作者:Sergey M.LOGVINKOV1Ihor A.OSTAPENKO2Oksana N.BORISENKO1Olga B.SKORODUMOVA3Andriy A.IVASHURA1
作者单位:1. Kharkiv National University of Economics named after Semen Kuznets 2. PSC “Druzhkovka Refractory Plant” 3. National University of Civil Defence of Ukraine
刊名:China’s Refractories
ISSN:1004-4493
出版年:2020-09-15
卷:29
期:3
起页:13-18
止页:
分类号:TQ175.1
语种:英文
关键词:
内容简介The article analyzed the main groups of thermal insulation(TIM) and slag-forming(SFM) mixtures produced by leading foreign companies: acidic ones based on the SiO2-Al2O3 system, basic ones based on the Ca O-Mg O-Al2O3 system and medium basic ones based on the Ca O(Mg O) system-Al2O3-SiO2. It is shown that achieving the necessary properties of the SFM and TIM requires strict observance of the mass content of the components of mixtures produced on the basis of synthetic materials in granular form with a given dispersion. Compliance with a given composition and dispersion is associated with the need to provide a given melting temperature(for intermediate ladles 1 250-1 450 °C, for molds 950-1 150 °C), neutrality to the cast metal, protection of the melt from secondary oxidation, minimization of heat loss from the melt mirror, absorption of non-metallic inclusions of various natures(Al2O3, Ca O, SiO2, TiO2, less often Mg O-containing) and sizes; as well as a number of specific requirements: compatibility with the working layer of the lining of the bucket, maintaining the work of the stoppers, minimizing harmful gaseous emissions, etc. It is known that Al2O3, TixOy, and Ca O refractory inclusions in steel cause the majority of defects on the surface of a cold-rolled sheet, therefore, the aim of the work was to analyze the physicochemical regularities and melting paths of the wollastonite-containing compositions during the assimilation of nonmetallic inclusions by them. To analyze the melting paths of the wollastonite-containing compositions in the Ca O-Al2O3-SiO2 system, a diagram of the primary crystallization field of anorthite and the adjacent boundary curves is shown, indicating the directions of temperature drop and designating invariant points. The presented scheme adequately reflects the topological regularities of the state diagram of the Ca O-Al2O3-SiO2 system. To analyze the melting paths of the wollastonitecontaining SFM compositions during the assimilation of Ti Ox impurities from steel melts, a diagram of the primary crystallization field of Ca Ti SiO5 sphene with adjacent boundary curves, the direction of temperature drop, and the designation of invariant points is presented. It is shown that steric and kinetic factors have a predominant effect on the formation of the three-layer layer in the SFM(molten, partially molten and unmelted layers). The influence will be the lesser, the more uniform the thickness of the entire SFM layer(when it is heated from the melt mirror), and the competing processes of solid-phase interaction will start, which provide a gradual accumulation of more refractory compounds and increase the melting temperature of the SFM.
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