The removal of hydrochloric acid utilizing magnesium-aluminum oxide (Mg-Al
oxide), as prepared by the thermal decomposition of hydrotalcite (HT), was
investigated. Cl- in hydrochloric acid can be removed almost 100% by adding
1.75 times the stoichiometric quantity of Mg0.70Al0.20O at 60 degreesC for
1 h. Mg2+ and Al3+ in solution after the reaction were not recognized, bec
ause the solution was weakly alkaline.