Corundum refractories with a combined nitride-containing binder

The synthesis of a combined nitride-containing binder is described. The main parameters for the production of corundum refractories with the combined nitride-containing binder are determined. The refractories have a high resistance to the effect of slag melts. Translated from Ogneupory, No. 3, pp. 15–18, March, 1995.     

Increasing the strength of green magnesia refractories by using combined binders

The effect of the pH of the lignosulfonate (LST) medium on the strength of the green and the qualitative parameters of magnesia parts is established. LST with a weak alkaline medium are recommended for periclase parts, and LST with a weak acid medium are recommended for chrome-containing parts. The effect of some modifying additions to LST is investigated with testing of it in batch production. Combined binders (mixtures of LST with sodium and ammonium bases) are shown to have a positive effect on the properties of the green and ready parts.Translated from Ogneupory, No. 10, pp. 21 – 24, October, 1994.AO Magnezit.     

Compressive fatigue behaviour of refractories with carbonaceous binders

Furnace linings of magnesia-carbon and micro-porous carbon bricks experience cyclic compressive loads. An experimental programme has been carried out to assess the sensitivity of these materials to compressive fatigue failure. Next to room temperature tests, a number of high temperature tests have been performed. Results of the fatigue tests have been analysed together with the data of the monotonic stress–strain loading and creep tests. Compressive fatigue failure has been seen in both the materials. The less brittle material has shown lower fatigue life. The curve relating the fatigue strains with the amount of cycles has been of classical sigmoid shape with three phases. The strain rates of the secondary (linear) phase have shown good correlation with the number of cycles to failure. The grain–matrix interface has been found to play the critical role in the initiation and propagation of the fatigue cracks.     

Phosphate binders in refractories for steelcasting

Refractories and Industrial Ceramics - Nozzles for steelcasting are more durable when produced with an aluminochromophosphate binder than with an aluminophosphate binder, the reasons being the more...     

Deformation of nonfired refractories on phosphate binders. 1. Specifics of nonfired refractories on phosphate binders

Brief data on phosphate binders and materials based on them are provided. Compositions are selected to investigate their deformation in heating under load and creep. __________ Translated from Novye Ogneupory, No. 1, pp. 34–39, January, 2007.     

Use of lignosulfonates as binders in refractories

The characteristics of lignosulfonates and their properties as a function of the polymolecular composition are considered. The properties of various kinds of lignosulfonates (produced from pulp cooking on various bases) have been studied and some ways to improve their surface properties are outlined.Translated from Ogneupory, No. 5, pp. 6 – 11, May, 1994.     

不同结合剂对高铝可塑料性能的影响

以铝矾土颗粒、细粉及黏土为主要原料,研究了自来水、饱和硫酸铝溶液、饱和硫酸铝溶液+磷酸二氢铝溶液3种结合剂对高铝可塑料性能的影响。结果表明:以硫酸铝为结合剂的保质期最长,以磷酸二氢铝+硫酸铝为结合剂的保质期最短;分别以硫酸铝和硫酸铝+磷酸二氢铝为结合剂的试样烘干后耐压强度高于以水为结合剂的;3种结合剂结合试样的体积密度和荷重软化温度(变形量分别为0.5%、1%、2%)相差不大。     

High-carbon binders in refractories and corrosion-resistant ceramics technology

The authors review the literature sources and patents of foreign companies in the field of application of high-carbon organic binders for refractories, composites and technical ceramics. The review reveals the advantages of the new generation of binders with improved properties and describes binders meeting contemporary environmental requirements and not containing free phenol and other carcinogenic and toxic components. Translated from Steklo i Keramika, No. 5, pp. 12 – 15, May, 1998.     

Temporary preservative binders for lime and lime-periclase refractories

It is established that in order to increase the atmospheric resistance of compacts from lime and lime-periclase clinkers the temporary binder should contain high-molecular-weight resin and fatty acids, which form water-insoluble salts on the CaO surface, and surface-active substances in addition to a hydrophobic plasticizer. The requisite amounts of the acid-containing component and the binder itself are calculated. Translated from Ogneupory, No. 3, pp. 18–21, March. 1995.     

酚醛树脂-CarboresP结合镁碳材料的性能与应用

研究了环境友好型含碳材料CarboresP在镁碳砖中的应用。采用MT14A镁碳砖生产工艺,改变CarboresP的加入量,对试样180℃处理后的体积密度、高温抗折强度(1400℃),以及1000℃埋炭处理后的显气孔率、耐压强度等指标进行了研究和对比,确定镁碳砖中合适的CarboresP添加量为1%,并且可适量降低金属防氧化剂的加入量;分析了酚醛树脂-CarboresP结合炭的显微结构,表明其为均质炭和非均质石墨化炭的混合结构,这将有助于改善炭化结构的抗氧化性能;采用尖劈试验绘制镁碳砖试样的应力-应变曲线,表明添加CarboresP的镁碳砖的特征长度LCH值得到明显提高,说明它具有很好的韧性和吸收应力的能力;与传统工艺生产的MT14A镁碳砖相比较,采用酚醛树脂-CarboresP“软性结合”工艺生产的MT14A镁碳砖,成型性能及热处理后各项性能指标均得到改善,在国内某40tLF-VD精炼钢包渣线上进行现场使用证明,平均使用寿命比现用渣线镁碳砖提高18.4%。     

Effect of organosilicon phosphate binders on physicomechanical properties of corundum-carbon refractories

The effect of organosilicon and aluminophosphate binders on the physicomechanical properties of corundum-carbon refractories is studied. The environmental safety of the binders is discussed. Binders for use in sintered and nonfired components are developed. __________ Translated from Novye Ogneupory, No. 2, pp. 35–39, February, 2006.     

1. Physicochemical aspects of the choice of silicon-bearing binders for production of refractories

The principles for selecting a silicon-bearing binder for refractory production are considered. The effect of the heat treatment temperature on the crystallization of SiO₂ gels with various prehistories is considered. It is shown that ethyl silicate binders have an advantage over other silicon-bearing binders that consists in that SiO₂ gel obtained from ethyl silicate éTS-32 can retain the amorphous state upon heating to over 1273 K. Translated from Ogneupory i Tekhnicheskaya Keramika, Nos. 1–2, pp. 8–11, January–February, 1999.     

Deformation of nonfired refractories based on phosphate binders. 5. Creep specifics in cement mixtures

The results of experimental studies of aluminosilicate cement are described identifying two temperature intervals of deformation, which differ in their creep regularities. The first range is typical of composites with an unstable low-temperature structure (heat treatment up to 800°C), and the second interval is typical of relatively stable high-temperature structures (> 1000°C). Two ranges of deformation are identified based on stress. In the first range the deformation process is determined by sintering shrinkage under a load which is lower than the surface tension; the second deformation range is typical of loads exceeding the surface tension. __________ Translated from Novye Ogneupory, No. 5, pp. 47–51, May, 2007. Continuation. See beginning in Vol. 48, Nos. 1–2, 2007.     

Sixtieth anniversary of the combined research institute of refractories

The path of the collective of the St. Petersburg Institute of Refractories is described, from its founding (namely, January 1936) to the present time. It is shown that for the 60 years of its work the institute has been closely tied with industry. Today, despite a reduction in capital expenditure, the institute has retained its personnel, experimental base, and main directions of experimental research.Translated from Ogneupory, No. 1, pp. 2 – 4, January, 1996.     

Deformation of unfired refractories based on phosphate binders. 7. Deformation of composites based on silicon nitride

Results are presented for a study of the deformation of phosphate composites based on Si₃N₄ and ZrO₂ making it possible to predict the behavior of these materials in service. __________ Translated from Novye Ogneupory, No. 9, pp. 49–52, September 2007. Completion. Started in Nos. 1–6 (2007).     

The service of periglase-chromite refractories in the bottom of a converter with combined blowing

Conclusions Without the use of guniting and effective buildup of a crust the life of a converter bottom lining under the conditions of Nizhnii Tagil Metallurgical Combine does not exceed 400–450 heats.Unstable life (150–300 heats) of the upper layer of the bottom lining is an indication of irrational heating up of the converter before service.As follows from the experimental heats, to increase the life of the area near the tuyeres and the joint of the converter bottom and wall linings it is necessary to use BPGK-72-12 periclase-carbon blocks.Translated from Ogneupory, No. 4, pp. 48–50, April, 1990.     

Deformation of nonfired refractories based on phosphate binders. 6. Deformation under heating and creep in corundum composites

The results of studying heating deformation and creep are described for two systems: electrocorundum — α-Al₂O₃ — phosphate binder and electrocorundum — pyrophyllite — phosphate binder. It is shown that composites with H₃PO₄ experience less deformation than composites with the alumochromium-phosphate binder, whereas using pyrophyllite instead of aluminum oxide increases creep deformation due to the presence of the liquid phase in the material. The effect of technological factors is investigated. __________ Translated from Novye Ogneupory, No. 6, pp. 58–62, June, 2007. Continuation. See beginning in Vol. 48, Nos. 1–2, 2007.