CN102173840A - Unburned MgO-Cr3C2-C brick for steelmaking - Google Patents

Abstract

The invention relates to an unburned MgO-Cr3C2-C brick for steelmaking. The unburned MgO-Cr3C2-C brick is made through mixing, forming, heat treatment and a finished product picking process by blending fused magnesites, Cr2O3 powder, SiC powder, graphite, an antioxidant and a bonding agent according to a certain proportion. Compared with the prior art, the invention has excellent chemical erosion resistant stability by introducing the Cr2O3 powder and the SiC powder into a carbon-containing refractory product, wherein the Cr2O3 powder can react with carbon contacting with the Cr2O3 powder at high temperature and form a high-melting-point stable phase Cr3C2 (Te=1810 DEG C) on a surface contacting with carbon granules and the Cr2O3 can promote the decomposition of SiC and deposit C so as to prevent oxidation loss and reduce damage caused by oxidation, therefore an MgO-Cr3C2-C brick product with better using performance compared with an Mg-C brick product is obtained; and in addition, C/Co can reduce Cr2O3 into Cr3C2 (in-situ Cr3C2) in situ at high temperature, therefore the problem of hazards of Cr<6+> on the environment can not be generated.

Description

Steel-making is with not burning MgO-Cr 3C 2-C brick

Technical field

The present invention relates in the Ferrous Metallurgy with not burning the carbon brick field, particularly further raising is not burnt magnesia carbon brick anti-slag liquid corrodes, performance and oxidation resistance are shaken in heat resistanceheat resistant steel-making with not burning MgO-Cr ₃C ₂-C brick.

Background technology

Magnesia carbon brick has refractoriness height, anti-slag and invades that performance is good, resistance to heat shocks reaches by force has good characteristics such as good stable performance, thermal conductivity is good, wear-resistant, spalling resistance is good under the high temperature.On electric furnace, converter, ladle and refining furnace, be used widely.Simultaneously, because magnesia carbon brick does not need high temperature to burn till, save the energy, manufacture craft is simple, thereby is applied rapidly by world many countries.And along with ironmaking, the development of Steel industry and the raising of production efficiency, the performance requriements of refractory materials is also improved constantly.How further to improve the high-temperature behavior of magnesia carbon brick, slag resistance and antioxygenic property, thus increase the service life, reduce ton steel refractory consumption amount, remain one of problem of domestic and international refractory material research.

Summary of the invention

In order further to improve high-temperature stability, non-oxidizability and the anti-scour property of magnesia carbon brick, increase the service life, the invention provides a kind of steel-making with not burning MgO-Cr ₃C ₂-C brick and preparation method thereof.

The technical solution used in the present invention is: a kind of steel-making is with not burning MgO-Cr ₃C ₂-C brick, made by weight ratio by following raw material:

20～30 parts of electrosmelted magnesite clinker 5mm～3mm,

20～30 parts of electrosmelted magnesite clinker 3mm～1mm,

10～20 parts of electrosmelted magnesite clinker≤1mm,

10～20 parts in magnesia 180 orders,

10～20 parts in graphite,

1～2 part of aluminium powder,

0.5～1 part in SiC powder,

Cr ₂O ₃2～3 parts in powder,

2～3 parts of wedding agents.

Above-mentioned steel-making is with not burning MgO-Cr ₃C ₂The preparation method of-C brick is as follows:

(1) by above-mentioned weight portion proportioning, take by weighing fused magnesite and bond that granularity is 5mm～3mm and 3mm～1mm, added the pre-mixed grind of puddle mixer 8～10 minutes, add then granularity for≤1mm and 180 purpose fused magnesites, graphite, aluminium powder, SiC powder and Cr ₂O ₃Powder, mixed grind 12～15 minutes;

(2) material that mixes is added in the mould, on 500 tons～800 tons friction presses, add and be pressed into base;

(3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 175～185 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.

Drying is a key link, must control the temperature curve of dry kiln, about 40～60 ℃ of dry kiln temperature ins, temperature is about 180 ℃ between heat preservation zone, between 40～60 ℃ of the temperature outs, general dry kiln length is not less than 24 meters, and go-cart is 40～70 minutes/car at interval, is not less than 16 hours time of drying.

Among the present invention, in magnesia carbon brick, introduce a small amount of Cr ₂O ₃Powder and SiC powder are with Cr ₂O ₃Powder is introduced in the carbon containing refractory, in hot environment, and Cr ₂O ₃Can form stable phase Cr with the carbon reaction of with it contact and at the contact carbon grain surface ₃C ₂, Cr ₃C ₂Belong to high-melting-point phase (Te=1810 ℃), have the stability of good chemical resistance of concrete, simultaneously Cr ₂O ₃Can also promote the decomposition of SiC, and deposition C, prevent oxidation loss, reduced the damage that causes owing to oxidation.At high temperature, C/CO can reduce Cr on the spot ₂O ₃Be Cr ₃C ₂(original position Cr ₃C ₂), thereby can not produce Cr ⁶⁺Problem to environmental hazard.

The invention has the beneficial effects as follows: the present invention is by adding Cr ₂O ₃Do not burn in the carbon containing refractory brick to MgO-C matter with SiC, cause Cr ₂O ₃At high temperature form Cr ₃C ₂The high-temperature stable phase, and promote SiC to decompose, thus the comprehensive function that the high-temperature stability of carbon brick, anti-scouring and antioxygenic property are not burnt in further raising.1000 ℃ of insulations were found after 4 hours: the rupture strength after burn (1) is significantly improved; (2) result of oxide layer test does not add Cr relatively ₂O ₃The little 2.0～2.8mm of decarburized layer; (3) use Static crucible method, drill out the blind hole of Φ 50mm * 50mm at the article center position, and be respectively charged into 40 gram scum and slags in the cinder hole.Find after 6 hours 1600 ℃ of insulations, corrode test result and relatively do not add Cr ₂O ₃The little 0.9mm～1.5mm of depth of erosion.(4) shake stability test of heat does not add Cr ₂O ₃Increase by 3～5 times.

Embodiment

1 one kinds of steel-making of embodiment are with not burning MgO-Cr ₃C ₂-C brick

(1) the weight part proportioning such as the table 1 of raw material

(2) preparation method is as follows:

(1) press the weight portion proportioning of table 1, take by weighing fused magnesite and bond that granularity is 5mm～3mm and 3mm～1mm, added the pre-mixed grind of puddle mixer 8～10 minutes, add then granularity for≤1mm and 180 purpose fused magnesites, graphite, aluminium powder, SiC powder and Cr ₂O ₃Powder, mixed grind 12～15 minutes;

(2) material that mixes is added in the mould, on 500 tons～800 tons friction presses, add and be pressed into base;

(3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 175～185 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.

Product the results are shown in Table 1.

2 one kinds of steel-making of embodiment are with not burning MgO-Cr ₃C ₂-C brick

The weight part proportioning such as the table 1 of raw material, the preparation method is with embodiment 1.

3 one kinds of steel-making of embodiment are with not burning MgO-Cr ₃C ₂-C brick

The weight part proportioning such as the table 1 of raw material, the preparation method is with embodiment 1.

Table 1

Claims (2)

1. a steel-making is with not burning MgO-Cr ₃C ₂-C brick is characterized in that being made by weight ratio by following raw material:

20～30 parts of electrosmelted magnesite clinker 5mm～3mm,

20～30 parts of electrosmelted magnesite clinker 3mm～1mm,

10～20 parts of electrosmelted magnesite clinker≤1mm,

10～20 parts in magnesia 180 orders,

10～20 parts in graphite,

1～2 part of aluminium powder,

0.5～1 part in SiC powder,

Cr ₂O ₃2～3 parts in powder,

2～3 parts of wedding agents.

2. the described steel-making of claim 1 is with not burning MgO-Cr ₃C ₂The preparation method of-C brick is characterized in that method is as follows:

(1) by the described weight portion proportioning of claim 1, take by weighing fused magnesite and bond that granularity is 5mm～3mm and 3mm～1mm, added the pre-mixed grind of puddle mixer 8～10 minutes, add then granularity for≤1mm and 180 purpose fused magnesites, graphite, aluminium powder, SiC powder and Cr ₂O ₃Powder, mixed grind 12～15 minutes;

(2) material that mixes is added in the mould, on 500 tons～800 tons friction presses, add and be pressed into base;

(3) base substrate is sent into the dry kiln drying, 40～60 ℃ of dry kiln hot-wind inlet temperature, temperature is 175～185 ℃ between heat preservation zone, and 40～60 ℃ of temperature outs are not less than 16 hours time of drying.