CN103787672A - Preparation method of slag line magnesia carbon brick for steel ladle - Google Patents

Abstract

The invention discloses a preparation method of a slag line magnesia carbon brick for a steel ladle. The preparation method comprises the following steps: (1) placing 28-32 parts of 5-20-mesh low-silicon fused magnesia, 22-26 parts of 20-50-mesh low-silicon fused magnesia, 8-12 parts of 50-200-mesh low-silicon fused magnesia and 1-3 parts of -200-mesh low-silicon fused magnesia into a mixing machine to mix for 30-40min; (2) then, adding 0.8-1.2 parts of -20-mesh graphite powder, 1-2 parts of -100-mesh zinc powder, 1-2 parts of -100-mesh aluminum powder, 0.5-1 part of -200-mesh borne nitride, 0.5-1 part of -200-mesh boron carbide, 1-2 parts of -200-mesh cerium oxide and 0.5-1.5 parts of asphalt powder to mix for 60-90min; (3) next, adding 3.5-4.5 parts of phenolic resin to remix for 60-90min; (4) forming by using a press and drying a green brick at the temperature of 200 DEG C for 24h.

Description

The preparation method of slag line magnesia carbon brick for a kind of ladle

Technical field

The present invention relates to technical field of ferrous metallurgy, relate in particular to the preparation method of a kind of ladle slag line magnesia carbon brick.

Background technology

Enter 21 century, iron and steel enterprise's structural adjustment, fine quality steel becomes the leading product of large-lot producer, as: superior alloy steel, ultra low-carbon steel, Clean Steel, the ratio of the steel grades such as high-strength steel increases year by year, fine quality steel requires strictly to control the carbon content in refractory materials in smelting process, to reduce the carburetting to molten steel, and liquid steel temperature raising and fall are little in secondary refining, the thermal conductivity of ladle lining is low, thereby cause the working conditions of ladle harsher, Working environment is more severe, in the urgent need to pollution-free to molten steel, the appearance of low carbon magnesia carbon brick for the high-quality ladle slag line of high durability.

Ladle slag line is generally 10～18wt% with the total carbon content of common magnesia carbon brick at present, and the one of the main reasons of magnesia carbon brick damage is the oxidation due to carbon in brick, thereby slag easily permeates, make to corrode aggravation, but the research of current ongoing low carbon magnesia carbon brick aspect mainly concentrates on the research of bonding agent and carbon raw, if: application number is that 200610046434.0 Chinese patents disclosed " magnesia carbon brick and the production method thereof of Containing antioxidants C-TiN composite granule " are respectively using C-TiN composite granule as oxidation inhibitor with graphite, electrosmelted magnesite clinker, bonding agent is through mixing, moulding, after thermal treatment, make, improve slag resistance, extend work-ing life, but because titanium material cost is higher, be difficult to promote the use of, and the carbon content of this magnesia carbon brick is high, will be to molten steel recarburization, application number is that 200710019767.9 Chinese patents disclosed " a kind of non-oxide composite low-carbon magnesia-carbon brick " have been introduced and in magnesia carbon brick, introduced non-oxidized substance (nitride or boride) and prepare carbon containing lower than 6% low carbon magnesia carbon brick, it has kept the performance of high-carbon magnesia carbon brick, what add due to it is the non-oxidized substance that pre-synthesis is good, cost is high, and hydration reaction may occur, and performance improves not obvious, application number is that 99107800.4 Chinese patents disclosed " antioxidant of carbon containing refractory " have been introduced a kind of antioxidant, at least one in its zinc powder by 0.15～10% (weight) or zinc powder and aluminium, magnesium, silicon, silicon calcium powder, silicon carbide, norbide, magnesium aluminum-alloy powder, silicon nitride powder forms, wherein zinc powder >=0.15%, granularity is less than 0.5mm, add metal powder to be only used for preventing the oxidation of carbon in carbon containing refractory, the mechanical behavior under high temperature of refractory materials is not affected.

Summary of the invention

The object of the invention is to propose the preparation method of a kind of ladle slag line magnesia carbon brick, magnesia carbon brick prepared by the method can reduce ladle slag line magnesia carbon brick in use to molten steel recarburization, solves the magnesia carbon brick goods spalling resistance causing after carbon content reduces simultaneously and reduces.

For reaching this object, the present invention by the following technical solutions:

The preparation method of slag line magnesia carbon brick for a kind of ladle, described magnesia carbon brick is made up of following raw materials according by weight: the low silicon electrosmelted magnesite clinker of 5-20 order 28-32 part, the low silicon electrosmelted magnesite clinker of 20-50 order 22-26 part, the low silicon electrosmelted magnesite clinker of 50-200 order 8-12 part, the low silicon electrosmelted magnesite clinker of-200 order 1-3 part,-20 order Graphite Powder 99 0.8-1.2 parts,-100 order zinc powder 1-2 parts,-100 order aluminium powder 1-2 parts,-200 order boron nitride 0.5-1 parts,-200 order norbide 0.5-1 parts,-200 order cerium oxide 1-2 parts, asphalt powder 0.5-1.5 part, resol 3.5-4.5 part, described preparation method comprises the steps:

1) low 5-20 order silicon electrosmelted magnesite clinker, the low silicon electrosmelted magnesite clinker of 20-50 order, the low silicon electrosmelted magnesite clinker of 50-200 order, the low silicon electrosmelted magnesite clinker of-200 order are put into mixer mixing 30-40 minute;

2) add again-20 order Graphite Powder 99s ,-100 order zinc powders ,-100 order aluminium powders ,-200 order boron nitride ,-200 order norbides ,-200 order cerium oxide, asphalt powder, mix 60-90 minute;

3) then add resol, remix 60-90 minute;

4) use pressing machine moulding, adobe is dry through 200 ℃ × 24 hours.

In order to reduce molten steel recarburization, under the prerequisite that guarantees magnesia carbon brick antistripping and resistance to fouling, must further reduce the carbon content of the slag line magnesia carbon brick supporting with carbon-free molten bath brick.But it is that magnesia carbon brick anti-thermal shock stability is reduced that reduction magnesia carbon brick carbon content the most significantly affects magnesia carbon brick character, and spalling resistance and resistance to fouling reduce.

The present invention is by adding the combination of zinc powder and aluminium powder, not only play oxidation resistant effect, and be mainly reaction in－situ to occur in applied at elevated temperature process generate non-oxidized substance, then fill to intert and in periclasite skeleton structure, play enhancing toughening effect, thereby significantly improve hot strength and the heat-shock resistance of magnesia carbon brick, improve its oxidation-resistance and slag resistance

Norbide and boron nitride can effectively prevent the oxidation of graphite and non-oxidized substance, make magnesia carbon brick be difficult for being soaked by slag and permeating.

Cerium oxide guarantee matrix part realize best sintering, in conjunction with effect.Greatly improve the work-ing life of working lining, reduce carbon melting loss and be mingled with, reduce ladle carburetting.

The beneficial effect of the inventive method is:

1) the inventive method is prepared ladle slag line magnesia carbon brick, and carbon content≤3%, to molten steel recarburization≤3ppm, has reduced the pollution to molten steel.

2, the metal powder Main Function in component of the present invention is reaction in－situ to occur in magnesia carbon brick applied at elevated temperature process generate non-oxidized substance, then fill to intert and in periclasite skeleton structure, play enhancing toughening effect, thereby the hot strength and the heat-shock resistance that significantly improve magnesia carbon brick, improve its oxidation-resistance and slag resistance.

3, the ladle slag line metallic composite low carbon magnesium carbon brick that the inventive method makes, volume density>=3.05g/cm ³, apparent porosity≤5%, cold crushing strength>=53MPa, 1400 ℃ are buried carbon high-temp folding strength>=30Mpa, carbon content≤3%, MgO content>=85%.

4, the ladle slag line metallic composite low carbon magnesium carbon brick that the inventive method makes, it is 78～83% (now conventional magnesia carbon brick residual strength conservation rate is 50～60%) that 1100 ℃ of heat-shock resistance employings, air-cooled air quenching method are once measured residual strength conservation rate.

5, the ladle slag line metallic composite low carbon magnesium carbon brick that the inventive method makes, oxidation-resistance, slag resistance, hot strength, heat-shock resistance improve obviously, and ladle slag line refractory brick life extends, and ton steel refractory consumption rate cost declines.

Embodiment

Embodiment mono-

The preparation method of slag line magnesia carbon brick for a kind of ladle, described magnesia carbon brick is made up of following raw materials according by weight: 28 parts of the low silicon electrosmelted magnesite clinkers of 5-20 order, 26 parts of the low silicon electrosmelted magnesite clinkers of 20-50 order, 8 parts of the low silicon electrosmelted magnesite clinkers of 50-200 order, 3 parts of the low silicon electrosmelted magnesite clinkers of-200 order,-20 0.8 part of order Graphite Powder 99,-100 2 parts of order zinc powders,-100 1 part of order aluminium powder,-200 1 part of order boron nitride,-200 0.5 part of order norbide,-200 2 parts of order cerium oxide, 0.5 part of asphalt powder, 4.5 parts, resol, described preparation method comprises the steps: 1) by low 5-20 order silicon electrosmelted magnesite clinker, the low silicon electrosmelted magnesite clinker of 20-50 order, the low silicon electrosmelted magnesite clinker of 50-200 order, the low silicon electrosmelted magnesite clinker of-200 order is put into mixer and is mixed 30 minutes,

2) add again-20 order Graphite Powder 99s ,-100 order zinc powders ,-100 order aluminium powders ,-200 order boron nitride ,-200 order norbides ,-200 order cerium oxide, asphalt powder, mix 60 minutes;

3) then add resol, remix 60 minutes;

4) use pressing machine moulding, adobe is dry through 200 ℃ × 24 hours.

Embodiment bis-

The preparation method of slag line magnesia carbon brick for a kind of ladle, described magnesia carbon brick is made up of following raw materials according by weight: 32 parts of the low silicon electrosmelted magnesite clinkers of 5-20 order, 22 parts of the low silicon electrosmelted magnesite clinkers of 20-50 order, 12 parts of the low silicon electrosmelted magnesite clinkers of 50-200 order, 1 part of the low silicon electrosmelted magnesite clinker of-200 order,-20 1.2 parts of order Graphite Powder 99s,-100 1 part of order zinc powder,-100 2 parts of order aluminium powders ,-200 0.5 part of order boron nitride ,-200 1 part of order norbide,-200 1 part of order cerium oxide, 1.5 parts of asphalt powders, 3.5 parts, resol, described preparation method comprises the steps:

1) low 5-20 order silicon electrosmelted magnesite clinker, the low silicon electrosmelted magnesite clinker of 20-50 order, the low silicon electrosmelted magnesite clinker of 50-200 order, the low silicon electrosmelted magnesite clinker of-200 order are put into mixer and mixed 40 minutes;

2) add again-20 order Graphite Powder 99s ,-100 order zinc powders ,-100 order aluminium powders ,-200 order boron nitride ,-200 order norbides ,-200 order cerium oxide, asphalt powder, mix 90 minutes;

3) then add resol, remix 90 minutes;

4) use pressing machine moulding, adobe is dry through 200 ℃ × 24 hours.

Embodiment tri-

The preparation method of slag line magnesia carbon brick for a kind of ladle, described magnesia carbon brick is made up of following raw materials according by weight: 30 parts of the low silicon electrosmelted magnesite clinkers of 5-20 order, 24 parts of the low silicon electrosmelted magnesite clinkers of 20-50 order, 10 parts of the low silicon electrosmelted magnesite clinkers of 50-200 order, 2 parts of the low silicon electrosmelted magnesite clinkers of-200 order,-20 1.0 parts of order Graphite Powder 99s,-100 1.5 parts of order zinc powders,-100 1.5 parts of order aluminium powders ,-200 0.8 part of order boron nitride ,-200 0.8 part of order norbide,-200 1.5 parts of order cerium oxide, 1 part of asphalt powder, 4 parts, resol, described preparation method comprises the steps:

1) low 5-20 order silicon electrosmelted magnesite clinker, the low silicon electrosmelted magnesite clinker of 20-50 order, the low silicon electrosmelted magnesite clinker of 50-200 order, the low silicon electrosmelted magnesite clinker of-200 order are put into mixer and mixed 35 minutes;

2) add again-20 order Graphite Powder 99s ,-100 order zinc powders ,-100 order aluminium powders ,-200 order boron nitride ,-200 order norbides ,-200 order cerium oxide, asphalt powder, mix 75 minutes;

3) then add resol, remix 75 minutes;

4) use pressing machine moulding, adobe is dry through 200 ℃ × 24 hours.

Claims (1)

1. the preparation method of a ladle use slag line magnesia carbon brick, it is characterized in that, described magnesia carbon brick is made up of following raw materials according by weight: the low silicon electrosmelted magnesite clinker of 5-20 order 28-32 part, the low silicon electrosmelted magnesite clinker of 20-50 order 22-26 part, the low silicon electrosmelted magnesite clinker of 50-200 order 8-12 part, the low silicon electrosmelted magnesite clinker of-200 order 1-3 part,-20 order Graphite Powder 99 0.8-1.2 parts,-100 order zinc powder 1-2 parts,-100 order aluminium powder 1-2 parts,-200 order boron nitride 0.5-1 parts,-200 order norbide 0.5-1 parts,-200 order cerium oxide 1-2 parts, asphalt powder 0.5-1.5 part, resol 3.5-4.5 part, described preparation method comprises the steps:

1) low 5-20 order silicon electrosmelted magnesite clinker, the low silicon electrosmelted magnesite clinker of 20-50 order, the low silicon electrosmelted magnesite clinker of 50-200 order, the low silicon electrosmelted magnesite clinker of-200 order are put into mixer mixing 30-40 minute;

2) add again-20 order Graphite Powder 99s ,-100 order zinc powders ,-100 order aluminium powders ,-200 order boron nitride ,-200 order norbides ,-200 order cerium oxide, asphalt powder, mix 60-90 minute;

3) then add resol, remix 60-90 minute;

4) use pressing machine moulding, adobe is dry through 200 ℃ × 24 hours.