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Information × Registration Number 0212U005215, 0111U005190 , R & D reports Title Reprocessing of manufacture technology of fired corundum refractories with Cr2O3 addition and mastering of improved manufacture technology of low-cement corundum concrete for lining of technical carbon production reactors and trial lots production. popup.stage_title Head Galchenko T., Registration Date 10-04-2012 Organization PUBLIC JOINT STOCK COMPANY "THE UKRAINIAN RESEARCH INSTITUTE OF REFRACTORIES NAMED AFTER A.S.BEREZHNOY" popup.description2 The research subject is fired corundum refractories with Cr2O3 additive, corundum concrete for lining of technical carbon production reactors.The purpose of the work is an improving of manufacture technology of fired corundum refractories with Cr2O3 additive and mastering of improved manufacture technology of low-cement concrete for technical carbon production reactors.The research methods are standard research methods of chemical composition and physical-ceramics properties of refractories and petrographic and electron-microscopic methods. An influence studies of the relationship of grainy (fused corundum made by PJSC "URIR NAMED AFTER A.S. BEREZHNOY") and finely ground of the mass components in ratio 65/35, 60/40, 55/45, 45/55 with a constant relationship between the fractions 3- 0,5 and < 0,5 mm, equal 3:1 and the maximum size of grain of grainy component (3-0,5, 2-0,5, 1-0,5 mm) to the properties of the vibrocast coarse-grained mass (with the addition 5% Cr2O3) and the samples from it were carried out. It is established the optimum grain composition, which ensures the maximum density of the green body samples - 3,12 g/cm3. Is investigated the dependence of the basic indices of the properties of samples on the temperature of firing (1580, 1750 °C). It is shown that the samples, prepared from the mass of optimum grain composition, after firing at 1750 °C are characterized by the high indices of properties (apparent density - 3,17 g/cm3, compression strength - 284 MPa, apparent porosity - 20,6%) with the comparison with the analogous properties of the samples, fired at 1580 °C. Are executed studies of the influence of the additives (1,0 - 7,5%) of the dispersed alumina of brands CTC -40 and CT 3000 SG on properties of the vibrocast coarse-grained mass of corundum composition (with the addition 5% Cr2O3) and samples, prepared from it with the vibrocast method. It is shown that with increasing of additive amount of disperse alumina of those brands from 0,1 to 7,5 % the tendency of little grooving of samples properties indices, fired at 1750 °C are observed. It is established that during introduction to 7,5% of additive of the dispersed alumina of brand CTC-40 or CT 3000 SG, is ensured the high spreadability of mass correspond 120 and 112% with its humidity 4,2 and 4,3%, and also the indices of the properties of the samples, fired at 1750 °C, which correspond to requirements TУ У 26.2-00190503-320: 2010. Is investigated spreadability under vibration of grainy mass with humidity 4,5%, which consists of the grainy (fractions 3-1, 1-0,5 and < 0,5 mm) and dispersed (fraction < of 0,02 mm) tabular alumina of brand T -60/T-64 (content in the mass respectively 40,10,15 and 20%), alumina ГК-2 brand with the predominant size of the particles ~ 4-10 µm ~ of 90 vol. % (10%), the chromium oxide with the predominant size of the particles ~ 4-8 µm ~ of 90 vol. % (5%) and the dispersive alumina ADS-1 + ADW-1, undertaken in the relationship 3:1 in quantity 1%, depending on the time of mass holding in the exsiccator. It is established that the freshly prepared mass has the high spreadability (140- 145%), which is been preservable for the elongation of approximately 3 hours and during this period mass is thixotropic, it means that in it coagulation structure is formed. With an increase in the time of holding of mass to 4, 8 and 10 hours its spreadability decrease and compose respectively 118, 75 and 20%. With further increase of the mass holding time to 12 hours its spreadability is practically the same as with the time of holding of 10 hours, T it means that it already substantially lost its thixotropic properties. Are made the electron-microscopic examinations of suspensions from the finely ground tabular alumina T -60/T-64, of alumina ГК- 2, the oxide of chromium (and without the oxide of chromium) and dispersive alumina ADS-1 + ADW-1 (for the comparison also with the dispersive additives of Castament FS 10 + Castament FW 10). It is shown that in the freshly prepared suspensions from these mixtures the high degree of the dissociation of particles observed, it means that their aggregation practically is absent. On the separated particles of corundum in these suspensions are formed amorphous (unstructured) semi-transparent shells, which are formed as a result of swelling of the dispersive additive of Castament FS 10 + Castament FW 10 or organic (polymeric) matter, which is contained in the dispersive alumina ADS-1 + ADW-1. By studies of the changes, proceeding in these suspensions after 30 minutes, 3, 6, 9, 12, 24 hours, are shown that the nature of a change of their microstructures in the dependence on the time of their holding in the exsiccator is analogous. Thickening amorphous (unstructured) semi-transparent shells is revealed after 30 minutes of maintaining suspensions in them on the separated particles of corundum. After 3 hours of maintaining suspensions, in them is already visible the formed coagulation structure predominantly through the point contacts between the particles, and is also visible incompact jelly, which was formed as a result of continuous absorption of water by organic (polymeric) matter with the condensational structure, it means that simultaneously with the coagulation in the suspensions condensational structure due to swelling of the organic (polymeric) matter, which is contained in the dispersive additives, begins to be developed. The density of jelly increases after 6 hours of maintaining suspensions from these mixtures, the jelly even more greatly compaction after 9 hours, while after 24 hours the density of jelly remains practically the same as after 9 hours, it means that the significant absorption of water by organic (polymeric) matter occurred after 9 hours of maintaining suspensions in them. Approximately 9 hours after the preparation of suspensions from the mixtures pointed out above condensational structure in them practically completely predominates above the coagulation structure. The increasing of the strength of the formed structure, as it was established in the work of № 2.10-3- K -1.1-2010-ВН, begins after 8-12 hours of maintaining mass in the exsiccator and concludes after 24-28 hours. The obtained results on the spreadability of mass and electron-microscopic examinations of suspensions attest to the fact that the time of its storage must not exceed three, maximum - four hours. Are executed the electron-microscopic examinations of the microstructure of burned with 1750 °C of the vibrocast samples of corundum composition, prepared on the basis of tabular alumina with addition 5, 10, 15% Cr2O3 and on the basis of melted corundum of the production of institute, containing addition 5% Cr2O3. The formation of similar dense microstructures in the samples of all investigated compositions is established. According to the results of the carried out work is developed the project of a change in № 1 to TИ 24 - ИО-178-2009, is developed put into the action a change of №1 to TИ 24 - ИО-168-2009. According to the results of the studies, executed in 2010, is in the present work mastered the improved technology of production (TИ 24 - ИО-168-2009 with chg. №1) low-cement corundum concrete of brand СКБГХ-2 is released the test batch, which is set to user for the execution of the brick lining of the reactor of the production of technical carbon. Raw-material base for the preparation of this fireproof production is as a result extended. IN PJSC "URIR NAMED AFTER A.S. BEREZHNOY" are prepared the test batches: on TИ 24-ИО-172-2009 of the articles of MK-90 brand with the indices of properties, which correspond to requirements TУ У 26.2-00190503-320: 2010; on TИ 24-ИО-168-2009 with chg. № of 1 traditional (brand СКБГ) and low-cement (brand СКБГХ-2) corundum concrete mixture with the indices of properties, which correspond to requirements TУ У 26.2-00190503-334: 2010. This refractory production is set to users for the internal and outside market (export in Russian Federation). Work should be continued in the direction of further perfection of the technology of the production of fired corundum with the additive Cr2O3 of refractory materials and technology of the production low-cement corundum with the additive of Cr2O3 of concrete, and also expansion of the volumes of the application of this concrete and testing in the service of fired corundum with the additive Cr2O3 of articles. Product Description popup.authors Грінева Н.І. Шулик І.Г. popup.nrat_date 2020-04-02 Close