CN111154950A

CN111154950A - Metallurgical heat-insulating covering agent

Info

Publication number: CN111154950A
Application number: CN201911420697.7A
Authority: CN
Inventors: 许永生
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-15

Abstract

The metallurgical heat-preservation covering agent is divided into alkaline and acidic, and the alkaline covering liquid comprises, by weight, 30% -40% of Ca0, 15% -20% of SiO ₂, 10% -20% of Al ₂ O ₃, 7% -10% of Na ₂ O, 10% -15% of C, 5% -7% of MgO, 0.5% -1% of Fe ₂ O ₃, 3% -4% of an expanding agent, 4% -5% of a heating agent and the balance of impurities; the acid covering agent comprises 20-30% of Ca0, 30-50% of Al ₂ O ₃, 5-10% of MgO and less than 5% of CaF in percentage by weight₂40-50% of C, 4-5% of expanding agent, 2-4% of heating agent and the balance of impurities. The invention can prevent the molten steel from secondary oxidation, adsorb floating impurities of the molten steel, does not react with the molten steel, avoids the pollution of the molten steel, does not erode the alkaline ladle lining, does not stick slag or nodulation in use, improves the cleanness degree of the ladle, is beneficial to ladle slag turning, solves the difficulty of slag turning, is easy to disintegrate, reduces the labor intensity of workers, and is also beneficial to the improvement of the ladle age.

Description

Metallurgical heat-insulating covering agent

Technical Field

The invention relates to a heat-insulating covering agent, in particular to a metallurgical heat-insulating covering agent, and belongs to the field of steel-making, iron-making and casting.

Background

In the steel-making and casting production, in order to prolong the heat preservation time of the molten steel in the ladle and ensure that the molten steel can be smoothly cast into a qualified steel ingot or billet, the molten steel must have a qualified temperature, because the molten steel in the ladle is directly exposed in the air, the temperature of the molten steel in the casting process is reduced too fast, and meanwhile, the molten steel exposed in the air is easy to be secondarily oxidized.

At present, carbonized rice hulls are mainly used as a molten steel covering agent, and are simple to prepare, but have the following problems: 1. the problem of environmental pollution; 2. the spreadability is poor, the carbonized rice hulls are often piled after being added into a steel ladle and cannot be spread rapidly, so that the surface of molten steel is partially exposed in the air, and the heat dissipation of the molten steel is fast; 3. poor heat insulation and preservation effects and short heat preservation time; 4. the tundish wall is sticky and has serious nodulation; 5. causing the operating environment of workers to be severe and being unfavorable for equipment. The surface of molten steel is encrusted, and the water gap is frozen.

Disclosure of Invention

In order to solve the problems, the invention aims to overcome the technical defects and provide a heat-insulating covering agent which is used for steel ladles, tundishes, ladles, furrows and electric furnaces and has good heat insulation, heating and spreading properties, and the technical scheme is as follows:

the metallurgical heat-preservation covering agent is an alkaline covering agent and comprises 30-40% of Ca0 and 15-20% of SiO in percentage by weight₂10% -20% of Al₂O₃7% -10% of Na₂O, 10-15% of C, 5-7% of MgO and 0.5-1% of Fe₂O₃3 to 4 percent of expanding agent, 4 to 5 percent of heating agent and the balance of impurities.

The melting point of the alkaline covering agent is 1190-1421 ℃.

The melting speed of the alkaline covering agent is 70-80 seconds.

The alkalinity of the alkaline covering agent is 0.4-0.5.

The metallurgical heat-preservation covering agent is an acidic covering agent and comprises 20-30 wt% of Ca0 and 30-50 wt% of Al₂O₃5 to 10 percent of MgO and less than 5 percent of CaF₂40-50% of C, 4-5% of expanding agent, 2-4% of heating agent and the balance of impurities.

The melting point of the acidic covering agent is 1200-1400 ℃.

The melting speed of the acid covering agent is 70-80 seconds.

The alkalinity of the acid covering agent is 4.0-8.0.

The invention has the beneficial effects that: 1. the spreadability is good, and the dust and the flame are small and uniform; 2. the initial temperature is low so as to ensure that a melting layer with proper thickness can be formed quickly and better isolate air, adsorb impurities and the like; 3. The proper melting speed ensures that the covering agent can keep a three-layer structure on the surface of the molten steel for a long time, and the amount of the heat insulating agent added in the subsequent heat is reduced; 4. the viscosity is proper and does not change along with the temperature sharply; 5. the slag surface does not crust with the time; 6. the water gap, the brick cup and the inner bag are not encrusted; 7. the dosage is less and the price is reasonable. The covering agent has the advantages that the covering agent has a single heat preservation function, can prevent molten steel from being secondarily oxidized, adsorbs floating impurities of the molten steel, does not react with the molten steel, avoids pollution of the molten steel, does not corrode an alkaline ladle lining, does not stick slag or form nodules in use, improves the cleanliness of a ladle, is beneficial to slag turning of the ladle, solves the problem of difficult slag turning, is easy to disintegrate, reduces the labor intensity of workers, and is also beneficial to improving the ladle age.

Detailed Description

The present invention will be described in detail with reference to examples.

Example 1

The metallurgical heat-preservation covering agent is an alkaline covering agent and comprises 30 percent of Ca0 and 15 percent of SiO in percentage by weight₂10% of Al₂O₃7% -Na₂O, 10% of C, 5% of MgO and 0.5% of Fe₂O₃3 percent of expanding agent, 4 percent of heating agent and the balance of impurities, the melting point is 1190 ℃, the melting speed is 70-80 seconds, and the alkalinity is 0.4-0.5.

Example 2

The metallurgical heat-preservation covering agent is an alkaline covering agent and comprises 35 percent of Ca0 and 17 percent of SiO in percentage by weight₂15% of Al₂O₃8.5% of Na₂O, 12.5% of C, 6% of MgO and 0.75% of Fe₂O₃3.5 percent of expanding agent, 4.5 percent of heat generating agent and the balance of impurities, the melting point is 1300 ℃, the melting speed is 75 seconds, and the alkalinity of the alkaline covering agent is 0.45.

Example 3

The metallurgical heat-preservation covering agent is an alkaline covering agent and contains 340 percent of Ca in percentage by weight0. 20% SiO₂20% of Al₂O₃10% of Na₂O, 15% of C, 7% of MgO and 1% of Fe₂O₃4 percent of expanding agent, 5 percent of heating agent and the balance of impurities, the melting point is 1421 ℃, the melting speed is 80 seconds, and the alkalinity is 0.5.

Example 4

The metallurgical heat-preservation covering agent is an acidic covering agent and comprises 20 percent of Ca0 and 30 percent of Al in percentage by weight₂O₃5% of MgO and less than 5% of CaF₂40 percent of C, 4 percent of expanding agent, 2 percent of heat generating agent and the balance of impurities, and the melting point is 1200 ℃, the melting speed is 70 seconds and the alkalinity is 4.0.

Example 5

The metallurgical heat-preservation covering agent is an acidic covering agent and comprises 25 percent of Ca0 and 40 percent of Al in percentage by weight₂O₃7.5 percent of MgO and less than 5 percent of CaF₂45 percent of C, 4.5 percent of expanding agent, 3 percent of heat generating agent and the balance of impurities, and the melting point is 1300 ℃, the melting speed is 75 seconds and the alkalinity is 6.0.

Example 6

The metallurgical heat-preservation covering agent is an acidic covering agent and comprises 30 percent of Ca0 and 50 percent of Al in percentage by weight₂O₃10% of MgO and less than 5% of CaF₂50 percent of C, 5 percent of expanding agent, 4 percent of heat generating agent and the balance of impurities, and the melting point is 1400 ℃, the melting speed is 80 and the alkalinity is 8.0.

Example 7

Table 1 shows a comparison of the use of the acidic coating agent of the present invention and carbonised rice hulls

From table 1, it can be seen that the average temperature of the steel ladle using the metallurgical heat-insulating covering agent after being calmed for 15 minutes is higher than the average temperature of the steel ladle using carbonized rice hulls, and the cooling rate of the steel ladle using the metallurgical heat-insulating covering agent is slower than that of the steel ladle using the carbonized rice hulls, which fully indicates that the heat-insulating property of the metallurgical heat-insulating covering agent is superior to that of the carbonized rice hulls.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The metallurgical heat-insulating covering agent is characterized in that the metallurgical heat-insulating covering agent is an alkaline covering agent and comprises 30-40% of Ca0 and 15-20% of SiO in percentage by weight₂10% -20% of Al₂O₃7% -10% of Na₂O, 10-15% of C, 5-7% of MgO and 0.5-1% of Fe₂O₃3 to 4 percent of expanding agent, 4 to 5 percent of heating agent and the balance of impurities.

2. The metallurgical insulating covering agent according to claim 1, characterized in that the melting point of the alkaline covering agent is 1190 ℃ -1421 ℃.

3. The metallurgical heat-insulating covering agent is characterized in that the metallurgical heat-insulating covering agent is an acidic covering agent and comprises 20-30 percent of Ca0 and 30-50 percent of Al in percentage by weight₂O₃5 to 10 percent of MgO and less than 5 percent of CaF₂40-50% of C, 4-5% of expanding agent, 2-4% of heating agent and the balance of impurities.

4. A metallurgical insulating covering agent according to claim 3, characterised in that the melting point of the acidic covering agent is 1200-1400 ℃.