Corundum-periclase-carbonic refractory material

FIELD: refractory industry, in particular manufacturing of refractory material for cladding of steel teeming ladles.

SUBSTANCE: claimed refractory material is obtained from refractory mass containing (mass %): <0.063 mm-grade corundum 16-20; 0.5-1.0 mm-grade periclase 4-12; graphite 6-10; metal aluminum 1-5; crystalline silicium 2-5; ethylene glycol 1.5-1.8; powdered phenol binder containing not more than 1.0 mass % of free phenol 2.7-3.3; and balance: 0.5-6 mm-grade corundum. Abovementioned <0.063 mm-grade corundum contains <0.020 mm grade in amount of 1-5 mass % or more based on total corundum mass.

EFFECT: refractory material with bulk stability, high mechanical strength and low oxidation susceptibility.

2 tbl

 

The invention relates to refractory industry, in particular the production of refractory bricks for lining of steel ladles.

Known carbon-containing refractories made from masses containing periclase and/or oxide, carbon-containing component, an antioxidant and a temporary binder, such as inventions by patents of the Russian Federation 2210459, B 22 D 41/32, 2003 [1]; 2120925, 04 35/103, 1998 [2]; 2145584, 04 35/66, 04 35/103, 2000 [3]; 2171243, 04 35/035, 04 35/103, 2001 [4]; 2151124, 04 35/035, 04 35/103, 2000 [5]; No. 2163900, 04 35/103, 2001 [6].

In terms of total essential features of the closest to the patented may include carbon-containing refractories by RF patent No. 2163900, 04 35/103, 2001[6].

It contains, wt%: aluminum-containing component (fused corundum) fractions 1-8 mm 50-70, pricessaturday (periclase) and alumina-containing (corundum) components faction 1-0 mm 0,063 mm - 20-40 (including the periclase particles less than 0,063 mm - 5-10), carbonaceous material (graphite) - 4-14, organic binder (powdered CFF, ethylene glycol) - 3,5-8, and, optionally, antioxidant (aluminum, silicon) - 1-5.

Positive as this lining is good mechanical strength, the disadvantage is the likelihood of thermal expansion and the formation of microcracks due to active synthesis of spinel content in the charge periclase particles less than 0.03 mm in the amount of 5-10 wt.%.

The present invention is to eliminate these drawbacks of the positive properties of refractory materials.

The technical result consists in increasing obamapalooza refractories, strengthening its structure.

To achieve this, according to the formula of the invention torontorealestate refractories made from pulp, which contains corundum particles less than 0,063 mm with the content of particles less than 0,020 mm not less than 50 wt.%, and phenolic binder powder contains free phenol content of not more than 1.0 wt.%, in the following ratio, wt.%:

corundum FR. less 0,063 mm16-20
periclase FR,5-1,0 mm4-12
graphite6-10
aluminum metal1-5
crystalline silicon2-5
binder phenolic powder
the content of free phenol of not more than 1.0 wt.%2,7-3,3
ethylene glycol1,5-1,8
corundum FR,5-6,0 mmrest

The essence of the invention lies in the fact that the optimal content in the mass of corundum particles less than 0,063 mm with the content of particles less than 0,020 mm not less than 5 wt.%, periclase specified grain structure of the proposed organic binder, allows you to condense and solidify the structure of refractories due to the formation of ceramic bond and a limited number of spinel in the process of high-temperature mineral formation, to avoid cracking of refractories by minimizing the emission of volatile, to ensure obamapalooza refractories, sufficient mechanical strength.

Spinel reduces wear, increases the resistance of refractories to the metal and the slag, but the process of education goes with volume expansion (ΔV=+7,8%), which leads to structural cracking of the refractory in the service process. To prevent cracking and save obamapalooza refractories, it is important to weaken the formation of spinel, which is achieved by limiting the content of magnesia in the mass 4-12 wt.% and delisting it is faction, the most activating the process of spinlooptime. When the content of magnesia in mass of less than 4 wt.% weakly manifest positive properties of spinel because of her lack of education, and the magnesia content of more than 12 wt.% increases irreversible structural-thermal expansion of refractory materials.

Corundum having a low temperature coefficient of linear expansion (TCLE), allows the refractories to withstand thermal load of the aircraft is cracking. Ceramic bond with carbide bonds formed during high-temperature mineral formation and also having a low linear thermal expansion coefficient, resists cracking and increases the mechanical strength of the refractory materials.

Used corundum FR. less 0,063 mm fraction contains less than 0,020 mm not less than 50 wt.%. Submicron fraction of corundum in the service process of refractories activates the sintering de-carbonized layer and creates erosion-resistant ceramic cluster of high strong refractory phases of the principal components, oxidation products of antioxidants and their interaction with each other, procrea structure, preventing cracking and increasing the mechanical strength of the refractory materials.

Proposed phenolic binder powder provides a sufficient mechanical strength as freshly-formed and heat-treated refractory due to irreversible hardening when heated with a thick binder of the frame and is more environmentally friendly binder than peck, as it contains a free phenol content of not more than 1.0 wt.%. Harmful volatile components are removed in the process of Belisario binder and the decomposition of phenol under the catalytic effect of aluminum oxide during the heat treatment formed of refractory materials.

The use of phenolic binder powder in combination with what etilenglikolem allows you to get a lot of high bulk density, good molding properties, granular structure, with a uniform distribution of the antioxidant and fine fractions. This is achieved by the introduction of ethylene glycol in two stages. At the first stage introduces two-thirds of the total number etilenglikola after dry mixing of corundum FR,5-6 mm, periclase FR,5-1,0 mm, aluminum metal and crystalline silicon with the purpose of uniform distribution of the antioxidant and moisturizing mixture. Then enter the corundum FR. less 0,063 mm, binder phenolic powder and graphite. Binder phenolic powder, dissolving the ethylene glycol, forms a very thin film on the surface of grains that stick thin fraction of the charge and graphite. The remaining part of ethylene glycol is introduced in the final stages of preparing the masses for the formation of a surface film of ethylene glycol on the components of the mass. This film prevents sticking of grains and the formation of pellets during the final mixing of mass and prevents caking mass during aging. This weight allows you to mould the raw material with an apparent density of 3,17-3,20 g/cm3at relatively low unit pressure and to obtain products with high mechanical strength. The content in the lining of a small amount of binder and uniformly distributed complex of antioxidant in the form of aluminum metal and Cree is a metallic silicon increases the resistance of refractories to oxidation.

The introduction of ethylene glycol is less than 1.5 wt.% not enough to moisten the mixture and dissolving the binder of phenolic powder, and the introduction of more than 1.8 wt.% preobladaet mass and causes cracks overclamping.

Introduction phenolic binder powder in refractories less than 2.7 wt.% does not provide sufficient mechanical strength raw products, and the introduction of more than 3.3 wt.% leads to increased loss of binder at high temperatures and increased oxidation of refractory materials.

Examples of compositions of the masses for manufacturing samples torontorealestate of refractories and their properties are listed in the table.

To obtain the refractories of the proposed structure used the following materials: electroplating corundum (Al2About3of 96.5 wt.%, MgO 2.5 wt.%), the fused periclase (MgO 97.5 wt.%), graphite (GOST 7478-75), phenolic binder powder with a content of free phenol of not more than 1.0 wt.% (THE 2257-241-00203447-97), ethylene glycol (GOST 19710-83), powder aluminum passivated (TU 1790-466652423-01-99), crystalline silicon (GOST 2169-69). The content in the mass of corundum FR. less 0,063 mm, wt.%: in example 1 to 20, in example 2 to 18.5 in example 3 to 18, in example 4 to 16, in example 5 - 17.

These components were dosed out in the quantities given in the claims, mixed, molded product of the friction press and thermoablative the ri 200-225° C.

The table shows that patenting refractories has a small additional increase after heat treatment, sufficient mechanical strength, low oxidizability.

Torontorealestate refractories, in addition to the above advantages, has lower conductivity and maintains the constancy of properties over a prolonged contact with the metal at elevated temperatures.

The combination in this refractories advantages magnesia carbon and refractory successfully allows it to operate in the lining of casting ladles, which confirmed the results of industrial tests.

Residual resizing when heating was determined according to GOST 5402.1-2000. Oxidation and ultimate compressive strength was determined after burning the samples in an oxidizing atmosphere at 1350°C for 1 hour. The oxidation was determined as the ratio of the amount of carbon remaining in the sample at a distance of 15 mm from its surface to its original number in percent. The ultimate compressive strength was determined according to GOST 4071.1-94 on samples from the same roastings.

Sources of information

1. RF patent 2210459, B 22 D 41/32, 2003 [1].

2. RF patent 2120925, 04 35/103, 1998 [2].

3. RF patent 2145584, 04 35/66, 04 35/103, 2000 [3].

4. RF patent 2171243, 04 35/035, 04 35/103, 2001 [4].

5. RF patent 2151124, 04 35/035, 04 35/103, 2000 [5.

6. RF patent №2163900, 04 35/103, 2001 [6] is a prototype.

1,9
Table 1

The compositions of mass torontorealestate refractories
Content, wt.%:
ComponentsThe inventive compositionKnown
123456
corundumto 75.274,273,174,473,825
the fused periclase9,59,5996,240
graphite67991015
aluminum metal1,91,8114
crystalline silicon2,82,82,724-
binder phenolic powder2,92,92,82,93,2-
ethylene glycol1,71,71,61,71,8-
soot-----5
coal tar pitch+FSF-----7
the boron carbide--- --1
modifying additive-----3
Table 2
Properties torontorealestate refractories
IndicatorsThe inventive compositionKnown
123456
The limit of compressive strength after heat treatment at 1350°C, N/mm227,728,021,117,618,010,0
Additional linear growth after heat treatment at 1350°,%0,40,30,40,50,41,0
Exclaimeth,%62,163,2 61,157,658,357

Torontorealestate refractories obtained from the mass, including the oxide fractions of 0.5-6 mm 0,063 mm, periclase, graphite, aluminum metal, crystalline silicon, phenolic binder powder and ethylene glycol, wherein the corundum particles less than 0,063 mm fraction contains less than 0,020 mm not less than 50 wt.%, and phenolic binder powder contains free phenol content of not more than 1.0 wt.%, in the following ratio, wt.%:

Corundum FR. less 0,063 mm16-20
Periclase FR. 0,5-1,04-12
Graphite6-10
Aluminum metal1-5
Crystalline silicon2-5
Binder phenolic powder
with a content of free phenol of not more than 1.0 wt.%2,7-3,3
Ethylene glycol1,5-1,8
Corundum FR. 0,5-6,0 mmRest



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: proposed device includes cluster unit with blowing unit arranged inside it; it consists of coaxial parts molded from refractory materials in form of truncated cone or truncated pyramid; said parts are engageable with one another forming passages between them for delivery of inert gas; on side of larger base of blowing unit flange is provided with hole for delivery of inert gas. Formed between flange and blowing unit is cavity. Blowing unit combined with cluster unit includes cylindrical porous refractory insert located between working part of blowing unit and metal flange. In central part of its lower base there is spherical recess in form of segment for receiving inert gas; upper base has square seats forming gas distributing cavity before working part of blowing unit. Cylindrical metal envelope welded to metal flange has at last two external beads over circle or metal angles welded to it. Passages in working part of blowing unit are oriented in way of motion of gas or are formed by projections over entire length on one of engageable taper or trapezoidal components of blowing unit. Cluster unit and porous insert are made from refractory material of definite composition on base of mineral binder; working part of blowing unit is made from carbon-containing mass of definite composition on organic binder. Monoblock unit of cluster unit and blowing unit is molded in molding built-up molding rigging. Use is made of multi-stage manual pneumatic ramming at initial stage of molding and automatic vibration ramming at final stage for obtaining large blowing units, up to 500 mm in height. Monoblock thus molded is subjected to heat treatment at a temperature of 200-400°C.

EFFECT: enhanced reliability and safety; guaranteed capacity of unit; increased service life.

14 cl, 7 dwg

The invention relates to the technology of refractory materials and can be used in the manufacture of refractories for the most challenging sections of the lining steel, steel and other metallurgical equipment

The invention relates to refractory industry, namely the production of highly resistant carbon-containing refractories for lining thermal units ferrous and nonferrous metallurgy, in particular, for BOFs, installations furnace steel processing, steel-making furnaces and other heating units

The invention relates to refractory industry, namely the production technology carbanionic refractories

The invention relates to the technology of refractory elastic materials intended for use in sealing, dividing, sealing products industries, vyplavlyaemoy metal, bottling it in a continuous billet, cast ingots, style

The invention relates to the production of refractory materials, namely the production of carbon-containing refractories used in the lining of metallurgical ladle treatment facilities and transportation of metal

The invention relates to the technology of refractories that can be used in metallurgy, and in particular to compositions for the manufacture of unburned products used in contact with molten metal

The invention relates to refractory industry and can be used in the technology of manufacture of refractory products

The invention relates to refractory industry, in particular to the production of carbon-containing refractories for lining various metallurgical equipment, such as converters, electric arc furnaces, ladle

FIELD: metallurgy.

SUBSTANCE: proposed device includes cluster unit with blowing unit arranged inside it; it consists of coaxial parts molded from refractory materials in form of truncated cone or truncated pyramid; said parts are engageable with one another forming passages between them for delivery of inert gas; on side of larger base of blowing unit flange is provided with hole for delivery of inert gas. Formed between flange and blowing unit is cavity. Blowing unit combined with cluster unit includes cylindrical porous refractory insert located between working part of blowing unit and metal flange. In central part of its lower base there is spherical recess in form of segment for receiving inert gas; upper base has square seats forming gas distributing cavity before working part of blowing unit. Cylindrical metal envelope welded to metal flange has at last two external beads over circle or metal angles welded to it. Passages in working part of blowing unit are oriented in way of motion of gas or are formed by projections over entire length on one of engageable taper or trapezoidal components of blowing unit. Cluster unit and porous insert are made from refractory material of definite composition on base of mineral binder; working part of blowing unit is made from carbon-containing mass of definite composition on organic binder. Monoblock unit of cluster unit and blowing unit is molded in molding built-up molding rigging. Use is made of multi-stage manual pneumatic ramming at initial stage of molding and automatic vibration ramming at final stage for obtaining large blowing units, up to 500 mm in height. Monoblock thus molded is subjected to heat treatment at a temperature of 200-400°C.

EFFECT: enhanced reliability and safety; guaranteed capacity of unit; increased service life.

14 cl, 7 dwg

FIELD: refractory industry, in particular manufacturing of refractory material for cladding of steel teeming ladles.

SUBSTANCE: claimed refractory material is obtained from refractory mass containing (mass %): <0.063 mm-grade corundum 16-20; 0.5-1.0 mm-grade periclase 4-12; graphite 6-10; metal aluminum 1-5; crystalline silicium 2-5; ethylene glycol 1.5-1.8; powdered phenol binder containing not more than 1.0 mass % of free phenol 2.7-3.3; and balance: 0.5-6 mm-grade corundum. Abovementioned <0.063 mm-grade corundum contains <0.020 mm grade in amount of 1-5 mass % or more based on total corundum mass.

EFFECT: refractory material with bulk stability, high mechanical strength and low oxidation susceptibility.

2 tbl

FIELD: refractory materials.

SUBSTANCE: invention relates to light-weight heat-insulating refractory materials. Invention relates to the development of corundum-containing light-weight refractory material modified with phosphate ions and molybdenum or tungsten anhydride or a corresponding acid taken in the amount 0.1-1.0% in the following ratio of components, wt.-%: indicated corundum, 83.9-88.8; wheat flour, 2.5-7.5, and technical lignosulfonate, 8.6-8.8. Invention provides enhancing strength, decreasing heat conductivity and roasting temperature of corundum-base light-weight refractory material.

EFFECT: improved and valuable technical properties of material.

1 tbl, 1 ex

FIELD: manufacture of refractory articles; manufactore of linings for heating furnaces, muffle furnaces for stomatology in particular, melting crucibles and shaped refractory articles.

SUBSTANCE: proposed burden contains the following components, mass-%: boron nitride, 25-55; synthetic corundum, 15-40; molten mullite, 10-15; alumina, 10-25; fire clay and kaoline, 5-15; rare-earth metal oxide from groups La2O3, Nd2O3 and Gd2O3, 0.5-5; alumo-containing compound, 0.1-5. Used as alumo-containing compound is aluminum hydroxide, aluminum chloride or aluminum carbonate.

EFFECT: enhanced chemical resistance to reaction-active melts; enhanced heat resistance and refractoriness in vacuum and in shielding atmospheres.

4 cl, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention concerns fireproof moulded goods applied as bricks or unconventional-sized articles for equipment of metallurgical melting vats. Structure of calcinated fireproof moulded article consists of secondary fireproof material with grain size up to 3 mm, calcinated or melted in advance, by at least 75 wt %, and features pore volume from 10 to 30%. After moulded article calcination its pores are at least partly filled with carbon-containing material, so that carbon content in article exceeds 3 wt % in conversion to weight of the moulded article, and open porosity after pore filling and tempering at given temperature comprises 4.5-7.5 volume %. Secondary material includes at least 90% of zirconium oxide.

EFFECT: reduced material shrinkage during calcination, enhanced thermal stability.

12 cl, 3 ex, 3 dwg

FIELD: chemistry; metallurgy.

SUBSTANCE: present invention pertains to refractory industry, particularly to production of refractory objects for lining steel-smelting furnaces and steel teeming ladles. The carbon oxide refractory material has the following components in the given ratios, wt %: corundum of the fraction 3-6 mm 5.0-20.0, 1-3 mm fraction 40.0-50.0, 1-0 mm fraction 4.0-22.0; alumina containing component of a fraction of not less than 0.063 mm (including a fraction of not less than 0.020 mm not less than 70 wt %) 7.0-9.0; molten periclase of a fraction of less than 0.063 mm 3.5-15.0; crystalline graphite 1.0-7.0; technical carbon 0.1-7.0; high-temperature artificial asphalt 0.2-5.0; organic binder 20.-3.5; organic binder solvent (over 100%) 1.0-2.0; antioxidant 0.5-6.0. The organic binder used is in form of dry phenol binder or a composition of dry phenol binder, hexamethylenetetramine and epoxy-novolak resin in the following ratio, wt.pts: dry phenol binder 100, hexamethylenetetramine 6-12, epoxy-novolak resin 10-100. The organic binder solvent used is superior organic alcohols. Besides crystalline graphite, the carbon containing part of the mixture contains artificial or synthetic carbon and high-temperature artificial asphalt. The finely ground mineral part of the mixture contains optimum quantities of an alumina-containing component, magnesium-containing component and an antioxidant.

EFFECT: compact and strong structure of the refractory material and reduced oxidation susceptibility during its production and operation.

3 cl, 2 tbl

FIELD: chemistry.

SUBSTANCE: inventions relate to fire-proof industry, namely to production of fire-proof materials, stable to impact of steel, cast iron, slags and non-ferrous metals. Fire-proof mass contains in wt %: graphite 5÷8; phosphate binding agent 4÷6; plasticiser 5÷10; fine-grained fire-proof powder filler from group: white electrocorundum, chamotte, with grain size less than 63 mcm 4÷25; organic fibres 0.05÷0.15; wastes of carbonaceous foundry ferrochrome production 2÷6; powder filler from group: white electrocorundum, silicon carbide or chamotte, with grain size 6÷0.5 mm - the remaining part. In method of obtaining fire-proof mass first graphite is mixed with 1/3÷1/2 of phosphate binding agent and kept after mixing for 2÷4 hours, separately mixture of fine-grained fire-proof powder filler and wastes of carbonaceous foundry ferrochrome production is prepared, as well as mixture of powder filler, organic fibre and remaining part of binding agent, after which earlier obtained mixtures are mixed together.

EFFECT: elimination of graphite burning out at high temperatures, reduction of porosity, increase of fire-proof materials strength.

2 cl, 1 tbl

FIELD: chemistry.

SUBSTANCE: proposed invention relates to chemical engineering of highly porous ceramic objects with a cellular structure, which can be used as catalyst carriers, filters, headpieces for mass- and heat exchange processes, high-temperature heat-insulating materials etc. A polyurethane matrix with a cellular structure of arbitrary geometrical shape is saturated with slip, consisting of inert filler - electro-cast corundum or a mixture of electro-cast corundum and silicon carbide, dispersed powder of aluminium oxide with additives of group II and IV metal oxides and polyvinyl alcohol solution. The object is dried, calcined and a block-type ceramic object (α-Al2O3) with effective porosity not less than 70-95% is obtained. The object is saturated with alumina sol γ-Al2O3 at pH=4.0±0.2, further dried and calcined at temperature not below 1550°C. Further, the object is saturated with high-molecular alcohol and undergoes pyrolysis in an inert carrier medium, for example nitrogen, at temperature of 350-550°C, depositing pyrolytic carbon onto the surface of the object. The object has weight content of carbon of up to 10%.

EFFECT: formation of a highly developed surface coating for a cellular ceramic object (microporosity reaches up to 30% and above), increased compression strength up to 2,5 MPa.

3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical engineering of highly porous ceramic articles with a cellular structure which can be used as filler for catalysts for liquid phase processes, filters, filler for mass- and heat-exchange processes, high-temperature heat-insulation materials etc. The method of making highly porous cellular ceramic articles by soaking a polymer matrix with slip consisting of inert filler - electrically fused corundum or a mixture of electrically fused corundum and silicon carbide, dispersed aluminium oxide powder with additives of oxides of metals of group II and/or group IV of the periodic table of elements and a solution of polyvinyl alcohol, followed by drying, calcining to remove the organic component and treating with alumina sol solution at pH 4.0±0.2, followed by additional drying and calcining at temperature higher than 1500°C. The articles are then soaked with aqueous solution of cobalt and iron nitrates in a vacuum of 26-40 kPa at room temperature. The articles are then fired at 350-400°C. Carbon nanotubes obtained by hydrolysis of methane at temperature of 770-800°C are then deposited on the articles in amount of 0.10 wt % of the weight of the article.

EFFECT: increase in specific surface area of articles.

3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to refractory industry, particularly production of refractory high-strength non-electroconductive articles from corundum and silicon carbide concrete on aluminophosphate binder. Refractory concrete on aluminophosphate binder contains orthophosphoric acid with concentration of 65-75% and a mixture of different fractions of electrocorundum 25A, with the following ratio of components according to FEPA 32GB 1971, wt %: electrocorundum of fraction 20 - 28-36; electrocorundum of fraction 46 - 22-24; electrocorundum of fraction 80 - 15-20; electrocorundum of fraction 220 - 25-35; orthophosphoric acid - 10-12 more than 100%.

EFFECT: high strength, fire-resistance and heat-conductivity, low porosity of articles.

2 cl, 2 tbl

Up!