Continuous casting tundish hollow particle carbon-free covering agent and preparation method thereof

Abstract

The invention relates to a continuous casting tundish hollow particle carbon-free covering agent, belonging to the iron and steel smelting field. The carbon-free covering agent comprises the followingcomponents by weight percent: 25-35% of SiO2, 8-20% of Al2O3, less than 1.5% of Fe2O3, 25-35% of CaO, 8-16% of MgO and less than 0.5% of H2O, wherein 0.15-1.0mm of particles account for 90-100% and the bulk specific weight is 0.6-0.9g / cm<3>. The continuous casting tundish hollow particle carbon-free covering agent has good spreadability, when added the covering agent can be molten fast and can cover the whole surface of molten steel, thus avoiding the secondary oxidation of molten steel; the covering agent has function of absorbing inclusion, can purify molten steel and increase the casting blank quality; the covering agent has good thermal insulation property, thus significantly reducing the temperature loss of molten steel; the slag of the covering agent can not incrust and stick to thestopper rod; and the content of carbon in molten steel is not increased.

Description

Technical field:

[0001] The invention belongs to the field of iron and steel smelting and relates to a tundish covering agent. It can improve the quality of molten steel, extend the service life of the tundish, does not increase carbon, has good thermal insulation and spreading properties, and has a good application prospect. technical background:

[0002] In order to maintain the temperature of molten steel, improve the quality of molten steel and prolong the service life of tundish, steel mills at home and abroad have done a lot of research work on the production and application technology of tundish covering agent in recent years, and achieved remarkable results. The production practice of domestic and foreign steel mills has proved that the performance of the hollow particle carbon-free covering agent has an irreplaceable effect on the steel grades with special requirements.

[0003] The carbon-free covering agent is based on CaO-SiO 2 -Al 2 o 3 as base material, Na ...

Examples

Embodiment 1

[0045] Take by weighing raw wollastonite (CaO content 45%, SiO 2 Content 50%) 50kg, high bauxite (Al 2 o 3 content 80%) 14kg, magnesia (MgO content 80%) 12kg, fluorite (CaF 2 content 90%) 2kg, industrial soda ash (Na 2 O content 56%) 5kg, limestone (CaO content 48%) 17kg, each raw material particle size is 200 orders. Put various raw materials into the conical mixer and stir for 15 minutes; put the mixed materials into the stirring water mill, add 50kg of water (the relationship between the water content in the raw materials and the water distribution has little effect), add the binder sodium carboxymethyl cellulose 2kg and cornstarch 0.5kg); grinding and slurrying, water milling time for 1 hour, and then spray drying to make hollow granules. Particle size 0.15mm~1.0mm: about 98%, bulk specific gravity 0.6g / cm3, H 2 O2 ) is 1.23, and the melting point is 1300°C (measured by an experimental melting point instrument). The product is packaged and put into storage.

Embodiment 2

[0047] Weigh the raw wollastonite (CaO: 45%, SiO 2 : 50%) 54kg, high alumina bauxite (Al 2 o 3 : 80%) 14kg, magnesia (MgO: 80%) 12kg, fluorite (CaF 2 : 90%) 1kg, industrial soda ash (Na 2O: 56%) 2kg, limestone (CaO: 48%) 17kg, each raw material particle size is 200 orders. Put various raw materials into a conical mixer and stir for 15 minutes; put the mixed materials into a stirring water mill, add 50kg of water (the relationship between the water content in the raw materials and the water distribution has little effect), add the binder sodium carboxymethyl cellulose 2kg and cornstarch 0.5kg); grinding and slurrying, water milling time 1.5 hours, then spray-dried to make hollow granules. Particle size 0.15mm~1.0mm: 95%, bulk specific gravity 0.8g / cm3, H 2 O2 ) is 1.20, and the melting point is 1350°C (measured by a melting point instrument in the experiment). The product is packaged and put into storage.

Embodiment 3

[0049] Weigh the raw wollastonite (CaO: 45%, SiO 2 : 50%) 57kg, high alumina bauxite (Al 2 o 3 : 80%) 14kg, magnesia (MgO: 80%) 12kg, limestone (CaO: 48%) 17kg (the particle size of each raw material is weighed to be 200 mesh). Put various raw materials (including flux: fluorite, magnesia, industrial soda ash) into the conical mixer and stir for 15 minutes; put the mixed material into the stirring water mill, add 50kg of water (the water content in the raw material is affected by the water distribution relationship Very small) Add 2kg of sodium carboxymethylcellulose and 0.5kg of cornstarch as binders; grind and make pulp, water mill for 1 hour, and then spray dry to make hollow granules. Particle size 0.15mm~1.0mm: 90%~100%, bulk specific gravity 0.6g / cm3~0.9g / cm3, H 2 O2 ) is 1.19, and the melting point is 1400°C (measured by a melting point instrument in the experiment). The product is packaged and put into storage.

Technical field:

[0001] The invention belongs to the field of iron and steel smelting and relates to a tundish covering agent. It can improve the quality of molten steel, extend the service life of the tundish, does not increase carbon, has good thermal insulation and spreading properties, and has a good application prospect. technical background:

[0002] In order to maintain the temperature of molten steel, improve the quality of molten steel and prolong the service life of tundish, steel mills at home and abroad have done a lot of research work on the production and application technology of tundish covering agent in recent years, and achieved remarkable results. The production practice of domestic and foreign steel mills has proved that the performance of the hollow particle carbon-free covering agent has an irreplaceable effect on the steel grades with special requirements.

[0003] The carbon-free covering agent is based on CaO-SiO 2 -Al 2 o 3 as base material, Na ...

Examples

Embodiment 1

[0045] Take by weighing raw wollastonite (CaO content 45%, SiO 2 Content 50%) 50kg, high bauxite (Al 2 o 3 content 80%) 14kg, magnesia (MgO content 80%) 12kg, fluorite (CaF 2 content 90%) 2kg, industrial soda ash (Na 2 O content 56%) 5kg, limestone (CaO content 48%) 17kg, each raw material particle size is 200 orders. Put various raw materials into the conical mixer and stir for 15 minutes; put the mixed materials into the stirring water mill, add 50kg of water (the relationship between the water content in the raw materials and the water distribution has little effect), add the binder sodium carboxymethyl cellulose 2kg and cornstarch 0.5kg); grinding and slurrying, water milling time for 1 hour, and then spray drying to make hollow granules. Particle size 0.15mm~1.0mm: about 98%, bulk specific gravity 0.6g / cm3, H 2 O2 ) is 1.23, and the melting point is 1300°C (measured by an experimental melting point instrument). The product is packaged and put into storage.

Embodiment 2

[0047] Weigh the raw wollastonite (CaO: 45%, SiO 2 : 50%) 54kg, high alumina bauxite (Al 2 o 3 : 80%) 14kg, magnesia (MgO: 80%) 12kg, fluorite (CaF 2 : 90%) 1kg, industrial soda ash (Na 2O: 56%) 2kg, limestone (CaO: 48%) 17kg, each raw material particle size is 200 orders. Put various raw materials into a conical mixer and stir for 15 minutes; put the mixed materials into a stirring water mill, add 50kg of water (the relationship between the water content in the raw materials and the water distribution has little effect), add the binder sodium carboxymethyl cellulose 2kg and cornstarch 0.5kg); grinding and slurrying, water milling time 1.5 hours, then spray-dried to make hollow granules. Particle size 0.15mm~1.0mm: 95%, bulk specific gravity 0.8g / cm3, H 2 O2 ) is 1.20, and the melting point is 1350°C (measured by a melting point instrument in the experiment). The product is packaged and put into storage.

Embodiment 3

[0049] Weigh the raw wollastonite (CaO: 45%, SiO 2 : 50%) 57kg, high alumina bauxite (Al 2 o 3 : 80%) 14kg, magnesia (MgO: 80%) 12kg, limestone (CaO: 48%) 17kg (the particle size of each raw material is weighed to be 200 mesh). Put various raw materials (including flux: fluorite, magnesia, industrial soda ash) into the conical mixer and stir for 15 minutes; put the mixed material into the stirring water mill, add 50kg of water (the water content in the raw material is affected by the water distribution relationship Very small) Add 2kg of sodium carboxymethylcellulose and 0.5kg of cornstarch as binders; grind and make pulp, water mill for 1 hour, and then spray dry to make hollow granules. Particle size 0.15mm~1.0mm: 90%~100%, bulk specific gravity 0.6g / cm3~0.9g / cm3, H 2 O2 ) is 1.19, and the melting point is 1400°C (measured by a melting point instrument in the experiment). The product is packaged and put into storage.