A Review of Slag Splashing

Abstract

This review critically evaluates the factors affecting the process of slag splashing. Two mechanisms are involved in slag splashing, namely 'slag wash coating' and 'slag ejection coating'. Our knowledge of slag splashing is largely based on physical modelling studies. It is necessary to optimise the following for good slag splashing:(ii) The characteristics of the nitrogen blow (Gas flow, Lance height, Lance angle, Slag depth); and (iii) Slag composition. It is important that the slag contains the right blend of low-melting and high-melting phases. The low-melting (FeO-rich) phases ensure good adhesion between the slag and refractory whereas the high-melting phases provide erosion resistance and a thermal barrier. Good slag properties are obtained with a FeO content of ca. 13 % and MgO should be supersaturated (Ͼ8 % MgO) to ensure that the slag is MgO-saturated rather than CaO-saturated so that high-melting MgO · Fe 2 O 3 is formed rather than the low-melting calcium ferrites.The factors affecting the uniformity of the slag-splashed layer are discussed.

Um Estudo Sobre a Influência De Propriedades Físicas Da Escória E De Parâmetros Operacionais Sobre O Processo De Slag Splashing

“…Então, a duração de recobrimento do convertedor considerado seria maior do que de 1,83 -2,32min. Esta duração está compatível com a prática operacional mencionada por Mills et al [1], a qual varia de 2 a 4min. O aumento da viscosidade cinemática decresce a área de recobrimento pela escória, Figura 7.…”

“…De acordo com Mills et al [1] , Strelbisky & Manning [2], o processo de slag splashing é caracterizado pela projeção de escória quimicamente recondicionada, via um fluxo de nitrogênio, contra a face quente do revestimento de trabalho do convertedor. Muitos fatores afetam o processo de projeção de escória tais como: dimensões do convertedor; velocidade do sopro de Nitrogênio; altura, inclinação e geometria do bocal da lança de nitrogênio; temperatura, composição e volume de escória.…”

CFD Analysis of Influence of Slag Viscosity on the Splashing Process in an Oxygen Steelmaking Converter

“…These results show that the efficiency of the slag splashing process decreases as the molten slag viscosity is increased. In accordance to Liu et al [3], the following empirical expression relates the kinematic viscosity of slag and the lance height with the mass of slag splashed per unit area, A, in g·m …”

“…Main factors which affect the splashing process are: operating parameters (jet speed, angle of injection, lance height, molten slag height), and slag properties (viscosity, density, surface tension) [3]. Operating factors have been previously studied by two of the authors of the present work [4], however further analysis is required in order to clarify the influence of the molten slag properties on the splashing process.…”

Slag Splashing in a Basic Oxygen Furnace under Different Blowing Conditions

“…Related to the transport of the molten slag to the converter sidewalls, two mechanisms are identified: washing coating, and ejection coating [3]. The first one occurs due to the bulk movement of the molten slag to rise above the initial level, and the second one due to the ejection of slag droplets which adhere to the vessel sidewalls [4].…”