A process control method for short-duration addition of scrap steel and hot metal in a converter

Abstract

The present invention discloses a process control method for short-time addition of scrap steel and hot metal in a converter, which relates to the technical field of steel production. The method includes a scrap steel control step in front of the furnace, which is used to stack various scrap steels of different qualities in a set ratio, and lay the scrap steel with the best sliding quality flat at the bottom and the scrap steel with the worst sliding quality at the top to form a scrap steel sliding stack that can slide along the scrap steel chute; a hot metal addition regulation step in front of the furnace, which is used to supplement the hot metal in the hot metal ladle according to the volume change of the hot metal ladle, so that the real-time hot metal volume in the hot metal ladle is always the target hot metal volume. The present invention solves the problem that the scrap steel chute cannot enter the furnace, avoids the problem of multiple iron supplementations and iron additions during the hot metal addition process, and plays a role in improving production efficiency.

Description

Technical Field

[0001] The present invention relates to steel production technology, and more specifically, it relates to a process control method for short-duration addition of scrap steel and hot metal in a converter. Background Art

[0002] In the operating workshop of a steel mill and the raw and auxiliary material workshop, it is necessary to improve production efficiency and further increase the utilization rate of production time. The double-tank scrap steel + hot metal addition duration is a key indicator for controlling the preparation time and improving production efficiency. From the current production experience, if the preparation duration reaches more than 10 minutes, it will seriously affect the improvement of production efficiency. Therefore, reducing the preparation time of hot metal and scrap steel that affect converter smelting and ensuring stable process control are the main goals in the production process.

[0003] Regarding the problem of excessive preparation time for hot metal and scrap steel, the main reasons are as follows:

[0004] 1. Scrap steel jams at the furnace mouth. The amount of scrap steel added is large, often reaching 35 - 40 tons. The scrap steel is irregularly placed in the scrap steel tank, and the addition order is chaotic, which is not conducive to the sliding of scrap steel. When adding scrap steel to the converter, it is easy to accumulate at the furnace mouth, causing an impact.

[0005] 2. Scrap steel jams in the slot. The size of the scrap steel is not standardized, the overall size is too large, and the combination of different scrap steels is unreasonable, which will result in poor sliding performance of the scrap steel in the slot and is easy to get stuck in the scrap steel slot and unable to enter the furnace.

[0006] 3. The hot metal addition by the overhead crane is not timely. The condition of the hot metal ladle is poor, and the amount of hot metal added is small, unable to meet the requirement of the charging amount, and multiple hot metal additions are required, which will increase the hot metal addition duration. In addition, if there is slag accumulation at the converter furnace mouth, it will cause the furnace mouth to become smaller, and the addition of hot metal will also be blocked, increasing the hot metal addition duration. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a process control method for short-duration addition of scrap steel and hot metal in a converter in view of the deficiencies of the prior art.

[0008] The process control method for short-duration addition of scrap steel and hot metal in a converter according to the present invention includes:

[0009] A control step for scrap steel in front of the furnace, which is used to stack various scrap steels of different qualities in a set ratio, and lay the scrap steel with the best sliding quality flat at the bottom and the scrap steel with the worst sliding quality at the top to form a scrap steel sliding stack that can slide along the scrap steel slot;

[0010] A step for scrap steel to enter the furnace, which is used to place the scrap steel sliding stack in the scrap steel slot and send the scrap steel sliding stack in the scrap steel slot into the converter by two overhead cranes with the same operating speed.

[0011] The step of adjusting and controlling the iron addition in front of the furnace is used to perform an iron replenishment operation on the molten iron in the molten iron tank according to the volume change of the molten iron tank, so that the real-time molten iron amount in the molten iron tank is always the target molten iron amount;

[0012] The iron adding operation steps are used to perform the preliminary operation before the iron adding to the converter through the second overhead crane to ensure that there is no slag accumulation at the furnace mouth; the molten iron ladle is hoisted to the converter furnace mouth through the third overhead crane and the iron adding operation is performed.

[0013] The scrap steel includes steel bar briquettes, heavy scrap steel, soybean steel, production scrap steel, and pig iron blocks.

[0014] The scrap steel with the best sliding quality is pig iron blocks.

[0015] The scrap steel with the worst sliding quality is steel bar briquettes.

[0016] The length of the scrap steel slide pile is ≤1200mm, the height of the scrap steel slide pile is ≤700mm, and the width of the scrap steel slide pile is less than or equal to the maximum width of the scrap steel trough.

[0017] The molten iron tank that is emptied of molten iron is detected. If agglomerates generated by condensation of molten iron exist in the molten iron tank, the current net weight of the molten iron tank is obtained, and a target amount of molten iron is injected into the molten iron tank.

[0018] If the current net weight of the molten iron ladle is greater than the set weight value, the molten iron ladle is de-agglomerated before being put into use.

[0019] The pre-operation actions include measuring the temperature of molten iron in the converter, sampling molten iron, and slag removal.

[0020] Beneficial Effects

[0021] The advantages of the present invention are: through reasonable scrap steel matching, a variety of scrap steels of different qualities are stacked into a scrap steel sliding pile that can slide along the scrap steel trough, which improves the sliding property of the scrap steel in the scrap steel trough, solves the problem that the scrap steel slot cannot enter the furnace, improves the efficiency of scrap steel entering the furnace, and thus reduces the time for scrap steel to enter the furnace. In addition, by real-time detection of the volume change of the molten iron tank, iron is replenished in time; and by the pre-operation operation before iron addition, the problem of multiple iron replenishment and iron addition during the iron addition process is avoided, the iron addition requirements are met, the operation efficiency of the molten iron tank is improved, and the effect of improving the efficiency of iron addition is played. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic flow chart of the process control method of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with embodiments, but it does not constitute any limitation to the present invention. Any person's limited number of modifications within the scope of the claims of the present invention is still within the scope of the claims of the present invention.

[0024] Referring to Figure 1 , a process control method for short-time addition of scrap steel and molten iron in a converter of the present invention includes the following steps.

[0025] The step of controlling scrap steel in front of the furnace is used to stack various scrap steels of different qualities in a set ratio, and lay the scrap steel with the best sliding quality flat at the bottom and the scrap steel with the worst sliding quality at the top to form a scrap steel sliding pile that can slide along the scrap steel chute. Among them, the scrap steel includes steel bar compacts, heavy scrap steel, bean steel, production scrap steel, and pig iron blocks. The scrap steel with the best sliding quality is pig iron blocks. The scrap steel with the worst sliding quality is steel bar compacts.

[0026] In actual production, the main reasons for scrap steel jamming in the chute are as follows: First, the sliding performance of the scrap steel at the bottom of the scrap steel chute is poor, and even the steel bar compacts with the worst sliding performance are at the bottom, resulting in jamming. Second, the front and rear parts of the scrap steel chute are not evenly filled, resulting in a higher steel pile in the middle part, forming a hump, increasing the cross-section, and being unfavorable for the scrap steel to enter the furnace. Third, the steel bar compacts are placed messily, horizontally and vertically, and the chute opening of the scrap steel chute is in the middle of the inner opening of the converter, resulting in a smaller opening of the furnace mouth. When placed unevenly, it is easy to jam the furnace mouth.

[0027] To solve the problem of scrap steel jamming in the chute, before the scrap steel enters the furnace, a layer of pig iron blocks can be laid at the bottom of the scrap steel chute to level the cylindrical surface of the scrap steel chute, and then heavy scrap steel, bean steel, production scrap steel, and steel bar compacts are added on it. Moreover, the strip-shaped scrap steel cannot be erected and needs to be placed horizontally with the scrap steel chute, and horizontal placement is prohibited. Among them, the proportions of adding heavy scrap steel, bean steel, production scrap steel, and steel bar compacts are not strictly limited, and the ratio of 1:1:1:1 can be adopted, or the ratio of 1:1 of steel bar compacts to the other three kinds of scrap steel can be adopted for addition.

[0028] In addition, the length of the configured scrap steel sliding pile ≤ 1200 mm, the height of the scrap steel sliding pile ≤ 700 mm, and the width of the scrap steel sliding pile is less than or equal to the maximum width of the scrap steel chute to ensure that the scrap steel sliding pile can be effectively added to the converter through the furnace mouth.

[0029] A video monitoring system should also be set up at the site of the configured scrap steel sliding pile. The situation of irregular scrap steel placement is adjusted in a timely manner through real-time monitoring.

[0030] Steps for charging scrap steel into the furnace are used to slide and stack scrap steel in the scrap steel trough, and two overhead cranes with the same operating speed are used to send the scrap steel stack in the scrap steel trough into the converter. One of the overhead cranes is used for handling, and the other overhead crane is used to charge the scrap steel into the converter. During charging, control the height of the trough opening of the scrap steel trough to make the outer edge of the trough opening close to the inner edge of the furnace mouth. When lifting to add scrap steel, keep the trough opening extending into the furnace mouth not less than 400 mm to prevent the phenomenon that the trough edge detaches from the furnace mouth due to the backward impact of the gravity inertia of the scrap steel, resulting in the scrap steel spilling outside the furnace.

[0031] Steps for regulating and controlling the hot metal charging in front of the furnace are used to perform iron supplement operation on the hot metal in the hot metal ladle according to the volume change of the hot metal ladle, so that the real-time hot metal amount in the hot metal ladle is always the target hot metal amount.

[0032] Specifically, detect the hot metal ladle emptied of hot metal. If there are lumps generated after the condensation of hot metal in the hot metal ladle, obtain the current net weight of the hot metal ladle, and inject the target hot metal amount into the hot metal ladle, so as to ensure that the input hot metal amount meets the requirements of smelting.

[0033] In addition, to avoid the problem that the excessive lumps in the hot metal ladle cause the hot metal ladle to be too heavy, the present invention sets a set weight value. When the current net weight of the hot metal ladle is greater than the set weight value, such as greater than 65 tons, the hot metal ladle is de-lumped and then put into use.

[0034] Steps for hot metal charging operation are used to perform pre-operation actions before hot metal charging into the converter by the overhead crane two to ensure that no slag accumulates at the furnace mouth. Specifically, the pre-operation actions include measuring the temperature of the hot metal in the converter, taking samples of the hot metal, and skimming the slag. The hot metal ladle is hoisted to the converter furnace mouth by the overhead crane three, and hot metal charging is carried out. The two overhead cranes work separately, which can effectively improve the operation efficiency of hot metal charging.

[0035] The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which will not affect the implementation effect of the present invention and the practicability of the patent.

Claims

1. A process control method for short-time addition of scrap steel and hot metal in a converter, characterized in that, Including The scrap steel control steps in front of the furnace are used to stack various scrap steels with different qualities in a set ratio, and lay the scrap steel with the best sliding quality at the bottom and the scrap steel with the worst sliding quality at the top to form a scrap steel slide stack that can slide along the scrap steel chute. The scrap steel charging steps are used to place the scrap steel slide stack in the scrap steel chute and send the scrap steel slide stack in the scrap steel chute into the converter by two overhead cranes with the same operating speed. The iron charging regulation steps in front of the furnace are used to perform iron supplementing operations on the molten iron in the molten iron ladle according to the volume change of the molten iron ladle, so that the real-time molten iron volume in the molten iron ladle is always the target molten iron volume. The iron charging operation steps are used to perform pre-operation actions on the converter before iron charging through overhead crane two to ensure that there is no slag accumulation at the furnace mouth; lift the molten iron ladle to the converter furnace mouth by overhead crane three and perform iron charging operations. The length of the scrap steel slide stack ≤ 1200 mm, the height of the scrap steel slide stack ≤ 700 mm, and the width of the scrap steel slide stack is less than or equal to the maximum width of the scrap steel chute.

2. The process control method for short-time addition of scrap steel and hot metal in a converter according to claim 1, characterized in that The scrap steel includes steel bar compacts, heavy scrap steel, bean steel, production scrap steel, and pig iron blocks.

3. A process control method for short-time addition of scrap steel and hot metal in a converter according to claim 2, characterized in that, The scrap steel with the best sliding quality is pig iron blocks.

4. A process control method for short-time addition of scrap steel and hot metal in a converter according to claim 2, characterized in that The scrap steel with the worst sliding quality is steel bar compacts.

5. The process control method for short-time addition of scrap steel and hot metal in a converter according to claim 1, characterized in that, Inspect the empty molten iron ladle. If there are lumps generated after the condensation of molten iron in the molten iron ladle, obtain the current net weight of the molten iron ladle and inject the target molten iron volume into the molten iron ladle.

6. The process control method for short-time addition of scrap steel and hot metal in a converter according to claim 5, characterized in that If the current net weight of the molten iron ladle is greater than the set weight value, perform lump removal treatment on the molten iron ladle and then put it into use.

7. A process control method for short-duration addition of scrap steel and molten iron in a converter according to claim 1, characterized in that, The pre-operation actions include measuring the temperature of molten iron in the converter, sampling molten iron, and skimming slag.

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