Corundum hydraulically hardening mass
(57) Abstract:Usage: as lining for thermal units roughing and nonferrous metallurgy, chemical industry, building materials industry, in particular for installations furnace steel processing. The mass contains, by weight. %: high-alumina cement 13-20, as such additives ilmenite concentrate from 0.7 to 3.0, and the rest of electrocorundum. table 2. The invention relates to the production of refractories for thermal units in ferrous and nonferrous metallurgy, chemical industry, building materials industry, in particular for installations furnace steel processing.In installations furnace steel processing unburned lining made of refractory mass is in contact with the molten metal and slag having a temperature often 1600oC. Therefore, the resistance in the service of unburned lining will be determined by qualitative indicators, it acquired during operation at a temperature of 1600oC.Known corundum hydraulically hardening mass brand MKN-94, manufactured from oxide and alumina cement. This mass and the N-94 are the lower limit of the compressive strength (20 N/mm2) and high open porosity (32%) after firing at 1600oC /1/.Known also similar mass:
MCT-1 on the basis of white electrocorundum, titanicthe electrocorundum and high-alumina cement,
MKTN-2 based on white fused corundum, high-alumina cement containing the additive of 1% titanium dioxide.Refractories of these mass after firing at 1600oC also have a high open porosity: 30% MCT-1 and 28% MKT-2. The ultimate compressive strength of the refractories of these mass after firing at 1600oC is somewhat higher than in the case of mass MKN-94, and is 35 N/mm2.Most are similar in composition (prototype) is a refractory material containing, by weight.High-alumina cement 13-20
Titanium slag 0,8-3
Refractories of this mass after firing at 1600oC have a lower open porosity (22,5-23,2%) and a higher ultimate compressive strength (43,0 was 47.1 N/mm2) than the refractory mass MKN-94, MCT-1 and MCT-2 /2/.With high open porosity refractory observed impregnation its molten metal and slag (having a temperature of mostly 1600oC), which leads to the m the refractories of the mass of the prototype after firing at 1600oC have a lower open porosity and higher strength in compression, the damaging effects of the above factors is reduced, but not sufficiently. Therefore, it is necessary to further reduce the open porosity and the increase in the compression strength after firing at 1600oC refractories made of hydraulically hardening mass corundum structure.This Yale is achieved by use of a hydraulically hardening refractory mass, which includes such additives ilmenite concentrate in the following ratio, wt.High-alumina cement 13-20
Ilmenite concentrate 0,7-3,0
Ilmenite concentrate has the following chemical composition, wt. TiO260,8, FeO 29,0, SiO23,7, Al2O32,4, MgO 0,3, Cr2O31,5, of 0.3 MnO, CaO 0,2, mGOK-2,4 (TU 48-4-267-73). Phase composition it is represented mainly by the mineral ilmenite FeTiO3unlike titanium slag, which is due to the smaller content of FeO predominant phase is rutile TiO2(chemical composition of titanium slag, m ptx2">Ilmenite concentrate has a lower cost compared to titanium slag as titanium slag is a by product of processing of ilmenite concentrate. Found that the use of ilmenite concentrate as an additive in compositions with oxide and high-alumina cement leads to a sharp decrease of open porosity refractories (16-18%) and higher tensile strength in compression (23-47%) after firing at 1600oC compared with the same mass, including the quality of such additives titanium slag (prototype).This unexpected phenomenon may be due to the fact that the ilmenite (FeTiO3in conjunction with impurities included in ilmenite concentrate (such as SiO2, MnO) has a more effective sintering activity than rutile (TiO2in conjunction with impurities (FeO, SiO2, MnO) that are part of titanium slag. The mentioned phenomenon requires a special investigation.The addition of ilmenite concentrate in the amount of less than 0.7% has no significant positive effect, and the introduction of its more than 3% is impractical because it leads to a significant reduction of the temperature of the beginning of softening under NASA additives to reduce the open porosity and enhance the compressive strength is unknown.Not found information about any use of a composition of the oxide, high-alumina cement and ilmenite concentrate.Based on this, we believe that the proposed solution involves an inventive step.Example. For the manufacture of the samples used:
oxide on THE 14-8-384-81 (mass fraction, Al2O398,8, Fe2O30,19, SiO20,61, Na2O+K2O 0,38);
high-alumina cement in THE 113-03-339-78 (mass fraction, Al2O374,86, CaO 21,54, SiO22,01);
ilmenite concentrate on THE 48-4-267-73 smaller 0,063 mm;
titanium slag on THE 48-10-31-78 smaller 0,063 mmThese materials were mixed in the ratios shown in table. 1, then the mixture was moistened with water in amount of 10% (over 100% of the dry mixture) and stirred until homogeneous. The wetted mass was stuffed in a split metal molds. After 24 hours the samples were removed from the forms and kept in a humid atmosphere. After 3 days of curing, the images were dried at 105-120oC and annealed in the furnace at 1600oC aged for 4 hours After roasting determined their indicators, which are listed in the table. 2. Samples for the determination of ultimate strength in compression and open porosity and - in the form of cylinders with a diameter of 36 mm, height 50 mmAnalysis of the data given in table. 1 and 2, shows that the use of ilmenite concentrate as such additives in corundum hydraulically hardening mass can reduce the open porosity of the samples up to 18.4-19,0% and increase their tensile strength in compression to 57.8-69,4 N/mm2after firing at 1600oC (compositions NN 1-3) compared with samples of composition # 4 (prototype) for which these indicators after firing at 1600oC, respectively 22,5% and 47.1 N/mm2.Thus, compared with the prototype of the proposed mass allows to obtain materials with open porosity at 16-18% lower, and the limit of compressive strength on 23-47% higher. Corundum hydraulic hardening mass, including aluminium oxide, high-alumina cement and titanium containing additive, characterized in that the quality of such additives it contains ilmenite concentrate in the following ratio, wt.High-alumina cement 13 20
Ilmenite concentrate 0,7 3,0
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.