KR101067488B1 - Non-explosive air-setting refractory mortar for probe measuring high temperature molten metal - Google Patents

Abstract

The present invention is to maximize the function of the product, such as precision measurement by suppressing the bubbles appearing on the surface of the mortar by explosion of the pressure of water vapor and gas at high temperature to improve the fire resistance, and reduce the ambient pollution, Explosion proof equipment used for high temperature molten metal measurement probes, characterized in that the refractory aggregate consisting of: and refractory mortar containing sodium silicate as an inorganic binder, which further contains 0.001 to 5% by weight of organic fibers as a pinhole forming agent. The present invention relates to a hard refractory mortar, and by discharging organic fibers at high temperature to form a pin hole, artificially securing a discharge path of water vapor and gas, thereby effectively controlling water vapor and gas generated from the inside of the mortar. Improves fire resistance and prevents loss of surfaces To prevent explosion and contamination of the vicinity of the bubble generating surface layer due to the surface and provides an effect capable of more precise and reliable measurement.

Mortar, Organic Fiber, Pinhole, Explosion Proof, Polypropylene, Polyethylene, Fire Resistant, Hardening

Description

NON-EXPLOSIVE AIR-SETTING REFRACTORY MORTAR FOR PROBE MEASURING HIGH TEMPERATURE MOLTEN METAL}

The present invention relates to a refractory mortar used at a high temperature, and to a refractory mortar that is resistant to thermal shock used as a material of a sensor requiring high precision and that can effectively control the generation of water vapor and gas.

In the metal refining and smelting industry, temperature and component control of hot molten metals are the main requirements that affect quality. Measurements such as temperature measurement and sampling for their verification must be fast, accurate and stable.

As shown in Figure 1 and 2, the temperature and components of the molten metal is a cylindrical tube (2) of the long axis protected by a plurality of outer shell protective tube, an immersion unit for immersing the molten metal at the tip of the cylindrical tube ( 1), the rear end of the cylindrical tube is measured by a probe (Probe) consisting of a manual holder (4) or an automatic device immersed in molten metal.

The immersion unit 1 is a thermocouple sensor having various types according to a range of temperatures used or an environment of an oxidizing or reducing atmosphere, a side sensor for measuring oxygen levels on an electrochemical principle, and a liquid level of molten metal. It can be configured with a level sensor, a sampling inlet for taking samples representative of the components of the molten metal, or a combination thereof.

The probe is a consumable sensor that collects and discards after measuring and sampling the temperature, oxygen level, liquid level, etc. within a few seconds, and protects the immersion unit 1 of the probe from high heat of molten metal of 1000 ° C. or more. In order to protect against droplet generation of molten metal, a fireproof material of heat insulation is formed, and cement, mortar, etc. are usually used as the fireproof material.

Among them, mortar is manufactured by kneading and drying the refractory aggregate containing aluminum oxide or silicon oxide and sodium silicate, which is an inorganic binder, and using it as a fireproofing material for insulation. Surface loss is easy to occur due to pop-out or explosion, and especially when exposed to high temperature suddenly, the temperature of the surface layer rises rapidly and water vapor and gas are generated inside the mortar. Water vapor or gas is condensed and concentrated, and water vapor pressure or gas pressure is formed in the surface layer, and the surface of the mortar is scattered by the compression and thermal stress and the surface of the mortar is scattered and the structural strength is significantly reduced.

Therefore, when mortar is used as a refractory material of a probe, when a probe located at room temperature is suddenly immersed in a molten metal of high temperature, a part of water, organic matter, and inorganic matter present in the mortar is generated by steam and gas due to the sudden temperature difference. Pressure is applied to the surface of the mortar, but softening and melting occurs from the surface of the mortar due to the silicon oxide and sodium component in the mortar, forming a coating layer of glassy layer, and the glass layer has no pores at all. Water vapor and gas are trapped inside it, so an explosion occurs at any moment.

As a result of the experiment, as shown in the photograph of Figure 3, after using the conventional fire retardant by mortar a number of explosion traces (bubble in the photo) occurs, as shown in the photograph of Figure 4 severe contamination around the immersion unit of the probe It can be seen that.

Therefore, when the conventional mortar is used as a refractory material for the probe, the surface of the mortar is not only lost and the fire resistance is lowered, but also adversely affects the measurement and sampling of temperature, oxygen level, liquid level, and the like. And, furthermore, cause failures and increase costs.

The present invention has been made to solve the above-mentioned problems in the prior art, by suppressing the air bubbles appearing on the surface of the mortar by the explosion due to the pressure of water vapor and gas at a high temperature to improve the fire resistance and reduce the ambient pollution It aims to check the accurate operation information by maximizing the function of the product such as precise measurement and reduce the cost.

In order to achieve the above object, in the refractory aggregate made of inorganic materials and refractory mortar containing sodium silicate as an inorganic binder, the refractory aggregate includes at least one inorganic material selected from aluminum oxide and silicon oxide, Explosion-proof used for high temperature molten metal measurement probes containing 70% by weight, the sodium silicate is contained 5 to 40% by weight, and further contains 0.001 to 5% by weight of organic fibers as a pinhole forming agent. Provides pneumatic refractory mortar.

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In addition, the pinhole forming organic fiber provides an explosion-proof hard-resistant refractory mortar used for high temperature molten metal measurement probe, characterized in that made of polypropylene or polyethylene.

      In addition, the polypropylene or polyethylene organic fiber has a length of at least 1mm and provides a explosion-proof hard-resistant refractory mortar used for high temperature molten metal measurement probe, characterized in that the needle shape as a maximum of 10mm.

In addition, the organic fibers of the polypropylene or polyethylene provides an explosion-proof hard-resistant refractory mortar used in the probe for measuring hot molten metal, characterized in that the diameter of less than 100㎛.

In addition, the present invention provides an explosion-proof hardened refractory mortar used for high temperature molten metal measurement probes, which further comprises 5 to 40 wt% of calcined refractory clay.

In addition, the present invention provides an explosion-proof hardened refractory mortar for use in high temperature molten metal measurement probes, further comprising 0.001 to 3% by weight of a peptizing agent and 0.001 to 3% by weight of a preservative.

As described above, the present invention disperses and inserts the pinhole-forming organic fibers in the mortar, and when the probe is exposed to high temperature, the organic fibers in the mortar are melted to form a pinhole, thereby artificially forming water vapor and gas. By securing the discharge passage, it is possible to effectively control the water vapor and gas generated from the inside of the mortar, thereby preventing the loss of the mortar surface to improve the fire resistance, and to generate bubbles and surroundings of the surface layer caused by the explosion of the mortar surface. It is possible to prevent pollution, to make more accurate and stable measurement, and to have the effect of confirming accurate operation information, and to reduce costs by adding organic fibers to the conventional aggregate and inorganic binder. Will have

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the present invention.

Figure 1 is a front cross-sectional view of the probe, Figure 2 is a state of use to manually immerse the probe into the molten metal, Figure 3 is a photograph after using the refractory material using a conventional mortar, Figure 4 is a probe of a conventional fire retardant using a mortar Photo, Figure 5 is a photograph after using the mortar refractory material according to the invention, Figure 6 is a probe photograph using the refractory material according to the present invention.

The present invention is a probe for measuring hot molten metal, wherein the refractory aggregate made of an inorganic material and refractory mortar containing sodium silicate as an inorganic binder further contain 0.001 to 5% by weight of organic fibers as a pinhole forming agent. Explosion-proof plowing resistant mortar used in.

The composition of the present invention includes a refractory aggregate made of an inorganic material, the refractory aggregate is excellent in fire resistance to sufficiently protect the immersion unit of the probe in the hot molten metal, and serves to fill between the inorganic binder.

The composition of the present invention includes sodium silicate (Na ₂ SiO ₃ ) as an inorganic binder, it is possible to combine the aggregate contained in the refractory mortar and maintain high strength and fire resistance even at high temperatures.

On the other hand, the main cause of the water vapor and gas generated when immersed in the hot molten metal is sodium silicate is the largest proportion, water, organics, minerals that existed in the mortar of the refractory material is generated as water vapor and gas Although to be discharged to the outside, the inorganic material present in the surface layer of the mortar is melted or softened to form a coating layer having no surface pores, and high pressure is generated due to the internal vapor and gas not being discharged to the outside, causing a small explosion. In order to prevent such an explosion, the present invention disperses and injects an organic fiber as a material of refractory mortar as a pinhole forming agent, so that the pinhole forming agent is melted in an instant when the refractory mortar is exposed to hot molten metal to pinhole on the fiber. (Pin hole) is formed to artificially secure the discharge passage of water vapor and gas to prevent explosion, thereby preventing the surrounding pollution, thereby enabling more accurate measurement.

The pinhole-forming organic fibers are preferably contained in a range of 0.001 to 5% by weight, when using less than 0.001% by weight is insufficient space to secure due to the melting of the organic fibers when exposed to high temperatures, the discharge of water vapor and gas smoothly This is because it is not effective in preventing explosion, and when used in excess of 5% by weight, gas generated from the organic fiber itself may act as a component pollution source of the immersion unit.

The present invention is characterized in that the refractory aggregate contains 50 to 70% by weight as one containing at least one inorganic material selected from aluminum oxide and silicon oxide, and the sodium silicate is contained at 5 to 40% by weight. Explosion-proof light-resistant refractory mortar used for the molten metal measurement probe.

In the present invention, the refractory aggregate includes at least one inorganic material selected from aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ), and these components are excellent in fire resistance to sufficiently immerse the probe immersion unit in a hot molten metal. It protects and plays a role in charging between the weapon binders.

However, refractory aggregate composed of at least one inorganic material selected from aluminum oxide (Al ₂ O ₃ ) and silicon oxide (SiO ₂ ) is contained in 50 to 70% by weight. This is because the workability decreases and the workability decreases, and when it exceeds 70% by weight, the strength and workability decrease.

Aggregate content may be used as fine aggregates, such as silica or light fine aggregates having a specific gravity of 1.5 or less, diameter 0.5 mm or less, specific gravity 1.5 or more, silica or heavy fine aggregates having a diameter of 1 mm or more, or mixtures thereof. It has the advantage of reducing the weight of the composition, especially in the case of using the light weight aggregate aggregated by firing glass sludge, since the surface of the aggregate is coated and the water absorption is low, the moisture content is low, so that the probe may be immersed in the hot molten metal. At this time, the amount of steam generated decreases.

The sodium silicate inorganic binder is contained in the range of 5 to 40% by weight, it is difficult to express the early strength when less than 5% by weight, the workability is lowered when it exceeds 40% by weight.

The pinhole-forming organic fiber is preferably made of polypropylene (PP) or polyethylene (PE). Since polypropylene or polyethylene has a low melting point, it is easily melted even at low temperatures to form a space. This is because the effect of preventing the explosion by facilitating the discharge is large.

The length of the organic fiber of the polypropylene or polyethylene is 1mm or more, preferably a needle shape having a maximum length of 10mm, if the length is less than 1mm is not easy to discharge steam and gas, if the length exceeds 10mm This is because the fire resistance of the present invention is impaired.

The pinhole-forming organic fiber of polypropylene or polyethylene preferably has a diameter of less than 100 μm, but when the diameter is 100 μm or more, it becomes an obstacle to precision measurement due to excessive water vapor and gas discharge from the inside of the mortar. This is because it reduces the fire resistance.

The present invention includes an explosion-proof refractory mortar used in a probe for measuring molten metal at high temperature, characterized in that it further comprises calcined refractory clay, and calcined refractory clay is a refractory formed by heating a clay to remove some or all of its volatile components. If the clay, and using the calcined refractory clay, while maintaining the fire resistance, it is possible to maximize the effect of the explosion-proof by reducing the amount of water vapor and gas generated in the refractory mortar.

However, calcined refractory clay is effective to use in the range of 5 to 40% by weight, the use of less than 5% by weight may increase the possibility of explosion-proof, when used in excess of 40% by weight of the present invention by weakening the fire resistance of mortar This is because the fire resistance of the can be lowered.

The present invention includes an explosion-proof refractory mortar used for high temperature molten metal measurement probes, further comprising a peptizing agent and a preservative, wherein each of the components used in the refractory mortar is easily dispersed using a peptizing agent, This is to maximize the effect of the invention by preventing the decay of organic matter using a preservative. However, it is effective to use both peptizers and preservatives in the range of 0.001 ~ 3% by weight, when less than 0.001% by weight of each material of refractory mortar is not easily dispersed, explosion-proof effect and corruption may occur. This is because when used in excess of the weight%, it causes the generation of water vapor and gas, and the effect of the invention as a refractory material is lowered.

On the other hand, explosion-proof refractory mortar used in the high temperature molten metal measuring probe of the present invention is suitable for the present invention requiring early strength since it has a hardening property at room temperature after construction.

Hereinafter, embodiments of the present invention will be described in detail, and the scope of the present invention is not limited to these examples.

Table 1 shows various examples according to the content, length, diameter, etc. of the refractory aggregate, the inorganic binder, and the pinhole forming organic fibers.

Table 1

practice
Yes
Fireproof aggregate
(%) bookbinder
(%) Pinhole Forming Agent (Organic Fiber) calcination
Fireproof
clay
Etc

Remarks Al ₂ O ₃
SiO ₂
Na ₂ SiO ₃
PP PE
Discourse
Dispersant content
(%) Length
(mm) diameter
(Μm) content
(%) Length
(mm) diameter
(Μm) One 30 32 38 Conventional example 2 30 32 37 0.05 6 35 Invention 3 30 32 36 2 6 35 Invention 4 30 32 25 0.05 6 35 12 Invention 5 30 32 35 2 6 35 One One Invention 6 30 32 37 0.0005 6 35 Comparative example 7 30 32 28 10 6 35 Comparative example 8 30 32 35 3 0.5 35 Comparative example 9 30 32 35 3 15 35 Comparative example 10 30 32 35 3 6 200 Comparative example

The experiment was carried out by immersing the probe for measuring the hot molten metal with refractory mortar having the composition of each example in a molten steel at a depth of 500 to 600 mm for about 5 to 10 seconds.

Table 2 shows the evaluation of the results according to the Example of Table 1 above.

The gas explosion traces shown in Table 2 were evaluated by visually observing traces of bubble formation on the surface of the refractory material. The gas explosion traces of the refractory mortar without the pinhole formers of Example 1 were evaluated as 'very poor' and based on this. Each test material was compared and evaluated. In Table 2, the probe contamination was evaluated by the combustion analysis ([C] gas analysis) on the recovered refractory mortar. The combustion analysis was performed by passing the sample taken through or in contact with a combustion assisting gas such as oxygen or chlorine. It is an analysis method that quantifies gas (CO, CO _2, etc.) generated at this time by heating and burning the sample. The pollution degree (prior example) of the probe in which the refractory mortar without the pinhole former of Example 1 was placed was evaluated as 'very poor', and the test materials were compared and evaluated for the pollution degree through the combustion analysis.

[Table 2]

Example Gas explosion trace Probe Contamination Remarks One × × Conventional example 2 ● ◎ Invention 3 ◎ ◎ Invention 4 ◎ ◎ Invention 5 ◎ ◎ Invention 6 × × Comparative example 7 ● × Comparative example 8 △ △ Comparative example 9 ● ○ Comparative example 10 ● ○ Comparative example

(Physical property determination ◎: Excellent, ●: Good, ○: Normal, △: Bad, ×: Very bad)

As can be seen from the results in Table 2, when the organic fiber for pinhole formation is mixed in the content (0.001 ~ 5%), length (1 ~ 10 mm), diameter (less than 100 ㎛) within the scope of the present invention Although traces and probe contamination were excellent, as in Examples 6 and 8, when the organic fiber for pinhole formation was smaller than the scope of the present invention, the vapor and trace contamination were not generated because the vapor and gas were not discharged smoothly. It was confirmed that the poor.

On the other hand, if the organic fiber for pinhole formation is larger than the scope of the present invention as in Example 7, Example 9 and Example 10, the gas explosion trace was good because the discharge of water vapor and gas was increased, but the gas acted as a pollution source. The probe contamination was found to be less than normal.

Therefore, the effect was excellent when the organic fibers for pinhole formation were mixed within the scope of the present invention, in particular, when the appropriate amount of calcined refractory clay of Example 4 was mixed with the appropriate amount of the peptizing agent and the preservative of Example 5. It was confirmed that the effect of the present invention in the most excellent.

That is, as can be seen from the photograph of FIG. 4, almost no traces of vapor and gas explosion are found compared to the case of using the conventional mortar of FIG. 3. As can be seen from the photograph of FIG. It was confirmed that almost no contamination of.

1 is a front cross-sectional view of a probe

2 is a state diagram used to manually immerse the probe into the molten metal

Figure 3 is a photograph after using the refractory material by the conventional mortar.

Figure 4 is a photograph after using the mortar refractory material according to the present invention.

5 is a photograph of a probe using a refractory material of the conventional mortar

Figure 6 is a probe photograph using the refractory material according to the present invention

♧ description of the symbols for the main parts of the drawing ♧

1. Immersion unit

2. Cylinder tube

3. Fireproof mortar

4. Holder

10. Melt

11. Molten metal

Bubbles of FIGS. 3 and 5 .. No gas explosion sign

Claims (7)

In the refractory aggregate made of inorganic material and refractory mortar containing sodium silicate as an inorganic binder, The refractory aggregate contains 50 to 70% by weight of one or more inorganic materials selected from aluminum oxide and silicon oxide, The sodium silicate is contained in 5 to 40% by weight, An explosion-proof hardened refractory mortar used for high temperature molten metal measuring probes, which further contains 0.001 to 5% by weight of organic fibers as a pinhole forming agent. delete The method of claim 1, The pinhole-forming organic fiber is explosion-proof hard-resistant mortar used for high temperature molten metal measurement probe, characterized in that made of polypropylene or polyethylene. The method of claim 3, The polypropylene or polyethylene organic fiber has a length of at least 1 mm and a maximum of 10 mm in the shape of a needle, explosion-proof hard-resistant refractory mortar used for hot molten metal measuring probes. The method of claim 3, The organic fiber of the polypropylene or polyethylene has a diameter of less than 100 ㎛ explosion-proof hard-resistant refractory mortar used for high temperature molten metal measuring probes. The method of claim 1, Explosion-proof hardened refractory mortar used for high temperature molten metal measurement probes, characterized in that it further contains 5 to 40% by weight calcined refractory clay. The method of claim 1, Explosion-proof light-resistant fire-resistant mortar used for high temperature molten metal measurement probes, characterized in that it further contains 0.001 to 3% by weight of the peptizing agent, 0.001 to 3% by weight of a preservative.

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