The effect of a temperature gradient on the phase formation inside a magnesia–chromite refractory in contact with a non-ferrous PbO–SiO2–MgO slag

Abstract

Furnace relinings represent a major operating cost in pyrometallurgy. External cooling is, therefore, often used to reduce the chemical wear by limiting the slag infiltration depth, reducing the reaction kinetics and lowering the solubility of refractory components into the liquid slag. In this paper a new experimental setup is used to study the reaction between a synthetic PbO-SiO 2 based slag and a magnesia-chromite refractory under a temperature gradient. Forsterite (Mg 2 SiO 4 ) is formed throughout the sample, removing SiO 2 from the infiltrated liquid slag. The resulting change in slag composition causes the liquidus temperature and the viscosity of the liquid to decrease partially countering the effect of the applied temperature gradient and resulting in the complete infiltration of the sample. The extent to which external cooling prolongs the lifetime of an industrial furnace thus depends on the slag properties and how they are modified after reaction with the refractory.

Corrosion Resistance of MgO and Cr2O3-Based Refractory Raw Materials to PbO-Rich Cu Slag Determined by Hot-Stage Microscopy and Pellet Corrosion Test

“…This is lower compared to the rest of the predominant phasesρ MgO = 3.59 g/cm 3 , ρ (Fe,Mg)Cr2O4 = 4.70 g/cm 3 -resulting in the major loosening of the microstructure and causing, if it occurs in excess, so-called "forsterite bursting", detrimental for the performance of refractories. The microstructure disintegration was previously reported for massive formation of forsterite as corrosion product [2,14,22,39,40,67,74,75].…”

“…The influence of PbO-rich non-ferrous slag [38][39][40][41] and PbO-rich ferrous slag [38,41], or PbO-CuO x -Cu mixture [2], on the corrosion resistance of MgO-Cr refractories is well recognized in the literature. In our recent work, we concluded that the higher the concentration of PbO in the lead-rich copper slags, the higher the degradation level of magnesia-chromite refractory [42].…”

Анализ Влияния Эксплуатационных Факторов На Стойкость Футеровок Разливочных Ковшей

“…При этом литературные источники отмечают, что эксплуатировать агрегаты, футерованные шамотными огнеупорами, можно только при постоянно поддерживаемых высоких температурах [7] [8,9].…”

Integrated Experimental and Thermodynamic Modeling Investigation of Phase Equilibria in the PbO–MgO–SiO2 System in Air

“…Scheunis et al [37,38] studied the chemical corrosion of magnesia chromia refractories in the presence of synthetic PbO-MgO-SiO 2 slags at 1200 °C. It was found that the MgO phase in the refractories reacted with the slag to form olivine (forsterite, Mg 2 SiO 4 ).…”