Scientific-technological solutions ensuring the production of high-alumina lightweight refractories

Three variants of the introduction of an active burning-off addition into the forming mixture for the production of high-alumina lightweight refractories are investigated. The optimum composition and drying regime are determined. The possibility of replacing 30 – 40% of finely milled KDSP powder by disthene-sillimanite sand with natural grain size is established. The method of photoelasticity by freezing the stress state of the model is used to determine the pressure developed in the mixture. Recommendations are given on the firing rate of the green with allowance for the dynamics of polystyrene pyrolysis. Articles with improved physicomechanical properties and operating characteristics are produced.Translated from Ogneupory, No. 6, pp. 13 – 15, June, 1995.     

Technology for refractories with a high-alumina bond

Conclusions We developed a method of introducing commercial alumina into the bonding part of the batch with combined fine grinding of the components in a tubemill for increasing the reaction capacity of the components of the bond in the firing and the formation of maximum possible amount of mullite (up to 80%).Enrichment of finely milled constituents of the batch with alumina improves the properties of the articles made on the base of kaolinitic raw materials.With the introduction of 30% commercial alumina in the bond composition the necessary density of the green products is obtained by using the staged method of pressing which enables us to press articles at a higher specific pressure.The advantage of the developed technology for producing high-alumina articles is that there is no need to make high-alumina grog or to crush it and grind it.     

Service of high-alumina refractories in ARC furnaces

Specimens taken from the inlets of the electrodes of an arc furnace and the near zone after service are investigated. It is established that the porous structure of the specimens caused by mullitization at high temperatures intensifies the effect of slag on the refractory material. The process leads to the formation of hercynite, ringwoodite, and spinel. The formation of hercynite reduces the service life of linings.Translated from Ogneupory, No. 8, pp. 27–29, August, 1995.     

Obtaining high-alumina cement at the semiluksk refractories factory

Conclusions We demonstrate that it is, in principle, possible to obtain refractory high-alumina cement on industrial equipment at the Semiluksk refractories factory. Technological parameters were developed for preparing raw mixtures, pressing the green articles and firing in a tunnel kiln. It was established that the mass percentage of SiO₂ in the raw mixture should not exceed 1.5%. For industrial production of high-alumina cement in department No. 1 it is necessary to implement measures on the mechanization of the production process.Translated from Ogneupory, No. 5, pp. 26–28, May, 1986.     

Ural cyanites as high-alumina raw materials for ceramics and refractories

Several cyanite deposits in the Urals are assessed (area of occurrence, predicted reserves) and two beneficiation schemes are proposed. It is argued that the beneficiated product can be used in the manufacture of both refractories and fine ceramic ware. Translated from Steklo i Keramika, No. 7, pp. 11–15, July, 1997.     

Structure of the production and use of magnesia refractories

The expediency of changing the structure of the production and use of magnesia refractories and modifying the refractory industry with orientation on refractories of a new generation is indicated.Translated from Ogneupory, No. 4, pp. 24 – 26, April, 1995.Published as a matter for discussion.     

废石与废渣在生产特种水泥中的应用

结合现有生产工艺，甘肃鸳鸯水泥有限公司时低碱硅质材料红砂岩和高铝高硅废石进行了模拟配料优化，选择“三组分”和“四组分”配料方案试烧特性水泥熟料，并成功生产出合格的低碱、中热、抗硫和道路水泥等各种特性水泥。同时该公司使用氟化盐工业废渣(即氟化盐石膏)代替天然石膏进行生产水泥的实验，结果表明，氟化盐石膏既能代替天然石膏作缓凝剂。又有利于降低水泥中的ω(R2O)值，且减少了环境污染，降低了生产成本。     

Hot slag resistance of refractories

Conclusions It is proposed to test refractories for hot-slag resistance by which is meant the complex property typifying the wear resistance of refractories with the single-sided action of high temperature and slags and subsequent sharp cooling.A laboratory gas-oxygen furnace design was developed for testing the slag resistance with one-sided heating with the aim of forming zones in the specimens.The spalling resistance of zonal magnesite-chromite and periclase-spinel goods was determined.According to the slag resistance and operating spalling resistance the periclase-spinel refractories are better than the spalling-resistant magnesite-chromite.     

Developing the production of high-alumina mortar

The St. Petersburg Institute of Refractories has developed a technology for manufacturing a high-alumina mortar of grade MMK85 used for binding high-alumina and corundum refractories. The mortar has been tested under laboratory conditions and shipped to the Volzhsk Pipe Plant for use in equipment of the electrometallurgical complex. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 3, pp. 30–31, March, 1998.