0.70%.

[0048] In this invention, during the blast furnace smelting of high-titanium vanadium-titanium magnetite, the blast furnace coke ratio is 380~450 kg / tp, and the blast furnace coal ratio is 100~150 kg / tp.

[0049] This invention provides a method for determining hearth buildup in blast furnaces smelting high-titanium vanadium-titanium magnetite, comprising the following steps: monitoring the temperature 300-1000 mm below the center of the taphole to obtain temperature data T; calculating the difference between the air volume and air pressure to obtain difference data X; and determining the degree of hearth buildup using temperature T and difference X. This invention utilizes the matching and variation of air volume and pressure, along with the temperature below the center of the taphole, to address the problem of timely hearth buildup detection in blast furnaces smelting high-titanium vanadium-titanium magnetite. Compared to existing methods that use Ti, Si, and C in molten iron to determine hearth buildup, this invention's method is more intuitive and timely, providing technical support for subsequent measures to eliminate hearth buildup.

[0050] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting, but this should not be construed as limiting the scope of protection of the present invention.

[0051] Benchmark Example

[0052] blast furnace volume 1350m³ 3 Operating parameters: coke ratio 421 kg / tp, pulverized coal injection ratio 140 kg / tp, slag TiO2 23.12%, molten iron [Ti] 0.20%, molten iron [Si] 0.16%. Under these conditions, the blast furnace blast volume for 24 hours is 3200 m³ / h. 3 / min, wind pressure 3186 (10 2 (pa), air volume and pressure difference 14, temperature 530℃ 500mm below the center of the tap hole; blower air volume 3000m³ 3 / min, wind pressure 2927 (10 2 (pa), air volume and pressure difference 73, temperature 570℃ 500mm below the center of the tap hole; blower air volume 2800 m³ / h 3 / min, wind pressure 2763 (10 2 The air volume and pressure difference were 37, and the temperature 500 mm below the center of the taphole was 560℃. At this time, the blast furnace was operating normally, there was no accumulation in the hearth, and the hearth was active.

[0053] Comparative Example 1

[0054] blast furnace volume 1350 m³ 3 Operating parameters: coke ratio 427 kg / tp, pulverized coal injection ratio 135 kg / tp, slag TiO2 22.7%, molten iron [Ti] 0.25%, molten iron [Si] 0.24%. Under these conditions, the blast furnace blast volume for 24 hours is 3200 m³ / h. 3 / min, wind pressure 3186 (10 2 (pa), air volume and air pressure difference 14, temperature 530℃ 500mm below the center of the tap hole; blower air volume 3000 m³ / h 3 / min, wind pressure 2998 (10 2 (pa), air volume and air pressure difference 2, temperature 486℃ at 500mm below the center of the tap hole; blower air volume 2800 m³ / h 3 / min, wind pressure 2801 (10 2 (Pa), air volume and air pressure difference -1, temperature 483℃ 500mm below the center of the taphole. At this time, the blast furnace is in normal production, the hearth shows a tendency to accumulate, and the hearth activity is low.

[0055] Comparative Example 2

[0056] blast furnace volume 1350 m³ 3 Operating parameters: coke ratio 421 kg / tp, pulverized coal injection ratio 121 kg / tp, slag TiO2 22.8%, molten iron [Ti] 0.24%, molten iron [Si] 0.25%. Under these conditions, the blast furnace blast volume for 24 hours is 2800 m³ / h. 3 / min, wind pressure 2838 (10 2 Pa), air volume and pressure difference -38, temperature 447℃ 500mm below the center of the tap hole; blower air volume 3000 m³ / h 3 / min, wind pressure 3042 (10 2 The blast furnace is operating normally, but there is a moderate buildup in the hearth and the hearth activity is reduced. The air volume and pressure difference are -42, and the temperature 500mm below the center of the taphole is 456℃.

[0057] Comparative Example 3

[0058] blast furnace volume 1350 m³ 3 Operating parameters: coke ratio 434 kg / tp, pulverized coal injection ratio 127 kg / tp, slag TiO2 22.5%, molten iron [Ti] 0.27%, molten iron [Si] 0.31%, under these conditions, the blast furnace blast volume for 24 hours is 3000 m³ / h. 3 / min, wind pressure 3076 (10 2Pa), air volume and pressure difference -76, temperature 433℃ at 500mm below the center of the tap hole; blower air volume 2800 m³ / h 3 / min, wind pressure 2871 (10 2 The blast furnace is operating normally, but there is a serious tendency for material buildup in the hearth, and the hearth activity is deteriorating. Under these circumstances, there is a possibility of severe material buildup in the blast furnace hearth, and the furnace airflow is turbulent. If measures are not taken in time, it may lead to abnormal furnace conditions and unsmooth material feeding. Measures such as reducing the airflow should be taken in time to prevent material hanging and pipeline formation, which could cause a major accident.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for determining the accumulation of ash in the hearth of a blast furnace for smelting high-titanium vanadium-titanium magnetite, comprising the following steps: The temperature at a depth of 300-1000 mm below the center of the taphole was monitored, and the temperature data T was obtained. Calculate the difference between the supply air volume and the supply air pressure to obtain the difference data X; The degree of buildup in the furnace hearth is determined by using temperature T and the difference X data.

2. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, The temperature at a depth of 400-600 mm below the taphole was monitored, and the temperature data T was obtained.

3. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, A thermocouple is pre-embedded 300-1000mm below the center of the tap hole to detect the temperature.

4. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, The difference data X is calculated using formula I: X = QH formula I; In Formula I, Q represents the air supply volume, expressed in m³ / s. 3 The calculation is performed per minute, where H represents the supply air pressure, expressed in units of 10⁻⁶. 2 pa calculation.

5. The method for determining the accumulation of blast furnace hearth in high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, The specific degree of accumulation in the furnace hearth is divided into four levels: normal state, general accumulation, medium accumulation, and severe accumulation.

6. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 5, characterized in that, The furnace hearth under normal conditions satisfies the following conditions: 500℃<T≤600℃, 5<X≤150; The generally stacked hearth satisfies the following conditions: 470℃<T≤500℃, -10<X≤5; The furnace hearth with medium stacking satisfies: 440℃<T≤470℃, -60<X≤-10; The severely accumulated furnace hearth satisfies the following conditions: 400℃<T≤440℃, -100<X≤-60.

7. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, The degree of buildup in the hearth is determined by monitoring the average temperature T and the average difference X over 24 hours.

8. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, The slag from the smelting of high-titanium vanadium-titanium magnetite has a TiO2 mass fraction of 20-26%.

9. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, In the blast furnace smelting of high-titanium vanadium-titanium magnetite, the mass fraction of Ti in the molten iron is 0.05~0.60%, and the mass fraction of Si is 0.05~0.70%.

10. The method for determining the hearth buildup in a blast furnace for high-titanium vanadium-titanium magnetite smelting according to claim 1, characterized in that, In the blast furnace smelting of the high-titanium vanadium-titanium magnetite, the blast furnace coke ratio is 380~450 kg / tp, and the blast furnace coal ratio is 100~150 kg / tp.

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