Interaction of molten salts in the systems SiO2-Al2O3

Abstract

The aim of this study was to realize and evaluate laboratory corrosion tests for a solution of problems such as wear of refractory materials at processing of aluminum, for example. The static crucible corrosion tests were carried out in laboratory resistive furnace at 850 °C during 2 h air atmosphere. Two standards of alumina-silica shaped refractory bricks were used as a corroding material. Pure sodium chloride and potassium chloride were applied as a corrosive media. The results of tests were evaluated by macroscopic, microscopic, chemical and semiquantitative EDX analysis. Sodium chloride shows more significant penetration and chemical interaction in penetrated area. EDX analysis confirms creation of the reaction layer between chlorides and elements of refractory lining. The products of reactions penetrate more deeply into A lining. K ions penetrate into the grains of the lining more intense than Na ions.

Distribution of Zn, Pb, K, and Cl in Blast Furnace Lining

“…Detailed knowledge about which Cl compounds will condensate and/or react with the lining material of the furnace is, to the knowledge of the authors, not available so far. The laboratory tests conducted by Grambalova et al are, to our knowledge, the only investigations, which describe the interaction between molten salts (KCl and NaCl) in the system SiO 2 –Al2O 3 . Their results demonstrated that if the refractory bricks get in contact with molten salts, Cl can be mainly found in the contact zone.…”

“…Dana et al, for example, mentioned that Cl is able to infiltrate into aluminosilicate bricks and cause corrosion. Grambalova et al described the interaction of molten salts in the system of SiO 2 –Al 2 O 3 . In their investigations they described corrosion caused by molten NaCl and KCl salts.…”