LINO3 EFFECT ON CORROSION PREVENTION OF ALUMINUM WITH COMPLEX SHAPES

摘要

The LiNO3 effect on aluminum corrosion prevention after land disposal of cement-solidified dry active wastes was examined quantitatively, in the event that the LiH (AlO2)(2).5H(2)O (Li-Al) preservation film was not formed on aluminum surfaces during the solidification process. It is especially probable for these bare surfaces to be left when the wastes include components of complex shapes. LiNO3 dissolves from the waste forms into underground water to form the Li-Al preservation film. So, we thought that the LiNO3 addition would prevent the corrosion. We measured the volume of hydrogen gas generation in mortar-soaked water during the Li-Al preservation film formation, as functions of LiNO3 addition amount, the weight ratio of water to mortar when the mortar-soaked water was produced, and the aluminum surface area, to quantify the effect. We found that aluminum corrosion was inversely proportional to the LiNO3 addition. Far the corrosion to be less than 10(-5) m in 10(3) h, the initially added amount of LiNO3 must be 1.5 wt% of the sum of cement and sand. Regardless of the weight ratio of water to mortar when the mortar-soaked water was produced, hydrogen gas generation with LiNO3 was 10% as much as that without it, in 5 x 10(3) h. Because of the Li-Al preservation film formation reaction, hydrogen gas generation was proportional to the cubic root of the aluminum surface area. [References: 5]