During the melting processes in steel-melting aggregates, lining destruction takes place due to the Magnesium oxide of lining dissolution in slag. In this study, different materials containing Magnesium oxide have been introduced into slag to increase lining stability. Efficiency estimation of raw siderite (10-0 mm class) using for this aim is considered in the present work. Initial slag (basic capacity СаО/SiO2=2,1) of industrial ASM (Arc Steel Melting) was corrected by high magnesia introduction additives (siderite). Slag has been loaded into a magnesia crucible, heated up to 1700∘C, aged during 1 hour and cooled with the furnace. The final slag phase composition analysis detected considerable changes in it: increase of MeO-phase refractory with MgO prevalence (melting temperature 2800 ∘С) and replacement of monocellitic silicate component (CaO⋅MgO⋅SiO2, melting temperature 1498 ∘С) by larnite (β-2CaO ⋅SiO2 melting temperature 2130 ∘С). Crucible slag resistance was estimated by thinning of it walls. Experiment results confirmed affect of MgO content in slag to linings solubility in it. It was determined that siderite additives increase MeO-phase (melting temperature more than 2000 ∘С) content in slag approximately by 30 % that is rather essential for lining service period increasing. It is confirmed that siderite additives prolongate magnesia lining stability of steel-making aggregates.
Keywords: Bacal siderite, refractory lining, steel-making aggregates, crucible, monocellit, magnesia