JPS6050380A - Method and device for recovering molten metal slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for recovering molten slag, and more particularly to a method and apparatus for recovering molten slag floating on hot metal and molten steel in a torpedo, ladle, or otherwise.

Conventionally, various types of molten slag generated in a series of steelmaking processes including hot metal pretreatment, such as slag generated by hot metal desiliconization treatment, dephosphorization/desulfurization slag in hot metal pretreatment, and 'p' in the tapping ladle. The treatment of floating agglomerated slag is carried out as follows: The molten slag resulting from desulfurization, dephosphorization, desiliconization, etc. through hot metal pretreatment is also subjected to vacuum suction conveyance (VSC> treatment) in some cases. However, the slag is mainly scraped into a waste pan by a slag dragger, transported by a special transport vehicle, and then left to cool on multiple cooling beds.However, this slag dragger When scraping molten slag, for example, it is impossible to completely separate the molten pig iron and molten slag, and the molten pig iron is inevitably entrained in the separated molten slag, resulting in a loss of molten metal. In order to recover the hot metal that has been scraped out, subsequent treatment steps become complicated, which also leads to an increase in slag treatment costs.

On the other hand, the agglomerated slag that forms in the ladle after tapping must be promptly removed in order to prevent rephosphorization into the steel and ensure steel quality. Losses in molten steel when using a series of processing methods using slag draggers are a more serious problem than losses in the case of hot metal;
Such a method cannot be adopted.

Therefore, at present, some attempts have been made to use the vacuum suction conveyance process described above, but most of the time, the molten steel is fed into the continuous casting or ingot-making process without being treated. It is being collected and processed along with the remaining steel residue.

Either method, such as using a slag dragger or removing it together with the remaining steel in the ladle, requires the complicated and expensive process described above, and the processing method requires a lot of labor, effort, and work. There is a problem in terms of safety.

Therefore, as a method to solve such problems, several vacuum suction conveyance devices as mentioned above have been proposed so far. −U, its hydrodynamic pressure (negative pressure)
There is also a method in which the molten slag is sucked in using the suction flow generated by the molten slag, and then only the molten slag is released into the air, but this method has problems with durability as the device is used continuously in a high-temperature, high-pressure atmosphere. Depending on the danger of steam explosion due to the mixing of water and high-temperature molten slag, and the viscosity of the slag, there may be problems such as insufficient suction performance with the suction force generated by simply injecting water and air into the interior. .

Furthermore, Japanese Patent Laid-Open No. 159424/1983 discloses a slag recovery process in the form of slurry using a vacuum suction conveyance system (VSC). This is a device for automatically removing molten slag on the surface of the molten metal. It has a cooling water chamber that can adjust the pressure and vent air around the entire outer circumference of the body, a convertible sleeve inside, and a suction at the tip of the body. The mouth pipe and cooling water chamber are equipped with a water injection port that injects water to instantaneously granulate slag, and the main body is connected to a vacuum pump to collect granular slag into a collection tank. It is partially used for desiliconization and dephosphorization slag treatment. In addition, there is also a method disclosed in Japanese Patent Application Laid-Open No. 56-90912.

However, these conventionally proposed methods
In both cases, the tip of the suction tube is placed away from the slag melting surface, and the molten slag is sucked in by the suction gas from the surroundings generated by creating negative pressure inside the suction tube. be.

In particular, in methods that utilize water jets for the generation of negative pressure and the production of granular slag, it is necessary to Furthermore, there are problems such as the risk of the water used for slag granulation getting mixed into the hot metal or f4wi, and countermeasures against deposits.

As mentioned above, the conventional slag treatment method (1) There is some hot metal when removing the molten slag. (2) For example, the processing cost increases due to multiple slag treatment processes such as slag transportation, crushing, and magnetic separation. (3) The quality of the iron ultimately recovered is poor, and the added value of τJ is low. , (4) The current situation is that there are many problems such as phosphorus in slag returning to steel, deterioration of steel quality due to so-called rephosphorization.

Therefore, the present inventors believe that if it becomes possible to easily and efficiently suck, separate, and collect only the molten slag, the above problems will be improved, and it will be immeasurable, including the problems of workability and safety. Focusing on the advantages of rationalization that can be achieved in one stage, the present invention was completed by creating an ax ancient fruit with various sides stacked on top of each other.

That is, the present invention allows a high-speed gas to flow through a high-speed fluid conduit,
The tip of a suction conduit that communicates with or branches from the high-speed fluid conduit is placed at a height of 20 tuna or less above the surface of the molten slag, or is in contact with or immersed in the molten slag, so that the high-velocity gas flows through the high-speed fluid conduit at high speed. A method for recovering molten slag, in which the molten slag is sucked through the suction guide by an upward lift force generated in the suction guide by flowing, and is then collected along with the high-speed gas, and a high-speed gas jet nozzle is provided at one end of the molten slag. A high-velocity fluid conduit whose other end constitutes a molten slag blowing section, and a high-velocity fluid conduit connected to and branched from the I-high velocity source fluid conduit, with the tip disposed at a height of 20 m or less above the molten slag surface or in contact with the molten slag. - A molten slag recovery device consisting of a suction conduit in which an upward lifting force is generated inside the high-speed fluid conduit by the high-speed gas from the high-speed gas jetting nozzle flowing at high speed in the high-speed fluid conduit.

Hereinafter, the present invention will be explained in more detail with reference to the accompanying drawings.

The accompanying drawing is a schematic explanatory diagram showing, partially in cross section, an example of a molten slag recovery device according to the present invention.

The illustrated molten slag recovery device 1 includes a high-speed fluid conduit 2 through which high-velocity gas (iffl or high-pressure air) flows at high speed, a suction conduit 3 that communicates with and branches from this conduit, and a high-velocity gas that supplies high-velocity fluid to the high-speed fluid conduit 2. It is composed of a jet nozzle 4. The other end of the high-speed fluid conduit 2 constitutes an F6 molten slag blowing section 5. In the molten slag blowing section 5, the granular slag entrained in the high-speed fluid is blown out together with the high-speed fluid. In addition,
The tip 6 of the suction conduit 3 is disposed at a height of 20 degrees or less above the surface of the molten slag, or is brought into contact with and immersed in the molten slag, and that portion is provided integrally with the suction conduit 3 or replaceably. It's okay to be hit. In the figure, reference numeral 7 indicates the graphite lining, and reference numeral 8 indicates the outer steel pipe.

According to the present invention, first, the high-speed gas jet nozzle 4
High-speed air is discharged from the duct and flows at high speed through the conduit 2 constituting the high-speed fluid conduit. As a result, upward suction pressure is generated within the suction conduit 3 constituting the suction conduit, and upward lifting force is generated. At this time, if the tip 6 of the suction conduit 3 is placed at a height of 20 weight or less above the molten slag surface or is in contact with or immersed in the molten slag 9, the molten slag is sucked into the suction conduit by the lifting force. The molten slag is then engulfed and entrained by high-velocity gas in the high-pressure fluid conduit 2, whereupon the molten slag solidifies and becomes granulated. Such granular slag is collected, for example, through a collection hombar connected to the molten slag blowing section 5.

In the present invention, the suction position of the tip 6 of the suction conduit 3 is set at a height of 201 or less above the molten slag surface or at a position where it is in contact with and immersed in the molten slag. This is because the slag suction force is significantly reduced, high-speed jet gas is required for the boat, and the slag suction efficiency is reduced.

The above-mentioned suction position is preferably in contact with the molten slag surface, but in such a case, the slag suction force (lifting force) is also large, and while suctioning some surrounding air from the molten slag surface, Since the molten slag is sucked, the slag is not blown away after suction and the force is strong, which is most preferable as it allows efficient work from a comprehensive standpoint. In addition, the suction position is
Depending on the case, the molten slag may be immersed, and in such a case, the greatest slag suction force (lifting force) can be obtained, and it is suitable as a suction method when the slag temperature decreases.

According to the present invention, by adjusting the high-speed gas jetting and the flow rate of the high-speed gas from the nozzle part 4, only the slag is sucked up by utilizing the difference in specific gravity between the hot metal or molten steel and the molten slag. Similarly, by adjusting the flow rate of high-speed gas, it is also possible to separate the slag to be dispersed depending on the particle size.

As described above, according to the present invention, the dedicated iL! The steps of transportation using a 1ull truck, dry focus treatment, pressurized crushing, and metal sorting are no longer necessary, and slag processing costs are significantly streamlined. Furthermore, the obtained slag is in the form of granules or powder, and is easy to handle when reusing it for appropriate purposes.

In addition, since it is a dry process that does not use water, safety issues such as steam explosions and water contamination with hot metal or molten steel are resolved, and ancillary equipment such as water treatment equipment is not required. By simplifying the post-processing of recovered slag, equipment costs can also be significantly reduced.

Furthermore, according to the present invention, since it is possible to completely separate only the molten slag, it is also possible to apply it to the molten slag floating in the ladle after tapping, and it is possible to apply it to the molten slag floating in the ladle after tapping the steel. This problem will also be solved.

Note that when focusing on the granulation of molten slag, the present invention can also be applied to so-called blast furnace slag, which is discharged separately from hot metal.

As is clear from the above explanation, according to the method and apparatus of the present invention, it is possible to easily separate and recover only the molten slag, and various problems in the prior art are solved at once, and the benefits are immeasurable. It is unknown.

[Brief explanation of drawings]

The accompanying drawing is a schematic explanatory diagram partially showing a molten slag recovery device in cross section according to the present invention. ■ = Molten slag recovery device 2: High-speed fluid conduit 3: Suction conduit 4: High-speed fluid jetting nozzle 5: Y8 Molten slag blowing part 6 Two tips 9: Molten slag Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Akira Hirose −

Claims (2)

[Claims] (1) High-speed gas is flowed through the high-speed fluid guide, and the tip of the suction guide that communicates with or branches from the high-speed P4 body guide is placed at a height of 2011 or less above the surface of the molten slag, or is in contact with or immersed in the molten slag. The molten slag is sucked through the suction conduit by an upward lift force generated in the suction conduit by the high-velocity gas flowing through the high-velocity fluid conduit at high speed, and is then entrained in the high-velocity gas and collected. A method for recovering molten slag. (2) A high-speed fluid conduit having a high-speed gas jetting nozzle at one end and a molten slag blowing section at the other end, and a high-speed fluid conduit connected and branched from the high-speed fluid conduit, with the tip end above the molten slag surface 2 (in or below). Collection of molten slag consisting of a suction conduit, which is placed at a height of , or brought into contact with and immersed in the molten slag, and where high-speed gas from the high-speed gas jetting nozzle flows at high speed within the high-speed fluid conduit, thereby generating an upward lift force inside the high-speed fluid conduit. Device.