Lithiation of Alumina in Molten Li/K Carbonates

Abstract

Using a high purity sapphire plate, the corrosion rate of alumina in molten carbonates was measured with a laser microscope. Results indicate that, when the CO2 partial pressure in the atmospheric gas is low and the operating temperature is high, the corrosion layer increases in thickness in proportion to a two-thirds power with time. As lithium aluminate, the corrosion product, tends to assume a granular shape and corrosion layers are likely to be porous, molten carbonates are believed to readily reach the surface of the alumina. For this reason, this phenomenon deviates from the square root rule which is, in general, applied in evaluating the corrosion of materials. When an alumina plate, blended with silica, is immersed in molten carbonates, part of the silica dissolves into the molten carbonates, thereby increasing the alumina plate surface roughness. The contact area between the alumina and the molten carbonates increased, resulting in increased corrosion.

Physical characteristics of capacitive carbons derived from the electrolytic reduction of alkali metal carbonate molten salts

“… 26 In all cases eutectics were fused in alumina crucibles topped with an alumina lid containing holes for the placement of electrodes and a CO 2 inlet and outlet. Alumina was chosen over other crucible materials as, in the presence of lithium-containing molten carbonates, alumina forms a corrosion layer of lithium aluminate, which increases the surface roughness of the material, 42 but is otherwise stable. Following fusing, eutectics were allowed to cool to room temperature, prior to being re-heated for carbon electrodeposition.…”

Synthesis of Various LaMO3Perovskites in Molten Carbonates

“…In situ X‐ray diffractometry was carried out to investigate the reaction mechanism between α‐LiAlO 2 (Nippon Chemical Industrial Co. Ltd., Tokyo, Japan) and La 2 (CO 3 ) 3 ·8H 2 O. In molten carbonate, α‐LiAlO 2 is more stable than α‐Al 2 O 3 , which reacts with lithium to produce α‐LiAlO 2 10 . Thus, we did not use α‐Al 2 O 3 but α‐LiAlO 2 for the in situ reaction observation.…”

Deformation Mechanism of Porous Nickel Oxide in Molten Li/K Carbonates

“…In this case, when the tem- perature of the molten carbonate is high and the CO2 partial pressure in the atmospheric gas is low, the particle sizes are known to increae rapidly. 6 The equilibrium solubility of nickel oxide in Li/K = 62/83 molten carbonate depends on the CO2 partial pressure. At higher CO2 partial pressures, acid dissolution is observed, and at low CO2 partial pressures, basic dissolution is observed.…”