The evolution of quasi-thin aluminite to thin aluminite is not only a change in grain size, but also a gradual increase in the completeness and order of crystallization, as well as a gradual reduction in the number of six coordination aluminum ions. The method of using grain size as the main difference between thin aluminite and pseudo-thin aluminite is put forward: the average grain degree below 10nm is considered as thin aluminite, and more than 50nm is considered as a kind of aluminite; 10 to 50nm is considered an intermediate product. Thin Aluminite can not be converted into Γ-al2o3 after dehydration, directly converted into Δ-al2o3
Preparation of pseudo boehmite by Naalo2-co2 method
The Naalo2-co2 method for preparing thin aluminite with no Sanshui alumina and low na^+ content, and through systematic study, solves the problem of producing Sanshui alumina miscellaneous crystals under high glue temperature or higher NaAlO2 solution, and NH4NO3 or dilute nitric acid as washing medium, The content of na^+ in quasi-thin aluminite can be reduced effectively, the amount of washing medium should be reduced by circulating washing, and the reason of the effect of drying temperature on the gelation properties of thin aluminite is discussed.