Molten iron silicon-increasing stirring device and system thereof

Abstract

The utility model provides a molten iron silicon-increasing stirring device and a molten iron silicon-increasing stirring system. The molten iron silicon-increasing stirring device comprises a molten iron silicon-increasing device installed beside an iron runner of a blast furnace casting house and a silicon powder stirring device installed above a molten iron tank, and the molten iron silicon-increasing device comprises a silicon powder hopper, a silicon powder tank and a silicon powder discharging chute tube which are sequentially arranged from top to bottom, an adjusting valve is mounted on a pipeline between the silicon powder tank and the silicon powder discharging chute tube; the silicon powder stirring device comprises a stirring head, a middle connecting pipe located on the stirring head, a gas supply pipeline communicated with the middle connecting pipe and a stirring head lifting mechanism connected with the middle connecting pipe and used for driving the middle connecting pipe to move up and down. According to the molten iron silicon adding stirring device, silicon can be efficiently and accurately added into the molten iron, meanwhile, silicon powder added into the molten iron can be efficiently, safely and fully mixed with the molten iron in a low-consumption mode, and the molten iron silicon adding stirring device has important significance for improving the quality of the molten iron and the competitiveness of enterprises.

Description

Technical Field

[0001] The utility model relates to the technical field of molten iron pretreatment process for blast furnace casting in the metallurgical industry, in particular to a molten iron silicon-enhancing stirring device and a system thereof. Background Art

[0002] Molten iron refers to the saturated molten iron obtained after the molten iron from the blast furnace or electric furnace is processed by the steelmaking process during the steelmaking process. The steelmaking process generally includes deoxidation, impurity removal, and composition adjustment. In this process, a certain amount of oxides and impurities will be removed, thereby reducing the silicon content in the molten iron. Generally, the silicon content of molten iron is between 0.02% and 0.05%.

[0003] Cast iron molten iron refers to the molten iron used to cast iron castings. Compared with molten iron for steelmaking, the silicon content of cast iron molten iron is higher, usually between 1.5% and 4.0%. This is because cast iron produces shrinkage defects and pores during cooling. If a certain amount of silicon is not added, the quality of the casting will be reduced or even the casting will fail.

[0004] The silicon content of molten iron for steelmaking and molten iron for cast iron is different, mainly due to their different production processes and properties. In the steelmaking process, molten iron needs to go through deoxidation and impurity removal to remove oxides and impurities, so its silicon content is relatively low. In the casting process, the quality of the casting is directly related to the performance and service life of the casting, so a certain amount of silicon needs to be added to ensure the quality and performance of the casting.

[0005] In short, the difference in silicon content between molten iron for steelmaking and molten iron for cast iron is the result of differences in production processes and properties. In the process of steel production and casting, correctly controlling the silicon content of molten iron can effectively improve the quality and performance of the product.

[0006] The main reason for increasing silicon in molten iron to replace direct smelting of cast iron in blast furnaces is the difficulty of smelting cast iron in blast furnaces. Compared with smelting steelmaking pig iron (containing Si 1% to 3.5%), smelting cast iron (containing Si <1%, now reduced to 0.1% to 0.2%) requires a large amount of silicon reduction reaction in the blast furnace, which requires high temperature and high coke ratio. The increase in silicon content in molten iron promotes the graphitization and deposition of carbon, while excessive furnace temperature and excessive carbon deposition in the furnace will hinder the blast furnace process, causing furnace conditions to be unfavorable and high coke ratio smelting, which in turn reduces blast furnace output. Due to the improvement of refined materials and blast furnace reduction processes, the direct reduction process in modern blast furnaces is reduced and the lower heat requirement is reduced, resulting in overheating of molten iron (molten iron temperature increased from 1450℃ to 1550℃) and enhanced carbon dissolution (molten iron carbon content increased from 4.0% to 4.5% to 5.1% to 5.5%). Under such conditions, blast furnace smelting of cast iron will be more difficult.

[0007] The application value of using the synthetic method of adding silicon outside the furnace to smelt foundry pig iron can be summarized as follows:

[0008] (1) The blast furnace can operate at low silicon content, and the furnace condition is smooth and the indicators are good. According to China's blast furnace production experience, for every 0.1% reduction in the Si content of pig iron, the blast furnace fuel ratio is reduced by 4-7 kg / t, and the output is also increased accordingly.

[0009] (2) Casting pig iron produced by siliconizing molten iron is of better quality than casting pig iron directly smelted in blast furnace. Because the casting molten iron smelted in blast furnace has high temperature and high Si content, the amount of carbon dissolved and gas and non-metallic inclusions increase, the graphite grains in the cast iron are coarse, and the organizational structure and mechanical properties deteriorate. The casting pig iron obtained by the siliconization method is siliconized in low-silicon and low-carbon molten iron. The original carbon has a low degree of graphitization, and the dissolved ferrosilicon plays a nucleating role, increasing foreign cores, refining eutectic clusters and graphite, and improving the uniformity and density of the cast iron organization, thereby improving the performance of the pig iron. At the same time, siliconizing molten iron also has the effect of reducing the sulfur content of pig iron.

[0010] (3) Siliconization of hot metal is a hot metal treatment system that must be established by steel mills to balance the ironmaking and steelmaking capacities and adjust the types of pig iron. There are often such situations: a steel mill has only one blast furnace, and the hot metal produced by the blast furnace cannot be used up by the steelmaking furnace, or the output of foundry pig iron to be produced by a steel mill is only equivalent to a part of the capacity of a blast furnace, and the steelmaking furnace of the steel mill cannot temporarily accept the hot metal from the blast furnace. With the hot metal siliconization equipment, the blast furnace can completely refine steelmaking pig iron, with low coke ratio, high output, and full use of its capacity. Hot metal that cannot be used up in steelmaking or foundry iron that needs to be produced, or hot metal from blast furnaces that is temporarily not needed by steelmaking furnaces can be siliconized to become foundry pig iron, thereby increasing the selling price of pig iron and reducing the difficulties and losses caused by iron grade conversion to smelting.

[0011] Siliconization of hot metal is a hot metal pretreatment process that adds ferrosilicon to hot metal to increase its silicon content to a predetermined value. It is mainly used to increase the silicon content of low-silicon hot metal smelted in blast furnaces into foundry pig iron. It is a new method for producing foundry pig iron. It can save energy and increase production in blast furnaces, and can improve the quality of hot metal castings. Utility Model Content

[0012] The main purpose of the utility model is to provide a molten iron silicon-increasing stirring device, which is intended to facilitate adding silicon to molten iron in a molten iron tank.

[0013] To achieve the above purpose, the utility model provides a molten iron silicon-enhancing stirring device, comprising a molten iron silicon-enhancing device installed beside the iron ditch in the blast furnace iron-making field and a silicon powder stirring device installed above the molten iron tank, wherein:

[0014] The molten iron silicon increasing device comprises a silicon powder hopper, a silicon powder tank and a silicon powder discharge chute arranged in sequence from top to bottom, wherein a regulating valve is installed on the pipeline between the silicon powder tank and the silicon powder discharge chute;

[0015] The silicon powder stirring device comprises a stirring head, a middle connecting pipe located on the stirring head, a gas supply pipeline connected to the middle connecting pipe, and a stirring head lifting mechanism connected to the middle connecting pipe for driving the stirring head to move up and down.

[0016] Preferably, a manual regulating valve for discharging material from the hopper and a pneumatic regulating valve for discharging material from the hopper are installed on the pipeline between the silicon powder hopper and the silicon powder tank.

[0017] Preferably, a manual regulating valve for discharging the silicon powder tank and a pneumatic regulating valve for discharging the silicon powder tank are installed on the pipeline between the silicon powder tank and the silicon powder discharging chute.

[0018] Preferably, the molten iron silicon increasing device also includes a silicon powder addition amount display screen and a pneumatic valve operating box, which is electrically connected to the hopper unloading manual regulating valve, the hopper unloading pneumatic regulating valve, the tank unloading manual regulating valve and the tank unloading pneumatic regulating valve.

[0019] Preferably, the molten iron silicon increasing device further comprises a support frame for supporting a silicon powder hopper and a silicon powder tank, and a silicon powder addition amount display screen and a pneumatic valve operating box are both installed on the support frame.

[0020] Preferably, the support frame is installed on a track, the support frame is installed on the track and is movable relative to the track, and the support frame moves on the track to the cantilevered platform to replace equipment and increase silicon powder.

[0021] Preferably, the support frame is fixed to the iron-out platform by bolts.

[0022] Preferably, the silicon powder tank is equipped with a tank weighing device.

[0023] Preferably, the silicon powder stirring device further comprises a stirring gas circuit valve group connected to the gas supply pipeline, and the stirring surge is adjusted by the stirring gas circuit valve group to adjust the stirring intensity of the molten iron.

[0024] The utility model also provides a molten iron silicon-enhancing stirring system, comprising the above-mentioned molten iron silicon-enhancing stirring device and a molten iron tank, each molten iron tank is equipped with a molten iron silicon-enhancing stirring device.

[0025] The molten iron silicon-increasing stirring device proposed in the utility model can realize efficient and accurate silicon-increasing in the molten iron, and at the same time, the silicon powder added to the molten iron can be fully mixed with the molten iron efficiently, with low consumption and safety, which is of great significance for improving the quality of molten iron and the competitiveness of enterprises. At the same time, the molten iron silicon-increasing stirring device has the advantages of simple structure, stable and reliable operation and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1This is a structural schematic diagram of the first embodiment of the molten iron silicon-increasing stirring device of the utility model;

[0027] Figure 2 for Figure 1 A schematic cross-sectional view of the structure in the AA direction is shown;

[0028] Figure 3 for Figure 1 A schematic cross-sectional structure diagram in the BB direction is shown;

[0029] Figure 4 This is a schematic structural diagram of a molten iron silicon-increasing device in a first embodiment of the molten iron silicon-increasing stirring device of the utility model;

[0030] Figure 5 This is a schematic structural diagram of a silicon powder stirring device in the first embodiment of the molten iron silicon-enhancing stirring device of the utility model.

[0031] In the figure, 1- blast furnace slag iron ditch; 2- blast furnace slag ditch; 3- blast furnace iron ditch; 4- molten iron tank; 5- molten iron silicon increasing device; 6- silicon powder stirring device; 7- silicon powder hopper; 8- hopper unloading manual regulating valve; 9- hopper unloading pneumatic regulating valve; 10- silicon powder tank; 11- tank unloading manual regulating valve; 12- tank unloading pneumatic regulating valve; 13- silicon powder unloading chute; 14- silicon powder addition amount display screen and pneumatic valve operation box; 15- stirring head lifting mechanism; 16- middle connecting pipe; 17- stirring head; 18- metal hose; 19- stirring gas circuit valve group; 20- stirring device operation box.

[0032] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] It should be noted that in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] The utility model provides a molten iron silicon-enhancing stirring device.

[0036] Reference Figures 1 to 5 The utility model proposes a first embodiment of a molten iron silicon-enhancing stirring device. In this embodiment, the molten iron silicon-enhancing stirring device comprises a molten iron silicon-enhancing device 5 installed beside the iron ditch of the blast furnace iron-making field and a silicon powder stirring device 6 installed above the molten iron tank 4, wherein:

[0037] The molten iron silicon increasing device 5 comprises a silicon powder hopper 7, a silicon powder tank 10 and a silicon powder discharge chute 13 arranged in sequence from top to bottom, wherein a regulating valve is installed on the pipeline between the silicon powder tank 10 and the silicon powder discharge chute 13;

[0038] The silicon powder stirring device 6 comprises a stirring head 17, an intermediate connecting pipe 16 located on the stirring head 17, a gas supply pipeline connected to the intermediate connecting pipe 16, and a stirring head lifting mechanism 15 connected to the intermediate connecting pipe 16 for driving the stirring head to move up and down. The stirring head lifting mechanism 15 can adopt a chain transmission structure.

[0039] Figure 1 and Figure 2 In the specific description, two molten iron tanks 4 are provided as an example, and each molten iron tank 4 is equipped with a molten iron silicon increasing device 5 and a silicon powder stirring device 6.

[0040] Further, refer to Figure 3 and Figure 4 A manual regulating valve 8 and a pneumatic regulating valve 9 are installed on the pipeline between the silicon powder hopper 7 and the silicon powder tank 10, so as to adjust the amount of silicon powder dropped from the silicon powder hopper 7. When the pneumatic regulating valve fails, the manual regulating valve can be used for manual adjustment, thereby ensuring the working reliability of the entire molten iron silicon increasing device 5.

[0041] Reference Figure 3 and Figure 4 A manual regulating valve 11 for discharging silicon powder from the silicon powder tank 10 and a pneumatic regulating valve 12 for discharging silicon powder from the silicon powder tank 10 are installed on the pipeline between the silicon powder tank 10 and the silicon powder discharging chute 13, so as to facilitate the adjustment of the amount of silicon powder dropped from the silicon powder tank 10.

[0042] Furthermore, the molten iron silicon increasing device 5 also includes a silicon powder addition amount display screen and a pneumatic valve operation box 14, which is electrically connected to the hopper unloading manual regulating valve 8, the hopper unloading pneumatic regulating valve 9, the tank unloading manual regulating valve 11 and the tank unloading pneumatic regulating valve 12. The silicon powder addition amount display screen displays the amount of silicon powder added.

[0043] Furthermore, the molten iron silicon increasing device 5 also includes a support frame for supporting the silicon powder hopper 7 and the silicon powder tank 10, and the silicon powder addition amount display screen and the pneumatic valve operation box are both installed on the support frame.

[0044] In this embodiment, the support frame is installed on the track, the support frame is installed on the track and is movable relative to the track, and the support frame moves on the track to the overhanging platform to replace the equipment and increase the silicon powder. That is, in this embodiment, the molten iron silicon increasing device 5 adopts a mobile structure.

[0045] Furthermore, the silicon powder tank 10 is equipped with a tank weighing device (not shown in the figure), so as to facilitate the adjustment of the weight of the silicon powder flowing out of the silicon powder tank 10 .

[0046] Further, refer to Figure 5 The silicon powder stirring device 6 also includes a stirring gas circuit valve group 19 connected to the gas supply pipeline (the stirring gas circuit valve group 19 and the gas supply pipeline are connected through a metal hose 18), and the stirring surge is adjusted by the stirring gas circuit valve group 19 to adjust the stirring intensity of the molten iron. The silicon powder stirring device 6 is also equipped with a stirring device operating box 20 for controlling the stirring gas circuit valve group 19.

[0047] The working process of the molten iron silicon-enhancing stirring device is as follows: when the blast furnace is tapping iron, after the molten iron flows through the iron ditch, the molten iron silicon-enhancing device 5 is opened after the opening degree is set; after the first tank of the molten iron tank 4 has completed receiving iron, the corresponding silicon powder stirring device 6 is started to stir the first tank of the molten iron tank 4; after the second tank of the molten iron tank 4 has completed receiving iron, the corresponding silicon powder stirring device 6 is started; after the stirring operation of the two tanks of molten iron is completed, the silicon powder stirring device 6 returns to a safe position through the track, and the molten iron transport vehicle pulls the molten iron tank 4 to the next process.

[0048] In the two-step operation of increasing silicon in molten iron and stirring, manual machine-side adjustment or automatic adjustment by setting a program is required. In the silicon increasing operation, the amount of silicon powder added needs to be adjusted according to the silicon content in the molten iron after sampling the molten iron. The molten iron silicon increasing device 5 is provided with a manual regulating valve, a pneumatic regulating valve and a material tank weighing device, which are used to adjust and display the amount of silicon powder added; in the stirring operation, it is also necessary to adjust the amount of stirring gas according to the uniformity of the silicon powder in the molten iron after sampling the molten iron. The silicon powder stirring device 6 is provided with a stirring gas circuit valve group 19, which is used to adjust the stirring surge and thus adjust the stirring intensity of the molten iron. Under the condition of the same amount of molten iron and the same operation time, a properly large amount of gas is conducive to the full dissolution of silicon powder in the molten iron.

[0049] The molten iron silicon-increasing stirring device proposed in this embodiment can realize efficient and accurate silicon-increasing in the molten iron, and at the same time, the silicon powder added to the molten iron can be fully mixed with the molten iron efficiently, with low consumption and safety, which is of great significance for improving the quality of molten iron and the competitiveness of enterprises. At the same time, the molten iron silicon-increasing stirring device has the advantages of simple structure, stable and reliable operation and easy implementation.

[0050] The utility model proposes a second embodiment of a molten iron silicon-enhancing stirring device. This embodiment is different from the first embodiment described above in that, in this embodiment, the molten iron silicon-enhancing device 5 adopts a fixed structure, and the support frame is fixed to the iron-casting platform by bolts. At this time, the replacement of silicon powder and equipment is solved by a crane on the iron-casting platform.

[0051] The utility model also provides a molten iron silicon-enhancing stirring system.

[0052] In this preferred embodiment, a molten iron silicon-enhancing stirring system includes a molten iron silicon-enhancing stirring device and a molten iron tank 4, each molten iron tank 4 is equipped with a molten iron silicon-enhancing stirring device. The specific structure and beneficial effects of the molten iron silicon-enhancing stirring device refer to the above embodiment and will not be repeated here.

[0053] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A molten iron silicon-enhancing stirring device, characterized in that: It includes a molten iron silicon increasing device installed beside the iron ditch in the blast furnace iron-making field and a silicon powder stirring device installed above the molten iron tank, wherein: The molten iron silicon increasing device comprises a silicon powder hopper, a silicon powder tank and a silicon powder discharge chute arranged in sequence from top to bottom, wherein a regulating valve is installed on the pipeline between the silicon powder tank and the silicon powder discharge chute; The silicon powder stirring device comprises a stirring head, a middle connecting pipe on the stirring head, a gas supply pipeline connected to the middle connecting pipe, and a stirring head lifting mechanism connected to the middle connecting pipe for driving the stirring head to move up and down.

2. The molten iron silicon-enhancing stirring device according to claim 1, characterized in that: A manual regulating valve for discharging materials from the hopper and a pneumatic regulating valve for discharging materials from the hopper are installed on the pipeline between the silicon powder hopper and the silicon powder tank.

3. The molten iron silicon-enhancing stirring device according to claim 2, characterized in that: A manual regulating valve for discharging the silicon powder tank and a pneumatic regulating valve for discharging the silicon powder tank are installed on the pipeline between the silicon powder tank and the silicon powder discharging chute.

4. The molten iron silicon-enhancing stirring device according to claim 3, characterized in that: The molten iron silicon increasing device also includes a silicon powder addition amount display screen and a pneumatic valve operating box, which is electrically connected to the hopper unloading manual regulating valve, the hopper unloading pneumatic regulating valve, the tank unloading manual regulating valve and the tank unloading pneumatic regulating valve.

5. The molten iron silicon-enhancing stirring device according to claim 4, characterized in that: The molten iron silicon-increasing device also includes a support frame for supporting a silicon powder hopper and a silicon powder tank, and a silicon powder addition amount display screen and a pneumatic valve operating box are both installed on the support frame.

6. The molten iron silicon-enhancing stirring device according to claim 5, characterized in that: The support frame is installed on the track, and the support frame is installed on the track and is movable relative to the track. The support frame moves on the track to the cantilevered platform to replace equipment and increase silicon powder.

7. The molten iron silicon-enhancing stirring device according to claim 5, characterized in that: The support frame is fixed on the iron-out platform by bolts.

8. The molten iron silicon-enhancing stirring device according to claim 1, characterized in that: The silicon powder tank is equipped with a tank weighing device.

9. The molten iron silicon-enhancing stirring device according to any one of claims 1 to 8, characterized in that: The silicon powder stirring device also includes a stirring gas circuit valve group connected to the gas supply pipeline, and the stirring surge is adjusted by the stirring gas circuit valve group to adjust the stirring intensity of the molten iron.

10. A molten iron silicon-enhancing stirring system, characterized in that: It comprises the molten iron silicon-enhancing stirring device as claimed in any one of claims 1 to 9, and also comprises a molten iron tank, each molten iron tank is equipped with a molten iron silicon-enhancing stirring device.

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