Additions of Salt Cake and KAlF_4 from Aluminum Production to Steelmaking Slags

摘要

Fluorspar, a mineral primarily composed of CaF_2 is the most commonly used slag fluidizer in steelmaking. Due to increasing costs for fluorspar steelmakers are seeking alternative means of achieving slag fluidity. The research has concentrated on other minerals or the wastes of other high temperature operating industries. A promising alternative to fluorspar has been identified in a previous work from this laboratory which is the salt cake from secondary aluminum production such as the flux in remelting aluminum scrap and dross. This material is widely available and also considered toxic (meaning that use in steelmaking helps to reduce environmental impacts from disposal). The present work is an investigation of the viability of using mixtures of salt cake and KAlF_4 in slag-fluidizing applications by measurements of viscosity and weight loss at high temperatures (to evaluate whether large amounts of potentially harmful gases are formed). In addition, characterization of raw materials and melted slags has been performed. In terms of fluidity the mixtures of aluminum salt cake and KAlF_4, are qualified for use as fluidizers. The results of the present study will be used to design plant trials.