Efficiency Estimation of the Bacal Siderites Using to Increase Stability of Steel-Melting Agregates Lining

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, magnesi

Thermodynamic Modeling of Iron and Nickel Reduction from B2O3-CaO-FeO-NiO Melts

At present, during solving theoretical and applied problems of metallurgical technologies improving, thermodynamic modeling (TDM) methods are widely used to calculate multicomponent and multiphase systems. However, existing methodology TДM are intended for the balance analysis in the ”closed” systems. The authors of [9] proposed a technique that allows, using TDMs, to describe metal reduction processes during gas bubbling of multicomponent oxide melts in approximation to “open” real systems. The applicability of the methods is estimated using the example of joint Nickel and Iron reduction modeling in the B2O3-CaO-FeO-NiO system by Carbon monoxide for ”open” and ”closed” systems. The data obtained comparison for ”open” and ”closed” systems show that the consecutive output of products (gas and metal) from working medium promotes achievement of the best parameters for Nickel extraction to alloy and to its residual content in oxide melt. Using this technique, the TДM process of joint reduction of Nickel and Iron in system B2O3-CaO-FeO-NiO by Carbon monoxide in ”open” system was undertaken at various temperatures in the 1273-1773K interval. Keywords: thermodynamic modeling, ”closed” system, ”open” system, joint reduction, Carbon monoxide, oxide melt, gas bubblin