CN107602136A - A kind of refractory material liner body for tundish and preparation method thereof - Google Patents

Abstract

The invention relates to a refractory lining body for a tundish, comprising a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is made of heavy calcium hexaaluminate material, the The bulk density of the heavy calcium hexaaluminate material is ≥2.8g/cm ³ . The heavy calcium hexaaluminate material used in the working lining of the refractory lining of the tundish in the present invention has high chemical purity, and the reaction products at high temperatures are all high melting point phases. According to different proportions, the phase It is calcium hexaaluminate (melting point: 1903°C) and corundum phase (melting point: 2050°C), so it has excellent high temperature performance, corrosion resistance, clean molten steel effect; at the same time, it can greatly improve the safety factor and thermal shock resistance of the tundish And thermal insulation performance, and the service life is also significantly improved.

Description

A kind of refractory lining body for tundish and preparation method thereof

technical field

The invention relates to a refractory material and a preparation method thereof, in particular to a refractory material for working lining of a tundish and a preparation method thereof.

Background technique

The tundish is an important thermal equipment in the steelmaking process, and the refractory lining of the tundish plays a very important role in the safe production of the tundish, the quality of molten steel, and the smooth operation of molten steel continuous casting. With the improvement of steel quality requirements, the refractory working lining of the tundish is required to have a long service life, good thermal insulation performance, and the function of purifying molten steel.

At present, the working lining of the tundish is generally composed of three layers, the working layer, the permanent layer and the insulation layer stacked in sequence. The working layer is magnesia smear material or magnesia dry material, the permanent layer is low cement material, and the insulation layer is refractory fiber felt. Generally, the magnesia-based smear material is poured into steel for a few hours before being used, and the bag is removed; the working layer of magnesia dry-type material is poured into steel for about 30 to 40 hours, and the bag is removed; when it is removed, about one-third of the working layer remains. Second, the waste is huge; in addition, impurities such as silicon dioxide and spinel in the magnesia working layer of the tundish enter the molten steel during the pouring process, affecting the quality of the molten steel.

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of refractory material for working lining of tundish and its preparation method. With high calcium content, it can absorb impurities in molten steel and has a purifying effect on molten steel.

The technical solution of the present invention to solve the above technical problems is as follows: a refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, and the working lining is made of heavy hexaluminum It is made of calcium hexaaluminate material, and the bulk density of the heavy calcium hexaaluminate material is ≥2.8g/cm ³ .

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the heavy calcium hexaaluminate material includes the following chemical components in weight percentage: 85%-94.5% of Al ₂ O ₃ , 0%-6% of MgO, 5.0%-9.0% of CaO, and the remaining components are less than or equal to 2%.

Further, the main crystal phase of the heavy calcium hexaaluminate material is CaAl ₁₂ O ₁₉ , and the main crystal phase CaAl ₁₂ O ₁₉ of the heavy calcium hexaaluminate material includes the following chemical composition in weight percentage, Al ₂ O ₃ 91%-93%, CaO 6.5%-8.5%, and other components less than 1.5%; the mineral phase content of the main crystal phase CaAl ₁₂ O ₁₉ of the heavy calcium hexaaluminate material is greater than or equal to 80%.

Further, the heavy calcium hexaaluminate material includes the following raw materials in weight percent:

Calcium hexaaluminate raw material with a particle size of 18-10mm 5-10%;

Calcium hexaaluminate raw materials with a particle size of 5-10 mm 15-20%;

Calcium hexaaluminate raw material with a particle size of 3-5 mm 15-20%;

Calcium hexaaluminate raw materials with a particle size of 1-3mm 15-20%;

Calcium hexaaluminate raw materials with a particle size of 0.088-1mm 15-20%;

Calcium hexaaluminate raw material with particle size <88μm 0-10%;

Corundum powder with particle size <88μm 0-10%;

Spinel powder with particle size <88μm 0-10%;

a-Al ₂ O ₃ micropowder 0~10%;

Pure calcium aluminate cement 0-10%;

0.10-0.15% of the total weight of the above-mentioned raw materials is added to the water reducing agent;

The bulk density of the calcium hexaaluminate raw material is ≥2.8g/cm ³ .

Further, the mass content of Al ₂ O ₃ in the spinel powder is ≥70.0%.

Further, the particle size of the a-Al ₂ O ₃ micropowder is ≤5 μm.

The beneficial effects of the present invention are: the working lining of the refractory lining used in the tundish of the present invention adopts heavy calcium hexaaluminate material with high chemical purity, and the reaction products at high temperature are all high melting point phases, according to different Proportion, the phase is calcium hexaaluminate (melting point: 1903°C) and corundum phase (melting point: 2050°C), so it has excellent high temperature performance, corrosion resistance, and clean molten steel; at the same time, it can greatly improve the safety of the tundish Coefficient, thermal shock resistance and thermal insulation performance, and the service life is significantly improved.

Based on the above refractory lining for a tundish, the present invention also provides a preparation method for the refractory lining for the tundish.

A method for preparing a refractory lining for a tundish, the working lining is made by cast-in-place method, or by prefabricated part method, and the permanent lining is made by cast-in-place method, or by prefabricated part Made by law, or made by firing refractory bricks.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, when using the method of pouring on site, mix the required raw materials according to the preset ratio, and add the preset ratio of water and water reducing agent, stir evenly, vibrate and form, and keep warm at the set temperature for 12 hours Above, the required refractory lining can be produced.

Further, when using the prefabricated part method, the required raw materials are mixed according to the preset ratio, and the preset ratio of water and dispersant is added, stirred evenly, put into the prefabricated part model, and the obtained product can be obtained after drying. The required refractory lining.

Furthermore, when using the firing method of refractory bricks, the required raw materials are mixed according to the preset ratio, and an appropriate amount of binder is added, pressed and formed, and fired at a high temperature of 1450-1650°C.

The beneficial effects of the present invention are: the working lining prepared by adopting the preparation method of the refractory lining used in the tundish of the present invention has strong corrosion resistance to molten steel, good thermal shock resistance, long service life, and good thermal insulation performance, etc. Features, the heavy calcium hexaaluminate material has a high content of calcium oxide, which can absorb impurities in molten steel and has a purifying effect on molten steel; the heavy calcium hexaaluminate material of the working lining is suitable for casting various steel types and can be used for a long time without using Replace and dismantle, saving a lot of resources.

Detailed ways

The principles and features of the present invention are described with examples below, which are only used to explain the present invention, and are not intended to limit the scope of the present invention.

In a refractory lining body used for a tundish of the present invention, the working lining adopts heavy calcium hexaaluminate material, and the permanent lining can adopt existing materials (for example: low cement material, medium heavy calcium hexaaluminate material , lightweight insulation calcium hexaaluminate materials and lightweight insulation bricks, etc.), heavy calcium hexaaluminate materials can also be used.

Example 1

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is poured with heavy calcium hexaaluminate material, and the heavy hexaaluminum The bulk density of the calcium hexaaluminate material is ≥2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

5% calcium hexaaluminate raw material with a particle size of 18-10mm;

Calcium hexaaluminate raw material with a particle size of 5-10mm 20%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 20%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 15%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 15%;

Calcium hexaaluminate raw material with particle size <88μm 5%;

10% of spinel powder with particle size <88μm;

a-Al ₂ O ₃ micropowder 10%;

0.10% of the total weight of the above-mentioned raw materials is added to the water reducer.

In Example 1:

The permanent lining is poured with low cement material, and its index is:

When the existing material is used for the permanent lining, the refractory lining body used in the tundish of the present invention also includes a thermal insulation lining, the thermal insulation lining is located outside the permanent lining, and the thermal insulation lining is made of refractory ceramic fiber board , whose index is:

Bulk density (g/cm ³ ) 1200℃×24h heating permanent line change (%) 0.33 -0.1

In Embodiment 1, the manufacturing steps of a refractory lining of a tundish of the present invention are as follows:

The first step is to paste the refractory ceramic fiberboard (insulation lining) along the tundish steel shell, support the permanent lining mold, pour the low cement material close to the refractory ceramic fiberboard, the thickness is about 200mm, demould after curing for 24 hours, and bake to 800 ℃ for 10 hours;

In the second step, after the low-cement material of the permanent lining is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept warm. It can be put into use within 8 hours.

Example 2

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is poured with heavy calcium hexaaluminate material, and the heavy hexaaluminum The bulk density of the calcium hexaaluminate material is ≥2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

7.5% calcium hexaaluminate raw material with a particle size of 18-10mm;

Calcium hexaaluminate raw material with a particle size of 5-10mm 17.5%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 15%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 20%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 20%;

10% corundum powder with particle size <88μm;

Spinel powder with particle size <88μm 5%;

Pure calcium aluminate cement 5%;

Add 0.11% water reducer by weight of the above raw materials.

In Example 2:

The permanent lining is poured with low cement material, and its index is:

When the existing material is used for the permanent lining, the refractory lining body used in the tundish of the present invention also includes a thermal insulation lining, the thermal insulation lining is located outside the permanent lining, and the thermal insulation lining is made of refractory ceramic fiber board , whose index is:

Bulk density (g/cm ³ ) 1200℃×24h heating permanent line change (%) 0.33 -0.1

In embodiment 2, the manufacturing steps of a refractory lining of a tundish of the present invention are as follows:

The first step is to paste the refractory ceramic fiberboard (insulation lining) along the tundish steel shell, support the permanent lining mold, pour the low cement material close to the refractory ceramic fiberboard, the thickness is about 200mm, demould after curing for 24 hours, and bake to 800 ℃ for 10 hours;

In the second step, after the low-cement material of the permanent lining is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept warm. It can be put into use within 8 hours.

Example 3

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is poured with heavy calcium hexaaluminate material, and the heavy hexaaluminum The bulk density of the calcium hexaaluminate material is ≥2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

7.5% calcium hexaaluminate raw material with a particle size of 18-10 mm;

Calcium hexaaluminate raw material with a particle size of 5-10mm 15%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 17.5%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 17.5%;

17.5% calcium hexaaluminate raw material with a particle size of 0.088-1 mm;

Calcium hexaaluminate raw material with particle size <88μm 10%;

Corundum powder with particle size <88μm 5%;

a-Al ₂ O ₃ micropowder 5%;

Pure calcium aluminate cement 5%;

Add 0.12% of the water reducing agent of the total weight of the above-mentioned raw materials.

In Example 3:

The permanent lining is poured with low cement material, and its index is:

When the existing material is used for the permanent lining, the refractory lining body used in the tundish of the present invention also includes a thermal insulation lining, the thermal insulation lining is located outside the permanent lining, and the thermal insulation lining is made of refractory ceramic fiber board , whose index is:

Bulk density (g/cm ³ ) 1200℃×24h heating permanent line change (%) 0.33 -0.1

In Embodiment 3, the manufacturing steps of a refractory lining of a tundish of the present invention are as follows:

The first step is to paste the refractory ceramic fiberboard (insulation lining) along the tundish steel shell, support the permanent lining mold, pour the low cement material close to the refractory ceramic fiberboard, the thickness is about 200mm, demould after curing for 24 hours, and bake to 800 ℃ for 10 hours;

In the second step, after the low-cement material of the permanent lining is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept warm. It can be put into use within 8 hours.

Example 4

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is poured with heavy calcium hexaaluminate material, and the heavy hexaaluminum The bulk density of the calcium hexaaluminate material is ≥2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

Calcium hexaaluminate raw material with a particle size of 18-10mm 10%;

Calcium hexaaluminate raw material with a particle size of 5-10mm 15%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 15%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 15%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 15%;

Calcium hexaaluminate raw material with particle size <88μm 5%;

Corundum powder with particle size <88μm 5%;

Spinel powder with particle size <88μm 5%;

a-Al ₂ O ₃ micropowder 5%;

Pure calcium aluminate cement 10%;

Add 0.13% of the water reducer by the total weight of the above raw materials.

In Example 4:

The permanent lining is poured with low cement material, and its index is:

When the existing material is used for the permanent lining, the refractory lining body used in the tundish of the present invention also includes a thermal insulation lining, the thermal insulation lining is located outside the permanent lining, and the thermal insulation lining is made of refractory ceramic fiber board , whose index is:

Bulk density (g/cm ³ ) 1200℃×24h heating permanent line change (%) 0.33 -0.1

In Embodiment 4, the manufacturing steps of a refractory lining of a tundish of the present invention are as follows:

The first step is to paste the refractory ceramic fiberboard (insulation lining) along the tundish steel shell, support the permanent lining mold, pour the low cement material close to the refractory ceramic fiberboard, the thickness is about 200mm, demould after curing for 24 hours, and bake to 800 ℃ for 10 hours;

In the second step, after the low-cement material of the permanent lining is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept warm. It can be put into use within 8 hours.

Example 5

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is poured with heavy calcium hexaaluminate material, and the heavy hexaaluminum The bulk density of the calcium hexaaluminate material is ≥2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

Calcium hexaaluminate raw material with a particle size of 10-18mm 10%;

Calcium hexaaluminate raw material with a particle size of 5-10 mm 15%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 15%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 15%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 15%;

Calcium hexaaluminate raw material with particle size <88μm 10%;

Corundum powder with particle size <88μm 8%;

a-Al ₂ O ₃ fine powder 6%;

Pure calcium aluminate cement 6%;

Add 0.14% of the water reducer by the total weight of the above raw materials.

In Example 5:

The permanent lining is poured with low cement material, and its index is:

When the existing material is used for the permanent lining, the refractory lining body used in the tundish of the present invention also includes a thermal insulation lining, the thermal insulation lining is located outside the permanent lining, and the thermal insulation lining is made of refractory ceramic fiber board , whose index is:

Bulk density (g/cm ³ ) 1200℃×24h heating permanent line change (%) 0.33 -0.1

In Embodiment 5, the manufacturing steps of a refractory lining of a tundish of the present invention are as follows:

The first step is to paste the refractory ceramic fiberboard (insulation lining) along the tundish steel shell, support the permanent lining mold, pour the low cement material close to the refractory ceramic fiberboard, the thickness is about 200mm, demould after curing for 24 hours, and bake to 800 ℃ for 10 hours;

In the second step, after the low-cement material of the permanent lining is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept warm. It can be put into use within 8 hours.

Example 6

A refractory lining body for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is made of heavy calcium hexaaluminate material, and the heavy hexaaluminate The bulk density of the calcium material is ≥ 2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

5% calcium hexaaluminate raw material with a particle size of 10-18 mm;

Calcium hexaaluminate raw material with a particle size of 5-10mm 15%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 15%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 15%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 15%;

Calcium hexaaluminate raw material with particle size <88μm 10%;

Corundum powder with particle size <88μm 5%;

Spinel powder with particle size <88μm 5%;

a-Al ₂ O ₃ fine powder 7%;

Pure calcium aluminate cement 8%;

Add 0.15% of the water reducer by weight of the above raw materials.

In Example 6:

The permanent lining is also poured with the heavy calcium hexaaluminate material; when the heavy calcium hexaaluminate material is also used for the permanent lining, the refractory lining body used in the tundish of the present invention does not need an insulating lining .

In embodiment 6, the manufacturing steps of a refractory lining body of a tundish of the present invention are as follows:

The first step is to pour the heavy calcium hexaaluminate material along the tundish steel shell to support the permanent lining mold, with a thickness of about 200mm, to release the mold after curing for 24 hours, and bake to 800°C for 10 hours;

In the second step, after the heavy calcium hexaaluminate material of the permanent layer is cooled to normal temperature, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm, demould after curing for 24 hours, and bake Bake to 1200°C and keep it warm for 8 hours before putting it into use.

Example 7

A refractory lining for a tundish, including a working lining and a permanent lining, the permanent lining is located outside the working lining, the working lining is made of heavy calcium hexaaluminate material, and the heavy hexaaluminate The bulk density of the calcium material is ≥ 2.8g/cm ³ , and the heavy calcium hexaaluminate material includes the following raw materials in weight percentage:

Calcium hexaaluminate raw material with a particle size of 10-18mm 7%;

Calcium hexaaluminate raw material with a particle size of 5-10mm 15%;

Calcium hexaaluminate raw material with a particle size of 3-5mm 15%;

Calcium hexaaluminate raw material with a particle size of 1-3mm 15%;

Calcium hexaaluminate raw material with a particle size of 0.088-1mm 15%;

Calcium hexaaluminate raw material with particle size <88μm: 8%;

Corundum powder with particle size <88μm 8%;

Spinel powder with particle size <88μm 3%;

a-Al ₂ O ₃ fine powder 7%;

Pure calcium aluminate cement 7%;

0.10% of the total weight of the above-mentioned raw materials is added to the water reducing agent.

In Example 7:

The permanent lining is made of lightweight heat-insulating bricks, whose indicators are:

In embodiment 7, the manufacturing steps of the refractory lining of the tundish are as follows:

The first step is to build lightweight insulation bricks along the steel shell of the tundish with a thickness of about 200mm.

In the second step, after the light insulation bricks are built, support the working lining mold and pour the heavy calcium hexaaluminate material with a thickness of about 100mm. After 24 hours of curing, the mold is demoulded, baked to 1200°C, and kept for 8 ready for use in hours.

The following table is the performance test results of a working lining for the refractory lining of the tundish in Examples 5-7:

It can be seen from the above table that the refractory lining used in the tundish of the present invention can greatly improve the safety factor, thermal shock resistance and thermal insulation performance of the tundish, and the service life can also be significantly improved.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (10)

1. A refractory lining for a tundish, comprising a working lining and a permanent lining, the permanent lining is located outside the working lining, characterized in that: the working lining is made of heavy calcium hexaaluminate material , the bulk density of the heavy calcium hexaaluminate material is ≥2.8g/cm ³ . 2. A refractory lining for a tundish according to claim 1, characterized in that: the heavy calcium hexaaluminate material includes the following chemical composition in weight percent: Al ₂ O ₃ 85%-94.5 %, MgO 0% to 6%, CaO 5.0% to 9.0%, and the remaining ingredients are less than or equal to 2%. 3. A refractory lining for a tundish according to claim 1 or 2, characterized in that: the main crystal phase of the heavy calcium hexaaluminate material is CaAl ₁₂ O ₁₉ , and the heavy The main crystal phase CaAl ₁₂ O ₁₉ of the calcium hexaaluminate material includes the following chemical components in weight percentage, Al ₂ O ₃ 91%-93%, CaO 6.5%-8.5%, and the remaining components are less than 1.5%; the heavy hexaaluminum The mineral phase content of the main crystal phase CaAl ₁₂ O ₁₉ of the calcium carbonate material is greater than or equal to 80%. 4. A refractory lining for a tundish according to claim 3, characterized in that: the heavy calcium hexaaluminate material comprises the following raw materials in weight percent: Calcium hexaaluminate raw material with a particle size of 18-10mm 5-10%; Calcium hexaaluminate raw materials with a particle size of 5-10 mm 15-20%; Calcium hexaaluminate raw material with a particle size of 3-5 mm 15-20%; Calcium hexaaluminate raw materials with a particle size of 1-3mm 15-20%; Calcium hexaaluminate raw materials with a particle size of 0.088-1mm 15-20%; Calcium hexaaluminate raw material with particle size <88μm 0-10%; Corundum powder with particle size <88μm 0-10%; Spinel powder with particle size <88μm 0-10%; a-Al ₂ O ₃ micropowder 0~10%; Pure calcium aluminate cement 0-10%; 0.10-0.15% of the total weight of the above-mentioned raw materials is added to the water reducing agent; The bulk density of the calcium hexaaluminate raw material is ≥2.8g/cm ³ . 5. A refractory lining for a tundish according to claim 4, characterized in that the mass content of Al ₂ O ₃ in the spinel powder is ≥70.0%. 6 . A refractory lining for a tundish according to claim 4 , characterized in that the particle size of the a-Al ₂ O ₃ micropowder is ≤5 μm. 7. A method for preparing a refractory lining for a tundish as described in any one of claims 1 to 6, wherein the working lining is made by casting in situ, or by It is made by prefabricated part method, and the permanent lining is made by cast-in-place method, or by prefabricated part method, or by firing refractory bricks. 8. A method for preparing a refractory lining for a tundish according to claim 7, characterized in that: when the method of casting on site is adopted, the required raw materials are mixed according to a preset ratio, and prepared With the preset ratio of water and water reducing agent, stir evenly, vibrate and form, keep warm at the set temperature for more than 12 hours, and then the required refractory lining can be produced. 9. A method for preparing a refractory lining for a tundish according to claim 7, characterized in that: when using the prefabricated part method, the required raw materials are mixed according to the preset ratio, and added The preset ratio of water and dispersant is stirred evenly, put into the prefabricated model, and after drying, the required refractory lining can be produced. 10. A method for preparing a refractory lining for a tundish according to claim 7, characterized in that: when using the firing method of refractory bricks, the required raw materials are mixed according to the preset ratio , plus an appropriate amount of binder, pressed into shape, and fired at a high temperature of 1450-1650 °C.