Treatment method for frozen hot-metal bottle

Abstract

The invention relates to the technical field of steelmaking, in particular to a treatment method for a frozen hot-metal bottle. The method comprises the following steps: firstly, treating the frozen tank surface of the hot-metal tank, melting the frozen tank surface in a small area by using high-temperature heat generated by iron oxidation, burning a plurality of small deep pits, increasing the contact area of hot-melt molten steel and the frozen tank surface, avoiding layering, and quickly melting the frozen tank surface; secondly, hot melting treatment is carried out on molten steel of a freezing tank of the hot metal tank, and the freezing tank meets the iron folding requirement by tapping steel into the freezing tank. Thirdly, carrying out thermal cycle treatment on the frozen molten iron of the molten iron tank, carrying out hot melting on the molten iron, carrying out frozen tank iron folding, immediately adding the molten iron into the converter after iron folding, continuously carrying out iron folding after iron adding, repeating for several times until the turnover requirement is met, finishing the frozen molten iron tank treatment, and carrying out normal turnover of the molten iron tank. The treatment period is 12 hours or below, no unconventional operation exists, the potential safety hazard is low, normal turnover of the hot-metal ladle and the turnover rate of the hot-metal ladle can be achieved, the production operation rate is increased, and smooth production is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of steelmaking, in particular to a method for treating a frozen molten iron tank. Background Art

[0002] The molten iron tank is a container used to store and transport high-temperature molten iron. The freezing of the molten iron tank refers to the situation where the temperature of the molten iron inside the molten iron tank drops to a certain level during the heating and insulation process, or even solidifies into the molten iron tank, causing the production to be unable to proceed normally.

[0003] In the actual production of steel mills, it is often the case that the continuous casting machine cannot pour molten steel due to production, quality, equipment and other reasons. In order to reduce economic losses, the molten steel must be returned to the furnace and re-added to the converter for smelting. During the molten steel return process, the returned molten steel is generally folded into the molten iron tank. Since the liquidus line of the returned molten steel is about 1500℃ and the molten iron temperature is 1320~1380℃, the temperature of the returned molten steel drops sharply after entering the molten iron tank, and it is easy to solidify. If it is not added to the converter in time, the molten iron tank will freeze, which will have a great impact on production.

[0004] At present, the lying cutting method is usually adopted to deal with frozen molten iron tanks. The processing cycle is particularly long, generally taking 1 to 2 months. In addition, during the processing, it is very easy for accidents such as bricks falling from the molten iron tank and burns to occur, which restricts the turnover of the molten iron tank and affects the smooth production. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a method for treating a frozen molten iron tank, which can quickly and safely treat the frozen molten iron tank, realize the normal turnover of the molten iron tank, and ensure smooth production.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for treating a frozen molten iron tank, the method specifically comprising the following steps:

[0008] 1. Surface treatment of hot metal tank and freezing tank:

[0009] Aim the ignited combustible gas pipe vertically at the surface of the frozen can, and use the high temperature heat generated by iron oxidation to melt a small area of ​​the frozen can surface, burning multiple pits with a diameter of 10 to 30 cm and a depth of 5 to 20 cm.

[0010] 2. Hot melting treatment of molten steel in molten iron tank:

[0011] Use 1680-1700℃ high temperature molten steel to directly tap into the freezing tank. When the clearance height reaches 500-600mm, stop tapping.

[0012] After all the liquid steel in the freezing tank is emptied, the above steel-discharging process is repeated until the freezing tank meets the iron folding requirements.

[0013] 3. Hot circulation treatment of molten iron tank and frozen molten iron tank:

[0014] After the molten steel is melted, it is frozen into iron in a tank with a temperature of 1350-1400℃. After folding, it is immediately added to the converter. After adding iron, the iron folding process is continued and repeated several times until the turnover requirement is met, that is, the weight of the processed iron tank is equal to the empty weight of the iron ladle.

[0015] 4. When the molten iron tank meets the molten iron tank turnover requirements, the molten iron tank freezing process is completed and the molten iron tank can be circulated normally.

[0016] 5. Take measures to prevent the molten iron tank from freezing:

[0017] ① Mix 30% to 60% by weight of high-temperature molten iron at 1350°C to 1420°C and 40% to 70% by weight of low-temperature molten iron below 1200°C to prevent the molten iron temperature from falling below 1200°C;

[0018] ② If the molten iron temperature is lower than 1150℃, pour the molten iron into the converter or mixing furnace within 1 hour;

[0019] ③ If the molten iron tank needs to recover molten steel, and the molten iron cannot be poured into the converter or mixing furnace within 1 hour, the molten steel should be poured into the LF furnace to heat it up. When the temperature is greater than 1660℃, it can be poured into the molten iron tank;

[0020] ④ If there is no converter or mixing furnace, add covering agent to the surface of molten iron;

[0021] ⑤ Before the molten steel is recovered in the molten iron ladle, pour 30 to 50 tons of molten iron into the bottom of the molten iron ladle.

[0022] Furthermore, in the step 1), the combustible gas pipe is an oxygen pipe.

[0023] Furthermore, in step 1), oxygen is passed into the oxygen tube, and the oxygen flow rate is controlled to be 0.5-2 Nm 3 / h, control the oxygen pressure to 1.0~1.2MPa; after the oxygen tube is ignited, control the oxygen flow rate to 5~10Nm 3 / h.

[0024] Furthermore, in the step 1), after the sampling paper tube is ignited, the oxygen tube is inserted into the sampling paper tube and the oxygen tube is ignited.

[0025] Furthermore, in the step 3), the empty ladle weight is 120-130 tons.

[0026] Compared with the existing method, the beneficial effects of the present invention are:

[0027] The present invention firstly processes the surface of the frozen tank of the molten iron tank, and utilizes the high temperature heat generated by the oxidation of iron to melt a small area of ​​the surface of the frozen tank, burns a plurality of small deep pits, increases the contact area between the hot molten steel and the surface of the frozen tank, avoids stratification, and makes the surface of the frozen tank melt quickly. Secondly, the molten steel in the frozen tank of the molten iron tank is subjected to a heat melting treatment, and the frozen tank is made to meet the requirements of folding iron by tapping steel into the frozen tank. Thirdly, the molten iron in the frozen tank of the molten iron tank is subjected to a heat circulation treatment, and the molten steel is heat-melted and then the frozen tank is folded into iron, and after folding iron, it is immediately added to the converter, and the iron is folded again after adding iron, and this process is repeated several times until the turnover requirements are met, the treatment of the frozen tank of the molten iron tank is completed, and the molten iron tank is circulated normally.

[0028] The processing cycle of the present invention is less than 12 hours, there is no unconventional operation, the potential safety hazard is low, the normal turnover of the molten iron tank can be achieved, the turnover rate of the molten iron tank can be improved, the production operation rate is improved, and the smooth production is guaranteed. DETAILED DESCRIPTION

[0029] The present invention discloses a method for treating a frozen molten iron tank. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0030] A method for treating a frozen molten iron tank, the method specifically comprising the following steps:

[0031] 1. Surface treatment of hot metal tank and freezing tank:

[0032] Prepare 10 to 15 3-meter oxygen tubes (oxygen tube diameter 10mm), oxygen point valve box, oxygen belt, and sampling paper tube. Connect the oxygen tube and oxygen belt, pass oxygen, and adjust the oxygen flow rate to 0.5 to 2Nm 3 / h, control the oxygen pressure at 1.0~1.2MPa, ignite the sampling paper tube, insert the oxygen tube into the paper tube, and ignite the oxygen tube. Aim the ignited oxygen tube vertically at the surface of the freezing tank, and adjust the oxygen flow rate to 5~10Nm 3 / h, using the high temperature heat generated by iron oxidation to melt a small area on the surface of the frozen tank, about 15cm in diameter and 10cm in depth. If conditions permit, burn more and arrange them randomly. The purpose of the small deep pits on the surface is to increase the contact area between the hot molten steel and the surface of the frozen tank, avoid stratification, and make the surface of the frozen tank melt quickly.

[0033] 2. Hot melting treatment of molten steel in molten iron tank:

[0034] After the surface treatment of the frozen tank is completed, the frozen molten iron tank is placed on the converter steel car. The converter smelts a furnace of high-temperature molten steel at 1680-1700℃ and taps the steel directly into the frozen tank. During the tapping process, the furnace commander should pay attention to the clearance of the frozen tank and control the clearance height to 500-600mm to avoid overfilling. When the clearance meets the requirements, stop tapping.

[0035] The frozen tank is quickly moved to the hanging tank position, lifted by a crane, and added to other converters. After all the liquid steel in the frozen tank is emptied, the frozen tank is returned to the previous converter steel car, and the previous process is repeated until the frozen tank meets the iron folding requirements.

[0036] 3. Hot circulation treatment of molten iron tank and frozen molten iron tank:

[0037] After the molten steel is melted, the frozen tank meets the requirements for folding iron, but the empty tank weight is still very heavy and needs to be further melted to meet the normal molten iron tank turnover requirements. After the molten steel is melted, the frozen tank is folded. The molten iron temperature is required to be 1350-1400℃. After folding iron, it is immediately added to the converter. After adding iron, continue to fold iron. Repeat this process several times until the turnover requirements are met (the weight of the processed molten iron tank is equal to the empty ladle weight of the molten iron ladle). The empty ladle weight of the molten iron ladle is 120-130 tons.

[0038] 4. Target requirements: The molten iron tank meets the molten iron tank turnover requirements, the molten iron tank freezing process is completed, the molten iron tank is put into use, and the turnover is normal.

[0039] 5. Preventive measures for freezing of molten iron tanks:

[0040] (1) When the molten iron temperature is lower than 1150℃, or is lower than 1200℃ for multiple times in a row, the molten iron should be added to the converter or mixing furnace in time. If there is no converter or mixing furnace, a covering agent should be added to the surface of the molten iron to reduce the exposure of the molten iron surface, reduce temperature loss, and reduce the occurrence of molten iron freezing.

[0041] (2) If the molten iron temperature is low and it is predicted in advance, high-temperature molten iron (temperature greater than 1350°C) and low-temperature molten iron (below 1200°C) can be mixed to prevent the temperature from being too low, causing cold iron to form on the bottom or wall of the molten iron tank, affecting the turnover of the molten iron tank, or even freezing the tank.

[0042] (3) The molten steel is recycled by the hot metal ladle. Since the solidification temperatures of molten steel and hot metal are different, during the mixing process, the temperature of the molten steel drops very quickly, resulting in small-scale solidification of the molten steel and hot metal. After a long time, large-scale solidification will occur, leading to freezing of the hot metal ladle. The treatment for this situation is as follows: If the amount of molten steel is small, it is preferentially poured into the converter. If the converter does not meet the conditions, consider pouring hot metal with a higher temperature into the hot metal ladle to dilute the proportion of molten steel in the hot metal ladle and reduce the occurrence of ladle freezing. If the amount of molten steel is large, it is preferentially poured into the converter. If the converter does not meet the conditions, consider pouring molten steel into other hot metal ladles, and re-pour the remaining molten steel in the hot metal ladle with hot metal at a higher temperature to dilute the proportion of molten steel in the hot metal ladle and reduce the occurrence of ladle freezing.

[0043] (4) If large-scale failures occur in the entire production process, such as continuous caster failures or converter failures, and the molten steel cannot be poured into the converter in time after hot recovery, it can be considered that after the molten steel is heated in the LF furnace to a temperature higher than 1660 °C, it is recycled back to the converter, and step (2) is repeated.

[0044] (5) Before recycling molten steel with the hot metal ladle, there must be 30 - 50 tons of hot metal at the bottom of the ladle to prevent the formation of a crust at the bottom of the ladle, causing freezing at the bottom of the hot metal ladle.

[0045] Example 1:

[0046] A method for treating frozen hot metal ladles, the process is oxygen burning for frozen ladles → hot melting of frozen molten steel in the ladle → hot circulation of frozen hot metal → the hot metal ladle meets the requirements → normal turnover of the hot metal ladle. This method specifically includes the following steps:

[0047] 1. Surface treatment of frozen hot metal ladles:

[0048] Prepare 12 oxygen pipes (oxygen pipe diameter 10 mm) with a length of 3 meters, an oxygen point valve box, 2 oxygen hoses, and 3 sampling paper tubes. Connect the oxygen pipes and oxygen hoses, supply oxygen, adjust the oxygen flow rate to 1.0 Nm 3 / h, control the oxygen pressure at 1.2 MPa. After igniting the sampling paper tube, insert the oxygen pipe into the paper tube and ignite the oxygen pipe. Align the ignited oxygen pipe vertically with the surface of the frozen ladle, adjust the oxygen flow rate to 8 Nm 3 / h, and use the high-temperature heat generated by the oxidation of iron to melt a small area of the surface of the frozen ladle, burning six small pits with a diameter of about 15 cm and a depth of 10 cm.

[0049] 2. Hot melting treatment of frozen molten steel in the hot metal ladle:

[0050] After the surface treatment of the frozen ladle is completed, place the frozen hot metal ladle on the converter steel cart. The temperature of the molten steel during converter smelting is 1696 °C, and directly tap the steel into the frozen ladle. During the tapping process, there is no abnormality. When the clear height is 520 mm, stop tapping.

[0051] The frozen tank is quickly moved to the hanging tank position, lifted by a crane, and added to other converters. After all the liquid steel in the frozen tank is emptied, the empty tank tare weight does not meet the iron folding requirements, so the frozen tank is returned to the previous converter steel car and the previous process is repeated. After the second hot melting, the molten iron tank meets the iron folding conditions.

[0052] 3. Hot circulation treatment of molten iron tank and frozen molten iron tank:

[0053] After the molten steel is melted, the frozen tank meets the requirements for folding iron, but the empty tank weight is still very heavy and needs to be further melted to meet the normal molten iron tank turnover requirements. The molten steel is melted and the frozen tank is folded. The molten iron temperature is required to be 1380℃. After folding iron, it is immediately added to the converter. After adding iron, continue to fold iron. After repeating this process 3 times, the weight of the empty iron ladle is 128 tons, which meets the turnover requirements.

[0054] 4. The processing time of this embodiment is 10 hours, and the molten iron tank reaches the turnover requirement range of the molten iron tank. The freezing treatment of the molten iron tank is completed, and the molten iron tank is put into use and has normal turnover.

[0055] 5. Take measures to prevent the molten iron tank from freezing:

[0056] (1) When the molten iron temperature is lower than 1150℃, or is lower than 1200℃ for multiple times in a row, the molten iron should be added to the converter or mixing furnace in time. If there is no converter or mixing furnace, a covering agent should be added to the surface of the molten iron to reduce the exposure of the molten iron surface, reduce temperature loss, and reduce the occurrence of molten iron freezing.

[0057] (2) If the molten iron temperature is low, high-temperature molten iron (temperature greater than 1350°C) and low-temperature molten iron (below 1200°C) can be mixed if it is predicted in advance.

[0058] (3) If the amount of molten steel is small, it should be added to the converter first. If the converter is not ready, consider adding hot molten iron to the molten iron tank to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing. If the amount of molten steel is large, it should be added to the converter first. If the converter is not ready, consider adding molten steel to other molten iron tanks. The remaining molten steel in the molten iron tank should be added with hot molten iron again to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing.

[0059] (4) If a large-scale failure occurs in the entire production process, such as a continuous casting machine failure or a converter failure, and the molten steel cannot be added to the converter in time after heat recovery, it can be considered that the temperature of the molten steel is required to be greater than 1660°C after entering the LF furnace for heating, and then recovered to the converter and step (2) is repeated.

[0060] (5) Before the molten iron ladle is used to recover molten steel, there must be 30 to 50 tons of molten iron at the bottom of the ladle to prevent crusting at the bottom of the ladle, which may cause the bottom of the ladle to freeze.

[0061] Embodiment 2:

[0062] A method for treating a frozen molten iron tank, the process of which is: burning oxygen in the frozen tank → melting molten steel in the frozen tank → thermal circulation of molten iron in the frozen tank → the molten iron tank meets the requirements → normal turnover of the molten iron tank, the method specifically comprising the following steps:

[0063] 1. Surface treatment of hot metal tank and freezing tank:

[0064] Prepare 12 3-meter oxygen tubes (oxygen tube diameter 10mm), oxygen point valve box, 2 oxygen belts, and 3 sampling paper tubes. Connect the oxygen tubes and oxygen belts, pass oxygen, and adjust the oxygen flow rate to 1.0Nm 3 / hour, control the oxygen pressure at 1.2MPa, ignite the sampling paper tube, insert the oxygen tube into the paper tube, and ignite the oxygen tube. Align the ignited oxygen tube vertically to the surface of the freezing tank, and adjust the oxygen flow rate to 8Nm 3 / hour, using the high temperature heat generated by iron oxidation to melt a small area of ​​the frozen can surface, burning about 8 small deep pits with a diameter of 15cm and a depth of 10cm.

[0065] 2. Hot melting treatment of molten steel in molten iron tank:

[0066] After the surface treatment of the freezing tank is completed, the frozen molten iron tank is placed on the converter steel car. The converter smelting temperature of the molten steel is 1702℃, and the steel is directly tapped into the freezing tank. There is no abnormality during the tapping process. When the clearance height is 580mm, the tapping is stopped.

[0067] The frozen tank is quickly moved to the hanging tank position, lifted by a crane, and added to other converters. After all the liquid steel in the frozen tank is emptied, the empty tank tare weight does not meet the iron folding requirements, so the frozen tank is returned to the previous converter steel car and the previous process is repeated. After the third hot melting, the molten iron tank meets the iron folding conditions.

[0068] 3. Hot circulation treatment of molten iron tank and frozen molten iron tank:

[0069] After the molten steel is melted, the frozen tank meets the requirements for folding iron, but the empty tank weight is still very heavy and needs to be further melted to meet the normal molten iron tank turnover requirements. The molten steel is melted and the frozen tank is folded. The molten iron temperature is required to be 1370℃. After folding iron, it is immediately added to the converter. After adding iron, continue to fold iron. After repeating this process twice, the weight of the empty iron ladle is 129 tons, which meets the turnover requirements.

[0070] 4. The processing time of this embodiment is 11 hours, and the molten iron tank reaches the turnover requirement range of the molten iron tank. The freezing treatment of the molten iron tank is completed, and the molten iron tank is put into use and turns over normally.

[0071] 5. Take measures to prevent the molten iron tank from freezing:

[0072] (1) When the molten iron temperature is lower than 1150℃, or is lower than 1200℃ for multiple times in a row, the molten iron should be added to the converter or mixing furnace in time. If there is no converter or mixing furnace, a covering agent should be added to the surface of the molten iron to reduce the exposure of the molten iron surface, reduce temperature loss, and reduce the occurrence of molten iron freezing.

[0073] (2) If the molten iron temperature is low, high-temperature molten iron (temperature greater than 1350°C) and low-temperature molten iron (below 1200°C) can be mixed if it is predicted in advance.

[0074] (3) If the amount of molten steel is small, it should be added to the converter first. If the converter is not ready, consider adding hot molten iron to the molten iron tank to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing. If the amount of molten steel is large, it should be added to the converter first. If the converter is not ready, consider adding molten steel to other molten iron tanks. The remaining molten steel in the molten iron tank should be added with hot molten iron again to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing.

[0075] (4) If a large-scale failure occurs in the entire production process, such as a continuous casting machine failure or a converter failure, and the molten steel cannot be added to the converter in time after heat recovery, it can be considered that the temperature of the molten steel is required to be greater than 1660°C after entering the LF furnace for heating, and then recovered to the converter and step (2) is repeated.

[0076] (5) Before the molten iron ladle is used to recover molten steel, there must be 30 to 50 tons of molten iron at the bottom of the ladle to prevent crusting at the bottom of the ladle, which may cause the bottom of the ladle to freeze.

[0077] Embodiment 3:

[0078] A method for treating a frozen molten iron tank, the process of which is: burning oxygen in the frozen tank → melting molten steel in the frozen tank → thermal circulation of molten iron in the frozen tank → the molten iron tank meets the requirements → normal turnover of the molten iron tank, the method specifically comprising the following steps:

[0079] 1. Surface treatment of hot metal tank and freezing tank:

[0080] Prepare 15 3-meter oxygen tubes (oxygen tube diameter 10mm), oxygen point valve box, 2 oxygen belts, and 3 sampling paper tubes. Connect the oxygen tubes and oxygen belts, pass oxygen, and adjust the oxygen flow rate to 1.0Nm 3 / hour, control the oxygen pressure at 1.2MPa, ignite the sampling paper tube, insert the oxygen tube into the paper tube, and ignite the oxygen tube. Align the ignited oxygen tube vertically to the surface of the freezing tank, and adjust the oxygen flow rate to 8Nm 3 / hour, using the high temperature heat generated by iron oxidation to melt a small area of ​​the frozen can surface, and burn 10 small deep pits with a diameter of about 15 cm and a depth of 10 cm.

[0081] 2. Hot melting treatment of molten steel in molten iron tank:

[0082] After the surface treatment of the freezing tank is completed, the frozen molten iron tank is placed on the converter steel car. The converter smelting temperature of the molten steel is 1686℃, and the steel is directly tapped into the freezing tank. There is no abnormality during the tapping process. When the clearance height is 500mm, the tapping is stopped.

[0083] The frozen tank is quickly moved to the hanging tank position, lifted by a crane, and added to other converters. After all the liquid steel in the frozen tank is emptied, the empty tank tare weight does not meet the iron folding requirements, so the frozen tank is returned to the previous converter steel car and the previous process is repeated. After the third hot melting, the molten iron tank meets the iron folding conditions.

[0084] 3. Hot circulation treatment of molten iron tank and frozen molten iron tank:

[0085] Although the frozen tank after hot melting of molten steel meets the requirements for folding iron, the empty tank weight is still very heavy and needs to be further melted to meet the normal molten iron tank turnover requirements. The molten steel is hot melted and the frozen tank is folded. The molten iron temperature is required to be 1360℃. After folding iron, it is immediately added to the converter. After adding iron, continue to fold iron. After repeating this process 3 times, the weight of the molten iron ladle is 127 tons, which meets the turnover requirements.

[0086] 4. The processing time of this embodiment is 11.5 hours, and the molten iron tank reaches the range of the molten iron tank turnover requirements. The freezing treatment of the molten iron tank is completed, and the molten iron tank is put into use and turns over normally.

[0087] 5. Take measures to prevent the molten iron tank from freezing:

[0088] (1) When the molten iron temperature is lower than 1150℃, or is lower than 1200℃ for multiple times in a row, the molten iron should be added to the converter or mixing furnace in time. If there is no converter or mixing furnace, a covering agent should be added to the surface of the molten iron to reduce the exposure of the molten iron surface, reduce temperature loss, and reduce the occurrence of molten iron freezing.

[0089] (2) If the molten iron temperature is low and it is predicted in advance, high-temperature molten iron (temperature greater than 1350°C) and low-temperature molten iron (below 1200°C) can be mixed.

[0090] (3) If the amount of molten steel is small, it should be added to the converter first. If the converter is not ready, consider adding hot molten iron to the molten iron tank to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing. If the amount of molten steel is large, it should be added to the converter first. If the converter is not ready, consider adding molten steel to other molten iron tanks. The remaining molten steel in the molten iron tank should be added with hot molten iron again to dilute the proportion of molten steel in the molten iron tank and reduce the occurrence of tank freezing.

[0091] (4) If a large-scale failure occurs in the entire production process, such as a continuous casting machine failure or a converter failure, and the molten steel cannot be added to the converter in time after heat recovery, it can be considered that the temperature of the molten steel is required to be greater than 1660°C after entering the LF furnace for heating, and then recovered to the converter and step (2) is repeated.

[0092] (5) Before the molten iron ladle is used to recover molten steel, there must be 30 to 50 tons of molten iron at the bottom of the ladle to prevent crusting at the bottom of the ladle, which may cause the bottom of the ladle to freeze.

[0093] The processing cycle of the present invention is less than 12 hours, there is no unconventional operation, the potential safety hazard is low, the normal turnover of the molten iron tank can be achieved, the turnover rate of the molten iron tank can be improved, the production operation rate can be improved, and the smooth production can be guaranteed.

[0094] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for treating a frozen molten iron tank, characterized in that: The method specifically comprises the following steps: 1) Surface treatment of hot metal tank and freezing tank: Aim the ignited combustible gas pipe vertically at the surface of the frozen tank, and use the high temperature heat generated by iron oxidation to melt a small area of ​​the frozen tank surface, burning multiple pits with a diameter of 10 to 30 cm and a depth of 5 to 20 cm; 2) Hot melting treatment of molten steel in molten iron tank: Use 1680-1700℃ high temperature molten steel to directly tap into the freezing tank, and stop tapping when the clearance height reaches 500-600mm; After all the liquid steel in the freezing tank is emptied, repeat the above steel tapping process until the freezing tank meets the iron folding requirements; 3) Hot circulation treatment of molten iron tank and frozen molten iron tank: After the molten steel is melted, it is frozen and folded in a tank. The temperature of the molten iron is 1350-1400℃. After folding, it is immediately added to the converter. After adding iron, the folding is continued. This process is repeated several times until the turnover requirement is met, that is, the weight of the treated molten iron tank is equal to the empty weight of the molten iron ladle. 4) When the molten iron tank meets the molten iron tank turnover requirements, the molten iron tank freezing process is completed and the molten iron tank can be circulated normally.

2. The method for treating a frozen molten iron tank according to claim 1, characterized in that: It also includes measures to prevent the ladle from freezing: ① Mix 30% to 60% by weight of high-temperature molten iron at 1350°C to 1420°C and 40% to 70% by weight of low-temperature molten iron below 1200°C to prevent the molten iron temperature from falling below 1200°C; ② If the molten iron temperature is lower than 1150℃, pour the molten iron into the converter or mixing furnace within 1 hour; ③ If the molten iron tank needs to recover molten steel, and the molten iron cannot be poured into the converter or mixing furnace within 1 hour, the molten steel should be poured into the LF furnace to heat it up. When the temperature is greater than 1660℃, it can be poured into the molten iron tank; ④ If there is no converter or mixing furnace, add covering agent to the surface of molten iron; ⑤ Before the molten steel is recovered in the molten iron ladle, pour 30 to 50 tons of molten iron into the bottom of the molten iron ladle.

3. The method for treating a frozen molten iron tank according to claim 1, characterized in that: In step 1), the combustible gas pipe is an oxygen pipe.

4. The method for treating a frozen molten iron tank according to claim 3, characterized in that: In step 1), oxygen is passed into the oxygen tube, and the oxygen flow rate is controlled to be 0.5-2Nm 3 / h, control the oxygen pressure to 1.0~1.2MPa; after the oxygen tube is ignited, control the oxygen flow rate to 5~10Nm 3 / h.

5. The method for treating a frozen molten iron tank according to claim 3, characterized in that: In step 1), after the sampling paper tube is ignited, the oxygen tube is inserted into the sampling paper tube and ignited.

6. The method for treating a frozen molten iron tank according to claim 1, characterized in that: In step 3), the empty ladle weight of the molten iron ladle is 120 to 130 tons.