Quality of refractories and the durability of coke furnaces

Papers presented at the Fifteenth Annual Seminar of Coke and Refractory Specialists are reviewed; the seminar was held in 2008 at OAO Dinur (Pervouralsk, Sverdlovsk Oblast).     

耐火制品显气孔率检测质量控制

叙述了耐火制品显气孔率检测质量控制图的绘制及应用；分析了影响检测质量的因素；指出了利用质量控制图来控制实验室检测质量的有效性。     

Quality enhancement of refractories the bosh and lower stack of blast furnaces

Conclusions Impregnation of blast-furnace aluminosilicate refractories with carbon-containing substance makes their structure more compact and greatly enhances the quality. The open porosity of the impregnated specimens decreases by 42–47 rel.%, the gas permeability is reduced, the compressive stress (in the cold) is increased by a factor of 1.5–2, the onset temperature of deformation under a load of 2 kgf/cm² is raised by 50–100°C, the slag resistance is increased by a factor of 2–4 (depending on the amount of coke residue), the alkali resistance is enhanced owing to the presence of coke residue, which, by blocking off the chamotte grains from the active reagents (K₂O, Na₂O), promotes formation of more refractory mineral compositions in the form of large crystals of mullite and-alumina, cemented by refractory glass of presumably nepheline composition.This enhancement of the refractory properties as a result of impregnation with carbon-containing substance will increase the resistance of the lining of the lower stack and the bosh of blast furnaces.Translated from Ogneupory, No. 3, pp, 34–39.     

Quality of refractories is the main way to power saving and efficiency

The conference at UkrNIIO held on March 14–15, 1995 under the motto The quality of refractories is a way to power saving and efficiency was attended by representatives of the Ukrogneupor Concern, research, design, and educational institutions, and refractory and other enterprises of Ukraine and Russia. More than 40 reports were presented on scientific developments, production, and use of refractories in various branches of industry.Translated from Ogneupory, No. 6, pp. 30–31, June, 1995.     

导电耐火材料及其常温电阻率测试仪的研制

简要介绍了直流电弧炉用导电耐火材料的理化性能及导电机理 ,根据其导电特性研制了导电耐火材料用常温电阻率测试仪 ,介绍了电阻率测试仪的结构及特点     

Thermal schock acoustic emission and microstructure of refractories II. Basic refractories

Acoustic emission generated on thermal shocks makes it possible to investigate the processes of cracking that take place in magnesia and magnesia-chromite refractories separately at heating and cooling stages, as well as on successive thermal shocks. It is dependent on the raw material type, technological process and the microstructure of products (i.e. number, size and shape of pores and cracks). The damage present after 20 thermal shocks in the material tested was illustrated by the microstructure examinations.     

Zircon-quartzite and zircon-clay refractories

Conclusions The authors have investigated the properties of zircon-quartzite and zircon-clay refractories. They have established that the use of both quartzite and zircon in the masses permits the preparation of refractories which expand during heating and have a fairly high refractoriness and softening point under a load of 0.2 MPa; in this connection regeneration of quartz and dissociation of zircon are not intensified. The best quality indices are displayed by specimens containing more than 60% of zircon.Refractories obained from zircon and clay have a high rate of sintering and a higher compressive Strength. There refractoriness and softening point under a load of 0.2 Mpa of specimens with less than 60% Zircon are low,owing to the accelerated decomposition of zircon in the presence of clay and to the resulting high content of the vitreous phase. The thermomechanical indices of the refractories increase with the zircon content.Translated from Ogneupory, No. 6, pp. 36–39, June, 1980.     

Producing mullite-corundum refractories at the zaporozhe refractories factory

Conclusions The Zaporozhe Refractories Factory has introduced a method for making mullite—corundum articles from alumina and Polozhe kaolin. The technology was developed by the Ukrainian Scientific-Research Institute of Refractories together with workers from the factory. We have mastered the mass production of articles for building the walls of stoves and hot-blast air ducts. The articles meet the requirements of GOST 2090175.blTranslated from Ogneupory, No. 7, pp. 5–8, July, 1979.     

Porosity of refractories

Conclusions To improve the quality control of refractory products we recommend that a study be made of the economic advantages of incorporating the term total porosity in standards and technical specifications alongside apparent porosity, and that the channel porosity and dimensions of channel pores for certain Soviet fireclay refractory products be determined.Translated from Ogneupory, No. 8, pp. 50–53, August, 1967.     

refractories WORLDFORUM

正refractories WORLDFORUM is a technical and scientific journal for the entire refractories sector: production, application and further development of high-temperature materials. refractories WORLDFORUM is published four times per annum in English, addresses refractories professionals world-wide, i.e. in the production of refractories as well as in industries processing and consuming refractories, raw materials and additives, plant and machine suppliers. Additionally the newsletter "Hot Topics" is published (online and in print) four times a year.     

Zirconia refractories

Results on the thermal conductivity of powders of monoclinic zirconia as a function of the grain size are presented. It is established that of all the investigated sintered powders of monoclinic ZrO₂ the 1 – 0.5-mm and 2 – 1-mm fractions have the lowest thermal conductivity and the least apparent density (2.190 and 2.262 g/cm³). Fused powders of monoclinic and stabilized ZrO₂ have a higher thermal conductivity than their sintered counterparts. Powders prepared from monoclinic ZrO₂ with a burning-off addition of polystyrene have larger pores in the grains, which increases the share of the radiation component in the heat transfer, and hence their thermal conductivity is higher than in powders obtained by sintering pure monoclinic ZrO₂. For the same reason, powders from void granules of the 3 – 0.5-mm fraction have a higher thermal conductivity than sintered monoclinic powders of ZrO₂.Translated from Ogneupory, No. 1, pp. 26 – 29, January, 1995.