JPH06271909A - Method for removing gas from mud in mud gun - Google Patents

Abstract

PURPOSE:To improve the refractory characteristic of mud by degassing mud used for an iron tapping hole in a blast furnace in a mud gun before using. CONSTITUTION:A partition plate 1 is fitted to a cylinder tip 3 of the mud gun to seal the mud gun, and then the pressurization of >=50kg/cm<2> is executed with a piston 9. By this method, pores in the mud 10 are reduced and the mud is made compact refractory and the erosion resistance is improved, and the unit consumption of the mud and the working load at the front of the furnace are reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the operation of a mud gun piston in a mud gun prior to filling the mud used for closing the tap hole of a blast furnace for producing pig iron in a mud gun. The present invention relates to a method for improving the refractory characteristics of a mud gun by performing deaeration.

[0002]

2. Description of the Related Art A mud used for closing a taphole of a blast furnace is in contact with molten iron and slag flowing out at a temperature of about 1500 ° C. during tapping, and therefore it is required to have a high corrosion resistance against them. To be In order to improve the corrosion resistance, mud materials and manufacturing have been improved. Generally, when pores are present in the refractory, the gas in the pores expands during the temperature rising process up to the temperature at which the refractory is used, which causes cracks in the refractory around the pores. In addition, the substance that has the erosion resistance to the refractory (the hot metal and the slag in the mud) penetrates into the pores, which accelerates the erosion of the refractory around the pores, which significantly impairs the durability of the refractory. Cause.

Therefore, when manufacturing a molded brick,
It is common to reduce pores in the densification process by repeating vacuum deaeration and / or compression in the molding step performed before the firing step. The mud is used for the purpose of easily handling after kneading the materials.
It is molded into a 3 kg block.

From the economical aspect of the manufacturing process, this molding process is usually performed by pushing the mud into the die with a screw and compressing the die by squeezing the die while opening the die on the side opposite to the screw. It is carried out by the method of discharging from the part. At this time, since a large amount of pores are eliminated due to the applied pressure, the applied pressure on the mud is 5 to 1
It is as small as 0 kg / cm ^2, and many pores remain. During the filling operation of the mud into the mud gun barrel, the block-shaped mud is thrown into the mud gun from above the barrel, and is pushed against the nozzle portion at the tip of the barrel by the forward movement of the piston of the mud gun. In this case as well, since the tip of the nozzle is open, the mud does not leak too much through the opening, so only a modest compression of 5 to 20 kg / cm ² is applied to the mud.

In a mud slicer used for an automatic mud filling device, which has been particularly used in recent years, the mud put into the hopper is cut into small pieces of 50 g to 1 kg by a rotating blade, and then a belt or the like. Since it is thrown into the mud gun via the, the mud gun's barrel contains more pores than the mud is supplied in blocks. The mud filled in the barrel is pushed by the piston when the taphole is closed, and is pressed into the taphole through the throttle of the nozzle. At this time, the mud is subjected to a large pressure of 50 to 200 kg / cm ² depending on the capacity of the mud gun, and is supplied into the taphole.

[0006]

However, it is necessary to close the tap hole in a short time in order to seal the hot metal, the slag and the gas in the furnace which are jetted under the high pressure in the blast furnace. For this reason, the press-fitting of the mud is performed for at most 10 to 30 seconds for the mud of 100 to 200 kg. In other words, from the viewpoint of reducing the pores of the mud due to pressurization, it is an extremely short time, and the gas that is squeezed out from some of the pores cannot be removed because it is extremely small, and It goes against the mud which moves to, and supplies the mud to the tap hole before it moves to the piston side and is not exhausted, which impairs the refractory characteristics of the mud. The present invention aims to improve the refractory properties of the mud by using a simple method to reduce the pores in the mud prior to filling the taphole.

[0007]

In order to achieve the above object, the present invention comprises attaching a partition plate to a cylinder tip of a mud gun for closing a tap hole of a blast furnace, sealing the partition plate, and then advancing the piston. The mud in the mud gun is degassed by applying a pressure of 50 kg / cm ² or more to the mud.

[0008]

Function: That is, when the mud is supplied to the barrel of the mud gun via the mud inlet and / or after the filling in the barrel is completed, a partition plate is attached to the tip nozzle opening which is the tip of the mud gun. Then, the mud is depressurized by pressing the mud toward the partition plate and holding it. As a method of sealing with a partition plate, a method of attaching a valve to a cylinder tip, that is, a tip nozzle to close it is also the method of the present invention.

The term "sealing" as used herein does not necessarily mean a completely airtight seal, but is deflated with a mud leak of about 10 kg or less, which is acceptable from the economical and workability standpoint. The airtightness may be such that the gas is discharged. As a pressing force to be applied and a pressurizing time, it is effective from the experimental results that the pressurizing force of 50 kg / cm ² is maintained for 30 seconds or more. Pressurized pressure is 200 kg / cm ²
When it was raised to 0, the effect was recognized even if it was held for 20 seconds.

Further, if the pressure is increased stepwise, the gas extruded from the pores can be uniformly discharged through the mud layer, and the effect can be further enhanced. Of course, it is more desirable to suck the air in the barrel and reduce the atmospheric pressure by using a vacuum pump or the like.

As described above, the mud is pressurized by the piston, and the gas contained in the space between the injected mud pieces and the pores inside the mud piece is pushed out of the mud, and the space between the piston and the barrel is pushed out. And a part of it is discharged from the gap between the cylinder tip and the partition plate. As a result, the pores of the mud are reduced, the mud has a finer structure, and the corrosion resistance as a refractory material is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a barrel of a mud gun with a partition plate attached. The piston 9 is retracted backward in advance, the mud is supplied into the barrel 7 from the mud insertion port 8, and is moved by the piston 9 toward the tip nozzle 2. The mud 10 transferred to the tip of the barrel is degassed by pushing the paston 9 toward the tip nozzle 2 and holding it for 30 seconds or more with a compression force of 50 kg / cm ² or more. FIG. 2 is an embodiment of the present invention showing a method of sealing the tip of the mud gun barrel to deliver the mud to the tap hole. By passing the partition plate retainer 5 attached to the partition plate 1 through the partition plate fixing metal 4 attached to the tip nozzle 2, the partition plate 1 is set in front of the tip nozzle 2, and then the cotter 6 is driven. The tube tip surface 3 is closely attached and sealed.

After the pressurization of the mud 10 is completed, the partition plate 1 is removed and the deaeration work according to the present invention is completed. In order to prevent the mud 10 from leaking between the cylinder front surface 3 and the partition plate 1, a packing 11 is attached to the partition plate. An example of the confirmation test of the effect performed in the blast furnace is as follows. A 150 kg mud is packed in a barrel and a compression force of 100 kg / cm ² is 60%.
^Second, a compressive force of 200 kg / cm ^{2 was} further applied for 60 seconds, and a mud of 150 kg was newly packed in the barrel and compressed twice under the same conditions as above. The tapping time of the blast furnace when using this 300 kg mud deaerated by one method of the present invention was 115 minutes. On the other hand, when 300 kg of mud that was not deaerated was used for the same tap hole, the tapping time was 105 minutes. That is, the tapping time was extended by 10 minutes due to the improvement of the characteristics of the mud as a refractory material.

[0014]

INDUSTRIAL APPLICABILITY The present invention is a method for reducing the porosity of a mud by a simple method, which can effectively improve the refractory properties of the mud, reduce the unit consumption of the mud, and stabilize the mud. It is possible to carry out tapping for a long time, which is very effective in reducing the load of tapping work in the blast furnace.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mud gun barrel having a partition plate according to an embodiment of the present invention.

FIG. 2 is a side view showing an embodiment of the present invention in which a tip nozzle portion of a mud gun barrel and a partition plate for sealing the tip nozzle portion are attached.

[Explanation of symbols]

 1 Partition Plate 2 Tip Nozzle 3 Tube Front Surface 4 Partition Plate Fixing Hardware 5 Partition Plate Pressing Metal 6 Cotta 7 Barrel 8 Mud Input Port 9 Piston 10 Mud 11 Packing

Claims (1)

[Claims] 1. A mud gun for closing a tap hole of a blast furnace, a partition plate is attached to the tip of the mud gun for sealing, and a piston is advanced to pressurize the mud at a pressure of 50 kg / cm ² or more. How to degas mud in the mud gun.