Fire-resistant support for the firing of ceramic components and method of its manufacture
(57) Abstract:Use: manufacture of refractory supports and firing of ceramic components, particularly capacitors. The inventive stand consists of a base made of a mixture containing alumina, silica sand and stuff bout aluminous products, and engobed cover, made of suspensions on the basis of an aqueous solution of polyvinyl alcohol powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3and powder ZrO2and the method comprises obtaining a mixture of the ceramic material, forming the bases of the stands, spraying her preliminary layer of the slurry on the basis of powder, zirconates, spraying on a preliminary layer of the active layer engobed cover, which is fixed based high-temperature processing during burning coasters. Technical result: reduced costs, increased service life and the expansion of technological capabilities coasters while improving the insulating properties of the coating and the reduction of energy consumption in the manufacture of supports. 2 C. p. F.-ly, 3 tables. The invention relates to the field of heat treatment of ceramics, in particular to construe in capacitor manufacturing in the manufacture of ceramic capacitors.Known refractory stand for firing ceramic capacitors consisting of zirconium dioxide, and the method of its manufacture, including extrusion and roasting racks (see patent GDR N 205886).This stand has good mechanical properties and practically no effect upon firing, by products on the basis of BaTiO3and other titanates, and the method is quite simple to implement. At the same time, the lack of stand and method of its manufacture is the high cost due to scarcity applied Zirconia and high firing temperatures (1650oC).Also known two-layer stand consisting of a base and the surface of the working layer, which are formed in a single unit under pressure (see application Germany N 3923655). The disadvantage of this stand is quite complex technology of its manufacture.The closest in technical essence to the invention is a ceramic engobed stand consisting of a base, made of a mixture based on alumina, Zirconia and chalk, and engobed coating made of a water suspension ZrO2(see and.with. USSR N 398527) and a method of manufacturing a refractory supports for firing ceramic clou its heat treatment, drawing on the basis engobed coating by dipping the base in a suspension of the material blanks of ceramic capacitors and roasting racks (see and.with. USSR N 672181).This stand is characterized by lower cost and relatively high strength and thermal sensitivity, and a method of its manufacture can improve the insulating properties engobed coating that provides a satisfactory quality capacitors.A significant drawback of the stand and method of its manufacture is that they, due to the nature of stand composition and methods of its manufacture, do not provide further reduce costs, increase service life and expanding the technological capabilities of the stand while improving insulating properties engobed cover from the base stand and the reduction of energy consumption in its manufacturing. In this case, the presence of the base stand costly and scarce ZrO2and the necessity of its preliminary heat treatment does not allow to reduce the cost and energy consumption in the manufacture of the stand. In addition, when the content in the basis of more than 60% of alumina during firing through engobed layer is of gotovac capacitor on the basis of BaTiO3with stand, which reduces the service life and the technological capabilities of the stand. When this method is applied on the basis engobed coating by dipping prebaked bases in aqueous suspension material, blanks capacitors it difficult to obtain the required thickness engobed layer and limits the maximum temperature of firing blanks capacitors on the basis of BaTiO3because when the firing temperature of more than 1260oC between engobed layer of material of workpieces capacitors on the basis of BaTiO3and the basis of stands containing more than 50% of alumina, is formed of fusible mastika, penetrating engobed floor and causing sticking of the baked goods to the stand, i.e., affects the insulating properties engobed coverage. All this reduces the effectiveness of the stand and the manner and limits the possibility of obtaining higher technical result.The inventive refractory pad and method of manufacture eliminates the disadvantages of the known stand and method and achieve higher technical result of lowering cost, increasing service life and the expansion of those is itia from the base stand and the reduction of energy consumption in its manufacturing.The invention consists in the fact that in the inventive refractory stand for firing ceramic components, mainly capacitors, consisting of a support made of a mixture of the ceramic material based on alumina, and engobed coating made of a water suspension of zirconium dioxide, the above technical result is ensured by the fact that the mixture of the ceramic material basics additionally contains quartz sand and stuff bout aluminous products in the following ratio, wt.alumina 47,5-51,7
quartz sand 0,8-1,5
stuff bout aluminous products and 47.5-51,
and engobed advanced coating made of a water suspension of the powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3with each suspension additionally contains polyvinyl alcohol in the following ratio, wt.ZrO238,5-44,5
polyvinyl alcohol 1,9-3,3
and powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3- 39,5-45,5
polyvinyl alcohol 1,8-3,2
In the present method of manufacture of refractory supports for firing ceramic components advantages is Yesenia prepared on the basis engobed coating with subsequent high-temperature firing stands, the above technical result ensures that engobed coating is applied by spraying on the basis of the preliminary layer from a suspension on the basis of an aqueous solution of polyvinyl alcohol powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3thickness of 0.05-0.1 mm with subsequent drying and spraying him working layer of the slurry on the basis of an aqueous solution of polyvinyl alcohol with ZrO2to obtain the total thickness engobed coating is 0.1-0.2 mm, which is fixed to the base by high temperature treatment in the firing stand.In this case, cost reduction, increase of service life and the expansion of technological capabilities stands at higher insulating properties engobed cover the base of the stand is achieved by the fact that for getting the basics of stand use non-deficient components in the form of alumina and stuff bout aluminous products, for example, used in the manufacture of stands, which reduces the stand and reduces shrinkage and deformation during firing, and the introduction of quartz sand increases the strength of the sintered base. In addition, the creation engobed coating in the form of intermediate is istwa coating and prevents chemical interaction alumina base with burnt pieces on the basis of BaTiO3. The suspension on the basis of aqueous solutions of polyvinyl alcohol have a high sedimentation stability, when specially selected size of the powders on the basis of ZrO2and applied the method of spraying suspensions make it easy to regulate and to obtain a given thickness engobed coating, and to exclude pre-heat treatment framework supports.Comparative analysis of the proposed stand and method of its manufacture with the prototype shows that the proposed stand is different from the known content in the mixture of the ceramic material basis of quartz sand and stuff bout aluminous products, additional execution engobed coating of an aqueous suspension of the powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3and each suspension further comprises polyvinyl alcohol, and the proposed method differs from the known methods of applying engobed coverage. Thus, the proposed stand and method of its manufacture are new, because the composition of the stand, and technological methods of its manufacture is not known to the current level of technology.Analysis of other technical solutions in this field of technology is the WHC and method of its manufacture have an inventive step, because the composition of the stand, technological methods of production and their significant differences explicitly does not follow from the prior art. In addition, the stand and method of its manufacture are capable of industrial application, which follows from the results of experimental verification of the achieved technical result and practical problems in the field of ceramic capacitor production takes place.The possibility of carrying out the invention is confirmed by information related to the process of obtaining coasters, examples of best of its composition and the results of experimental verification.Method of making refractory supports for firing ceramic components is as follows.Of taken in a predetermined ratio of the alumina material of the fight aluminous products and finely ground quartz sand receive the mixture of the ceramic material basis, which plastificator aqueous solution of polyvinyl alcohol and the resulting mass is formed when specific pressure of 250-300 kg/cm2the Foundation supports the required dimensions. After that, the obtained unfired based spray applied two-layer engobed coating of slurry on one of suspension on the basis of an aqueous solution of polyvinyl alcohol with ZrO2. To do this, the required number powders zirconates and ZrO2with a specific surface area of not less than 8000 cm2/g of polyvinyl alcohol and water and cook the suspension for spraying pre-coat and suspension for spraying the working layer engobed coverage, in each case, the polyvinyl alcohol is dissolved in water under heating, and then mixed with the powder zirconates and ZrO2to obtain a homogeneous sedimentation sustainable systems. The resulting suspension is based on an aqueous solution of polyvinyl alcohol powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3sprayed on the surface of the base stand and get on it the first preliminary layer engobed coating with a thickness of 0.05-0.1 mm, which is dried at 120-150oC for 30 minutes. Then dried on a preliminary layer of sprayed suspension on the basis of an aqueous solution of polyvinyl alcohol with ZrO2and get a working layer with a total thickness of engobed coating of 0.1-0.2 mm, then the base with a deposited layer of suspensions calcined at a temperature of 1420-1640oC while still allowing engobed floor with the base and receiving a fireproof surface. Polurethane 1320-1360oC turnover stands more than 20 cycles.Specific examples of optimal formulations stand, illustrating the invention, is shown in table.1.Specific examples of optimal methods the proposed method of production of stands, illustrating the invention, is shown in table.2.Properties of the proposed refractory supports are confirmed by the test results, the details of which are given in table.3.As follows from the table.3 we stand in comparison with known as. C. the USSR N 398527 2 times more durable differs in 40 times less ZrO2and their cost is 2.5 times lower. This stand can be used for roasting all types of capacitors and have less energy in production.The optimal composition of the stands and the manufacture method is confirmed by experimental data, provides the greatest technical result of the claimed ratio of components and technological methods of production of stands.Practical application stands and method of manufacturing the ceramic capacitor manufacturing allows to reduce the consumption of scarce doucine refractory supports, prototypes and conducted their tests in the experimental conditions of production. 1. Fire-resistant support for the firing of ceramic components, mainly capacitors, consisting of a support made of a mixture of the ceramic material based on alumina, and ingibirovannihe coatings from aqueous suspensions based on zirconium dioxide, characterized in that the mixture of the ceramic material basics additionally contains quartz sand and stuff bout aluminous products in the following ratio, wt.Alumina 47,5 51,7
Quartz sand 0,8 1,5
Stuff bout aluminous products 47,5 51,0
and ingibirovannoj coverage made from aqueous suspensions of powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3with each suspension additionally contains polyvinyl alcohol in the following ratio, wt.ZrO238,5 44,5
Polyvinyl alcohol 1,9 3,3
Water 53,6 58,2
Powder zirconates from a number of CaZrO3, SrZrO3< / BR>and BaZrO339,5 45,5
Polyvinyl alcohol (1.8 to 3.2
Water 52,7 57,3
2. Method of making refractory supports for firing ceramic radiology coasters drawing on prepared Foundation ingibirovannihe coating with subsequent high-temperature firing stands, characterized in that ingibirovannoj coating is applied by spraying on the basis of the preliminary layer from a suspension on the basis of an aqueous solution of polyvinyl alcohol powder zirconates from a number of CaZrO3, SrZrO3and BaZrO3thickness of 0.05 to 0.1 mm with subsequent drying and spraying him working layer of the slurry on the basis of an aqueous solution of polyvinyl alcohol with ZrO2to obtain the total thickness ingibirovannihe coating of 0.1 to 0.2 mm, which is fixed to the base by high-temperature heat treatment at burning coasters.
FIELD: refractory industry, in particular corundum parts for ferrous and non-ferrous metallurgy.
SUBSTANCE: on the step of batch preparation surface of fused corundum filler spheroid particles is damped with oleic or stearic acid in amount of 0.5-0.0 mass % in respect to total mass of phosphate binder. During agitation fine dispersed intergrinding mixture containing (mass %): Al2O3 47-80, ZrO2-SiO2 20-53, and phosphate binder (e.g. phosphoric acid or aluminum phosphate) is added. Batch contains (mass %): fused corundum filler 50-70; fine dispersed intergrinding mixture 30-50; phosphate binder over 100 % 5-10. Batch is homogenized, formed, solidified in air, baked at decomposition temperature of zircon concentrate, and cooled with isothermal holding at 1100-9000C.
EFFECT: corundum-based articles with improved strength and heat resistance.
7 cl, 2 tbl
FIELD: metallurgy, in particular equipment for steel treatment in liquid state.
SUBSTANCE: hydraulically cured bulk contains (mass %): high aluminous cement 2.5-5; alumina 18-25; modifying additive 1.5-3; and balance: electrocorundum. As modifying additive preliminary synthesized material containing 45-55 % of Al2O3 and 42-52 % of CaO is used.
EFFECT: refractory material sintered at 16000C with decreased opened porosity and increased mechanical strength.
FIELD: non-iron metallurgy, in particular cladding of metal plunge.
SUBSTANCE: claimed refractory concrete contains (mass %): corundum mass 82-85; high-aluminous cement 4-5; electrical filter dust from silicium production 4-5; phosphoric acid 2-3; and water 3-4. Method for cladding manufacturing using the said concrete includes former installation into plunge; charging of refractory concrete into space between plunge internal wall and former, vibratory compaction, and two-step drying: at first at 20-250C for 5-7 days and then by graduated heating and drying. Namely, at first cladding is heated up to 1500C with rate of 6-80C/h and kept for 9-11 h; then cladding is heated up to 4000C with rate of 13-150C/h and kept for 14-16 h; then cladding is heated up to 6000C with rate of 20-220C/h and kept for 10-12 h. Cladding obtained by claimed method stands on silicium refining plunge up to 90 air thermal cycling.
EFFECT: cladding of improved strength.
2 cl, 4 tbl, 1 ex
FIELD: manufacture of refractory materials of corundum composition; manufacture of articles for lining of different thermal units working at high temperatures.
SUBSTANCE: charge includes synthetic corundum modified with readily decomposing additive of aluminate composition (for example, aluminum nitrate, aluminum formiate, bauxite, etc.) in the amount of 1-5 mass-% and phosphate binder. Used as phosphate binder is aluminum-boro-phosphate binder at the following composition of components, mass-%: modified corundum, 90-93 and phosphate binder, 7-10. Proposed charge makes it possible to reduce its sintering temperature and porosity of articles at enhanced strength and heat resistance and additional residual change in sizes at heating (by 1-13%).
EFFECT: enhanced efficiency.
1 tbl, 4 ex
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: manufacturing refractory materials.
SUBSTANCE: refractory packing mass comprises, in mass %, 51-61 of grain corundum, 32-43 of the mixture of fine corundum and refractory clay, and 5.5-7.5 of orthophosphoric acid.
EFFECT: enhanced strength.
3 cl, 1 tbl
FIELD: refractory articles for manufacturing of ceramic units operating at 1800°C.
SUBSTANCE: claimed raw mixture contains (mass %): fused corundum of grade <0.05 mm 45-50; fused mullite of grade 0.4-1 mm 15-22; ethyl silicate 1-2: and additionally it contains fused corundum of grade 0.5-0.8 mm 20-25; fused mullite of grade 1.0-2.5 mm 5-8; and graphite 2-5. Method of present invention makes it possible to increase refractoriness up to 1900°C and simultaneously to decrease backing temperature to 1450-1550°C.
EFFECT: raw mixture for production of refractory articles with increased refractoriness.
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.
FIELD: abrasive materials.
SUBSTANCE: invention is destined to provide high-strength corundum materials suited to manufacture of abrasive disks. Method of invention comprises preparing alumina-zirconium blend, fusing it from below and introducing reducer under surface of melt through the bed of blend in the second half-melting, tapping melt, and crystallization and cooling thereof. When being tapped and crystallized melt is protected against contact with air oxygen. Crystallizer contains metal vessel with upright metallic plates mounted inside the vessel with gaps between them. Crystallizer further has a holder to mount plate set. Outline of the lower part of plates follows outline of the vessel bottom. In the top part of each plate, V-shaped cut is made so that all cuts form together longitudinal groove to pour melt.
EFFECT: increased stability of physical structure on cooling, increased strength of grain and improved performance characteristics of abrasive tool, reduced laboriousness and material loss during crystallization operation, spared consumption of metallic reducer, and prolonged service time of crystallizer.
3 cl, 1 dwg, 1 tbl
FIELD: refractory materials.
SUBSTANCE: invention relates to manufacture of corundum refractory articles based on mullite-corundum binder and used in linings of heat assemblies employed in variant industry fields. Method of invention comprises preparation of blend by way of moistening grainy corundum constituent with suspension of activating mullite-forming additive in industrial-grade lignosulfonate aqueous solution followed by mixing with finely ground corundum constituent, formation of articles from thus prepared blend, drying thereof, and firing at 1200-1500°C. Activating mullite-forming additive is finely ground silica/alumina mixture in eutectic weight ratio 94.5/5.5, respectively, used in amount 2-4% of the weight of total content of corundum constituents.
EFFECT: reduced power consumption on production of corundum refractory products due to lowered (by 200-500°C) firing temperature and reduced refuse.