Solid-phase interaction of X-ray amorphous aluminas differing in their histories with sodium carbonate

The solid-phase interaction of X-ray amorphous alumina samples with sodium carbonate at 500-900degreesC has been studied as affected by the history of an alumina sample. Five procedures were tested for alumina synthesis: the decomposition of Al(NO3)(3) . 9H(2)O; Al-2(C2O4)(3) . nH(2)O; hydroxides prepared by Al3+ ion precipitation from aluminum nitrate or aluminum chloride solutions by concentrated aqueous NH4OH taken in 20% excess; or a hydroxide prepared by freeze-drying of frozen cryogranules of a colloidal aluminum hydroxonitrate solution. The behavior of X-ray amorphous alumina was significantly affected by its chemical history when it was in a solid phase with sodium carbonate.